Yep, you guessed it! Rain continues across the area on this Wednesday, and it will be heavy at times. Widespread heavy rain shifts back into the area after sunrise this morning and continues through midday or the early afternoon before the widespread steady stuff shifts east of us, and we have more in the way of scattered waves of downpours for the afternoon. Between those two waves, we have a brief opportunity for afternoon temps to sneak up to the 58-62 degree range for highs today. Additional heavy downpours and rumbles of thunder are likely this evening, but in none of this today is severe storm activity expected in our local area. That potential will stay off to our south. We will have to monitor for more flooding to possibly happen today, similar to what happened across especially northwest Alabama on Tuesday. That may be a bit more widespread today on both sides of the state line after the widespread 1.5 to 2.5 inches of rain we had yesterday. This round of activity clears out after midnight, and we turn cooler behind it temporarily. We start Thursday morning with temps down into the 30s across the area!
Temperatures will be temporarily cooler for Thursday and Friday, especially Thursday. Daytime highs are back to the mid 40s, and overnight lows Thursday night are well down into the 20s. It’s a quick-hitting shot of chilly air though, with high pressure shifting east and winds returning to a southerly direction Friday. That gets us to the mid 50s by afternoon with mostly sunny to partly cloudy skies. Clouds and moisture quickly move back in overnight Friday night into early Saturday morning as a warm front lifts north across the area. That brings additional showers and maybe a rumble of thunder. That activity moves north Saturday morning as the warm front shifts north into northern Tennessee or southern Kentucky. We get a stronger southerly wind, with gusts over 30 mph, and maybe even some breaks of sunshine during the late morning and afternoon of Saturday. That allows temperatures to climb to near 70 or into the lower 70s as dewpoints climb into the 60s with Gulf moisture moving north into the area.
That primes our atmosphere for additional thunderstorm development by mid/late afternoon and going into the evening and overnight as a more dynamic storm system moves into the area. When combining that moisture and instability with the dynamic lift and wind shear that will be present with the storm system, strong to severe storms will be possible across the entire area Saturday afternoon into Saturday night. The baseline minimum expectation is that a line of strong to severe thunderstorms will move into the area after dark into the overnight with the potential for damaging straight-line winds, flash flooding, and spin-up type tornadoes (most likely in the EF0-EF1-EF2 type range). That line of storms may be a little more efficient at producing damage than what we would usually see from the rain we are getting this week and how that will weaken the soil and tree root systems, making it easier for wind to knock over trees and power lines. However, in addition to the evening/overnight line of storms, we will be watching for the possibility of individual supercell thunderstorms that may try to form ahead of the line in the mid/late afternoon to evening hours of Saturday. IF these are able to form, they would be taking advantage of an environment that has wind shear profiles and instability favorable for tornadoes, and any supercell development would bring us more of an elevated type of tornado threat. That type of development is still a bit uncertain. We’re still in the process of trying to figure out if we will have enough lift (upward motion) ahead of the line to get those supercell storms to form. It’s a possibility for sure, but it is not a guarantee. Even if they are not able to form, there would still be the potential for a few tornadoes with the actual line of storms itself.
In addition, these severe storms Saturday PM/night will be the third round of heavy rain this week. Not counting what fell on Tuesday, between today/tonight and Saturday’s activity, we expect another 3 to 5 inches of rain across much of the area, with isolated heavier totals possible. Adding this to the 1.5 to 2.5 inches that fell on Tuesday, that will mean an increasing chance of not just creek/stream flooding Saturday evening and overnight, but also flash flooding as well. The flooding threat may peak across the area with that third round of heavy rainfall Saturday evening and overnight, and it may end up being an areawide elevated flash flood threat.
Take the next few days between today and Friday to make sure that you have a severe weather safety plan in place ahead of the storms on Saturday. Make sure you have a safe place to shelter designated ahead of time. It is also critically important to make sure you have multiple reliable ways of hearing watches and warnings, including something that will wake you out of your sleep since some of these storms will happen after dark and into the overnight on Saturday. We will be right here to track the storms and provide live coverage as necessary! Keep checking back in for updated information as we narrow down the specific details for the Saturday storm threat as we go through the next few days…
