A Winter Storm Warning is in effect for the entire Tennessee Valley Weather viewing area. Cloud cover will increase throughout the afternoon today ahead of the system, with the first snowflakes/sleet pellets falling mainly after 3am. We have made some slight adjustments to our forecast, which I will highlight first. The TL;DR version: we are watching a TREND of warmer air inching northward, resulting in adjustments to our snow-ice totals. Less snow and more sleet/ice for some.
Here are our updated forecast maps for snow and ice accumulation for the viewing area. We’ve nudged some boundaries northward to account for this new trend we are seeing in the data. If a meteorologist is taking a model run for face value, they are not doing their job. That being said, we have adjusted our forecast due to multiple weather models trending northward with the warmer air. It’s about trends at this point, not face-value model data. We have pushed the “heavy snow band” north, which now excludes southern parts of Lauderdale, Limestone, Colbert and Lawrence Counties in Alabama. This is due to the warmer temperatures nudging northward. The other snow total thresholds have also been adjusted northward to account for this change. This is not us backpedaling on original forecast thoughts, a winter weather forecast, especially in the South, is EXPECTED to change as we get closer to the event. We are simply providing the most up-to-date information.
I am going to show here the high-resolution HRRR model, which, to be quite frank, is leaning on the colder side of the higher resolution models, yet it is still trending northward with the warmer air. Again, it’s all about trends here. Precip will be widespread with heaviest rates during the morning and early afternoon between 6am – 2pm.
Note by Friday afternoon, temperatures are right at or just above freezing. This is something that we have been expecting and forecasting all along, however the warmer temperatures have trended northward, to cover a greater amount of our viewing area. Snow/sleet/freezing rain will taper off by the evening, with just some leftover flurries through Saturday. Timing of this winter storm has remained the same.
I am also including the NAM and our in house Baron 3K model, to show you the trends we are seeing. Both models agree on a more northward trend of warmer temperatures. I will note, the Baron 3K model has been running a few degrees too warm lately, and a few degrees WILL make all the difference here. I think this run of the NAM model is also slightly overdoing the northward nudge of the warmer temperatures, but again, this is a trend we can’t ignore. Like I said, we are not taking these model runs for face value, but we are noting the trends.
All this being said, the adjustments to our forecast may change some numbers, but they do not change the IMPACTS expected with this winter storm. Hazardous travel conditions will begin early Friday and could potentially last through the weekend. This is due to melting and refreezing. Each day will see improvement, but we have to get everything melted and dry before conditions alleviate for the overnights. Spotty power outages are possible in the area of heaviest snowfall due to the snowflakes being wet & heavy. We will have to monitor spotty outages south of the Tennessee River, but I do not think power outages will be a widespread issue.
