One more 2010 chase?

This is the GFS forecast graphic for two weeks from today, and it shows a setup that could allow another round of severe weather to roll through the Mid-Atlantic.  I know, I know,  this is way too far out to count on anything like this to actually develop.  But I've always said our chase season wasn't officially over until Veterans' Day, and this is close!

Wrapup of 27 Oct chase

     This velocity radar grab (courtesy of Weather Underground) shows the low level rotation in the storm relative to my position at the red "X".  This was just before I pulled up stakes and moved a couple miles eastward to get out of the rain shaft.   At 2056 UTC (9 minutes before this radar grab) the local airport KEZF - located ~4 miles west of the "X" -  recorded a 5 mph wind backing to the south, which lasted for over 3 hours before the wind direction veered to southwest.  (The winds for over 2 hours prior to this time were recorded being from the west at 5-8 mph.)  Barometric pressure was steady for several hours before and after this event as was the temperature / dew point, which was recorded as 76/75 degrees F in the 2056 UTC observation.
     Thus the only appreciable change in the meteorological parameters being recorded at the local airport was a wind shift that coincided with the passage of this storm and lasted for several hours.  NWS Sterling had issued a tornado warning on this cell at 2037 UTC, so the rotation was already evident on radar by the time the storm reached its closest approach to the airport location.   So, did the storm itself create the wind shift, or was there a localized boundary that increased the low level rotation that resulted in the rotating wall cloud and funnel that I witnessed?  Hmmmmm.......

No longer 0 for October!!!!

The incredible storm system that created weather warnings over more than half of the 50 states created its own local havoc in the Fredericksburg area today.  Even as I write this another tornado warning is underway for King George County, but it's too dark for me to feel comfortable chasing as there is little or no lightning to illuminate features. 
I started out the day driving through pouring rain to southern Maryland for work, eventually leaving there mid-afternoon and witnessing convective towers all around me.  I spied a ragged wall cloud under a cell near the Chesapeake Bay, but I was too interested in getting back into familiar chase territory to stick around.  Crossing into Virginia I checked radar at a local WiFi spot and saw that another convective line was moving northeast toward Fredericksburg, so I motored toward a favored viewing spot off Route 3 a few miles east of town and settled in to watch a cell pass by just south of the Rappahannock.  About 20 minutes later I noticed another storm moving into the Rappahannock river valley from the southwest so I moved a couple miles further west to get a better look and was rewarded with a view of a wall cloud.  I called in a spotter report to NWS Sterling at 5:00 pm and then saw this development a couple minutes later:

Zooming into the area near the isolated rain shaft under the wall cloud I verified another 2010 funnel sighting:

Never extending further than this - and thus no tornado - the wall cloud began to morph into yet another configuration that was fascinating to watch:

As this drew nearer to my position the rains began in earnest so I retreated a couple miles further east to keep watch, but I never saw any other funnels.  Lightning was a very infrequent occurrence, indicating that these updrafts were fairly shallow but that the low level shear was significant.   Great chase!!!  Now it's off to view and edit the video...

Midnight chasing?

It now appears that strong storms will blow through here late tonight, with another possibility of storms tomorrow morning and early afternoon.  Models are showing a strong line coming through the Fredericksburg area around 3:00 a.m. Wednesday morning with more cells building and transiting the area between noon and 3 pm.  Will I get a chase in?  Hmmmm......

Possible storms tomorrow, better chance Wednesday

There is at least a bit of forecast instability tomorrow afternoon that is backed up by the Storm Prediction Center's general thunder forecast for our area.  We may have a few booms tomorrow but it doesn't look like a chase opportunity.

Wednesday, however, may be a different story.  More available instability (on both the GFS and WRF models now) coupled with both speed and directional wind shear could lead to rotating updrafts that afternoon as a cold front sweeps in from the west.  Hopefully we'll have some discrete storms without the annoying overcast and widespread rains we've had with the past few frontal passages.  I'll have my chase gear with me that day and will hopefully be able to head out to intercept a cell or two.  I NEED another chase before winter sets in!!!

