The atmosphere is very complex today, with the area of dry air left by Beryl still hanging around NE Alabama, and an area of clouds that has moved across much of central Alabama this morning.
These clouds are starting to break up some now, but they have kept temperatures in BHM in the lower 80s so far. Meanwhile, NW Alabama has gotten hours of sunshine already, and temperatures there are approaching 90. CAPE values (instability) have reached 1,500 J/kg or higher NW of a line from Moulton to Fayette...while the air is still fairly stable from BHM up I-59. If the clouds continue to erode, any strong sunshine will warm temperatures in central Alabama quickly into the upper 80s, making the air here unstable also. These clouds are probably the biggest forecast challenge of the day. But, the sun is shining brightly now here in Trussville, and it seems likely that the clouds will break up enough to let in sunshine this afternoon for a while, destabilizing the atmosphere.
Thunderstorms have formed over parts of south Alabama, and strong storms are currently in northern Mississippi. A severe thunderstorm watch has been issued there until 900 pm. These storms, and additional ones, may affect parts of NW Alabama (from about Jasper NW) later this afternoon, and could produce damaging winds and hail.
The main event will still be overnight/early tomorrow morning, when the cold front comes through. We still expect a line of storms to form ahead of the front, with the possibility of damaging winds. These clouds having been around all morning may have helped to lessen the threat for widespread severe wind gusts tonight, due to the air being cooler and more stable, but it will still be unstable enough when the front comes through early tomorrow morning for some damaging straight line winds in some locations.
Continue to monitor this blog, and watch J-P tonight at 5:00 on Fox 6 for more information on this storm. This will not be a tornado outbreak nor anything like that, but we could still have damaging winds, downed trees, and power outages, especially in NW Alabama, but even as far SE as TCL, BHM, and Clanton if temperatures warm up this afternoon.
Dr. Timothy A. Coleman
UAH Research Meteorologist
Fox 6 Severe Weather Expert and Blogger
Follow me on twitter timbhm