Wednesday is Storm Day
There’s a reason March is used for tornado drills in our schools. You see the spring severe storm season usually starts in April and peaks in May-June here in Appalachia. That means a March drill that teaches kids what to do during a tornado alert will be fresh in their memories come April-May, just in case. Take Kentucky where the tornado drill is slated for next week.
Trouble is the weather knows no temporal bounds so even though the calendar says February, data into the weather center suggests localized high winds are possible on Wednesday late afternoon-evening. .
Here’s a logical blueprint of the two rounds of Leap Day storms I expect.
Around dawn a surge of warm and moist air will be knifing toward the tri-State area from the Mississippi Valley. At the same time the cool, dry air left behind from this past weekend will have welled up against the mountains from the Smokeys of Tennessee to the Cumberland Plateau of Kentucky to the Cheat and Greenbrier Valleys of WV. This cool, dense air will make one last stand to hold its ground against the advancing warm, moist air.
In response to this clash of air masses a round of showers and non-severe thunderstorms will cross the region in time for the school bell delivering a burst of heavy rain with a few lightning strikes. High winds are unlikely with this initial surge of rain since the air will be cool. Nuisance street flooding is possible as some storm culverts back up.
By mid morning, the first slug of rain will be shifting to the north and east. Then the farther south you live the better chance the sun will appear in the afternoon as temperatures soar into the 60s by lunchtime with 70 in reach by late day.
Trouble is almost certain to brew in that warm and humid air mass as by day's end a cold front will be crossing the region. Since that muggy air is a notorious breeder for severe afternoon and evening spring storms, there is reason for concern on Wednesday especially to our west.
Assuming a second line of storms forms to our west in the afternoon and grows locally severe, it would march eastward at 50 miles per hour and arrive here in the 3 until 7 pm time period.
So what might this second round of thunderstorms look like? Since the air will be much more humid compared the morning activity, I would expect a heavier even torrential brand of rain that lasts a shorter time compared to the morning action. Cannon shots of thunder would crescendo through our hills.
Once this second storm line passes, a night of window rattling winds will set in with gusts all night long near 40 miles per hour.
Extra for Experts
This spring I am going to be adding information for those who are really into the science of meteorology. Here's my take on the Wednesday afternoon storm line.
As for the prospects of strong winds as the second line passes, the magnitude (speed) and nature (straight versus circular) of the winds will be at issue. The National Weather Service will closely scrutinize the winds aloft with their Doppler Radars to decide whether to issue tornado or severe thunderstorm watches. Since the winds aloft will be so strong and lined up from west to east from the Mississippi River to the crest of the Appalachian mountains, this may be a case where tornado watches on the flat plains to our west change to severe thunderstorm watches (aka straight line wind storms) locally.
Here's the link we use to follow severe storms all spring-summer long. Bookmark it if you are really into weather.