UPDATE 5:20 PM, 10/18: Fast-moving cold front brings chance of brief but windy showers/few storms on Thursday
UPDATE 5:20 PM: A line of showers and storms is moving eastward through the Interstate 77 corridor toward the New River and Roanoke valleys, with individual cells in the line moving northward to northeastward. While moisture and instability are somewhat lacking, strong winds aloft provide the potential for any shower or storm cell in this line to provide brief gusty winds. The line may diminish or break up soon as it advances eastward. Follow the latest Radar / Future Cast for the location of storms and any warnings that may be issued. END UPDATE
UPDATE 9 AM: Not surprisingly, the line of showers that was once a mighty squall line near the Mississippi River has washed out advancing east through the mountains. While the Storm Prediction Center has lifted the slight risk zone it had earlier over most of Virginia, it is possible this line of convection will resurge later today, mainly to our east, where shear may support a threat of high winds or even an isolated tornado or two. Also, there is a possibility of new showers or storms firing along the lagging cold front to our west later this afternoon and evening. Moisture and instability are lacking, so it doesn’t look like a widespread severe weather situation or even rainfall, but be aware of the possibility of brief, perhaps windy passing showers with some thunder possible. END UPDATE
The snowfall prediction contest is under way. I’m accepting entries through Nov. 8. Specific instructions (no different than last 3 years) are at the bottom of the column linked here.
Another in the series of fast-moving cold fronts is on its way. This one is so fast moving, it’s actually going to arrive 12-24 hours BEFORE early-week projections, and that means during the day Thursday. As it pushes through, the lift and shear with the front may provide some opportunity for windy showers or even a brief strong storm or two, likely late morning or early afternoon in Southwest Virginia. The Storm Prediction Center has colored all of Virginia except the far southwest and southeast corners in a slight risk of severe weather for Thursday, mainly for the potential of strong winds. The severe risk will definitely be greatest to our east, where more sunshine and a warmer, more unstable atmosphere will have a better chance of pumping storms up high into the atmosphere. For Southwest Virginia, a relatively thin, quick-moving line of showers is likely, with some strong gusts of wind possibly brought down to the surface. Moisture is lacking, so it’s not likely we’ll see as much rain as we did Monday. Also, this is the kind of system that has a decent chance of entirely jumping the Blue Ridge, which means a line of showers may break up crossing the mountains and then redevelop as a stronger squall line, or scattered thunderstorms, to the east in the Piedmont. Bottom line: A brief period of windy showers is possible Thursday, likely near midday, with a couple rumbles of thunder not out of the question, but it won’t be a total shock if it jumps over us.
This front will once again reinforce the sunny, dry cool mornings/mild afternoons (30s-low 40s lows, 60s highs) weather pattern through the weekend. We could be getting a little more toward the warm side of normals (70s highs, 40s-low 50s lows) by early next week.