The system that will eventually cause our chance of snow flurries or light snow showers on Friday is currently sitting over the St. Louis area. This is an upper-level low that’s been sitting and spinning around over the Midwest since the weekend. This system will gradually shift southeastward and across our area over the next 24 to 48 hours.
Above is a chronological timeline breakdown of what we expect to happen, beginning this morning and continuing through Friday overnight, using our in-house Baron Futurecast model. It seems to have a good handle on the situation, based on what we expect, and it also is in agreement with the general consensus of other reliable model data out there. You can click on each image to see it in its full size.
Today and tonight: We start off mostly clear to partly cloudy around daybreak this morning with temperatures to begin the day in the upper 20s to lower 30s. Clouds thicken back across the area later this morning and this afternoon, with high temperatures climbing into the low to mid 40s. A spotty light sprinkle is possible early this evening, but the chance of that is only around 10 percent. A few light snow flurries may try to sneak in from the northwest toward the early morning hours, but it appears these will be drying out and evaporating as they move into the area. Overnight lows get down to around the freezing mark.
Friday into Friday evening: Clouds stick around through the day as the upper-level low crosses the area. Daytime highs only get into the upper 30s to lower 40s. By midday to early afternoon, redevelopment of scattered showers under the upper-level low looks to start near I-40 in middle Tennessee and then swing down across our portion of southern middle Tennessee, north Alabama, and northeast Mississippi. Surface air temperatures may drop into the mid 30s as this activity moves in because of the initial evaporational cooling that will take place, but temperatures will lock in ABOVE freezing. Despite that, air temperatures a few thousand feet above the ground will be significantly colder, and this will allow the potential for a few snowflakes to mix in with the rain showers. This activity will diminish and shift out of the area during the late evening as the lift from the upper low pulls away and we lose the daytime “heating” that was driving the instability under the upper low to redevelop the shower / flurry activity.
Because of air temperatures, ground temperatures, and pavement temperatures all above freezing for the duration of the event, coupled with the light and spotty nature of the snow showers not being able to overcome those factors, we do NOT expect impacts from this event in our local area. The Baron Futurecast snow totals output above shows it best. We just don’t expect any real accumulation across our area. Yes, you CAN get accumulating snow when air and ground temperatures are above freezing. Most of our big snows in history here have actually happened with warm ground temperatures! However, it has to consistently fall heavy enough for a long enough period to overcome the warmer temps, and that just very much is not the case this time. For you snow lovers that are hoping for a good snow, I’m sorry to say that this just won’t be the one for you in our local area. The winter season is very young though, it’s an active pattern we have set up, and most of our significant snow events in history here happen in January through March. There is still time for you to get what you’re looking for! It just won’t be with this system Friday.