Late September serendipity

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

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?

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

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

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?

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?

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

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?

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