Threat Upgraded

Around 10 am, the Storm Prediction Center upgraded the risk of severe weather today to moderate for a good chunk of southern Mississippi and all of Southeast Louisiana (Day 1 Outlook). The radar showed a line of thunderstorms stretching along the MS/LA border southward just west of Baton Rouge and into the Gulf of Mexico. Several tornado warnings were in effect for thunderstorms in this line.

The surface low had deepened a bit with a pressure of 996 millibars on the latest analysis and it was located over the point where OK, LA, TX, and AR all come together (referred to as the ARKLATEX). It was moving just a hair east of north.

Shear profiles based on the morning soundings are favorable for tornadic supercells along and ahead of the line of thunderstorms. Low level moisture and instability were the highest in Southeast Louisiana nosing up into Southwest Mississippi. Highest helicity values were actually in Central Arkansas, but helicity values of 500 to 750 were also just ahead of the cold front in Southeast Louisiana. SBCAPE values were still mediocre but instability was on the increase with surface dewpoints in the mid and upper 60s flowing northward across the moderate risk area.

Still appears that the major severe weather threat will be confined primarily to the Gulf Coast area and just inland. It seems we deal regularly with the question of instability and how far north it can come.

-Brian-

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