Sunday 29 March: The first bust of the season

I did chase this afternoon, but I found little success in doing so. Even tho' we were initially under a slight risk (which was downgraded to a "See Text" by the SPC) nothing happened in our neck of the woods. All the serious storms scooted up the Shenandoah Valley and then into Maryland before I could get to them. I did see a couple of showers and even a bit of lightning on a storm in western Fauquier county, but it was hugging the Blue Ridge and moving northeast at 30+ mph, which would have required me to keep up on winding country roads with little or no visibility. I wound up parking in Culpeper at a known WiFi spot where my son eventually joined me, and we watched as the cold front and an outflow boundary created no more fuss than a couple of innocent showers. The best part of the whole afternoon was (a) catching up with my son and (b) standing in the Culpeper parking lot at 5:42 pm when the cold front went through, shifting the wind from southwesterly to northwesterly and dropping the temperature a good 5-8 degrees F almost instantaneously.
I did have serious disagreement with the NWS Sterling forecast for storms east of the Blue Ridge based on the moisture there that forecasters said would help fire convection. For the life of me I couldn't figure out where this moisture was as the dewpoints east of the Blue Ridge were very low (mid-40's F) for storm formation, especially given air temperatures in the mid-70's. Was I looking at different observations than they were?

Chasing Saturday? Nope! Sunday instead.

Well, the typical springtime cold air damming wedge has asserted itself over the Mid-Atlantic and is holding the warm front to our south along the NC border. Thus we won't get into the warm unstable sector until sometime tonight, and I'm not willing to drive to NC this afternoon for storms that will likely not fire until after dark. However, forecast models for tomorrow support the SPC's Day 2 prediction of a slight risk for Virginia, with the text portion of the forecast even mentioning the "T" (tornado) word. The only hitch is timing; if it happens too early in the afternoon I'll have trouble getting into chase position given church responsibilities tomorrow. I'll have my chasing gear with me anyway...

Volcanic mesocylones?

http://www.physorg.com/news157210366.html

What, so now I can go chase volcanic eruptions, too?

Saturday severe weather? Looking southeast

The above graphic bears out my suspicions posted yesterday that the SPC might issue a Slight Risk for parts of Virginia. The models show a warm front hanging up in the Richmond/Petersburg area for most of the afternoon (typical for early spring), and with a bit of sunshine the resident instability could very well lead to storms. At the moment I'm planning to head down that way Saturday afternoon, with a final target location pending the actual position of the warm front. Right now I'm leaning toward the Disputanta vicinity on Rte 460 as a base, but we'll see. Oh, and the last bit of text that went with the SPC Day 3 forecast?
"AN UPGRADE TO MODERATE RISK MAY WELL BE REQUIRED IN LATER OUTLOOKS ONCE FORECAST DETAILS BECOME CLEARER." !!!

Thunderstorms in Saturday's forecast

Hmmmmmm...things are looking up for Saturday afternoon and evening. The latest NWS Sterling forecast for our area calls for thunderstorms, and this seems to be borne out by the GFS mixed layer CAPE forecast above. Additionally, the SPC Day 4-8 severe weather forecast shows an area of potential severity in southern Virginia which could lead to a slight risk forecast when the Day 3 forecast comes out tomorrow. I may be able to exercise my chase paraphernalia this weekend!

Mid-Atlantic chase season is inching our way

I'm grasping at straws, and I freely admit it. The SPC Day 3 convective forecast actually shows a small chance at severe storms for Thursday in the southwestern corner of Virginia. Now, that's nowhere near exciting enough to hop in the chasemobile and drive several hours for a maybe, but this does provide a modicum of hope for SDS relief. The longer range models don't seem too worked up about severe weather chances popping up anytime soon, but I can always dream!

Yep, a goooood chase day out west!