Pyrocumulonimbus???

Yep, and here the link to an article about it.  I didn't even know there was such a cloud classification but apparently it's a pretty impressive event.

Meanwhile there's not much on the chasing horizon.  The next forecast for convection here in Virginia is next week as the pattern changes and the jet stream opens up the Gulf for moisture and provides SBCAPE:

This may be the first strong autumn cold frontal passage that could provide a chase or two, but I'll be content to wait out the models and see just how realistic this one is.

Climate models: Taking things way beyond their context

Sorry for this diversion from storm chasing.  I had to post this link to Roger Pielke's blog.  He articulates a lot of what I've been trying to say over the past few year regarding the whole global warming thing.  The climate models that policy makers are quoting are nowhere near as mature and ready for primetime as folks seem to think they are. Unfortunately anyone who dares to question or (horrors!) disagree with the global warming crowd is immediately branded a simpleton who can't be trusted and shouldn't be listened to.  That's not the way I was taught the scientific method...I thought we were supposed to question and test everything until proven absolutely unquestionably true.  Even then questions should still be encouraged to improve our knowledge, not shouted down in hostile public forums.

Should we be concerned about what we're doing to our environment?  Absolutely!!!!  But let's not base our solutions to a complicated interconnected web of causes and effects on incomplete modeling and political grandstanding. 

0 for October (and September)

Even tho' the current radar shows storms moving southeastward along I-64 nearing Richmond we had no such luck around here today.  Chaseable storms have been scarce as hens teeth (does anybody still use that ancient analogy?) since early July around here, even while Jesse Ferrell of Accuweather has been chasing and photographing some neat storms up in central PA.  The overall pattern this year has been odd to say the least, but I'm hoping the situation rights itself by next spring so I can get back into productive chasing here in northern Virginia.  I haven't given up on 2010 yet but hope is beginning to fade...

Chase today and tomorrow?

It's not really impressive, but this is the simulated radar for this afternoon at 6 pm (or is that evening?).  This and the 4 km WRF model show limited convection in the area late today so I'll be keeping an eye on radar in case I get the itch to chase something.  Meanwhile the SPC has our region in a 5% "See Text" tomorrow as a cold front presses southward and displaces the very warm air - for October - overhead.  I see a bit of speed shear for tomorrow, but not much directional shear until after dark.  But I'll take what I can get this late in the season!

UPDATE 5:40 pm:  Currently watching a shower on radar that has just moved east of the Blue Ridge into Madison county.  It doesn't look like much and it won't get here 'til after dark, but the local model forecasts look like they've been verified!  If it explodes into something worthwhile I'll chase it locally even after dark.

UPDATE 8:15 pm:  Nope.  Updraft fell apart after sunset.  Nothing on radar now.

Late day chase tomorrow?

Simulated radar view for 7:00 pm tomorrow shows convection in the area.  That's right about dark, but I could be tempted to chase if the setup is close enough (or if it's strong enough and I can get to it!).  Keeping my 2010 chase season hopes alive...

Another fall chase hope?

This was a surprise when I checked the models and the SPC Day 3 (above).  There is decent CAPE and a negative LI for Monday afternoon thanks to a forecast frontal zone setting up near the Mason-Dixon line.  I'll certainly keep this on the chasing radar!

Thursday's shutout

It's still baseball season so the analogy holds.  We had plenty of wind shear Thursday with a number of weak updrafts radar-indicated to have rotation.  However, the heavy rain, low ceilings, rapid storm movements, and poor visibility all combined to keep me from jumping in the chasemobile in pursuit.  I was relegated to walking outside a couple of times as rotating cells zoomed by, but I never saw anything of note. 
To get a really good Virginia chase opportunity from tropical systems involves less rain and overcast and more sunshine to fire up some vigorous convection to complement the available wind shear.  That was how we got our tornado outbreak in September 2004 from the remnants of Ivan.  I still have my gear available given that our climatological chase season doesn't end until Veterans' Day (per my own observation), but this year's wacky weather pattern doesn't engender a lot of confidence for another chase opportunity.