Storms-R-Us

Not really a chase...but it is January after all

2012-01-27T09:29:00.004-05:00

This morning's cold frontal passage may have been more spectacular if it had been delayed 6 hours or so but it was still neat to see a spring-like air mass change in the middle of winter. Here are a couple of photos I snapped from the front stoop.

The high temperature this morning at Shannon airport was 68 degrees (F) at 8:55 a.m. with a dew point of 59. These values have already dropped significantly and will continue to do so throughout the day.
Not really a formal chase, but I'll take it!

Statewide tornado drill March 20th

2012-01-21T10:53:00.001-05:00

It's never too early to start plugging this event, even if there is snow and ice on the ground!

Ten year chronology update

2012-01-19T22:52:00.002-05:00

I'm still plowing through my previous storm chase accounts in the process of consolidating all of them into a new book for the period 2002-2011. I'm currently moving slowly through 2009 as I've had to basically write the narrative from scratch. The 2009 chase book I published using the Blurb.com software tools was mainly a photo volume with captions composed of excerpts from that year's blog posts. The result was okay for a photo book but lousy as a sustained narrative to match up with the rest of the accounts. Now the challenge is to match up this new narrative with the style of the older ones that were written over a period of several years.

What else is a storm chaser to do during the winter?

Storm chase season 2012: what will it be like?

2012-01-11T11:31:00.002-05:00

This is always a fun time of year to guess what the upcoming chase season will bring. The La Nina pattern ushered in an early severe season last year with the April tornado outbreaks across the Southeast, so what will this year look like?

The best current news is that western Texas and Oklahoma have been seeing more rainfall and snowfall this winter than last. This should replenish the soil moisture that was so lacking in 2011, aiding both the farmers and other folks that live out there plus enhancing the chasing potential by sharpening the dry line and its effect on storm initiation. Even though it's still pretty dry out that way I expect chasing in the TX/OK panhandles to be more productive this year than during 2011.

As for the rest of Tornado Alley my guess is that 2012 will resemble last year...under the assumption that the current La Nina hangs on through spring. Thus the late spring Hokie Stormchase crew will have to be on its toes with the flexibility to take advantage of brief windows of chasing opportunity.

Now, for Virginia: I have my fingers crossed that this mild winter and abundant rainfall will lead to an early start to the chase season, perhaps with a couple of fruitful March chases. That would mean I only have about 8 weeks to wait!

Virginia chasing chronicles update

2012-01-02T23:00:00.003-05:00

Culpeper county wall cloud Sept 27th 2002

Over the past few weeks I have been steadily working on a compilation of 10 years worth (2002-2011) of Virginia storm chase accounts. To date I have made it through 2005 with an initial cut at a new format and will restart the effort - after a holiday break - this week. After all ten years worth is dumped into the current publishing software the serious editing and formatting can begin, and I expect that process will take most of the winter. My goal is to get the final product up on the Blurb.com website by the end of March with options for both hard copies and ebooks.

That should keep my mind off SDS (supercell deprivation syndrome) for the winter!!

Not bad for the first day of winter!

2011-12-23T11:03:00.003-05:00

Okay, so it was actually the first day of astronomical winter...but this graphic showing storm reports from yesterday is still impressive for this time of year. The overall atmospheric pattern hasn't opened up the polar express to the southeastern U.S. yet so the warmth and moisture of the Gulf of Mexico is still providing convective fuel. Hope damage and injuries from yesterday's storms were minimal.

New Virginia storm chase book in the pipeline

2011-12-17T09:48:00.003-05:00

One of this winter's projects is to merge all my existing accounts of Virginia storm chasing (Vol. 1, Vol. 2, and Vol. 3) with a writeup covering the past two seasons to create one volume that spans Virginia storm chasing for the ten year period 2002-2011. I've been working on a writeup of the 2010 and 2011 seasons the past couple of weeks, and once that's complete I'll begin the process of merging the existing versions with this latest one via the Blurb.com Booksmart software.

The cool part is that the newest version of the publishing software will allow creation of an ebook for iPhones/iPads. I'm looking forward to seeing how well that works!

Updated Virginia chasing summary for 2002-2011

2011-11-30T16:52:00.002-05:00

I just finished updating the statistics for Virginia stormchasing for the period 2002-2011 and have come up with the following totals for these 10 years:

# Chases: 233

# Hail events: 15

# Wall clouds observed: 73

# Funnels observed: 27

# Tornadoes observed: 4

Now, for a couple of caveats:
(a) The total numbers for the ten different Mays are artificially lowered by the fact that May is the month I chase in Tornado Alley when possible, thus missing Virginia storms.
(b) The number of tornadoes may also be artificially lowered due to not being able to observe the near-ground environment under the funnels to determine whether the circulation actually reached the ground. I suspect that was the case for several funnels, but...

2011 Virginia chase season: DONE

2011-11-26T12:24:00.004-05:00

And so I've declared it. After a few near misses during November's warmth I have declared this chase season to be over. It's time to tally up what I've seen this year and to possibly pen another book to cover the 2010 and 2011 seasons.

Here are two pictures that bookend this season:

28 February shelf cloud in eastern Culpeper county

13 October wall cloud in western Spotsylvania county

I'm now looking forward to some 2012 early spring chasing and possibly another expedition to Tornado Alley under the auspices of the Virginia Tech Stormchase team. I may post here occasionally before next spring but most of my weather posting until then will be over at Fredericksburg Weather. Stay tuned!!

2011-11-20T18:43:00.002-05:00

Been tracking the potential for severe weather across the country this week. Here's the NWS Sterling Office's latest forecast discussion for Wednesday:

"PREFRONTAL TROF AND CDFNT WILL ENTER FCST AREA ON WED. ALTHOUGH BNDRY LYR XPCD TO RMN STABLE DESPITE PRESENCE IN WARM SECTOR... STEEPENING LAPSE RATES IN ASSOCIATION WITH ARRIVING POSITIVELY- TILTED UPR TROF AND CONTD FETCH OF WARM AND MOIST GULF AIR WILL PROVIDE MODEST ELEVATED INSTBY THAT MAY BE SUFFICIENT FOR TSTMS. TSTMS WERE INTRODUCED TO THE GRIDS WED AFTN AS SFC BNDRYS CROSS THE FCST AREA."

There will also be enough windshear to create the potential for rotating updrafts as well...

Visible cold front evidence

2011-11-17T11:27:00.002-05:00

The cold front associated with the severe weather the past couple of days is shown here on the 1601Z visible satellite image. I added the blue line for emphasis, but it's pretty easy to tell where the front is by the line of convection. Myrtle Beach and Charleston SC are warm now, but their temperatures will be falling soon.

More indications of instability Wednesday

2011-11-15T13:37:00.002-05:00

The 12Z NAM run is now showing 500-750 J/kg of CAPE for tomorrow (Wednesday) afternoon in eastern Virginia. That's not impressive until one realizes how good the shear and helicity values look, which means that we'll be looking at a classic low CAPE / high shear setup for the Mid-Atlantic tomorrow. That's obviously why the Storm Prediction Center has upgraded southeastern VA to a slight risk (15%) for severe storms, with Fredericksburg and much of the rest of the eastern portions of the state under a 5% risk.

My main concerns regarding chasing tomorrow are the potential for heavy rain (poor driving conditions) and low ceilings (poor visibility), but I can mitigate that by perusing satellite views and surface observations. If chasing conditions are marginal I won't be wandering too far afield, but if the sun pops through somewhere chaseable in eastern Virginia I will extend my range a bit beyond the normal sites. After all, I may not get another opportunity to chase for several months!

Convection this week?

2011-11-13T21:28:00.002-05:00

Both the NWS Sterling forecast discussion and the models are hinting at possible instability Tuesday and/or Wednesday afternoon this week. The really interesting thing is that the wind shear, moisture, and helicity will be in place to almost certainly create rotating updrafts...if the instability is manifested. You can bet I'll be watching the models and forecasts over the next couple of days!

End of the 2011 Virginia storm chase season?

2011-11-08T10:41:00.003-05:00

Maybe....and then again maybe not. The GFS model is now indicating some CAPE in central and northern Virginia for next Wednesday afternoon (11/16) as a front approaches, accompanied by negative LI's and some decent wind shear. Admittedly this is a long way out to trust any model solutions but it's worth keeping an eye on. I have stated many times that Veterans' Day usually signals the end of the chase season here, and this would be close enough to that self-proclaimed finale to qualify. More to follow as the days - and model solutions - pass.

Hokie stormchase team leads to VT meteorology program

2011-10-31T09:59:00.002-04:00

This article shows the correlation between the Hokie stormchase team and the new meteorology major at Virginia Tech that formally begins with the upcoming spring semester. The planning stages for the 2012 stormchase are already underway, and yours truly is excited to be a part of it.

October surprises all over!

2011-10-29T14:34:00.004-04:00

This radar representation from 10:22 a.m. today show an indicated area of rotation during our October surprise nor'easter, a fabrication just as trustworthy as the hail markers that were shown earlier in the morning. At least I can explain the "hail" as sleet or graupel reflections; not sure what this area of "rotation" was unless it was a localized low pressure area (cold air mesolow?) within the overall surface low area.

NWS Sterling tornado survey from Oct 13 storms

2011-10-27T16:47:00.002-04:00

This link provides the final data from the official storm survey conducted by the NWS Sterling team. It appears that the tornado in Fauquier county that occurred around 5:00 pm Oct. 13th was from the same portion of the storm that produced the northern wall cloud I photographed roughly 30 minutes beforehand. As recorded in a prior post I later retraced this storm's path via radar and found that it was likely the same cell that caused a mini-panic on the University of Maryland's College Park campus later that afternoon.

When I started out from home that day I had two alternatives to intercept the tornado-warned cell that was heading north from Louisa county. I chose the southern route (State Route 3) to Culpeper, but if I had chosen the northern route (U.S. Route 17) toward Bealeton I may have seen this tornado...but then again, maybe not as I didn't have mobile radar access to alert me to the development of this particular cell. I might have wound up too far west to see it!

Can we say "wedge" and "coastal front"?

