Wednesday, April 20, 2011

Slight Risk For Isolated Severe Storms Wednesday

We have the slight risk for a few isolated severe thunderstorms later this afternoon and early evening as a cold front approaches from the west and we warm this afternoon into the mid to upper 80s.

Good moisture (dew point temperatures in the low 60s) is moving into central and eastern Virginia, transported from the Atlantic and Southeast by our persistent southerly flow. High clouds (remnants from a squall line last night that tracked through Kentucky and Tennessee) are streaming over western Virginia before Noon, with full sunshine along and east of I-95. Here's the visible satellite image of our region, taken at 11:15 AM:

With plenty of sunshine in this area, we should reach peak afternoon heating that could lead to a few strong to severe thunderstorms developing in central and eastern Virginia. Any storms that do develop in this environment will be capable of damaging straight-line winds and potentially some large hail. The tornado threat appears low in our region.

The surface cold front associated with this low pressure system now tracking through the eastern Great Lakes will sweep through central Virginia tonight, bringing in a cooler air-mass to end the work week. It will also end any severe threat shortly after sunset this evening.