While we all enjoy the nice warm-up this week it will likely be all coming to an abrupt end Friday. With a strong cold front moving into the Southeast with a chance for strong to severe storms. Like most of these cool season severe weather threats this is going to be one of those high shear, low CAPE events. By that I mean lots of wind energy but limited surface based warmth and humidity to build your typical thunderstorms.
In these events we typically have very little lightning and very low topped thunder showers but lots of potential wind that can mix down to the surface. The threat will be maximized just to our west over the Tennessee valley Thursday with a dying line of thunderstorms early Friday morning 4-8am. The timing would appear to working in our favor to reduce the threat.
SPC Outlooks for Day 3 and Day 4:
The set-up on the NAM model:
This is the typical late winter set-up with a very potent low and Jetstream energy that moves into a warm and humid air mass for this time of the year over the Southeast. The squall line will likely be very active over the Ohio and Tennessee valleys Thursday afternoon and evening. The question is how much is left once it arrives in the Western Carolinas?
There is limited CAPE or fuel but more than enough wind shear and energy. I hate these set-ups because you end up getting quick damaging wind events and even brief tornadoes that form in-between radar scans.
Very warm temperatures this week will make it feel like a taste of spring with highs near 70°. The cold fronts this time of the year bring loads of wind with the winter time Jetstream energy but limit CAPE leads to low topped thunder showers. My biggest fear is that with the recent winter storm with the snow and ice has weakened many trees. With just strong winds we could see numerous trees and limbs come down Thursday night into Friday.
If the timing of the front slows down until Friday afternoon this could lead to more instability and a higher risk of strong storms. Stay tuned to the forecast this week and be weather ready as Friday approaches. Right now I put our severe weather threat at around 30%.