Tuesday, August 9, 2011

August 9 Severe Weather Discussion (Featuring TornadoTrack Map)

Discussion... Slight risk for severe weather in Central/Southern Plains, and also in a large portion of the Southeast US.
CAPE in both areas will remain poorly organized, more-so in the Plains area. Maximum CAPEs in the Plains will be around the 1500-2000 j/kg marks, while portions of the Southeast could reach past 2000j/kg. The storms in the Plains will really have to hold off for much of the day in the face of the cap over the area. A cap is an atmospheric quality that is basically warm air aloft preventing thunderstorms. The cap's strength will start off past -200 units, but eventually erode into -100 units, then nosedive past -200 again later on. There will be some disorganized sections of -100 units of cap over the Southeast. -100 units isn't considered a huge cap, but -400 and below is pretty strong to 'break', or allow storms to form. The SPC has a period of tornado threat set out for the people in the slight risk area, but reviewing EHI (spinning +energy in the atmosphere) as well as the jet stream, it's really looking like the CO/NE/KS borders will have the best possibility for tornadoes today, with a lesser threat south of that region. After reviewing all sorts of wind shear (winds going in different directions at different levels) parameters, it looks like that region will be in quite a hotspot today. Storms that occur in both regions will have high PWAT, or precipitable water values. Let's say there's 2 inches of PWAT. This means, if any section of the atmosphere were compressed in one column, there would be 2 inches of water plus the rest of the atmosphere. Higher PWAT values mean heavier rain and a higher likelihood for flooding. PWAT's are high in both slight risk areas, but highest along the Florida area, where over 2.5 inches is being forecasted.
TornadoTrack Map Below.

I will be out of the office until 3:15 pm CDT today.