A winter storm will impact the Mid-South this weekend, but the chances of appreciable snowfall here on the northern Cumberland Plateau are quite low. It looks like it’ll be a close miss for our region, in terms of snowfall, due to just a little too much warm air.
After one of the warmest starts to January in our history, Ol’ Man Winter has finally arrived back in East Tennessee today, with temperatures that are a little more seasonable for this time of year. The cold air will deepen tonight; we’ll drop into the teens, and likely won’t get out of the mid 30s on Thursday before dropping back into the teens by sunrise on Friday.
So it’s cold enough for snow as the next storm system approaches the region Friday night, right?
Wrong. The cold air will erode pretty quickly, and we’ll likely be in the mid 40s on Friday. We may drop below freezing Friday night as precipitation chances go up, but just barely, and then warm air advection will kick in on Saturday as heavier precipitation arrives, getting us back to around 40 degrees.
Snow is possible with the onset of the storm system late Friday night into Saturday morning, but warming temperatures on Saturday mean a changeover to all rain is likely. Then, as the surface low pulls away late Saturday and allows colder air to filter back in, we could go back to snow on Saturday night. A change back to all rain is likely Sunday, with diurnal heating getting us back into the low 40s. A change back to snow could occur Sunday night.
Even if snow does fall, accumulation will be difficult. Ground temperatures will be relatively warm, even though we’re going to spend the next couple of nights in the teens. Surface temperatures may also prove problematic. The latest run of the GFS forecast model keeps us above freezing both Friday and Saturday nights. The NAM model drops us to freezing Friday night, but just barely. Additionally, it looks like there’s a pretty good chance that only a minimal amount of precipitation will occur Friday night, with the bulk of it holding off until after sunrise on Saturday.
Graphical interpretations of the GFS model are currently showing 1-3 inches of snowfall for Scott County, primarily on Saturday morning, but I wouldn’t put much stock in that right now. A closer look at the numbers show that the GFS isn’t supportive of much snowfall here. In his morning forecast discussion, National Weather Service at Nashville meteorologist Scott Unger noted this:
I’ve started to show the potential for some very light snow accumulation Saturday morning. Best places for this occur are likely going to be on the Cumberland Plateau, as well as counties against the KY state line. We’ll likely be dealing with some kind of precipitation throughout the weekend. Whether there is anything wintry mixed in will likely depend greatly on eventual overnight temperatures Saturday and Sunday mornings. That said, it is looking a little better for some accumulation to occur at some point this weekend, whether it’s Saturday or Sunday morning is still in question.
There are still a lot of question marks with this storm system, because forecast modeling has been inconsistent. The exact placement of the storm system could mean that we’re colder (or warmer) than currently anticipated, the timing of the onset of precipitation could be faster (or slower), and those things would obviously change things somewhat.
However, what’s not likely to change is that the areas most impacted by this storm will be Missouri and Illinois, and to a lesser extent northern Kentucky and southern Indiana and Ohio. We could see some very minor accumulation here on the Tennessee plateau early Saturday or early Sunday, but for the best chance of finding snowfall that’s measured in inches, you’ll likely need to head north on U.S. Hwy. 27 for a couple of hours.
Further out: If you’re a fan of cold and snow, the near-term isn’t improving any for you. The pattern continues to favor cold outbreaks, but the 15-day outlook from the GFS model isn’t showing any significant cold as get later into January. The next storm system will likely be next weekend (Jan. 18-20) and we might see colder air filter in on the back side of that system, but for now there’s nothing impressive to talk about.