September is very much a hit-or-miss month for chasing storms in the Old Dominion. Cold fronts – if timed right – can bring one or two opportunities, typically shelf cloud producers vs. mesocyclones (rotating updrafts). The main hope for the latter this time of year is tropical remnants rolling across the state which can produce low-topped supercells.
Hermine didn’t comply as it stayed well offshore (fortunately for folks along the coast!). And at the moment there don’t appear to be any other tropical systems coming along that could fill the bill. Thus we’re down to watching and waiting as cold fronts begin their autumnal march across the country.
At the moment the next such setup looks to occur Friday of this week as a boundary crosses Virginia. Forecast CAPE (instability) and shear values are both rather low so it may not even be worth considering. Next week, however, a cold front with better upper level support may bring a chance for decent chasing.
Here’s a depiction of the supercell composite parameter for late Wednesday afternoon. Admittedly this is an off-hour (06Z) GFS run and it’s pretty far out (207 hours) to trust in details:
Nevertheless both the CAPE and shear look decent. If this timing is correct I should be able to chase that afternoon. That’s important because September’s schedule is very full of non-chasing activities.
The 2016 Virginia storm chase season is quickly winding down.