Clouds have been thick today over the heart of the viewing area, keeping temperatures down into the lower and middle 70s. Locations further south that have seen breaks in the clouds are in the low 80s. More clouds will be arriving through the evening with a shower possible before about 1am. We could see one or two areas of fog tonight, but the stronger winds tonight will keep most fog formation at bay.
Tomorrow is a day we are watching closely as a strong upper level trough will swing through the heart of of country, sparking strong to severe storms to our west, and these storms will work our direction overnight Thursday into Friday morning. There is a lot going on, and so a fairly technical discussion follows below.
This trough, as it moves northeastward, is going to take most of the upper level energy with it. As it does, the greatest threat for severe weather will be to our north. However, models have been slowing down the timing of the system for arrival locally the last few runs, making it more likely this will be a early morning event for East Mississippi and West Alabama. We will have plenty of moisture and warm air in place for instability, but our main concern is going to be the presence (or lack there of) of upper level support. With little divergence overhead to allow storms to breathe, this looks to be mostly a damaging wind event with a squall line for us. However, some of our higher resolution models are hinting that as storms arrive around sunrise and just after, they could be discrete storms, which will enhance, although slightly, a tornado threat. This does not look to be a tornado threat for us as all hodographs (charts of wind speed and direction with height) are pointing that after about midnight Friday, the atmosphere will not be conducive to rotating updrafts. The atmosphere will be primed for a straight-line wind event if storms can remain strong enough to tap into the wind above the surface, which will be difficult as the upper level energy moves further north.
Once the front clears, we will start to clear out very late Friday and most of Saturday. The front will start to return north as a warm front late Saturday into Sunday, meaning southern locations (especially along and south of Highway 84) could see rain late Saturday. Heavy rainfall will return Sunday and Monday as our next system lifts north from the Gulf Coast to the Ohio Valley, which means plenty of rain for us. The track may also lead to more storms Monday, which may or may not have the potential to become severe if we can warm back up from the rain we see on Sunday.
As the system exits Monday night, rain showers will still linger into Tuesday and perhaps Wednesday as the last little bit of moisture is rung from the atmosphere. There is also an outside shot on Wednesday or Thursday morning that we could see temperatures try and flirt with the freezing mark, but it is too early to pinpoint that at this moment.