Lot's of action already, and there's more to come! I checked radar a few times this afternoon and realized that the starting location I would have targeted - west of Wichita KS - would have afforded me a daylight chase of at least two storms that showed both large hail cores and radar-indicated rotation. The drawback to these early spring systems is that the individual storms are streaking along at 30+ knots, making it difficult to keep position on. Oh well, I guess I'll have to settle for reading other chasers' reports for now...

Moderate Risk in Tornado Alley, nothing here

I have been haunting the long range models all weekend and have found little to cheer about regarding chasing opportunities here in northern Virginia. The GFS shows a cold frontal passage next Saturday afternoon, but the European (ECMWF) predicts this same frontal passage on Sunday morning. Such model divergence lends little confidence in long range forecasts, but today's local Sterling WFO forecast discussion at least hinted at the possibility of issuing a thunderstorm forecast for next weekend. Either way I'm jealous of the chasers in the Plains given tomorrow's SPC forecast of a Moderate Risk as the forums buzz with target locations and chaser groupings. I'll be watching for chaser reports tomorrow evening as I keep my fingers crossed that the severe weather out that way will be in unpopulated areas.

Eve of the first day of spring

As I contemplate the approach of spring I am fighting a virulent strain of SDS (supercell deprivation syndrome) that doesn't seem likely to be assuaged anytime soon here in the Mid-Atlantic. The above is a depiction of the GFS model prediction of convective instability for next Thursday afternoon (3/26) showing a very slight amount of mixed layer CAPE. This is the only potential convection that the GFS shows for the next 10 days in our region. The Plains is likely to see pretty decent chase conditions this coming Monday, but it looks like we'll be shut out here for a while. Oh well, the May "chasecation" to the Plains isn't far off!

Mid-Atlantic sogginess

Okay, I'm officially tired of gray, drippy skies and chilly temperatures while it's actually warmer and sunny north and west of here. This is a typical cold air damming wedge, which is due to an onshore eastern wind off the cool ocean waters and is somewhat "normal" for springtime here in the Mid-Atlantic. We do need the rain given the growing drought conditions in our region, but it would be nice to see some sun now and then. Looks like Tuesday may provide a little sunshine, with Wednesday looking even better.

As for chasing potential the long range models aren't showing much hope for storms in our area through early next week. We may still get a chase in before the end of March, but it looks like the final week of the month may be the first opportunity.

Virginia snow: widespread fall, localized accumulation

So it's March in Virginia...that can mean everything from snow to severe weather (and chasing!). Today it meant snow, as we woke up to a coating of the white stuff on grass and cars but not on the road surfaces. We actually had an inch or so covering the ground when we headed out for Richmond this morning, but by the time we had traveled a mile or two westward we saw absolutely no accumulation. Weird...but true! In Richmond it snowed, sleeted, and eventually turned to rain mid-afternoon, so we experienced a little bit of everything today except warm and dry weather. I am definitely infected with SDS (supercell deprivation syndrome)...

See-saw weather

After last weekend's beautiful weather we're settling back down to more normal March weather: cool, cloudy, and windy, with a bit of precipitation thrown in. Unfortunately that also means a chance for frozen stuff, which sounds like what we're in for tonight and tomorrow. Of course I had already decided to take tomorrow off and enjoy a long weekend with wife and family, and I expected sunny and warmer weather. What was I thinking????

When it's May....we're chasing!

Things look like they've crystallized for our May chasing trip to the Plains. I'll be meeting my brother (who is driving up from Austin) at the Dallas/Ft. Worth airport the morning of May 7th, meaning I get my rear end out of bed at oh-dark-thirty that day to catch my flight. Hopefully there will be something worth chasing that day, and we'll have several hours to drive in the appropriate direction to set up for the chase. Then, it's o'er the Plains we go for nine days, culminating in my flight back East on the 16th. Given that (a) we're spending a week and a half this time and (b) it's an odd-numbered year (even-numbered years haven't been kind to us) we're hoping that we can catch some action. We haven't been totally shut out the past couple of trips, but it says something when I've seen more tornadoes back here than I have out west.
I will miss having my son and daughter-in-law along this year, but with a new baby boy coupled with a change in job and a resulting relocation a chase trip is not in the cards for them this time.

