Saturday, March 10, 2012

Severe Weather Threat for Tomorrow

I am printing a general risk of thunderstorms with embedded stronger cells for southern Missouri and most of Arkansas as a small jet streak and lower level jet stream combine to produce some wind shear that will be of use to any storms that try to develop. While instability mechanisms will not be the most abundant, a higher theta-e (basically increases instability in higher theta-e) and negative tilt to the storm system should cover the cost.

There is an orange area in central Arkansas, which indicates my thinking of a potential of some potential weak super cells and severe weather reports tomorrow. I outlined an orange area as the most recent WRF highlights some high-precip storm cells in that area, usually indicative of some severe weather in those cells. Also, the highest theta-e may be present in the general area in orange, adding instability to the storm cells. Additionally, the Storm Prediction Center has highlighted central Arkansas for a 30% risk of severe weather, which is a high-end slight risk of severe weather. The lower level jet stream will also be over 40 knots, increasing wind shearing and also the risk for some tornadic activity in the atmosphere.
Meteorologists use something called a hodograph to determine if the atmosphere is conductive for tornadoes. It is looking like the atmosphere will be supportive for some spinning motion, but again, instability is crucial, and we will have to see if the higher theta-e and negative tilt to the storm will step up to replace that missing CAPE.

-Andrew

1 comment:

ERN WX said...

SPC has 10% risk for tornadoes in part of Arkansas. The big discouraging factor I see for severe tstms is the area of clouds, rain, and weak tstms. CAPE/instability doesn't look too impressive as a result. There is shear and some other dynamics can support a tornado though.