Southeast Texas is outlooked by the Storm Prediction Center for a moderate risk of severe weather today and tonight, but nothing is happening so far. SPC even issued a mesoscale discussion (MCD 0242) just after 2 pm discussing the presence of the capping inversion. I took a look at the 18Z sounding from CRP, and I was impressed with the inversion strength. That appears be around 5 to 6 degrees C just above 800 millibars, somewhere around 6 to 7 thousand feet. That cap looks stronger to me than the cap we had across Central Alabama on February 5th.
The cap can be eroded by changing conditions both above and below the inversion. The capping inversion was also evident in the stratocumulus cloud deck seen in the satellite pictures. A strong boundary as seen in the surface observations was approaching the moderate risk area with dew point drops of over 20 degrees and strong convergent flow. This along with the approach of the upper trough should dramatically increase the risk of surface based thunderstorms in the next several hours. Helicity values just ahead of the boundary were off the scale with values from 500 to 900. So watch out for things to blow rapidly in the next few hours.
-Brian-
