One more cool day. Warmer temps ahead. Severe storms late Wednesday PM into the evening.

We begin our Monday morning with broken cloud cover across the skies of the Tennessee Valley. Temperatures are again on the chilly side, in the low to mid 40s as the of the time I'm working on this blog post. That is thanks to high pressure parked over the Ohio Valley and Great Lakes driving northerly winds into our area. We have a few more hours to go before sunrise, and it's very possible that we once again make it down as low as the upper 30s before we start to warm up for the day. Regionally, we don't have any weather systems immediately impacting our weather as we look at the satellite and radar composite, although we do have a few stray showers moving through eastern Tennessee into the Carolinas.

Expect a mix of sun and clouds to continue through the rest of the day. With the broken cloud cover and easterly winds still in place on the north side of the frontal boundary to our south, we look to stay on the cool side for one more day. Afternoon highs will likely climb into the upper 50s and lower 60s, although we can't completely rule out some mid 60s south of the Tennessee River over northern Alabama if there is a bit more sun. Winds become more southeasterly as we head into the overnight. This, and added cloud cover as the front to our south begins moving north as a warm front, means overnight temperatures won't be quite so chilly... in the mid 40s or so for morning lows by daybreak on Tuesday. Tuesday begins our big warm up as winds strengthen and turn more southerly, possibly gusting over 20 mph during the day at times. Models seem to be underdoing temperatures as they often do in warm air advection patterns, and we expect Tuesday afternoon highs to reach between 75 and maybe as warm as 80 degrees. Futurecast here paints a little green on the map for Tuesday, but this is more than likely feedback from the warm air advection and not actually showers that will develop. Models often have a tendency to do this in warm air and moisture advection patterns and is one reason they often underdo temperatures then.

Southerly winds are even stronger on Wednesday as the pressure gradient tightens as a strong area of low pressure ejects out of the Plains, Sustained winds of 15-30 mph are a good bet during the day, even out ahead of the late day storms, and some gradient wind gusts could meet or exceed 40 mph. It is very likely that we will eventually be placed in a Wind Advisory for Wednesday. High temperatures look to reach the upper 70s and low 80s areawide, with dewpoints by late afternoon climbing into the low to mid 60s, making the atmosphere unstable ahead of a line of strong to severe storms that will move through our area during the late afternoon and evening.

The Storm Prediction Center has a Level 3 of 5 risk of severe weather that comes as far north as portions of northwest Alabama south of the Tennessee River, and a standard Level 2 of 5 risk of severe weather that includes the entire remainder of our viewing area. The main timeframe right now is as early as 4PM to as late as 10PM for the line of storms to move through, but we will be working to fine tune and narrow down this timing today and tomorrow as this system gets into higher resolution modeling. There is little to no signal for discrete storms ahead of the line; so, this will predominantly be the one line of storms. That means that damaging straight-line winds will be the main threat, but a few tornadoes embedded within the line will be possible. The damaging wind threat may be widespread, and some wind gusts in the line have the potential to exceed 70 mph in a few places. Because of that, it wouldn't be a shock to see the Level 3 risk expanded across more of the area in future updates, and we can't rule out the risk being upgraded. While a few tornadoes are possible in the line, this does NOT look like a tornado outbreak or anything like that. However, the damaging wind threat may make this a potentially significant severe weather event.

We are back to cooler and quiet weather behind that system from Thursday through the rest of the week. Daytime highs return to the mid 60s or so, and overnight lows return to the 40s. Our next chance of rain beyond the midweek system will be Saturday and Sunday as a few showers will be possible as a weather disturbance passes mostly to our south but skirts by the area. This may bring a short-lived cool spell Sunday into early next week before the weather pattern may once again turn active toward the extended range.