Severe Weather Risk and Winter Weather in Mountains: Saturday Evening Update on the Approaching Weather System

Good evening. I want to update our followers on the progress of the weather system that will impact our area throughout the day on Sunday. A line of showers and thunderstorms currently over Central Tennessee will move east and weaken as it moves away from the best forcing. This band of showers and thunderstorms will likely arrive in our area between 3 and 5 am Sunday.

There is a possibility of isolated severe storms across the area briefly Sunday morning. Very isolated damaging wind gusts would be the main risk due to strong 30-40 kts wind profiles and a small area of 100j/kg surface-based CAPE just ahead of the front. The morning convection should be the only risk for severe weather across our area, and it isn’t enough to get too excited about. The prefrontal boundary gets east of our area before the daytime destabilization occurs.

We’ll get a copious amount of rain tonight and on Sunday. While the severe weather risk will move away from us as the system moves in quicker, the trough will slow down and briefly stall across the area, which could cause heavy rain to repeatedly fall over the same areas for a couple of hours on Sunday afternoon. The dynamics and strong forcing could result in additional rainfall totals of 1 to 3 inches tonight, leading to localized flash flooding on Sunday. Even though we’ve been experiencing drought and have been dry, heavy rainfall of this magnitude in a short time could cause sporadic flash flooding.

As the front moves forward, cold air will follow and encounter the mountains, causing precipitation to turn into snow. Unfortunately, it will take a while for the cold air to spill over the mountains into the foothills; by then, the moisture will have already moved out. We will experience dry conditions across the foothills on Sunday night, but it will be windy. The wind should help dry the roadways and prevent widespread black ice issues outside the mountains.

Model projected additional rainfall through Sunday Evening