Clouds are hanging tough on this Monday, and they will continue to be with us overnight. That will help temperatures from getting too chilly overnight, with lows bottoming out in the mid to upper 30s for most of us by daybreak on Tuesday.
Temperatures actually look to stay near seasonable normals for the next several days. Afternoon highs through at least Thursday will be running near 50 degrees with overnight lows ranging from the upper 20s to the upper 30s. Our average high is in the low 50s and our average low is in the low to mid 30s for this time of year. We are not too far at all from where we should be. Another front moves in late Thursday into Friday with cooler air, but even then, we don't get too terribly colder than our seasonable norms as we head into the weekend.
That weather system on Thursday is expected to bring a decent chance of showers to the area. No severe weather is expected, and we really aren't expecting thunder either, but showers are fairly likely through the day... lingering into the evening as the system moves out overnight. There is even a CHANCE that we may see a few wet snowflakes TRY to mix in across Tennessee late Thursday night, but it's a very low chance, and at least as of now... we are keeping our official forecast as all rain.
That may be a completely different story as we head later through Sunday evening and especially into the first half of Monday. Models are starting to converge in agreement on the idea of a storm system that comes out of southern Texas into the Gulf States and spins up a strengthening surface low down in the northern Gulf. This will throw moisture back northward into the area late Sunday into Monday, and with colder air very close by, there is a reasonable chance that a wintry threat may evolve from this. Unlike the last few systems where cold air behind a cold front is chasing moisture that's already moving out of the area, this is your classic Gulf low type storm system that is historically the favorable setup for an accumulating snow event in Tennessee, Alabama, and Mississippi.
Here's what we do know and what we don't know right now:
At least as of right now, models are in good agreement on the overall large scale setup with the cold air nearby and a Gulf low storm system throwing moisture northward into the area to interact with that cold air. However, we are still a week away, and even though models are in good agreement now... that doesn't mean it will remain the case. This very well could change, and there is PLENTY of time for changes to occur.
However, based on the overall setup and the amount of agreement there is among all the big forecast models, we feel it is safe enough to at least put a CHANCE of a rain/snow mix in the forecast for Sunday night into Monday. If you're going to look for a system days out for the potential for snow in our area, this is what it would look like.
The exact track and intensity of the Gulf low is IMPORTANT to the overall outcome. The stronger the low, the more dynamic the system is and the higher the potential there is for a more significant event. The weaker the overall system, the less significant the winter threat should be. It doesn't always work that way, but most of the time it does. If the system tracks too far south, we will have the colder air we need, but the moisture will stay south of us. If the system tracks too far north, we would probably see more moisture, but temperatures would be warmer. The EXACT track of the low is important.
Because we're still several days out and we just don't know the answers to those concerns above, there is NO POSSIBLE WAY TO KNOW THE EXACT LOCATION AND POSSIBLE SNOW AMOUNTS. However, we CAN have decent confidence in the GENERAL IDEA of a potential snow event at the start of next week... that has the potential for accumulations.
Obviously, we will be fine tuning the forecast over the coming days as data continues to hunker down on the smaller details, and we will adjust the forecast accordingly.