2011-10-19T13:56:00.004-04:00

With the shear in place and a nearby surface low pressure all I'm waiting on is some sunshine to fire off storms and provide the impetus for me to scoot out the driveway for a chase. Hopefully the cold air wedge over the Piedmont will give way to the warmer and moister conditions represented to the east of the coastal front (black line above) soon enough to fire off some daytime storms.

Reflections on the 13 October severe weather

2011-10-14T12:04:00.007-04:00

After a good night's sleep my frustration at missing yesterday's tornadic storms has quieted. I've realized that no one expected the magnitude of the outbreak so I'm not the only one caught unprepared for a wild October chase day in northern Virginia. Frankly I only expected one or two good cells to pop, so when I saw the tornado warned cell charging northward from Louisa county toward Culpeper I figured that was the storm of the day. I didn't make arrangements for having mobile internet capability because I didn't think I needed it...I just needed to get my tail to the Culpeper vicinity as fast as I could drive there through the afternoon traffic.

As it turned out, of course, there were a myriad of interesting storms yesterday afternoon. I found that out when I struggled through traffic to get west of Fredericksburg and noticed the wall cloud south of Route 3 that stopped me from my pursuit of the Culpeper storm. At the same time I was watching that cell I also noticed a wall cloud to my north that I now believe was the storm that provided the excitement on the University of Maryland campus later on. Here's my evidence:

Photo of northern wall cloud at 2029Z

2030Z radar velocities

The orange star is my location, the yellow circle is the wall cloud circulation to my north, and the green circle is the tornadic portion of the Culpeper storm I was originally trying to get to.

2116Z radar velocities

The yellow circle is the same wall cloud circulation now in the Manassas vicinity (tornado warning issued at 5:07 pm included a mention of this storm). I tracked the circulation via a radar loop.

2233Z radar velocities

The yellow circle indicates the circulation near the University of Maryland campus at about the same time the University warnings were issued. Again I tracked the feature via radar loop which showed this cyclic cell continuing to develop new circulations on its right flank, thus providing the northeastern trajectory of the rotating area of the storm.

So now I feel a bit better about having witnessed one of yesterday's possibly tornadic storms, even if I didn't get any cool video of a tornado. But stormchasing to me is more than just catching tornadoes, and I still enjoyed the storm structures and the multiple wall clouds that I did intercept yesterday.

Video of first 13 Oct wall cloud

2011-10-13T21:10:00.001-04:00

This is the feature that distracted me from intercepting the tornadic storm near Culpeper.

The title of this post? Aaaaarrrrrrgggggghhhhhh!

2011-10-13T20:16:00.006-04:00

The reason? I missed every possible tornadic storm this afternoon. My original target was east of Culpeper to intercept a tornado warned cell that was cruising northward from Louisa county where a tornado with damage was reported in Mineral. This same cell received tornado warnings all the way northward past Manassas, but did I get to it in time? Nooooooo....I had to stop and photo/video a wall cloud just west of Fredericksburg and call it in to the National Weather Service office in my capacity as a Skywarn spotter.
There was even another wall cloud to the north of this one, under a different updraft:

After these escaped from view I continued my way west toward the original storm but it had moved north. I did consider heading into Fauquier county to catch up with it, but the back road I tried had a lot of water ponding on it and the rain was still coming down in buckets. Thus, I headed back east to hear yet another tornado warning on a different cell north of Fredericksburg - where I don't chase because of the traffic - and have since seen video of a definite tornado that crossed I-95 near Quantico.
Rather frustrated I continued east of Fredericksburg and came across this probable wall cloud that was vacuuming up scud underneath another vigorously growing updraft:

Note the geese formation in the upper right; they didn't seem too concerned over the whole thing.
When this dissipated I headed for home to grab a radar update as this chase featured only the Mk 1 eyeball (my biggest error of the day). Radar at home showed another tornado warned cell stomping northward from Louisa county toward Fredericksburg, so I dutifully rolled back down the driveway to try a dusk intercept of said storm. Alas, I couldn't see much even with the lightning from this weakening cell so I finally trudged homeward for the final time. And as of this writing yet another storm is headed in our direction... but this one will be a front porch intercept.

Hope dwindles for a mid-October chase

2011-10-08T11:48:00.002-04:00

The upcoming coastal low pressure originally appeared to have a chance of tracking west of Virginia, which would have situated the Old Dominion firmly in the warm sector (or in the right front quadrant of a tropical system) and providing impetus for some convection. Per the above forecast graphic it now seems that next week's event will be strictly rain - and lots of it - from an autumn nor'easter.
I still won't declare an end to the Virginia chase season until my empirically derived Veterans' Day cutoff, but the potential for another 2011 chase is dwindling.

Late September serendipity

2011-09-27T16:53:00.004-04:00

Today's setup just didn't look good enough to plan a chase but I woke up from a brief after lunch nap to the sound of thunder and a line of storms heading directly toward us. I couldn't say no, so after watching the line for a while I noticed one cell with some indicated rotation and picked that one out of the crowd to chase.
After first moving toward the Stafford county regional airport I decided that the line's trajectory was moving the interesting parts east of Route 1 thus I headed in that direction. After a couple of stops to photograph and video the line I wound up at a favorite viewing spot in western King George county a few minutes before the storm I was tracking became severe-warned. Surface winds were out of the east/northeast and the cells themselves were pushing outflow winds out of the northwest, and my location was directly underneath the confluence shown here on a doppler radar display:

My location is at the yellow star

I was literally under a broad area of rotation and could see it in the low level cloud motions. There was even a hint of an inflow band from the east in this photo looking northward:

I didn't see any definite wallclouds or anything else severe so I waited until the tropical downpour lightened and headed for home. Good local chase, but I'm still thinking about tomorrow!

Convection chances are slim

2011-09-25T16:20:00.002-04:00

Both the GFS and the NAM are showing some surface-based instability for both Monday and Wednesday afternoons but I'm not holding my breath for anything chaseable. The previous "setups" have proven shaky at best and this one looks like it will follow the same pattern. There is some overall shear available given the upper level low over the upper Midwest which is kicking up decent jet stream level winds, but the lower level winds aren't stirring my chaser's soul. Unfortunately the Storm Prediction Center agrees with me.

To ease the pain of the dwindling 2011 storm chase season I have been posting Virginia chase accounts each Monday over at the Fredericksburg Weather blog. This week's account will be from the 2007 chase season.

Is the 2011 chase season over?

2011-09-17T14:01:00.003-04:00

So far the tropics haven't provided any convection worth chasing here in northern Virginia, altho' I did go out once or twice over the past couple of weeks to see what could be seen (which wasn't much). Given that we're now past the peak of hurricane season and that the overall weather pattern seems to be keeping any Atlantic hurricanes at bay I'm not sanguine about the chances for a tropically-flavored chase unless the Gulf of Mexico decides to become more active.

The next best setup would be a strong autumn cold front - or two - swooping down from the northwest to plow into a juicy airmass along the East Coast and fire up some chaseable storms. Based on past experience this is still a possibility at least until Veterans' Day (November) so there are a few weeks left for potential chase opportunities. But it's beginning to look like this year's storm chasing is mostly in the books, leaving it up to next spring to provide more convective excitement. That's why yesterday's meeting in Blacksburg regarding plans for the 2012 Virginia Tech stormchase was so important...it keeps the candle lit!

Wednesday's probability verified, but after dark

2011-09-09T21:42:00.002-04:00

This radar grab from Wednesday evening shows a tornado warning and the accompanying rotation over Dahlgren Virginia. This was the second tornado warning of the evening - the first being a bit further east over the Northern Neck - so the 5% probability for tornadoes forecast by the Storm Prediction Center did verify. The only problem with chasing this cell was that the spinup happened after dark when I don't chase. However it's just as well I didn't go out given the amount of rain that had fallen in that area and the probable condition of the roads at that time. Sometimes discretion is the better part of valor.

Eyes on Wednesday afternoon

2011-09-06T12:54:00.003-04:00

As of the 12Z runs this morning both the NAM and the GFS models are showing sufficient instability (CAPE) and wind shear Wednesday afternoon to produce some decent storms in northern Virginia. The lift mechanism will be the currently stationary front over southeastern Virginia, which will push back to the northwest as a warm front. Surface winds will be southeasterly while upper level winds veer around to southerly and southwesterly, so low level rotation may be the order of the day. Potential chase locale will be determined largely by where the front sets up in early afternoon and where the sun peeks through to help create the instability and initiate convection.
Watching and waiting...

UPDATE 3:30 pm:
Bingo!! Apparently the Storm Prediction Center assesses tomorrow's severe risk here in Virginia the same way I did, which is somewhat comforting.

Wednesday chasing courtesy of Lee?

2011-09-05T09:54:00.002-04:00

The models have spoken: remnants of TS Lee will be in place to provide conditions for rotating storms in eastern Virginia. Now, if the sun can poke through Wednesday afternoon and provide some instability...

Tropically-induced chase condition?

2011-09-03T08:58:00.002-04:00

If this forecast track and timing for Tropical Storm Lee's remnants holds, northern Virginia could see a potentially good chase day this coming Thursday afternoon if sunshine can stir up some instability. I'll be monitoring the situation!

Deja vu for Monday

2011-09-02T10:14:00.003-04:00

This Storm Prediction Center graphic for Day 4 (Labor Day Monday) looks suspiciously like the Day 4 graphic posted yesterday that covered Sunday. Guess the models slowed things down overnight.

UPDATE 4:00 p.m.: Just rechecked the Day 4-8 convective outlook and found no areas shaded at all. The above graphic must have been left over from yesterday's Day 4-8 outlook. We'll still have a chance at storms each of the next several days but the severity is in doubt.

Labor Day weekend chase?

2011-09-01T09:37:00.001-04:00

Hmmmm...decent chance of a chase day this coming Sunday! I'll have to keep an eye on the models starting tomorrow sometime.

