Heavy rain ends this morning, Showers continue at times, Severe storms possible later Wednesday

Heavy rain will be coming to an end from west to east across the area this morning, but flooding issues will still continue.  Our Flash Flood Watch in north Alabama will continue through 6:00pm this evening.  Any additional rain today will only aggravate the flooding situation with our area already completely saturated and local waterways running very high.  However, with rain becoming more spotty and off and on, and not nearly as heavy, that will allow for some recovery time and for the flooding situation, especially the flash flooding (rapid water rises) to back off some.  The heavy rain complex this morning will help shift the frontal boundary to our south into central and southern Alabama, and by afternoon our temperatures will likely be down into the lower 50s with winds out of the north.  This will be short-lived, however, with rain shifting north into Tennessee and northwest Mississippi as the warm front around 5,000 ft above the ground moves northward into Tennessee.  This will leave an open door for winds to turn easterly and then southeasterly overnight and for the front to our south to begin to move back northward as a warm front.

 

The Storm Prediction Center has removed the Level 3 of 5 risk from their latest outlook for Wednesday but has almost the entire coverage area, including the Shoals metro area, remaining in a Level 2 of 5 risk level.  This is because forecast data has consistently shown that even though it will be warm and humid near the surface and in the low-levels of the atmosphere by afternoon after the warm front zooms northward during the day, temperatures above that in the mid-levels will also be warm (compared to what you need to be in place on a severe weather day).  This means that, despite afternoon temperatures in the low 70s and dewpoints in the low to mid 60s, instability will be low because there’s not a significant decrease in temperature with height.  This means there’s not as much energy for storms to work with, and it especially makes it harder for individual supercells to form out ahead of the cold front as it approaches.  Still, having said that, there is still a risk of severe storms during the afternoon and evening, likely in a general 3pm-midnight timing.  Because of the warm, humid air near the surface and the strong wind shear in place, even though instability is low, there is still a risk that a few storms may produce damaging winds of 50-60 mph and possibly a few tornadoes.  Keep in mind that, because of the saturated ground, it’s not going to take winds nearly as strong as usual to knock down trees and cause damage.  Storms will likely be in a line, with not much of a chance for individual supercells to form ahead of the line.  We can’t 100% rule that out, but the risk for supercells ahead of the line is low and decreasing.  Because of this, there is still the risk of a few tornadoes, but the risk isn’t especially high, and conditions do not point toward a major or significant tornado threat.  Still, as we have seen numerous times this winter alone, there can be isolated strong tornadoes in squall lines and with low instability, and we have also seen that even “low-end” and “weak” tornadoes of only EF0-EF1 intensity can be a threat to your life, especially if you live in a mobile home or other manufactured housing.  So, even though it’s not looking like a “major” tornado risk, you still need to take the risk that’s there seriously and be prepared and aware as we go through Wednesday afternoon and evening.

That front moves through during the early morning hours of Thursday and drops temperatures from the low to mid 50s in the morning down to the low to mid 40s by afternoon as northwest winds usher in colder air.  Then, temperatures really drop the next two nights with overnight lows Friday and Saturday mornings in the mid 20s.

There’s an uncertain chance of a few showers over the weekend, but we may be taking this rain chance out of the forecast, as it looks like forecast models are starting to come into agreement that that disturbance will likely stay off to our south.  However, the next weather system looks to bring a returning chance of showers and thunderstorms to our area by the beginning of next week.  The good news is that, at this time, it looks like that we will not have the atmospheric conditions in place for a severe weather threat at that time.