Long range models continue to show another cut off upper level low moving across the Ohio valley region, and that will bring the chances for another round of severe weather to the majority of WNC on Wednesday night & into the early hours of Thursday morning. Lightning, heavy rain, gusty winds, and even isolated hail cannot be ruled out with this system, so you will need to be on guard Wednesday evening.
Flash Flooding Threat Increases
The threat for flash flooding with this system is certainly there with models showing a very stout upper level low rotating through. This excess lift will create a strong line of storms that will affect WNC on Wednesday night and into Thursday. Below you can see the most recent GFS model run rainfall totals. What appears to be possible is another 1.5”-2”+ of rainfall for WNC.
Now let’s compare the GFS with what the European model is showing below. As you can see, both models indicate that at least another inch and half of rainfall will be likely through early Thursday morning. This will create flash flooding concerns for some locations around WNC.
Timing
When this system moves through exactly is somewhat uncertain at this point in time, but it is increasing in likelihood that showers will begin mid afternoon Wednesday, then a strong front will move through later into the evening on Wednesday night. Below you can see the most recent NAM 3km model run and how it depicts the storm progression.
Severe Weather Threat
The main threat with this system appears to be straight line winds and the chance for flash flooding. Looking at soundings and the threat for hail seems somewhat less compared to the last system, but turning of the winds with height will certainly occur, so hail cannot be ruled out. There are still some major details that need to be hammered out with this system so stay tuned I will keep you updated!