Not Irene, but cold front inspired storms

2011-08-25T20:28:00.005-04:00

The Storm Prediction Center (SPC) centered a slight risk for severe weather in my chase area and I took full advantage, leaving home around 2:00 p.m. to head for the Route 29 corridor near Culpeper in hopes of catching a discrete storm in the lee of the Blue Ridge mountains. Unfortunately the storms crossed the ridge as a line and continued on their way, but I did manage to choose the strongest cell to follow thanks to radar and GPS. I rambled through a bit of eastern Culpeper county to find a spot to watch and found this view of an oncoming shelf cloud:
Continuing eastward from here I found an even better vantage point from which to observe the severe-warned storm approach and watched for several minutes.

When the rain shaft approached I scooted northeastward toward the back side of the town of Lignum and wound up catching this view of a suspicious feature very near the rural route I was on:
It was suspicious not only in looks but also in that CG's were raining down in its vicinity plus a very large hailstone suddenly and without warning smacked the middle of my windshield. I couldn't tell how large it had been but the leftover slush pattern was about three inches in diameter. After that surprise I saw and heard several other hailstones but none seemed larger than quarter-sized. I stopped in Lignum to watch and video this lowering but never saw any rotation.

Then, somehow I came up with the not-so-bright idea to closely follow and even core punch this storm as it continued eastward. Thus I pulled out onto Virginia Route 3 and gave chase, noting the further east I traveled that the rain intensity increased, the wind speed picked up dramatically, and the smaller twigs and leaves that were showering the highway began to get larger and more numerous. When I reached the Lake of the Woods vicinity I was finally convinced that I needed to get off the road for safety's sake. By this time the rain was horizontal, branches were snapping off trees and landing in the roadway, and the continuous pea-sized hail sounded like shotgun pellets bouncing off the car's exterior.

When conditions improved significantly I eased back out onto the highway and moved east a few miles, stopping just behind the storm to call in a report to the NWS Sterling office. (I had tried to do so earlier but couldn't get a call through.) Watching for a while longer I finally headed home through the damage path of this severe storm, including a number of traffic signals that were non-functional due to widespread power outages. After playing "dodge 'em" cars at a few intersections I made it home to no electricity for a couple of hours. The upside? The sunset:
And this doesn't begin to do it justice...

Sunday afternoon line of storms

2011-08-21T17:53:00.003-04:00

When the SPC listed Northern VA today as not only under a Slight Risk for severe weather but also with a 5% tornado probability I had my gear ready to go by lunchtime. Shear looked good, instability was excellent for the Mid-Atlantic, a prefrontal trough provided lift, and dewpoints had climbed to near 70 degrees F. Lacking a cap convection began firing east of the Blue Ridge much earlier than I'd expected from the short range models, so I headed to Bealeton at 1:30 pm in hopes of catching a solitary supercell (or two!). Unfortunately by the time I got into position the discrete cells with severe thunderstorm warnings had already begun the process of coalescing into a line so I was forced into an eastward cycle of retreat, watch, photograph, and retreat again.

Tiring of this I beat feet southeastward as quickly as I could along Fauquier and Stafford county rural routes until I reached the Stafford Regional Airport just off Interstate 95. There I was able to park, watch the line approach, and plan my next move. I saw plenty of scud and lowerings but nothing I could pin to a wall cloud. Meanwhile the storms' intensity diminished as they moved eastward.

Line approaching Stafford Airport

As the rain approached I scooted eastward into King George county east of Fredericksburg, stopping at a quarry just off Virginia Route 3 where I watched the line approach. Again, I saw features that seemed to indicate preliminary storm organization but nothing materialized by the time the rain washed over me. It was a good chase but somewhat disappointing in that the potential for some rotating storms seemed to vanish before my very eyes.

Translating weather terms into more common language

2011-08-18T11:14:00.003-04:00

Given recent weather-related tragedies - one being the stage collapse at the Indiana State Fair - I have been more cognizant of people's tendency to either misinterpret or ignore official weather forecast terms. Pondering this and wondering what may be done to alleviate the situation has occupied my background thoughts for several months now since a late-night conversation between chase vans (via CB radio) brought similar issues to light during the May 2011 Hokie Stormchase trip. There are no simple answers to the problem of translating official weather "geekspeak" into a more common vocabulary that the wider public will relate to, but one factor that may shed some light recently dawned on me: Meteorologists tend by nature and education to be "numbers oriented" while the average person is not, leading to very different understandings between the two groups of what the numbers mean.

As an example today's National Weather Service (NWS) forecast for the Fredericksburg VA region indicates a 30% chance of thunderstorms. That is a summation of the forecast solution spit out by the numerical models used by meteorologists, thus the official forecast and accompanying graphics depict that solution. As I see it the problem is that the average person doesn't always relate to the numbers represented by the probabilities and instead focuses on the thunderstorm portion of the forecast, either basing their weather-related concerns on the fact that there WILL be storms at their location or ignoring the forecast because they don't understand what the numbers mean. In point of fact here is the official definition of probability of precipitation lifted from the NWS glossary:
"The probability that precipitation will be reported at a certain location during a specified period of time." How helpful is that definition to a non-numbers person? Not very.

Possibly an even grimmer misinterpretation lies with the probabilities given along with official NWS severe weather forecasts. Here is today's tornado probability map from the Storm Prediction Center (SPC):
Note that a 5% tornado probability exists for northern Nebraska and southern South Dakota. What does that mean? Here's the explanation copied from the SPC graphic: "Probability of a tornado within 25 miles of a point."

Numerically that can also be interpreted that there is a 95% chance of NO tornadoes within 25 miles of a given point in those states, and if the average person seizes on that interpretation the odds are that they will ignore the potential threat. However context is crucial here in that a 5% probability is significant enough for storm chasers to pay attention to that area as a place to bag a tornado sighting. Even more importantly, a 5% tornado probability forecast for the Mid-Atlantic is a very significant number given that (a) tornadoes don't happen here as often as they do in Nebraska or South Dakota and (b) the population density is much greater, providing a higher probability of damage and injury if a tornado does occur here. Thus the value of providing a numerical probability without an accompanying translation into locally understood terms means the populace could very easily misinterpret or even ignore the forecast when they don't think in terms of numbers the way that meteorologists do.

Does this explain away the aforementioned tragedies? Of course not...but maybe it does behoove the forecasters - and even us amateur weather geeks - to provide the general public with a more broadly understood interpretation of the numbers spit out by the forecast models.

August 14 driveway "chase"

2011-08-15T11:20:00.002-04:00

After a weekend away we arrived home an hour before storms hit the Fredericksburg area. I decided to give "chase" from my driveway as (a) I was done with driving for the day, (b) the storms were in a line that would have necessitated a continuing eastward retreat to stay out of the rain, and (c) evening was upon us with full dark fast approaching. So I set up my monopod with video on top of a car and attempted both digital stills and handheld video with the other camera. Unfortunately it was almost too dark for stills and the autofocus on the handheld so the fixed video became the key player, but here's one touched-up still photo:

Overall the storms were rainy, a bit noisy, and only somewhat windy, but they were storms!

August 3: The Fizzle

2011-08-03T22:30:00.004-04:00

Today was supposed to be the best chasing conditions in several weeks, given a surface low crossing Virginia and plenty of wind shear, moisture, and a frontal approach. So what happened? Overcast from an earlier mesoscale convective system (MCS) blotted out the sun and eliminated enough instability to prevent severe weather.
Ever the optimist I began watching the radar picture around lunchtime, finally convincing myself that a cell on the leading edge of a large rain area was worth chasing. I rolled down the driveway at 2:45 pm toward Bowling Green to intercept this storm but never made it to my original target. I motored down Virginia Route 2 keeping one eye on the radar and noticed the leading edge cell was developing northward as well as eastward, so to intercept the better convection I made a U-turn just north of Bowling Green and headed northward.
After a couple of fits and starts I realized that I wasn't going to see much in the enveloping gray mush so I continued northward in an attempt to catch a solitary cell developing ahead of the main area. Approaching Corbin this updraft to the north caught my eye:
There was no visible lightning or rotation but it did look like it could develop into something interesting, so I continued northward to New Post in order to dart southeastward on U.S. Route 17.
By that time the cell had become rain-wrapped and invisible but I spied another updraft to the northeast and gave chase south of the Rappahannock River on Rte. 17. This storm had an interesting base with all kinds of funky scud underneath:
Just to the left of this scud was another rain-wrapped feature that I was really interested in but couldn't see very well. None of my photos or videos caught any detail either, and by the time I finally crossed the Rappahannock northward on the U.S. Route 301 bridge several cells had coalesced over King George county and the bases were no longer visible in the heavy rain. No warnings, no rotation, and only a little lightning and thunder...but it was a chase!

August 1 chase

2011-08-02T12:05:00.006-04:00

The SPC had our area listed under a 5% chance of severe weather Monday August 1st with high winds the main threat. When storms began firing and moving southeast I took notice of a complex northwest of Culpeper and ignored a juicier set of cells traversing the DC suburbs (to my later chagrin). Thus my target was Culpeper and I left the driveway just before 4:00 pm to motor in that direction.
The original line that was visible as I drove west - complete with discrete bases and rain shafts - collapsed before I could get to it but another cell built behind it just east of the mountains. As this storm grew and others fired near and around it I videoed, photoed, and then hop-skotched east and south ahead of it to keep an eye on it. I stopped on a ridge top just off U.S. Route 522 to catch this view.
Lightning was flashing from several cells, and the rain foot evident in the right hand storm in the photo was an indication of strong outflow winds.
I kept moving south along Route 522, stopping several times to watch the cells - several with radar-indicated hail markers - coalesce into a line while marching toward me. At one vantage point I noticed a feature that acted and looked suspiciously like a very small wall cloud, with abundant CG's raining down from and around it.

I finally chose to let the line catch me near Ware's Crossroads so I could head back toward home on Virginia Route 208 through the Lake Anna area. As I did so I adjusted the scale on my radar view and noticed two very nice severe-warned cells pounding King George county about 20 minutes from my home. Yep, those were an outgrowth of the previous storm complex that had traversed the DC suburbs before diving south and east. If I had waited a couple more hours I could have chased in my back yard...

More storms to chase soon?

