The entire Tennessee Valley is under an Enhanced Risk for severe weather on Saturday. All modes of severe weather are possible including a few strong tornadoes.
An Enhanced Risk means that severe weather is expected to be more widespread with a few of the storms being a little more intense.
This round of severe weather is part of a very dynamic setup. Ahead of an area of low-pressure and the associated cold front is incredibly strong southerly flow. This brings in a lot of very warm/moist air which somewhat helps prime our environment.
While this is a very organized line of showers and thunderstorms, some discrete cells out ahead of this main line are certainly possible.
This looks to be a late morning and afternoon event. We’re pretty confident in the timing, but again a few discrete cells out ahead of the main line are possible.
The biggest concern with this line of storms will be damaging winds and tornadoes. Damaging wind gusts could be in excess of 70-80 mph, and a couple of the tornadoes could be on the stronger end of the spectrum.
A lot of this will depend on the environment we end up having to work, and our level of instability.
One way of forecasting rotation is to look at helicity. Helicity is a measure of rotation in an updraft. With that in mind, the above map is the forecast helicity or the forecast rotation within the line of thunderstorms. This is not a guarantee that we will see tornadoes in these highlighted areas, but it is a very handy tool that tells me where areas of greater rotation could develop.
Outside of the threat for damaging winds associated with the thunderstorms, is the general windy conditions that will exist across the Tennessee Valley.
A Wind Advisory will go into effect at 12:00 AM Saturday and expire at 9:00 PM Saturday. Wind gusts will likely exceed 45 MPH. wind gusts of this magnitude are not common for this area.
Have multiple ways to receive weather alerts Saturday. With gusty winds uncommon to the Tennessee Valley forecast before the storm even arrives power outages and wind damage are possible.