Severe weather this evening?

With the record-breaking warmth and severe storms over the Ohio and Tennessee Valleys, there has been quite a bit of talk about the potential of severe weather here in Virginia this afternoon and evening, as a cold front approaches the region. The extreme heating has brought some instability, but it's not all that impressive. Low level wind shear is increasing, and certainly a few storms may develop. I'm sure you've noticed the wind gusts we've had out there today. Very strong winds just above the surface may get dragged down in any developing storms this evening, so the main severe threat would be wind.

The technical numbers...

We use several indices to determine severe weather potential. I'll touch on a few of these here, as forecasted by the model data. The lifted index goes negative this evening, but it's not all that low...indicating a lack of significant instability. The SWEAT index flies up over 400. It does this very rapidly by about 7 P.M. and a number like this often indicates a strong risk of severe weather and even tornadoes. While this is highly unusual for February around here, this is a very unusual weather situation for this time of the year. The Showalter Index is another stability index and isn't all that impressive for Richmond this afternoon. The overall numbers are a bit more impressive to the north, and the severe weather threat may indeed be higher for DC over to Eastern Maryland during the evening.

So what to expect?

We'll see a round of showers move across the region this evening with embedded thunderstorms. I don't expect an outbreak of severe weather, but a few storms may contain some very strong wind gusts.