OK, so even SPC had a hard time dealing with today’s setup. Short and longer range models disagreed on timing of today’s convection but all of them indicated potential trouble as 700 mb temperatures hovered in the 8-9 degree C level. That’s a pretty stiff cap for the Mid-Atlantic, suggesting a strong forcing mechanism was needed to sustain updrafts…and there wasn’t such a mechanism evident. Moreover destabilization was dependent on a cold air damming wedge eroding which is always a crap shoot in the Mid-Atlantic.
Thus this succession of malleable SPC Day 1 convective outlooks. First, the morning graphic showing much of Virginia in a Marginal Risk:
Then the mid-day and mid-afternoon outlooks came out looking very different:
Notice any differences????????? That’s quite a range, indicating lots of uncertainty about today’s setup.
Regardless of any lingering doubts I rendezvoused with Nick Gilmore, a former Hokie Stormchaser and WDBJ7 intern who now works for public radio. He is putting together a story about storm chasing and wanted to chase with me in an opportunity to gather more material. We met at 2 pm and headed for the VA Route 40 corridor east of Rocky Mount.
After stumbling across road construction – the bane of storm chasers everywhere – on Rte 40 we found a relatively quiet spot near Union Hall to await the action. Two areas of convection developed, one south of us along the U.S. Route 58 corridor and another along and north of the Roanoke valley. Given that more sunshine and thus higher CAPE (instability) values was evident to the south we drove in that direction.
Winding up in a favored observation point in eastern Henry county we watched and waited for the southern activity to approach. As it did so the rain shield weakened and shrank, dashing our hopes of a southern storm intercept. All was not lost, however, as the northern convection had held together and looked to be strengthening.
Of course this meant we were woefully out of position so we rolled east on Rte 58 at highway speeds and curved north on U.S. Route 29 to continue the journey. Fortunately the northern complex was chugging eastward at a sedate pace so we were able to match latitudes by the time we reached the VA Route 24 intersection. Diving west there we wound up on VA Route 43 where we finally were rewarded with this view of the storm base:
By this time the cell was severe warned, the only such warning in the state of Virginia:
As it ponderously slid eastward we found another vantage point from which we had this view of the obviously rotating southern wall cloud:
Retreating south once more as the rain/hail shaft approached this was our next view of the nearing wall cloud from the intersection of Rtes 24 and 43:
Wanting to avoid a potential hail shaft we then retreated a couple miles further east on Rte 43 and conveniently found a spot where we parked as the mesocyclone base passed just to our north. CG’s accompanied by booming thunder rained down all around as the cell cycled up one more time. It came very close to pushing out another wall cloud right in front of us:
We were literally at the western edge of the complex at this point:
Shortly after this the storm ramped down, the wall cloud faded, and the severe warning was removed. So we pulled up stakes and headed for home satisfied with the knowledge we’d intercepted the storm of the day in Virginia.