2011-07-31T09:31:00.002-04:00

Here at the height of the summer doldrums it's hard to scare up a storm or two to chase. Recent activity has stayed well to the south across central and southern Virginia as the racetrack around the heat dome over much of the country has steered storms away from the Fredericksburg region. None of the recent setups have had enough severe potential to provide the incentive to travel several hours in the heat and humidity to intercept ordinary storms. However with a couple of weak fronts on the way hopes are rising for local convection both Monday and Wednesday of this week. The overall setup doesn't look promising for severe storms either day but anything that provides rain at this point is of interest.

Meanwhile the tropics are becoming more active so that too is an area to keep an eye on for severity. Not wishing severe weather on anyone, but it is true that some of the best chasing in the past few years has been during the passage of tropical storm remnants through the area.

July 25 Heat wave breaker

2011-07-25T18:44:00.000-04:00

Today's storms formed along a pre-frontal trough early in the afternoon, meaning I needed to get out earlier than normal to chase. Unfortunately all the NWS radars in Virginia - and possibly the nation - stopped providing internet access for roughly 90 minutes during the time I really needed situational awareness. In desperation I rolled out the driveway with my chase gear in a mobile reconnaissance, using the MK 1 eyeball to determine what storms may be worth chasing. Fortunately I guessed right and headed east into King George county where I set up shop at a favored vantage point to observe oncoming cells.

I got out of the car to take a few still photos after I'd set up my dash video, and was immediately chased back inside the vehicle by this:

It's been a long time since I was outside and had a CG hit that close, and I just about had to go home and change pants. There had been no CG's visible prior to this one, but they certainly rained down with vigor after this.

At this point the radars were back up so I noted that the cell I was watching exhibited some rotation on it. That rotation was literally right above my head as the scud gathered and rose into the updraft. I watched carefully until the rain set in but never could identify a wall cloud. Given that the only direction I could go to keep up with the storm was south - the Rappahannock River prevented that option - I plowed thru the heavy rain westward to reposition in a small break in the line for the next cell and took a few pictures but didn't see much else. I still have that video to review but there were no more close CG's.

Cheering on the outflow boundary

2011-07-22T17:47:00.003-04:00

The white arrow points to a southward moving outflow boundary laid down by earlier storms northwest of DC. As this image shows the boundary has already fired storms (cell just north of the center of the line) and the hope is that it will continue down this way and fire up cells around here. Anything to beat the heat!!!

7:07 pm UPDATE: Alas, the boundary died out as it reached the Stafford Courthouse area, along with the updrafts it was creating. Storms tomorrow?

Virginia Tech meteorology program approved

2011-07-20T16:56:00.002-04:00

I posted this article over at the Fredericksburg Weather blog and decided it was important enough to post here as well. Kudos to the new Virginia Tech meteorology program!!!

Meanwhile, even tho' the NWS Sterling radar is off line today I've been keeping an eye on the Wakefield radar in case some decent - and reachable - convection fired. So far nothing has gone up where I could get to it, but we could still see a storm or two before dark.

July 13 cold front approach

2011-07-13T20:59:00.004-04:00

Given that today's cold front passage is supposed to ease back the heat and humidity I was anxious to chase the storms associated with it, so I motored up to Bealeton on Route 17 and stopped there at 3:00 pm to monitor the situation. The frontal storms lined up west to east with individual cells moving to the southeast, and I sat there almost 45 minutes for them to get close enough to see details. The best two cells were traversing the DC suburbs so I regretfully ignored them as I waited for a chaseable storm to distinguish itself.

One finally did become severe-warned as it crossed the Blue Ridge southwest of me so I dropped down to Culpeper on Route 29 and checked radar again. That cell was still the best available so I continued south on Route 15 to Orange, parking on a hill just north of town to watch the approach. It was outflow dominant and pushed out a shelf cloud:
When the rain shaft got too close I moved south through town as a very bright CG struck somewhere close with ear-pounding thunder.

As I struggled to stay ahead of the line I was able to snap a photo from underneath the shelf cloud:
I dove southeast down Route 33 from Gordonsville to stay ahead of the rain and the very strong outflow. Doing so took me to Louisa before I could find a spot to pull off the road and conduct a "static core punch" as I let the line overtake me. Even tho' the core of the cell just north of me had a hail marker on it all I witnessed was rain and wind. A chase, but nothing severe.

July 8th chase: Part 2

2011-07-08T20:17:00.004-04:00

After I pulled off the storms east of Fredericksburg I dove south to Thornburg to intercept the tornado-warned cell that continued to show rotation on radar in Orange county. This cell was moving to the east as part of the frontal line scouring out the tropical air mass. Unfortunately for me I was cut off from a clear shot at this storm by another storm ahead of the front that was scooting to the northeast. I relied heavily on my GR3 display plus GPS to put me in a position to rescue something worthwhile out of what was becoming a royal rainy mess.

I finally wound up near the intersection of Gordon and Brock Roads in western Spotsylvania county to watch the approach of the area of interest in the approaching line. The cloud deck ahead of the line looked like cold air had already partially stabilized the air mass:
Since radar still showed some rotation in the line I stuck with it and wound up watching an area of scud building into what may have become a wall cloud if conditions had been a bit riper.
And here's a video of the gathering scud (again sped up 4x):

I still have a bit more video to review in hopes that I caught a CG or two, but the chase was over by 5:30 after the frontal passage. Some July fun!

July 8th chase: Part 1

2011-07-08T19:27:00.003-04:00

Given an SPC Slight Risk and an increase in overall shear over yesterday's model runs I awaited convection to fire today with great anticipation...and was not disappointed. When several cells approached the Stafford / King George county line from the southwest early in the afternoon I positioned myself along Route 3 east of Fredericksburg to observe. The northernmost cells were already crossing the Potomac River to my north when I arrived at my first site, where I finally coaxed my laptop to boot up so I could look at GR3 radar. When I noticed some good-looking storms crossing the Blue Ridge mountains I decided to head west in their general direction but yet another updraft entering the "magical" Rappahannock River valley caught my eye.
It was obviously sheared toward the northeast so I watched it until rain obscured my view. Moving a half mile to the west I caught this view:
The entire updraft was definitely rotating and I was able to catch it on my dashboard video and speed it up a bit:

I watched it for several minutes until the cell weakened. At that point I succumbed to the siren call of the storms now across the Blue Ridge since one of them was already tornado-warned. Part two to follow..,

Blurry vidcaps from 3 July "chase" and probable Friday July 8th chase

2011-07-07T21:45:00.002-04:00

These two vidcaps are from Sunday July 3rd's storm system that rolled through the Fredericksburg area. It provided some great CG's and strong winds, but the worst of the storm scooted by just north of us. This "chase" was notable in that my daughter and her husband accompanied me...it was his first chase!!

Tomorrow the setup looks better for severe storms given that the upper level winds look to be a bit stronger as an upper trough approaches from the west. The complicating factor will be exactly where the weak surface front sets up. Areas to the north of said front will likely not see much sun. Thus if we can stay south of the front and allow the sun to peek through enough to destabilize things there will be storms worth chasing.

Chesapeake Bay Breeze

2011-07-02T19:17:00.000-04:00

One of the factors in Mid-Atlantic storm chasing is the presence of the Chesapeake Bay. It affects both storm access - bridges are few and far between - and storm initiation and intensification. The latter two are a direct result of the "Bay breeze", a localized phenomenon that occurs when the overall wind field is light and a circulation develops between the water and the land. The air over the warmer land rises and is replaced at the surface by cooler air from atop the Bay waters. The result is a mini-cold front that can both create storms and intensify existing ones. Here is a radar depiction of today's Bay breeze:

The weak radar return inside the yellow oval is the Bay breeze. It is advancing toward the northwest and will likely meet the storms heading southeast from Pennsylvania. The result could be an intensification of said storms, possibly resulting in low level rotation. I'm sure the NWS Sterling mets are keeping their eyes on this.

Pre-frontal storms

2011-06-28T19:54:00.008-04:00

Knowing that today was my only shot at chasing this week I haunted the models, radar, and observations all morning and early afternoon. A lee trough ahead of a cold front was supposed to fire some storms as the SPC had our area under a Slight Risk even tho' the overall shear values were low. Finally, after 3:00 pm, I decided that I couldn't wait any longer and pointed the chasemobile westward toward Wilderness in hopes of catching some storms firing near the mountains.
At Wilderness I stopped to check radar and found a nice looking cell southwest of the town of Orange so I headed south along Route 20. After a couple of other radar stops I finally wound up in the Unionville vicinity at the intersection of Routes 20 and 522, awaiting the approach of the slowly moving storms. Unfortunately the cells near Orange kept dying out as I sat there waiting for them, so I gave up on them and motored north on 522 toward Culpeper to intercept a cell crossing the Blue Ridge with indicated rotation. Sure enough I spied a wall cloud west of the town:
Realizing that a line was coalescing east of the mountains I found a northeast bound rural route by which to parallel the storms and keep ahead of the rain. Finally reaching a good vantage point I was able to see the wall cloud and its striated updraft now southeast of Culpeper:
I moved a couple of miles further northeast to stay ahead of most of the rain. As I watched, however, the line continued to coalesce and this cell began to produce a shelf cloud:
I now realized that the complex had me cut off from crossing the Rappahannock River via Route 29 north of Culpeper, so my only choice was to scoot southeastward along Route 3 toward Fredericksburg. I snapped this shot from a median pulloff as the storm continued north of the river:
Overall it was a decent chase with limited expectations of severity, and that's what I got. But it was a chase!!

Frontal passage with no reachable storms

2011-06-24T18:48:00.004-04:00

With a cold frontal passage through the area early Friday afternoon I was hoping for at least one decent cell to chase. There wasn't - it all happened well to the east - but I did at least identify and track a convective line that eventually intensified over the Delmarva peninsula. I set up shop on Route 3 east of Fredericksburg to watch the line, with particular interest in the southern end:

Alas, the northern end of the line was the part that developed this time and those cells were already heading northeast and were close to crossing the Potomac River by this time. I followed the line eastward to Route 301 but threw in the towel early when nothing else developed, even after the SPC had posted a Mesoscale Discussion for all of Virginia east of the Blue Ridge. For a week that originally held at least a modicum of chasing potential the past few days have been a big disappointment.

