Potential Severe Wx Outbreak Fri/Sat in the Mid-South
Posted: Tue Apr 26, 2005 3:48 pm
NAM and GFS both indicate a classic pattern for severe weather including tornadoes Friday into Saturday from the Ozarks all the way to the Appalachins, extending northward into the Ohio Valley south to perhaps the Gulf Coast. Both show deepening lows (~995 mb) as it moves east into the Ohio/Tn/Lower MS Valley. Strong instability develops ahead of the associated cold front with capes progged off the NAM at 2500+, Lis -5 and below, SWEAT 500+, in addition to steepening lapse rates. Powerful jet dynamics are also expeceted. Wind shear is also strongly evident, with helicity values over 200 with some areas in the western OH Valley peaking at 500+ at 0z Sat, and EHI 3+. Moisture return is indicated to be quite sufficient with tds 60+ and some areas approaching 70. This was recently overestimated with the most recent event, but in any event this would not be a problem. The Euro shows a slightly different setup, keeping some of the main energy further west, and limiting the severe weather threat, but for now am going with NAM/GFS.
This all points to the potential for big time severe thunderstorms, including supercells and tornadoes. The best threat, including maybe some long tracked and damaging tornadoes would appear to be Eastern AR and Southeast MO Friday Evening, however a tornado threat could exist everywhere. This should spread east on Saturday into the Southeast. One thing of concern would be wind profiles along the front, and whether they go unidirectional. as well as the amount of forcing. This may lead to more linear organization, but its too soon to say for sure.
Storm motions also appear to be very fast, so chasers in this area (there are actually some in these parts) could have a hard time with this one. But, if the models are right, chasers are probably going to go out anyway and not miss this opportunity.
Of course 4 days out plenty of things can change, but I feel the threat appears to be quite significant, as many others are saying. I am not a met, just an enthusiast, but know severe weather patterns, and this one is. Pro chasers and mets are also commenting, and are saying much the same, even making comparisons to some of the big outbreaks from the springs of 1995 and 1998.
Should be very interesting to watch this as it unfolds. Those in the area keep in touch with later forecasts as the timing and threat is fine tuned.
This all points to the potential for big time severe thunderstorms, including supercells and tornadoes. The best threat, including maybe some long tracked and damaging tornadoes would appear to be Eastern AR and Southeast MO Friday Evening, however a tornado threat could exist everywhere. This should spread east on Saturday into the Southeast. One thing of concern would be wind profiles along the front, and whether they go unidirectional. as well as the amount of forcing. This may lead to more linear organization, but its too soon to say for sure.
Storm motions also appear to be very fast, so chasers in this area (there are actually some in these parts) could have a hard time with this one. But, if the models are right, chasers are probably going to go out anyway and not miss this opportunity.
Of course 4 days out plenty of things can change, but I feel the threat appears to be quite significant, as many others are saying. I am not a met, just an enthusiast, but know severe weather patterns, and this one is. Pro chasers and mets are also commenting, and are saying much the same, even making comparisons to some of the big outbreaks from the springs of 1995 and 1998.
Should be very interesting to watch this as it unfolds. Those in the area keep in touch with later forecasts as the timing and threat is fine tuned.
I've already posted the AFD from my area in another thread, this looks to be a HUGE SYSTEM!
