We're watching the weekend weather closely for the possibility of severe weather in Alabama. It's still early and much can change. We're looking at the potential for either a high impact severe weather event locally or severe weather that could be confined more to South Alabama. I want to stress this far out we have a good bit of uncertainty, but the ingredients are there and the system could affect your weekend plans.
The Storm Prediction Center is already highlighting their "Day 5" risk area. Their thinking is the system will have a higher severe weather threat Montgomery southward toward the Gulf Coast. This is based largely off the GFS model and the location of the highest instability/shear. Certainly not a bad forecast at this point. The concern is whether or not that instability streams a bit farther north or is limited by the coastal thunderstorm development. The Gulf of Mexico will be "wide open" if we do not realize the storm development along the coast priming our area for severe storms.
This is the surface map for Sunday morning. Note the position of the warm front. The warm front could remain south of us.
However, there are some indications we could see the warm front lift farther north. Areas south of the "red line" would be the focus for severe thunderstorm development because of the unstable and very juicy airmass.
Below is the GFS model output with helicity and (CAPE) instability for Saturday afternoon. While the highest instability remain farther south, it is concerning since the wind shear favor severe weather locally even if we achieve only modest instability. Dewpoint temperatures are forecast to reach the mid 60s based on both the GFS and Euro models through the afternoon and evening for Central Alabama.
Right now I would plan on at least some severe weather across our area Saturday afternoon/evening through Sunday morning. The best chances would likely remain south of I-20, but this could change. It is also possible we could see a more limited severe threat with storms confined to South Alabama northward to Montgomery. This type of setup favors severe thunderstorms that produce hail, strong winds, heavy rainfall, and even tornadoes. We need to watch this closely over the next few days as the high resolution data arrives. Be sure to check back to the blog frequently as well as our WBRC First Alert weather app, WBRC.com, and of course our newscasts.
WBRC First Alert Chief Meteorologist