Wednesday, April 10, 2013

April 11th Severe Weather Event


I expect a severe weather event to unfold tomorrow, April 11th.

Short range model guidance suggests the cold front currently working its way east across the nation will fire off another day's worth of severe weather. Highest risk appears to be placed across Alabama and Georgia in the area of the highest instability. Overall instability is moderate at best, with highest values in the aforementioned areas. Helicity in the atmosphere will be decently high across all areas, but the lack of high instability makes for a rather low-moderate tornado risk. I can see a situation in which weak tornadoes evolve from this set-up, but I do not expect several big tornadoes across the Medium Risk area. High Wind index looks to be high for this event, as the typical cold front merging of severe thunderstorms occurs to form a squall line. New model forecasts indicate instability will be higher than previously thought, and that storm cells may be stronger than previously thought. I'm going to stay with my current thinking on the graphic above; I feel that the graphic best interprets my thinking right now.

Main concern for any tornadoes rests in the areas you see above with isolated storm cells. This image is valid for 8 PM Central Time, 9 PM Eastern Time on April 11th. Any tornadic activity is most likely to originate from isolated thunderstorms popping in Georgia, the Carolinas and Tennessee. These isolated storms would feed off of the instability and decent helicity to possibly provide a base for tornadic activity. The extent of this potential tornado activity is to be determined, and that determination should be made tomorrow morning.

Andrew

2 comments:

Stacey said...

Oh my. so at 8:00pm tomorrow evening we in Middle TN will still be dealing with this mess? I just want it to be done. I'm in a panic. thank you for the update

Anonymous said...

Kemper co MS got struck by a violent killer tornado. Damage looks at least EF2 based on what was leaked. Soon more photos and info will be leaked.