A backdoor front sagging south through Virginia plus an upper level wrinkle approaching from the west were the two factors in Wednesday’s (7/5) decision to chase. SPC had the southern third of the state under a Marginal Risk with mostly a threat for damaging wind from wet downbursts:
After perusing short term model solutions I decided to pick up my chase partner at 1 pm and head to the U.S. Route 29 corridor. The models had storms firing by mid-afternoon along the backdoor/wedge front just east of Rte 29 with another convective round due from the upper level support after 6 pm further southwest. As we rolled east the low clouds cleared and sunshine began to heat the very soggy airmass over the Piedmont. Shear wasn’t much but promised to increase as the front crawled south and west.
We sauntered to Gretna, sat for a while, and then moseyed south to the Blairs truck stop while watching radar. Storms did fire along the front but looked like a globby unchaseable wedge front mess on radar (been there done that too many times in 2017). Moreover they were a bit further east than I’d anticipated and I was concerned that if we went after them we’d be woefully out of position to catch the next round.
So…we sat…and waited…and sat some more. Giving up on the eastern activity we finally motored south to Danville where we turned west on U.S. Route 58. At Martinsville we continued west on 58 and waited a while longer at the Blue Ridge airport with this view to the west:
Finally tiring of this magnificent view (we wanted storms!) we backtracked to Rte 58 and drove west through the municipalities of Patrick Springs and Stuart VA just to say we did. After a U-turn literally at the base of the Blue Ridge Mountains we rolled back east to a convenience store that we knew from a previous chase had some decent eats for dinner.
Grabbing our purchases we headed outdoors to a shaded picnic table to feast. Just as we sat down we heard a peal of thunder and this showed up on radar:
The second wave had arrived! Since this cell was moving rather slowly we finished our dinner and then pushed back west to an open field where storm #1 was in full view:
It was visually rotating – note the striations – and the lowering on the leading edge was likely a wall cloud that didn’t last long. We watched from here for a bit before diving back east for this awesome view:This was a full-fledged no kidding Virginia supercell complete with mesocylone and tilted updraft. It spun for quite a while as we watched it slowly float eastward occasionally dropping lowerings, none of which lasted long.
Meanwhile a line of discrete storms had formed across the mountains and began marching eastward. Reluctant to leave the open vista of storm #1 we gave in and pushed back west to check out the new activity. Storm #2 was approaching from the southwest with a wall cloud under its western edge:
Meanwhile storm #3 – our heads were on a swivel at this point – was moving in from the north and west with more interesting features:
To catch a better glimpse of this we again moved back east to our previous vantage point to watch this third storm cross the mountains with a large shelf cloud pushing out ahead of it:
Even while we observed this I had the itch to head back west to recheck storm #2 since we couldn’t see it from here. It was booming out loud peals of thunder and my recollection of the small wall cloud we’d seen kept eating at me. So we moved back west – again! – and were rewarded with a clear view of a much bigger (and obviously rotating) wall cloud as this storm literally headed directly toward us:
As we watched storm #2 with its wall cloud approach our location storm #3’s shelf cloud – backlit by the evening sun – neared from the west:
It was about this time that I realized we were sitting under the spot where these two storms were going to collide:
As these two complexes neared each other the outflow from storm #3 interacted with storm #2 and the wall cloud morphed into a shelf cloud as we watched. Some interesting greenage was evident right in front of us:
After my chase partner reminded me (I was very busy looking at other things) I checked the VIL on storm #2 and became a bit apprehensive about being blasted by hail from it. Fortunately the heaviest core passed by just to our east and weakened as it neared. Otherwise I was prepared to quickly scoot westward on Rte 58 to avoid it.
As the two systems collided overhead we were treated to a tremendous display of very close CG strikes as we huddled inside the chasemobile with windows rolled up and not touching anything metal. (Hopefully my dashcam video caught some of them but I haven’t reviewed it yet.) This was the radar velocity frame (left) and reflectivity frame (right) just as the two updrafts began to merge:
Surprisingly enough the rain wasn’t that heavy at our location and we completely avoided any hail that may have resulted from this merger. We let things move off to the east a bit and then called it a day, rolling back toward home with an ultimately very successful chase under our belts.