Search

Details on severe weather risk for Friday night into Saturday morning. Tornadoes are a threat.


The early morning update from the Storm Prediction Center expanded and upgraded the risk of severe weather across our area for Friday and Friday night (valid until 6:00 AM Saturday morning). A Level 3 of 5 risk (orange on the map) of severe weather has now been added for portions of southern middle Tennessee, just clipping far northwest Alabama, and includes a good portion of north Mississippi. The Level 3 of 5 risk area includes regions along and west of a line from Columbia, Tennessee to Collinwood, Tennessee to Iuka, Mississippi. Larger communities in our viewing area included in this risk are: Columbia, TN; Hohenwald, TN; Waynesboro, TN; Savannah, TN; Iuka, MS. To the east of there, a Level 2 of 5 risk (yellow on the map) of severe weather has been expanded to include areas deeper into middle Tennessee and northwest Alabama. Within our viewing area, this Level 2 of 5 risk includes larger communities such as Lawrenceburg, TN; Lewisburg, TN; Pulaski, TN; the Shoals metro of northwest Alabama; Athens, AL; Russellville, AL; Decatur, AL; Moulton, AL. The Storm Prediction Center's wording in their outlook product states that "severe thunderstorms capable of producing several tornadoes and scattered to numerous damaging winds appear probable" and that "some of these nocturnal tornadoes may be strong". For this reason, we have bumped our tornado and damaging wind risks to the Elevated range on our products, for the potential for potentially widespread damaging winds and embedded tornadoes with the main line early Saturday morning and an increasing potential for supercells over parts of the area (mainly the Level 3 risk area) Friday evening into the overnight that would have the potential for strong tornadoes (EF2 or greater intensity).


Round One (Conditional Risk) - Supercells with Enhanced Tornado Risk (Timing- 6PM Friday to 4AM Saturday):


Baron High-Resolution Futurecast Model:

HRRR Model:


This is the portion of the threat that is still a bit uncertain, although we are starting to get increasing signals for the potential. During the evening hours, a lead disturbance on the south side of the upper-level trough may provide enough lift in the atmosphere to break the cap out in the open warm sector over north Mississippi and southwestern Tennessee so that individual supercell thunderstorms have a chance to form. The Baron model isn't as aggressive at doing this at the moment, waiting until closer to midnight and farther to the west into west Tennessee to spark that kind of development. However, the HRRR and some of the other high-resolution models that have had a good track record with the past couple of systems, as well as the Euro global model that has led the way with this system so far and the Monday morning event, have a little more lift with that lead disturbance, and they develop supercell storms from north Mississippi up into middle Tennessee as early as 7-9 PM in the evening, carrying into the overnight hours and growing in coverage. Should these storms be able to develop, they would then move northeastward into middle Tennessee and possibly into adjacent portions of northwest Alabama during the overnight. Because of the instability in place and the very strong wind shear that will be present, IF these supercells are able to form, they would have an enhanced tornado threat... including the potential for long-track strong tornadoes (EF2 or greater intensity). This was the main reason the Storm Prediction Center upgraded to a Level 3 risk in these regions, and if this signal continues, they may have to expand that Level 3 risk deeper into southern middle Tennessee and northwest Alabama in later outlooks. The time window for this POSSIBLE supercell threat runs from about 6-7 PM Friday evening through around 3-4AM Saturday morning when the main line begins to move in from the west.


Round Two - Main Line of Storms with Damaging Winds and Tornadoes Possible (Timing- 3AM to 9AM Saturday):


This is the higher confidence portion of the overall severe weather threat. Ahead of the cold front, as the lift increases as the storm system approaches, storms to our west will congeal into a big line of storms and move east toward our area during the early morning hours of Saturday. Storms look to approach our western counties around 3-4AM, and then move from west to east across the area from then through around 8-9AM. Damaging winds of 50-65 mph, with a few 70 mph gusts possible, will be the main threat with this line of storms, but tornadoes will remain possible as well... especially with the broken look the line has, with bowing segments and possible supercell-like structures embedded in the line. Because of the strength of the wind shear and the broken nature of the line, we can't completely rule out a strong tornado within the line itself either; however, that threat wouldn't be as high as it would be with any supercells during the evening and overnight of Friday.


