Thursday, March 27, 2014
Severe Weather Update
3:50 PM Thursday Update.... This video goes over hi res model data for this evening's severe weather threat and the threat later Friday. There is high confidence a line of storms will develop over northwest Arkansas. There's a lower degree in confidence of storm development in front of that main line across west central areas of the state. This video explains.
At this point, I'm still not expecting an "outbreak" of severe weather, but it does looks like we will have some in Arkansas later today (Thursday) and again later Friday afternoon. Wind and hail should be the primary severe weather threat, but an isolated tornado or two can never be ruled out.
This episode of rain and storms revolves around the presence of a frontal boundary and 2 waves of energy. The first arrives late today and tonight, then another later Friday afternoon.
I have put together 4, 4 panel charts explaining this situation thoroughly for you. These maps come from weatherbell.com and the Weather Prediction Center. Before I get into these, let me explain.
The first panel in the upper left is the 4KM NAM simulated radar
The second panel in the upper right shows you surface based CAPE (Convective Available Potential Energy). This is the instability needed for thunderstorms.
The 3rd panel in the lower left is the surface dewpoint. For severe thunderstorms this time of year, you generally need to see those values in the mid 50s and higher.
The 4th panel in the lower right is the frontal position according the the Weather Prediction Center. This panel will not match the exact time of the other 3 panels, but it's very close and gives you a good idea
Remember, I'm using one particular computer model and it's never perfect, but I think this has a good handle on the situation. You may need to click to enlarge each one.
Posted by Todd Yakoubian on Thursday, March 27, 2014