The storm relative wind shear (relative variable for rotation in the atmosphere) is expected to stick around till the early hours on Thursday. So we might have a long night of watching things tonight.
Wednesday, January 20, 2010
So far Southern Louisiana has seen two tornadoes. This section of Louisiana is in the middle of the most unstable air mass. East Texas and South Central Louisiana currently have CAPE (Convective Available Potential Energy) near 1500 J/kg and South Mississippi is only at 500 J/kg. We can see this played out when storms show strengthening in Louisiana but weaken after crossing the Pearl River. Instability is lagging a bit since the sun has been down, but this is enough instability to still be a concerned when you mix the instability with the available wind shear.