A FLASH FLOOD WATCH continues for all of our North Alabama counties through 1:00 AM on Thursday. As of this morning, Wayne, Lawrence, Giles, and Marshall Counties in Tennessee have been added to the Flash Flood Watch until 7:00 AM Thursday. Several areas of northwest Alabama and into southern middle Tennessee have already received 2 to 4 inches of rain, and radar estimated some 5 to 6 inch totals in spots as early as 9:00 PM Monday evening. Rounds of moderate to heavy rain continue in places early this morning, with the flooding threat continuing.
As we head deeper into today, the flooding threat will remain elevated with any additional heavy rain, even with scattered storms, only aggravating the areas that have saturated grounds or are already primed for flooding. However, our focus by midday today will begin to quickly include the risk of a few strong to severe storms across our region. In the overnight update, as we expected, the Storm Prediction Center expanded the Level 1 of 5 risk of severe weather to include all of our area for later today and into this evening. We will break down the overall timing in detail with Futurecast in this blog, but our main window of opportunity will be from about Noon until the mid-evening (we are going with roughly 9:00 PM, but don't take the start and end times to the exact). This is a lower-end type threat, but the threat is definitely not zero, and a few warnings may be issued later today. A few of the storms may produce 40 to 60 mph wind gusts that can cause tree or power line damage, hail up to as large as quarters in one or two storms, and there will be the threat of a few spin-up tornadoes across the area today.
Heavy rain across the area early this morning will begin to shift northward and gradually weaken with time as we head into the mid morning hours. There will likely be lingering spotty showers or even an isolated thunderstorm into the late morning and midday hours, however. By late morning, as drier air in the mid-levels of the atmosphere works overhead, it looks like we may see a few breaks in the cloud cover that should allow a little bit of sunshine to get through. Folks that have lived in the Tennessee Valley for a while know that any amount of sunshine during the morning and midday of a storm threat day isn't necessary positive news. That sun heats the earth, which in turn heats the lower atmosphere, and that makes things more unstable and favorable for storm development and intensification.
By midday and into the early afternoon, during the daytime heating hours, scattered individual thunderstorms begin developing over central and north Alabama that then increase in coverage and expand northward across north Alabama and through northeast Mississippi and middle Tennessee. These are the storms we will have to watch later today and into the evening for a few of them to be severe. Please note that they will be moving south to north or even southeast to northwest as they rotate around the upper low back over northwest Mississippi. These may behave similar to the severe storms we sometimes see in the outer rainbands of landfalling tropical systems. The individual nature of the storms, combined with the ingredients at play in the atmosphere, will support these storms having rotating updrafts and being mini supercells. That is the reason we are concerned that there may be a few short-lived spin-up tornadoes. These will continue into the mid-evening hours before we begin to lose daytime heating, and ingredients for severe weather begin to diminish. There may be additional scattered storms and heavy rain deeper into the overnight, but after 9:00 or 10:00 PM, while we can't 100% rule out a strong storm, the atmosphere won't be nearly as supportive for additional severe weather.
We advise that you take the time this morning, before these storms develop, to review your safety plans and make sure you have multiple reliable methods to receive watches and warnings. If you have a weather radio, make sure that there are fresh batteries installed in case you lose power. If you haven't already done so, download the free Tennessee Valley Weather App. The QR Code above will take you to the download link in your appropriate app store. The app has push notifications if the geolocation of your phone is in a warning (but NOT alerting you if the part of your county is not in danger, versus sirens and weather radios that alert for a whole county at a time, even when your town isn't in danger). The app also has interactive VIPIR radar and a link to our 24/7 digital weather channel, where we will have live coverage should any warnings be issued (in addition to our social media platforms).
You can watch our 24/7 digital weather channel and our live streaming severe weather coverage on Roku, Amazon Fire TV, and YouTube by searching for "Tennessee Valley Weather". This will let you put our live coverage up on a television or other larger screen that you may have available to you. In addition, if you happen to lose power or you are away from TV and internet, if tornado warnings are issued in our area later today, we will be simulcasting our live coverage on the WLX Radio Family of stations. That includes WLX 97.5 FM in southern Tennessee and 98.3 FM in northwest Alabama, The X 106.1 / 93.1 FM, The Legend WDXE, and WKSR in Giles County, TN.
The weather center will be staffed later today to provide live coverage as conditions warrant, and if any of our 14 viewing area counties across southern Tennessee, northwest Alabama, and northeast Mississippi be placed in a tornado warnings, we will have LIVE NON-STOP coverage until the danger is over.