As of early this Tuesday evening, we still have this WINTER STORM WATCH in place across north Mississippi and west Tennessee that includes Hardin County TN and Tishomingo County MS of our viewing area. This watch goes into effect beginning 6:00 pm Thursday evening and runs until 6:00 am Saturday morning. Local National Weather Service offices have already stated that they expect to issue a Winter Storm Watch for middle Tennessee and north Alabama either during the overnight hours of tonight or during the daytime hours of Wednesday. The reason why we aren’t already under a watch is because our start time in southern middle TN and northwest AL is a little later than it is farther to the west. While the winter storm will start impacting areas to our west during the evening hours of Thursday, our local area doesn’t start seeing impacts until the early morning hours of Friday. In order for a watch to be issued, you have to be a certain number of hours away from the start time of the winter storm, and we get into that timeframe between late tonight and the daytime hours of tomorrow. There is excruciatingly high confidence that a Winter Storm Watch WILL be issued for the remainder of our viewing area counties!
Confidence continues to run high (and steadily increase) in the general idea that a high-impact winter storm is on the way to the Tennessee Valley for Friday into Friday night, beginning as early as near or a little before sunrise Friday morning. As we get closer to the event and models are able to start getting a better handle on the low-level temperature profiles with time, the general trend has been for more and more of our viewing area to stay as all heavy snow or heavy snow mixed with a little sleet for the entire duration of the event. This is now not just true for southern middle Tennessee, but that zone has expanded deeper into northwest Alabama as well. In these areas, several inches of snow accumulation are likely, and travel will be hazardous in widespread fashion for Friday and Friday night. South of the Tennessee River, there is still the potential for an afternoon changeover to a wintry mix or even a bit of rain. However, the trend has been for any changeover like that to be shorter-lived, and the changeover itself is becoming less guaranteed than it previously was. But even here, several inches of snow accumulation are likely, and widespread hazardous travel is just as likely in these areas as well!
You may have seen some of our TV friends and other forecasters already starting to talk about initial snowfall projected amounts, but we are holding off on doing that for now. That is because we typically wait until about 36 hours before the start of a winter event before we release our forecast projected totals. We wait because things can change that may alter the forecast, but these changes usually (but not always) start presenting themselves in the high-resolution data by 36 hours. Remember, it’s not our job to be first, it’s our job to be ACCURATE while still giving you lead-time to adequately prepare! Ben Luna may verbally hint around at some first-stab-at-it ranges on his morning show tomorrow, but we will be holding off on an “official” projected snowfall forecast map from us until Kelli’s midday show. We do already have a pretty firm idea of the general range we expect for snowfall accumulations, but we will be fine tuning those numbers tonight and tomorrow before presenting them publicly.
Having said that, we can look at the various pieces of raw model data and the ensemble sets to get a basic idea of where the forecast is heading. Above are the mean (average) values for all the ensemble members in each model ensemble set for various communities in our viewing area. The GFS ensemble set is on the left, the Euro ensemble set is in the middle, and the Canadian ensemble set is on the right. As you can see, there is very good consensus in the general idea of a 4″+ snowfall across most/all of our area, but there is ensemble model support for totals to be higher than that. Also, keep in mind that these are mean (average) numbers for these various ensemble sets. We have found that, historically over the years, a 75th percentile value ends up closer to verification in these heavy snow setups than the actual mean (average). That would open the door for potentially slightly higher values than what you see on the chart. Again, this is all raw model data and statistics, but it does give us a general idea of the basic direction the snow totals forecast is likely heading toward for our viewing area.
Travel will be very hazardous in widespread fashion Friday and Friday night, and lingering travel impacts will likely extend into the weekend depending on how much snow, sleet, and freezing rain our area does end up experiencing. If at all possible, travel is highly discouraged in these areas as conditions go downhill, but we know there will be some people who have no choice but to get on the roads for various understandable reasons. If you do have to travel during this storm, make sure you have the necessary emergency items in your car, make sure your vehicle is winterized ahead of time, give yourself plenty of extra time for your trip, and let friends or family know where you are going and when you intend to arrive so they know to send for help if you don’t check in when you’re supposed to. Also, be sure to check on friends, family, neighbors, etc., to make sure they are ready for the storm. Take appropriate measures to protect pets and livestock, make sure you home and vehicle are winter-weather ready, and if you use electrical heating devices, please keep basic common sense fire safety in mind!
You can rest assured that we will continue to make adjustments to the forecast over the next couple of days as the smaller-scale details become more clear. Be sure you are in touch with the latest forecast information. Remember, an old forecast is a bad forecast!