The storm killer

2011-06-22T20:00:00.007-04:00

At least that's what I feel like my nickname should be after the last two days of chasing. Today I even waited until a complex of cells looked decent on radar and close enough to go after:
The convective complex sprawled from Louisa county into western Spotsylvania, and the southwestern edge was continuing to punch up new cells, so I headed south to the Thornburg area where I spied a nice rain-free base at the southern end. Continuing south to a sports facility in Caroline county I stopped to watch the entire complex begin to fall apart:

The frustrating part was that the cell to my south was pounding Ashland at this time and sounding very active but I was out of position and didn't want to travel any further south and east. Within 15 minutes after this picture was taken there was literally nothing left but blue sky so I moseyed back toward home. Can't call this a B-U-S-T, but it certainly wasn't satisfying.

Lightning video from June 21 storm

2011-06-22T12:51:00.002-04:00

This particular CG (cloud-to-ground) made me jump during yesterday's storm intercept! All the more reason I stay in the car when lightning is near.

Summer solstice chase (June 21)

2011-06-21T20:55:00.006-04:00

Even tho' the SPC Slight Risk area barely grazed Charlottesville I decided to give chase to a nice-looking cell that moved southeasterly from the home of UVa. Radar indicated some rotation on the southeastern edge of the storm so I strove mightily to get there, rolling down Route 15 through Gordonsville and eventually south of I-64. (It was a bit out of my normal chase range but I was craving a chase given that I'd missed a few last week.) As I approached Palmyra the storm became severe-warned and my expectations ratcheted upwards despite the fact that I could see a shelf cloud but no wall cloud and experienced significant outflow winds.

Southeast of Palmyra and not too far from the metropolis of Columbia I stopped on a rural lane to watch the approach, disappointed that the overall complex had significantly weakened and looked like it was falling apart. To my delight the storm began hurling CG's as it pulsed back upward in strength and I recorded a number of them on my dashboard video, including a very close one that startled me.

After the rain started in earnest I motored back northward in hopes of getting a structure shot of the storm but was thwarted by the everpresent treelines.

Timing, timing, timing...

2011-06-20T10:22:00.000-04:00

The Storm Prediction Center convective forecast today shows another Moderate Risk for areas out west that we chased during the May Virginia Tech storm chase trip. Over the past week or so the storm chasing has heated up - pun intended - out west, which has led to teeth grinding sessions among both the May and June trip personnel at having missed some of the best chasing of the season. But, as I've said on numerous occasions, storm chasing is a four-dimensional activity. Not only does the chaser have to be in the right place on the map (x,y,z) but he/she has to be there at the right time (t) as well. Now if I can just find a funding sponsor that would finance two or three weeks out in Tornado Alley...!!

Meanwhile I am back in place for Virginia chasing and am keeping an eye on the forecast and the radar locally. I don't foresee a lot of severe weather this week but there will be thunderstorms that may interact with outflow boundaries and other local phenomena to increase low level shear. I will be out looking!!

A no-chase week

2011-06-17T22:19:00.000-04:00

There have been at least a couple of decent storms I would have chased this week, but they've all been trumped by the waiting for and subsequent celebration of the birth of our second grandson. Some - albeit very few - things take precedence over storm chasing, and this is certainly one of them. I'll be back in the saddle sometime soon, and there will be other storms to catch!

Saturday June 11th chase

2011-06-13T22:42:00.000-04:00

I have been remiss at posting a chase account from Saturday but herein is a summary. After perusing models and radar I motored toward Culpeper with the goal of being there by 2:00 pm to get set up ahead of the storms. This turned out to not be early enough as cells were firing east of the Blue Ridge by that time and were quickly coalescing into a squall line. The best looking storm was heading eastward near the town of Orange so I jumped south to the Lahore Road / Route 522 intersection and set up shop on a rural route near there, where I recorded this CG on my in-car videocamera:

The other noteworthy features of this cell were heavy rain and strong (~30 kt) outflow so I continued a mile further south to stay ahead of the line and recorded this awesome view of the line's approach:

Turning north on Route 208 I was stopped by road construction on the bridge crossing Lake Anna where I photographed this view of the shelf:

This video shows evidence of the strong outflow via a dust cloud crossing Route 208:

I was going to call off the chase when I reached Route 1 in Thornburg but caught sight of a lowering to the east so I continued eastward across I-95, across to Route 2, and then north to Route 17 in Spotsylvania county. Still glimpsing the lowering I charged eastward down Route 17 to Port Royal but never did get another good look at the lowering thanks to tree lines and hills. At that point the cell just to my north was severe-warned and was pounding King George county with hail reported up to 1.75" size but I called off the chase at that point and headed homeward.

Maybe a Saturday chase?

2011-06-11T10:29:00.000-04:00

Yesterday's chase potential was significantly reduced once a backdoor front slid into the eastern half of Virginia during the early afternoon. Temperatures and instability both fell and shoved the convective potential to the Blue Ridge and points westward. The cells that fired there did so under conditions that weren't dynamic enough to entice me to travel toward Charlottesville for slow moving heavy rainers/hailers, altho' from radar indications I felt at least one cell just north of that city probably had a decent wall cloud under it.

Today looks a bit better for chaseable storms even tho' the overall shear isn't impressive. A lee trough should trigger convection further north and east and I'm counting on leftover outflow boundaries to provide a bit of low-level shear to help with storm development. We'll see how it all develops and whether I chase today.

Next chance for storms is Friday, and updated info on VT Meteorology program

2011-06-08T09:35:00.000-04:00

The MCS that swept through West Virginia and Kentucky yesterday also threw out a thick overcast in our direction that suppressed any potential convection, so yet another possible June storm chase was quashed. Normally June is a very productive chase month here in Virginia with me scrambling to find the time to review photos and video from the last chase before setting out on the next one. However this year's unusually early summer pattern has severely restricted productive June chasing both here and in most of the standard chase territory in the Plains. Hopefully that will change a bit for us starting Friday as a stationary front sets up in the Mid-Atlantic and provides a trigger for convection for a few days.

In other news the proposed Virginia Tech Meteorology program is receiving more attention now that it has only one more wicket to pass through before it becomes official. This article on the VT website provides some more perspective as to the benefits such a program will bring to the citizens of Virginia.

Hokie Stormchase 2011 is now officially over

2011-06-06T09:55:00.000-04:00

The second group of the 2011 Hokie Stormchase is heading back to Blacksburg as I write this, due in sometime today. I was not along for this trip but have been following their efforts to catch storms as part of a VT field course. Unfortunately the second group ran into a "death ridge", the jet stream pattern that pushes the storminess north toward the Canadian border and has provided us with a generally northwest flow of upper air for the past week or so. As a result they struggled to find decent storms to chase but have hopefully sharpened their forecasting skills during a difficult time.

All this is part of the soon-to-be-approved undergraduate meteorology major at Virginia Tech, which will be located in the Geography department within the College of Natural Resources and Environment. In conjunction with the National Weather Service forecast office in Blacksburg such a program will prove beneficial to the state of Virginia as a practical application of research and analysis efforts to weather-related challenges faced by state residents. A natural fit with our land-grant university, the new VT meteorology program should be a great benefit to Virginia citizens.

June 1 2011 Virginia hail fall video

2011-06-02T13:14:00.000-04:00

This is what a lone storm chaser talks to himself about while hail is falling down around his vehicle.

June 1: A good day to chase

2011-06-01T21:13:00.000-04:00

Based on the model forecasts I left home for Culpeper early this afternoon and arrived there around 2:00 p.m. to await convection given the monster CAPE values (>6000!) in northern Virginia. Turned out that I was a bit early as things didn't start bubbling until 4:00, when several updrafts formed and almost immediately were tagged with hail icons on radar. Fortunately they were moving slowly at around 15 knots so I didn't have to make immediate decisions on where to go. I wandered around the Culpeper vicinity for a while, stopping to watch a rain free base under the first cell to see if any lowerings would occur:

Nothing formed so I moved south along Route 522 to stay ahead of the developing line of storms as the cells coalesced until I realized that I could get far enough south on that highway to catch the "tail-end Charley" storm. Stopping a few miles south of Unionville I watched that cell crawl in my direction as it exhibited another rain free base:

Nothing showed under this storm either as the rain shaft pounded down just a couple hundred yards to the north. I had just about decided to pull back out onto Route 522 and head back north when this cell exploded with numerous CG's (cloud-to-ground lightning) and hail started to fall. The storm intensified literally over my head as I watched - and listened to - a ten minute hailfall that started with half-inch stones and wound up pile-driving my car with stones up to 1.5 inches in diameter:

The quarter (1" diameter) is shown for comparison.

(Note: my chasemobile actually has a few hail dents now...source of a chaser's pride!)

After the very noisy hailfall finished I did head north and then back home, not wanting to chase that storm through the wilds of Spotsylvania county and around Lake Anna. At home all was dry and storm-less, but a magnificent mammatus display near sunset made it all worthwhile:

A June 1st chase looking likely

2011-05-31T13:17:00.000-04:00

The models are pointing to good chase setups for both the Hokie Storm Chasers currently in Nebraska after a successful chase yesterday and for those of us here in the Mid-Atlantic. Storm initiation for northern Virginia appears to be mid-afternoon so I will be positioning myself a bit earlier than normal tomorrow, probably getting to a chase target by 2:00 pm. Said target is TBD until I can get a look at the short-range local models tomorrow morning, and storm motions out of the northwest will help determine the road network needed to track the cells. My guess is that I will default to my usual Culpeper target as that locale provides a plethora of good roads in many directions coupled with relatively open farmland vistas, but nothing is definite at this point.

