Wednesday, February 23, 2011

Threat for Strong to Severe Storms Friday

A powerful storm system currently located across the far southwestern U.S. will bring central VA a chance for strong to severe thunderstorms on Friday. It appears as though the best combination of wind shear, moisture, and lift will be across the Mississippi Valley on Thursday, where an outbreak of severe weather is likely. Our atmospheric parameters won't be quite as conducive for severe weather in central VA, but modest heating and very strong wind shear will interact with fairly meager amounts of low-level moisture to give us a slight chance for a few severe storms. The lack of rich low-level moisture will be the limiting factor in what otherwise might be a better event for us. Here's how I think things will play out with this system: We'll see increasing clouds on Thursday, with only a slight chance for a few showers before sunset. Showers will increase in coverage Thursday night into Friday morning, but I don't think we'll have the lift and moisture in place quite yet for thunderstorms during the overnight period. Showery weather will taper off in the morning, with a period of sunshine developing. Temperatures will warm into the upper 60s and low 70s as strong southwesterly winds bring more moisture into the area Friday afternoon. The cold front will move through Richmond at 4 PM, likely accompanied by a broken line of showers and storms. A few storms could be strong to severe, especially east of I-95. All of the activity that develops will be east of the area by 7 PM. Cloud bases will be high, so despite strong wind shear, tornadoes don't appear very likely. Strong mid-level forcing and cold air aloft will result in a hail threat, with strong downburst winds possible as well. Whatever happens, Stay With CBS 6, We'll Keep You Ahead of the Storm. ZD