It is critical that you have a plan of action in place before this threat of severe weather reaches the area Friday night. We have been talking about Friday night's storm threat for a few days already, but you have one full day today and most of the day tomorrow to prepare if you have not already done so. Know where you are going to go to shelter in the event a tornado warning is issued for your area.


  • Being in a mobile home or any type of manufactured housing is dangerous in a tornado, even if they are tied or strapped down. Mobile homes offer wonderful, affordable, housing, but they are not designed to withstand tornadic winds... especially if it is a stronger tornado like what may be possible in parts of our area. If you live in a mobile home or some other type of manufactured housing (housing that was built elsewhere and transported to its location), your plan has to be to leave before the storms arrive and go to a more sturdy, reinforced building. If there are no community shelters in your area or friends or relatives that have a sturdy and reinforced site-built structure for you to use as shelter, a business such as a convenience store that's open 24 hours, a restaurant that is open, a hotel, etc., is a better alternative than staying in your mobile home. You don't have to be there the whole night. Just leave your mobile home for that reinforced structure before the storms arrive, and you will be able to leave when the danger is over. Especially because this is an overnight threat with fast-moving storms in which you won't have much time to react, make that plan for where you would go NOW so that you are just reacting as second nature if a tornado warning is issued. Make sure now that the location you would want to go will be open during the overnight hours.

  • The other most dangerous place to be during a tornado is a vehicle. Car, truck, van, bus, it doesn't matter. Vehicles can easily be lofted, thrown, and severely damaged by tornadoes, putting your life in danger if you are inside. If you are driving and find yourself in a tornado warning, head to the closest sturdy structure like what is described above, and stay there until the danger is over. If all else fails, you can try to seek shelter in a ditch or culvert area by lying as flat as possible and covering your head and neck to try to protect yourself from flying debris. However, you must be aware of the potential for flooding if you do that, and if you are hunkering down near your vehicle, there is the potential for your vehicle to be tossed or rolled on top of you.

  • If you live in a site-built home of some kind, you have more options, and unless you live in an apartment complex that has no decent safe place to shelter, you don't have to leave. If that is your case, however, treat your situation like the mobile home scenario described above. In a site-built home, the main idea is to think low, small, and toward the center of the building. In almost every case, you don't have to be underground to survive a tornado, but if you do have access to a basement, storm shelter, or certified safe room, that is great. If not, go to a small interior room such as a bathroom, hallway, or closet on the lowest floor of the building that you can get to. If you are on the second floor, head downstairs if at all possible. The room or hallway you choose needs to be near the center of the building, putting as many walls between you and the outside (and the tornado) as possible. Those walls are just extra layers that debris would have to travel through, and they help hold up the ceiling in most cases. Keep in mind that an open breezeway in an apartment complex does not count as an interior hallway. Winds would be funneled through there and put you in danger. Make sure that your safe place is away from windows and sliding glass doors. This is important. That glass will break if struck by debris, and then the glass shards go flying and become shrapnel.

  • When you are in your safe place, you need something sturdy to protect your head and neck from flying debris. Some type of helmet like a bicycle helmet, batting helmet, motorcycle helmet, football helmet, construction hard-hat, etc., is ideal. If you don't have these, a thick textbook or even a metal cooking pot would help. You may look goofy, but it may safe your life! We have learned over the years from treating physicians in emergency rooms that the majority of tornado victims die from blunt force trauma to the head and neck areas because of being struck by debris either while being airborne or when the structure collapses on top of them. Something a simple as a cheap $5 bicycle helmet can offer reinforcement to your head and neck area. This is not just for kids! EVERYONE in the family needs this protection! Even layers of pillows, blankets, and comforters can help protect you to some degree from smaller flying debris like smaller glass shards.

  • You need hard-soled, closed-toe shoes, and since this is an overnight threat, it is a good idea that you have those by your bed so that you don't have to hunt for them if you are awakened and have to quickly shelter. You need these shoes in the unfortunate event that your home may be struck by a tornado and you have to walk across a tornado debris field to get to help. Tornado damage areas are often littered with broken glass, sharp metal objects, broken boards that have splinters and nails and other sharp things, and you can seriously injure your feet by walking across this if you don't have protection. Also, within your shelter area, we ask that you have a whistle or airhorn. This is so that you can call out for help in the event you are trapped in tornado debris. It is better to have a little airhorn (just a couple dollars in a dollar store) that you can squeeze, instead of having to expand your lungs and blow if you may be injured) and make a loud noise that first responders can hear so that they can find and rescue you.