Chaser's chagrin: picking a decent storm when a really good one forms near home

2011-05-27T20:40:00.000-04:00

I watched on radar a northwest / southeast oriented line of storms marching toward our region this afternoon and noticed that the northern cells were maintaining the best organization as they propagated toward Culpeper. Thus I chose that end of the line to investigate and plunged into the havoc of the Friday-of-Memorial-Day-weekend traffic to head first to Bealeton and then to just west of Remington. The northern end was impressive enough as it approached a pastoral farm setting:

No lowerings appeared under the rain free base on the southern end of the cell, but a hail shaft was evident both on radar and visually:

Hail shaft to my west appears as the lighter area of precipitation slightly to the right of center.

My position is marked with the white "x"; hail marker is the green triangle.

Before the heavy rain arrived I motored leisurely through the town of Remington and stopped on a rural road outside of town to look back at the storm. While I was doing so I noticed a very strong cell approaching the Fredericksburg area on the southeastern end of the line. This cell, which eventually received a tornado warning, was THE storm of the day to chase and I was woefully out of position. I tried to get back to the area in time but was unsuccessful...thus the chaser's chagrin. But, I did chase today!!

Few more pictures from the Hokie Storm chase

2011-05-26T21:28:00.000-04:00

Cyclic wall cloud formation underneath 5/21 Nebraska supercell. Wall cloud at right is dying out while the one at center is wrapping up. (Stuff at left is just cloud fragments...i.e. scud)

Nebraska supercell structure May 21.

Hokies watching the sunset underneath a storm in Kansas 5/20

Ummm...don't go too far! May 20 wall cloud in Kansas that blasted us with a 30+ knot RFD.


A highly doctored closeup of the 5/22 tornado in Iowa. The naked eye could see it clearly but the gray tones played havoc with camera lenses.

I'm sure more pictures will be posted over at the Hokie Storm chase blog.

Back to Virginia chasing

2011-05-26T09:16:00.000-04:00

It looks like there will be storm chase action today, tomorrow, and possibly Saturday that I could get to. Today would involve a trip west toward the Blue Ridge as things here around I-95 probably won't be conducive to storm development. I will be watching radar this afternoon and may be heading to the Route 29 corridor, or if things look good enough I may cross the Blue Ridge up to the Winchester vicinity where the lift mechanism looks better. There's plenty of instability and moisture available, with a bit of wind shear thrown in. We'll see!

May 22 Iowa tornado video clip

2011-05-23T10:56:00.000-04:00

This tornado yesterday was a small one but exciting to our crew. This is my poor attempt at capturing it on video. The town's tornado sirens sent a chill up my spine when they sounded.

May 22: Hokie Stormchase magic!

2011-05-23T01:28:00.000-04:00

May 22nd has been a tornado day for the Hokie Stormchase team over a number of years, and today was no exception. We intercepted a tornado in the little town of Merango, Iowa and began filming it just as the tornado sirens began sounding. Fortunately this tornado missed the town, but others caused lots of damage and deaths today (especially in Missouri). We mourn the losses of those folks at the same time we exult that we witnessed an actual tornado. This is a bit confusing emotionally for us as I'm sure it is for the reader, but that is the nature of storm chasing.

Here is a not-so-good still photo of the tornado. I'm hoping that an edited video will look a bit better.

May 21 photos

2011-05-22T08:28:00.000-04:00

"Doughnut hole" wall cloud and lowering over field

Wall cloud and rotating lowering (at left) over York NE

Our last view of the storm before it became rain-wrapped and we lost sight of it. A tornado was reported shortly after this by another onlooker.

Hail!! These stones had been sitting on the side of the road for a while, so they had melted a bit. Three inch hail was reported on this storm. Needless to say we were very careful to avoid the hail shaft!!

Municipal building in Wahoo NE where we ate dinner after we lost the storm due to the lack of decent roads. Yes, we found it ironic that a bunch of Hokies ate in Wahoo territory.

May 21: Nebraska chase...after abandoning our original target

2011-05-22T01:39:00.001-04:00

Yet another late night which will be followed by an early morning tomorrow as we overnight here in Walnut Iowa. Our original target for today was to be southeastern Kansas and we actually motored south from Salina this morning until a new Storm Prediction Center forecast was issued at 11 a.m. CDT. That, and a bright blue sky with no clouds caused us to swap ends and caravanned northward to southern Nebraska. We found an outflow boundary from earlier storms and parked underneath it in along a quiet country lane with no other chasers anywhere in sight to wait.
As things percolated a storm finally went up just to our north and we gave chase to what eventually became a tornado warned cell. We saw mean looking rotating wall clouds, a funnel or two (one could have been a tornado but we didn't confirm debris under it), and some very large hail. I'll post photos as soon as Blogger decides to behave. Meanwhile check out the photos that I'm sure will be on the Hokie Stormchase FB page.
Tomorrow's target: north-central Illinois.

May 20: Family of Kansas supercells

2011-05-21T02:27:00.000-04:00

I can't begin to describe in any details what we saw today, but awesome doesn't even come close. Here are a few of the pertinent events:
(1) For the third day in a row the student forecasters put us in a severe watch area several hours BEFORE the SPC issued the watch.
(2) We stayed on the tail-end of a line of supercells developing along a very thin corridor in south-central Kansas.
(3) I got almost knocked off my feet by my first true Rear Flank Downdraft.
(4) We saw more rotating wall clouds than I can remember.
(5) We drove through - and had to stop several times for - a hail shaft in which we witnessed dime-sized hail...and that was the small stuff.
(6) We wove our way through a chaser convergence of interesting proportions.
(7) We witnessed an astoundingly beautiful sunset.

Here are a few of the many pictures I took today:

The second (or third or fourth) wall cloud of the day.

The original wall cloud from the storm that generated the RFD; it was too close (1/2 mile away) to fit into the frame.

The sunset, of which photographs do not do justice.

Quick update from Salina KS

2011-05-20T01:32:00.000-04:00

Yes, we HAD to visit Wakita...which chasing aficionados recognize as the town that was destroyed in the movie "Twister". The museum commemorating the movie wasn't even open, but we took lots of pictures. This one shows the anemometer on top of the mesonet probe pointing at the iconic water tower in the town.

After that was done we headed for south central Kansas to position ourselves between the dry line and a warm front. To make a long story short things didn't work out as we planned even given a tornado watch. The storms that did survive congealed into a low ceilinged mess, but we did salvage a very late evening chase that produced a wall cloud while we watched and a tornado report after dark (that we didn't see). Here's a couple of the Hokie chasers watching the action north of I-70:

That's about all my muddled brain can think to write tonight...maybe more tomorrow after a night's sleep.

Great targeting...but no storms

2011-05-19T09:15:00.000-04:00

We were at the right place...but no cigar. Now for a few details:

During our morning meeting yesterday we decided our target was somewhere near El Reno OK, and we wound up at a truck stop a couple of exits west of there on I-40 watching a bulge in the dry line as storms tried to form. We could literally see the dry line visually as it was evidenced by a line of cumulus clouds followed by bright blue sky to the west.
When the line came too close we moved a bit north and west and settled at a sports complex in Calumet OK, where I snapped the photo above. We sat here for about 3 hours, watching convective towers build and die in a panorama to our south and west. While we were there the Storm Prediction Center issued first a Mesoscale Discussion and then a tornado watch box. Our location was smack dab in the middle of this box so our forecasting was right on target and a few hours ahead of the SPC!! Unfortunately no storms whatsoever fired in the box and the SPC took down the tornado watch as we were on the road to our destination for the night in Enid OK.
Today we're heading to central Kansas where the conditions look much better for supercells and tornadoes. Track us on the Hokie Stormchase page. We're in hopes of some good results today, but we hope all the severe weather happens in rural areas without impacting folks out here.

Timing is everything

2011-05-18T09:59:00.000-04:00

This Storm Prediction Center graphic shows the storm reports from yesterday. The cluster of reports - and yes, tornadoes - in northeastern Colorado was somewhat further north than our target yesterday, but all these reports were early evening. Since we needed to cut off the chase before that time and head south for Wednesday's events, we bailed from our southwestern Kansas location about an hour before these storms fired. We knew the potential wasn't really good for these type storms so we didn't wait around, but this setup reinforced a lesson storm chasers know all too well: chasing is a 4 dimensional activity. You not only need to to know where to go but also when to be there.

Today's target: Oklahoma. Exactly where is subject to the discussion in our morning meeting that will happen in an hour.

Our first (and only...hopefully) B-U-S-T

2011-05-18T00:31:00.000-04:00

Today was a marginal setup at best, and this morning we completely shifted our target from Childress TX up to eastern Colorado based on some new model data plus the Storm Prediction Center putting up a small tornado probability for that area. The dynamics involved a low pressure system in Colorado, a dryline, and an advancing upper level disturbance. Unfortunately what was missing was (a) moisture and (b) timing, so we wound up watching a bright blue sky in southwestern Kansas. Oh well...
Tomorrow's target is south central Oklahoma where the setup looks a lot better than today's. We'll see some storms tomorrow; of that I am convinced!!

Tuesday's target: Childress TX

2011-05-17T00:00:00.000-04:00

We pushed hard today and wound up in Shamrock Texas, roughly 90 miles east of Amarillo in the Panhandle. The conditions for storms aren't great tomorrow since a big area of high pressure - following the low that is plaguing the East Coast with dreariness this week - has shut off moisture flow from the Gulf of Mexico. Without that moisture storm formation is next to impossible, so we're keeping our fingers crossed that enough wetness will climb northward from the Gulf to provide some storms tomorrow. We're banking on that with our Childress target tomorrow. The models indicate that we may see something tomorrow, but Wed. thru Fri. looks even better.
The good news is that Childress isn't very far south of where we are now, so we can all catch up on some sleep tomorrow morning!

Article on VT storm chaser plus heading to the Texas panhandle today

2011-05-16T08:47:00.000-04:00

Kathryn Prociv has just graduated from Virginia Tech and is riding in my van as a returning VT storm chaser and assistant field instructor. This article is a nice explanation of what she does and what her plans are.
Today's road trip involves a straight shot west on I-40 to somewhere in the TX panhandle. We're just about to begin our morning meeting to discuss the overall forecast for tomorrow so our final target is still TBD, but the panhandle is a good junction point for us.