Okay, it's March...where's the warmer air?

You can tell it's March in northern Virginia when the low temperature yesterday morning was 7 degrees F, the low this morning was 9 degrees, and the forecast highs this coming weekend are in the low 70's. (One would think that the snow cover that is prevalent here mid-week should be a distant memory in a couple of days.) An additional clue as to what season is here is provided by the SPC's Day 4-8 convective outlook above. The potential activity forecast for Sunday is, I hope, a harbinger of the activity I hope to see during our May "chasecation". At any rate I'm starting to pay more attention to the convective forecasts as the 2009 chase season is just about upon us, even here in the frozen Mid-Atlantic.

March definitely coming like a lion!

I'm finishing up my morning coffee and contemplating the magnitude of the shoveling job ahead of me. It looks like we have 7-8" of snow on the ground but it's tough to tell given the drifting caused by the winds. According to radar the snow should stop in the next few minutes and then....boots and shovel!
Despite the outcries from snow lovers that we haven't have a good snow here for a while I beg to differ. Here in northern Virginia I seem to remember us have decent snows (6" or more) every 3-5 years, so I went back to the Sterling WFO archives and this is what I found for monthly snow totals at Reagan National Airport:

Feb '79 (President's Day storm) 30.6"
Jan '82 15.3"
Feb '83 21.0"
Jan '85 10.0"
Feb '86 12.9"
Jan '87 20.8" Feb '87 10.3"
Jan '88 13.1"
Mar '93 15.5" (at Dulles Airport)
Jan '96 23.8" Feb '96 15.2"
Jan '00 14.5"
Feb '03 28.7"
Feb '06 8.8"

Thus, a Mar 09 "big snow" fits in with the overall pattern, altho' I'm not sure why National Airport shows very little snow in Mar '93 for the big storm then. I seem to remember at least a foot of snow or so, but the airport may have had more ice.

Snow, chasing book, and upcoming trip to Tornado Alley

As I'm writing this I'm watching a serious snowstorm get started here in northern Virginia, with totals forecast to be in the 5-10" range depending on where one is located. As I've stated in earlier posts winter is most assuredly not my favorite season, and shoveling snow is one of my most unfavorite activities. However, it doesn't look like I'll get much choice over the next 24 hours or so.

Meanwhile, I did receive the second printing of volume two of my stormchase book this week (minus the extra 30 pages of someone else's cookbook contained in the original printing). I've already corrected several obvious format and grammatical errors, but the primary changes involve changing and / or re-editing a number of pictures. It's amazing how different a printed photograph looks when compared to the view on my laptop...

And finally, I booked flights to and from Dallas in May for the latest White family Tornado Alley chase trip. (Unfortunately my son and daughter-in-law won't be available for this year's trip, but I'm sure we'll find time to chase together between here and Roanoke.) My brother will be driving up from Austin to pick me up and we'll have nine days to troll for supercells. I plan to blog daily to detail our efforts, which will - hopefully - be productive this year.

I just looked again and, yep, it's still snowing...

Mid-Atlantic whopper of a snowstorm?

The above HPC graphic shows the 10% and 40% probability curves for at least 12 inches of snow for a wide swath of the eastern Mid-Atlantic. Suffice it to say that the probability curves for lesser amounts are almost off the chart. We haven't had a Major (for us, anyway) snowstorm for several winters, so we are due for one but I confess I'm not looking forward to it. Shoveling and the overall messy conditions that follow a snow rank among my least favorite things to do, exacerbated by the fact that today is the first day of meteorological spring. (That other spring date is an astronomical thingie....) I'm ready for thunderstorms, not Arctic blasts!