The other important part in this is being weather aware, understanding watches and warnings, and having multiple reliable ways of hearing warnings. Be sure you know the difference between a warning and a watch. A warning means that the danger is NOW and you need to seek immediate shelter. A watch means that severe weather is possible over the next several hours and that you need to be alert for changing weather conditions and listen for warnings to be issued.


You must have multiple reliable ways of hearing warnings, and since this is an overnight threat, that includes having a way for one of those methods to wake you out of your sleep if you are issued a tornado warning. Sirens serve a great purpose, to warn people outdoors that danger is coming and that they need to seek further information. There are times when you may hear them indoors. However, the acoustics of our homes are different than they used to be years ago. Our homes aren't soundproof, but they are more resistant to outside sounds penetrating the walls than they used to be. It's harder to hear a siren a few miles away than it used to be years ago, and it's about downright impossible for a siren's sound to be loud enough inside your home for it to wake you out of your sleep in the middle of the night with howling wind and roaring thunder outside! You are putting your life in danger if you trust a siren to wake you up at night for a tornado warning!


The best way for having an alert method to wake you up is a NOAA Weather Radio. These sound a loud alarm in your home, and these can be battery powered so that they still operate of the power goes out. Keep in mind that both sirens and weather radios operate on a county-by-county basis instead of the polygon warning system. There can be times when your weather radio will sound and the sirens sound for a warning that is valid for a PART of your county, but you're not actually in that part of the county that has the warning. Use this as an alert to tell you to seek out more information to see if you are in the polygon warning area or not, and if you are, head to shelter immediately... if not, you are safe for the time being.


Redundancy is key, and the next most reliable method for receiving warnings is a good smartphone app. Yes, Wireless Emergency Alerts are built into your phone, but they don't sound for most severe thunderstorm warnings. They do sound for higher-end flash flood warnings, and all tornado warnings. However, they sound based on the geographic latitude and longitude of the cell tower your signal is coming from, not your phone's GPS coordinates. This means that if you are in a rural area and your closest cell tower is miles away, you may not get an alert for a tornado warning that includes your phone's location but does not include the tower's location... and vice versa, you may get an alert for the tower's location for a storm that is not endangering you. The Tennessee Valley Weather App (completely FREE download) uses either the coordinates of addresses that you manually set or the GPS coordinates of your device to determine if YOU are in the polygon warning area (or your work, school, church, family members, etc., for other locations you can manually set). If one of those actual locations are in the polygon warning, you get the alert. If not, you don't get the alert, even if another part of your county is in the warning... and it is supposed to work that way. The graphic above pertaining to our weather app and weather radios has a QR code that you can scan to take you right to the download link for the Tennessee Valley Weather App within your app store, and again, it is a 100% FREE download.


For the latest weather information, in addition to our social media platforms and our website at tnvalleyweather.com, you can tune in to the ALL LOCAL Tennessee Valley Weather Channel. That is our locally produced 24/7 digital weather channel centered right here in the Tennessee Valley. You can find the live streaming link on the front page of our website, or now on YouTube, Roku, or Amazon Fire TV by searching for "Tennessee Valley Weather". This will let you watch our daily forecasts and live severe weather coverage on your smart TV devices, tablets, mobile devices, etc., and that live streaming link is also found within our weather app.


If you happen to lose power, you can find our live simulcast of tornado warning coverage on the Radio7Media/WLX Radio family. That is WLX Radio, 97.5 FM in southern middle Tennessee and 98.3 FM in northwest Alabama. We also broadcast that coverage on 106.1 FM / 93.1 FM The X, WDXE, and WKSR.


Please refer to the map with the blue above with the blue highlighted counties. This is a map of our official viewing area counties. We serve 14 counties out of southern middle Tennessee, northwest Alabama, and northeast Mississippi. It is our policy that if any of these counties are issued a Tornado Warning, we are on the air with LIVE NON-STOP coverage on our channel and all social media platforms until the warning has expired, has been cancelled, or the danger is over. We also provide frequent live updates during severe thunderstorm warnings and flash flood warnings, as well as regular status-type updates during tornado watches and severe thunderstorm watches.


The Tennessee Valley Weather Center will be fully staffed Friday night and Saturday morning to provide live coverage for any severe weather that may threaten our viewing area. Be sure you stay in touch with the latest weather information as we approach this weather situation.

818 views0 comments