Day 1 of the 2011 Hokie Storm Chase

2011-05-16T00:33:00.000-04:00

Not a lot to report other than nearly 700 miles driven and spending the night in Forrest, Arkansas. We're heading toward an initial target Tuesday afternoon which may be in the Texas Panhandle, and it appears that Wednesday thru Friday may be very fruitful chase days here in the Plains. You can follow our physical progress on the Hokie Stormchase blog. Oh, and I am getting a few funny looks by having the mesonet probe on top of my van!!

Virginia Tech Mesonet probe installation

2011-05-14T09:28:00.000-04:00

Spent yesterday helping Dave Carroll (VT instructor and storm chase leader) "trick out" the chase vans with radio gear and this mesonet probe prototype:

We will be testing this rig out during this year's storm chase to help finalize the design for future VT meteorology research. Guess who gets to drive the van with the probe?

We leave Blacksburg Sunday morning and will head westward to either the Texas panhandle or northeastern Colorado for a Tuesday afternoon chase, with the final destination to be chosen later.

2011 Hokie Storm chase to commence this weekend!!

2011-05-11T14:54:00.000-04:00

I will be heading westward this weekend as one of the van drivers for the May 2011 Virginia Tech Hokie storm chase team. I'll post thoughts, photos, and maybe a video or two here as time permits during the chase. Meanwhile, here's a photo of the May 11th 2006 tornado I witnessed from a distance of 150 yards at Todds Tavern in Spotsylvania county. Five years ago!!

(Apologies for the poor picture quality...it was snapped as I was sprinting back to the car to get the heck out of there!)

Storm Ready status needed!!

2011-05-05T09:15:00.000-04:00

I posted this article over at the Fredericksburg Weather blog in hopes of stirring up some community interest in better severe weather coordination in the greater F'burg area. Perhaps a mention of it in this blog will help rally the cause as well.
Certainly last week's record tornado outbreak should help focus our attention on the need for better severe weather warnings in our area. Given the forecast "hole" in which Fredericksburg resides - receiving insufficient focus from both DC and Richmond area media - and given the general lack of attention that folks around here assign to the potential for severe weather effects on our community, we need better planning, education, and communication regarding such things. A "Storm Ready" qualification would go far in providing better response and warning coordination for our area rather than relying on our typical ad hoc response to the effects of a severe storm plowing through a crowded public venue or neighborhood. We may not have tornado sirens like communities out in Tornado Alley but we do have available technologies that could get the word out quickly. Let's use them!

Another missed potential chase

2011-05-02T13:34:00.000-04:00

This is the Storm Prediction Center's convective forecast graphic for Tuesday, May 3rd. After a quick glance at a model (the NAM) there appears to be plenty of instability and wind shear available for some chaseable storms. Unfortunately I won't be available to chase tomorrow, but I'll be keeping an eye on radar!

April 27 chase writeup

2011-04-28T19:03:00.001-04:00

After perusing the model outputs the morning of April 27 my pulse quickened a bit. The wind shear from the surface up to 500 mb (~18,000 feet) was noteworthy, and the forecast low level helicities for late afternoon were off the charts. I was positive this was a chase day but I wasn’t sure how early I needed to head out until the SPC posted a tornado watch just after lunch for the entire NWS Sterling forecast area.

Given a southwest to northeast storm motion forecast I figured my best bet was to catch cells close to the eastern slopes of the Blue Ridge mountains and track them as they traversed the Piedmont. Thus my initial target was the Culpeper / Route 29 corridor, but as I traveled west on Route 3 past Wilderness I noticed a singular cell to my south. Stopping just after 4:00 pm southeast of Culpeper I checked out my new wireless setup – consisting of a MiFi card and my iTouch – and found that the base of that cell was just crossing I-64 and heading northeast. What was more important was that (a) the storm was severe warned and (b) the base was rotating.

Abandoning my original target I charged south down Route 522 to cut in front of the storm in hopes of getting on its south side. I managed to do that – barely – and wound up at 4:45 pm parking near a cove at the north end of Lake Anna that afforded a great view of the approaching storm. The rain shaft was a couple of miles north of me as I sat directly under a rain-free base that represented the rotating mesocyclone. (Mesocyclone is circled in blue and my location is at the tip of the black arrow in the radar graphic below.)

Photo looking north at 4:54 pm

I saw faint evidence of lowerings and gathering scud, and the winds were at my back as I faced the storm – the inflow meaning the storm was gathering strength instead of gusting out – and noticed a bit of greenage almost overhead.

After watching the storm from that vantage point for almost 20 minutes I left to give chase through the wilds of the Spotsylvania / Orange county border area. I managed to keep the base in sight despite the everpresent tree lines and winding roads while noticing more scud gathering as I attempted to keep up with the now-accelerating storm. Finally maneuvering my way onto Mine Road in Orange county I rambled eastward at the best possible speed but couldn’t get any closer as I witnessed this funnel at 5:30 pm.

By this time I knew this storm was tornado-warned (duh!) but the further east I motored the worse the afternoon traffic got, so I attempted an end around and dived southward on Brock Road down to Todds Tavern in Spotsylvania county. After stopping to gather my wits and catch my breath I noticed that another storm trailing the first one was looking very interesting. A quick check of radar verified rotation so I reversed course and headed northward to Route 3 just east of Wilderness, where I witnessed a very obvious lowering. In the face of the nightmare traffic I rolled eastward a couple of miles to a crossover on Route 3 near the Chancellorsville Battlefield that provided a clear view to the northwest and set up shop around 6:00 pm to watch and take photos.

Photo looking northwest at 6:09 pm

From this location I phoned in a wall cloud and funnel report to the NWS Sterling office which issued a tornado warning on this new storm shortly thereafter. I couldn’t see the ground under the obviously rotating funnel so I couldn’t verify a tornado…but I’m pretty sure my later photos show a tornado in progress.

After the rain wrapped around it and I could no longer see any details I finally trudged home amid thoughts of resting and editing photos and videos. However, more rotating storms approached from the south after dark so I gave chase without success. The tornado warned cell I targeted fell apart before it crossed from Caroline county into eastern King George county. If I had been adventurous enough I would have blasted northwest to chase a tornadic storm that roared through the Culpeper area, but by that time I was pretty much done…even if Nature wasn’t.

Initial video edit

2011-04-27T22:33:00.000-04:00

This is the first video clip of the second wall cloud / funnel / tornadic storm this afternoon. This is a brief clip from my low-tech non-HD video. The location is near Chancellorsville Battlefield, in the median of Rte. 3 looking northwest.

A tornadic day in Virginia

2011-04-27T20:19:00.000-04:00

Quick post of a couple of pictures and brief writeup. I have videos to edit plus there are more storms on the way that I might have to check out in a night chase.

I started out heading toward Culpeper today but was redirected - via my newly integrated MiFi and iTouch connection - southward down Rte 522 to the Lake Anna area where I intercepted a rotating rain-free base of a slowly moving storm. I sat literally underneath the rotation with no wall cloud or funnels evident for 20 minutes until the storm trudged off to the northeast. Of course when I gave chase through the wilds of Orange and Spotsylvania counties the storm accelerated and I struggled to keep up. Once I got situated on Mine Road I glimpsed this as I headed east toward Fredericksburg:

For obvious reasons this storm was tornado warned.
I began to lose the storm given the treelines and increasing traffic so I turned south on Brock Road in Spotsylvania county in an end-around attempt but gave up at Todds Tavern, where I gathered my wits and checked radar again. The trailing storm was also showing evidence of rotation so I headed back north to Route 3 near Wilderness, saw a lowering, and promptly sped east to park in the median and take these photos:

My initial view

After it evolved a bit.

I did my SkyWarn duty and called in a funnel report to NWS Sterling and this storm became tornado warned as well.

As I write this yet another storm is bearing down on Fredericksburg with indicated rotation and a tornado warning. More probably to follow!!

Chasing weekend?

2011-04-23T09:37:00.000-04:00

The SPC has our immediate area on the fringes of potential severe weather both this afternoon (Saturday) and Easter Sunday, but I'm not jumping up and down about the possibilities after reviewing the models. Trust me, I will be watching radar and will head out to chase this afternoon if anything warrants it but I'm not holding my breath. As for tomorrow I will have my chase gear available but there are more important things to consider on Resurrection Day, so that chase potential remains a big "we'll see".

And the answer is "no, I didn't chase today"...

2011-04-16T22:14:00.000-04:00

One of the hardest decisions I've had to make in recent years was to not chase today. I could list all the main factors (too much overcast and limited visibility, no mobile radar access, storms traveling in excess of 60 mph, ...) but the truth is I didn't feel much like doing anything today. In fact, I even voluntarily went to see a doctor today to check out this respiratory crud to make sure it wasn't morphing into bronchitis or something worse. That in itself says a LOT about the decision to stay home vs. chase.

So, I missed an epic storm chase day in Mid-Atlantic history. Kudos to those who went out and witnessed some of the most awesome East Coast storms of recent years. Oh, and excuse me for my teeth grinding and fits of frustration today...between the naps on the couch.

A Saturday chase is in the cards

2011-04-15T15:20:00.000-04:00

The Storm Prediction Center has upped the ante for tomorrow by calling for a Moderate Risk in the coastal Carolinas. Meanwhile Northern VA is likely to be under the gun as well for severe storms with potential for rotation which should roll through between 3 and 8 pm. I feel a tug to head south to the Moderate Risk area but I really don't want to travel that far tomorrow, so it looks like I'll be starting in the Charlottesville area and chasing north and east. Photos and videos to follow later in the weekend!

Hmmmm.....Saturday may be more than just a washout

2011-04-14T08:28:00.000-04:00

The models have been hinting at the chances for some strong storms Saturday, and now the SPC has chimed in with their evaluation. The forecast text uses words like "low-level shear" and "rotating storms", which leads to the "T" (tornado) word. I'll have to put chasing on the agenda for Saturday afternoon!

Monday, once again?

2011-04-08T16:30:00.000-04:00

I've been keeping an eye on this coming Monday as another potential chase day, but the latest model runs all seem to have slowed down the passage of an approaching cold front that would trigger storms. It looks like another nocturnal frontal passage after a very warm day (highs into the 80's!), so unless a potent pre-frontal trough occurs east of the mountains I don't think daylight chasing is in the cards. The best I can hope for at this point is sufficient lightning to allow me to see something if I do go out Monday night.

The cold front approacheth

2011-04-04T21:38:00.000-04:00

This is early spring in its full glory...nighttime cold frontal passages that nix chasing but tend to keep me awake listening for storms anyway. The pre-frontal line of storms that was pounding its way thru KY and WV is weakening a bit as it runs into dryer more stable air east of the mountains (dewpoints are in the upper 40's in the Piedmont). Any storms that do hold together will be low-topped, meaning no lightning to reveal storm structure and probably no hail either. However, the winds are a bit worrisome and that's why the Storm Prediction Center has us outlooked for strong winds rather than the other severe stuff (you know, hail, tornadoes, that kind of stuff).
Tomorrow morning will be the proof of the pudding when the cold front dives across the Piedmont and coastal plain. I'm expecting that front to be nearing our location about the time I leave the house, meaning a wet and windy drive to work. Maybe if I'm lucky I'll be juuuuuuusssssttttt ahead of it...

Okay, who ordered up a hailstorm tonight?

2011-04-03T21:51:00.000-04:00

I was watching TV this evening, minding my own business, when my wife poked her head in the room and said she thought was hearing thunder. Sure enough when we both stepped outside we were rewarded with a nice CG with anvil crawlers. Stepping back in I found this on the radar:

Not much to look at, but I took my trusty low-tech camcorder outside to try to catch some lightning frames. I did:

But this was after I had to move back inside due to a pea-sized hailfall. What's up with this? Must be elevated storms firing ahead of - or along - a northward moving warm front. It was cool nonetheless!

Local "hail showers" today, but Tuesday's potential is diminishing

2011-04-02T20:50:00.000-04:00

This radar grab from 3:13 p.m. illustrates the showers that sped through northern Virginia today, including the warned storm shown above that had 1.0 inch hail reported near Dale City. There were also a couple of unofficial local hail reports around the Fredericksburg area from other cells. Following a cold frontal passage around noon a cold air pool aloft enhanced the instability that created these showers.
As far as Tuesday's severe potential goes the current models are indicating a cold frontal passage in the morning, robbing storms of the additional instability that would result from peak heating in the afternoon. Regardless, I'll be watching radar for anything worth scooting outside to witness while hoping that the models are incorrect and/or the front slows down. An April chase would be great!

Next week?

2011-03-31T20:21:00.000-04:00

Right now the GFS is hinting at instability in Northern Virginia each day Mon-Wed next week. Tuesday looks like the best storm chances overall, and the Storm Prediction Center in Norman OK has issued a forecast graphic to that effect. I don't see a lot of directional wind shear at the moment, but speed shear is plentiful so I would guess we will see a squall line or two. Have to wait for the NAM forecast cycle to cover those same days to get another "opinion" on what will happen, but I'm already anticipating an early April chase...or two!

A nice springtime intercept, but the best stuff came after dark

2011-03-23T21:11:00.000-04:00

That's my explanation and I'm sticking to it!! I headed for Culpeper this afternoon to get out from under the cold air damming wedge that gummed up northern and eastern Virginia today and wound up breaking out into sunshine by the time I made it to Lignum. That was the good news; the bad news was that the upper level disturbance the models had forecast to come through and fire storms between 4 and 5 pm weakened and passed through further south than originally thought. So there I was in Culpeper, twiddling my thumbs under a bright blue sky.
Patience paid off, however, as the storms over West Virginia finally crept my way. I dithered over whether to head north to intercept a nice cell heading toward Warrenton or to head south to catch one nearing Orange. The latter storm wound up with a severe TS warning on it and I could get to it with more daylight left, so south I went. I scooted south on Rte 522 to a point in southern Orange county just south of the rain shaft and watched as the back edge drifted by:

Other than some CGs nothing else materialized so I dithered again over whether to follow this storm northeastward through the wilds of Spotsylvania county. I finally decided on a route - 10 minutes later than I should have - and gave chase. As I caught up with the back edge I began to notice that it had lifted a bit and smoothed out in appearance, evidence that it had stumbled into the cold air wedge and the convection was becoming elevated. Lightning was still plentiful as I made it back to the barn just before full dark.
Then, this line barged in our direction:

Notice the TVS icon (purple triangle)...it passed through the area I had left only two hours previously!! Even tho' it was fully dark I wasn't a happy camper at having missed it, but hey, it was a chase!

Storms in the morning, storms in the evening

2011-03-21T20:00:00.000-04:00

I was actually shocked this morning - no pun intended - to witness lightning in the western sky as I prepared to venture off to work. I strove mightily to get there before the rain to no avail, but seeing CG's before full daylight will definitely get the chaser's blood pumping.
Knowing there was a chance of storms also this afternoon kept drawing my attention to the radar display, but as of 5:00 pm or so I didn't see much chance of chasing anything worthy during daylight hours. However I was pleasantly surprised to have a line come through as dusk fell, and I located myself (black "X") in a weak spot in the line to observe its passage:

I witnessed lots of lightning but didn't catch any on video as I finally had emptied the batteries of all remaining charge. My inexpensive handheld weather radio also bit the dust as the antenna broke after a couple of years of keeping it together with luck and an overly large screw. But, that's what early season local intercepts are for: working out the kinks from several months of chasing inactivity before the real stuff begins in earnest.

Monday and Wednesday

2011-03-20T12:54:00.000-04:00

At the moment the GFS model is showing some weak instability for the Mid-Atlantic both tomorrow (Monday) and Wednesday afternoons while the NAM agrees only with tomorrow's prognostication. The upper level winds are fairly strong but unidirectional out of the west both days, while the surface winds look to be southwesterly. We may have enough environmental forcing for some thunderstorms both days but severity is very much in doubt right now. Regardless, I'll be watching the radars both afternoons!

Close, but no cigar

2011-03-11T21:42:00.000-05:00

I was out watching the squall line pass through last evening but didn't see anything noteworthy other than some early season lightning. While I was out I heard this tornado warning issued for the Warrenton area. The above velocity frame grab shows the rotation just outside of the town. The NWS survey team today verified EF-1 damage in Bealeton that was reported 9 minutes prior to the above frame. As the blog post title says....

Thursday?

2011-03-07T18:21:00.000-05:00

Having just dumped out 2.1" of rain from my backyard analog gauge we're looking at that much or more to come between Wednesday afternoon and Thursday night. With this system Virginia could also see another chance at severe weather, but the current storm track appears to favor the Tidewater area for instability to go along with the shear that will be present. I doubt that I'll be able to get out and chase, but I'll certainly be looking carefully at radar to see what may happen. Soon enough my schedule and the weather's schedule will match up for an honest to goodness chase, but it's hard waiting!

Not much to look at, but it is still February

2011-02-28T17:01:00.000-05:00

When the convective line ahead of today's cold front showed up over 3 hours earlier than local models had forecast - and since the SPC had issued a tornado watch for our region - I made a quick decision to head out early and plowed westward toward Culpeper. The approaching line beat me to it so I pulled off Rte 3 west at Lignum just before the rain started. My location is marked with the purple cross on this radar depiction:

This photo was taken within 4 minutes of the above radar frame, looking northward:

I was a bit concerned that there was no lightning accompanying this potentially severe line, meaning the cells hadn't developed tall or strong enough updrafts to achieve charge separation given the very small amount of available instability. (Besides not seeing any lightning or hearing thunder I employed my low-tech lightning detector...the chasemobile's AM radio. No static discharges = no lightning anywhere near) That's not a good sign if one is interested in chasing severe storms.
As the most interesting part of the line headed north of the Rappahannock river I was left to retreat eastward along Rte 3, stopping briefly in Fredericksburg and then trying to get back in front of the line by motoring further east and south. Winding up in Essex county on Rte 17 I got far enough ahead of the line to enjoy roughly 45 seconds of the warm sector before the cold outflow again caught up with me. At this point the tornado watch had been called off and nothing remotely severe was likely to happen, so I snapped a few scud photos while enjoying the outing.

OK, I'll bite...tomorrow is a chase day

2011-02-27T12:48:00.000-05:00

After perusing some short range models it now seems that the chances for chasing in northern VA tomorrow afternoon have improved considerably. Even tho' the cold front won't make it past the I-95 corridor until after dark there should be at least a couple of pre-frontal TS cells that could show rotation given the shear and helicity profiles. Thus - given that I can free up my schedule tomorrow afternoon - I will be heading to the Bealeton area to position myself to intercept rapidly moving cells on their SW-NE trajectory. That also gives me the option of diving southeastward to stay ahead of the line(s) to track more cells.
The main disadvantages I will face tomorrow are the lack of a cellular internet connection (haven't yet decided on which option to use this year) and the relatively early darkness on a late February day. I can somewhat mitigate the first disadvantage by stationing myself near WiFi coverage until I actually give chase, but the second factor will likely prove to be the main limitation tomorrow. Either way I'm ready to conduct my first chase of 2011!!

And another February severe setup

2011-02-26T17:27:00.000-05:00

Here's the Day 3 SPC convective outlook for Monday, showing us in a slight risk area. This comes after tomorrow's SPC prediction of another Moderate Risk for the Mid-South, with possibly another tornado outbreak like Thursday's. The only sticking point with Monday's setup for us is that the bulk of the activity will likely occur after dark. I'm hoping for something chaseable during daylight hours but that still remains to be seen.

W-I-N-D but nothing else

2011-02-25T16:36:00.000-05:00

I did pay attention to the radar earlier this afternoon in case something blossomed that was worth venturing out to "chase". (I use "chase" loosely as any attempt would have been a lucky intercept, watching the storm scream by at the speeds they were moving today.) There were a couple of severe TS warnings in Maryland, but I saw nothing worth venturing out to see. I did traipse outside to look at one passing cell but didn't see anything worth noting.

Maybe a repeat Monday afternoon? The setup looks similar, so we'll see...