Wednesday, November 14, 2007

Updated outlook for this afternoon and evening



The SPC has moved the risk area for severe weather further down into North Alabama. Here are a few excerpts from their discussion:

DEEPENING TROUGH ALOFT OVER THE CENTRAL U.S. WILL BECOME MORE NEGATIVELY TILTED AND AMPLIFY AS IT ADVANCES ACROSS THE GREAT LAKES/MS RIVER VALLEY DURING THE PERIOD

AT THE SURFACE... STRONG COLD FRONT WILL CONTINUE MOVING RAPIDLY EWD ACROSS THE GREAT LAKES AND SEWD INTO THE MID SOUTH/LOWER MS RIVER VALLEY THIS AFTERNOON.

HOWEVER...SURFACE DEW POINTS IN THE MID 60S AND MILD NOVEMBER AFTERNOON HIGHS SHOULD BOOST MLCAPE TO NEAR 1000 J/KG INTO THE LOWER MS RIVER VALLEY/MID SOUTH REGION LATER THIS AFTERNOON.

EFFECTIVE SHEAR REMAINS SUFFICIENT FOR SOME ROTATION/PERSISTENCE TO THE STRONGER CORES AND THESE MAY YIELD HAIL TODAY. MORE ROBUST CONVECTION SHOULD AWAIT STRONGER HEATING AND DEVELOP ALONG AND AHEAD OF THE COLD FRONT INTO SRN AR/NRN MS/WRN TN DURING THE MID TO LATE AFTERNOON. FORECAST SOUNDINGS ACROSS THIS REGION INDICATE LOW AND DEEP LAYER SHEAR MORE THAN ADEQUATE FOR A FEW SUPERCELLS OR SMALL LINES MOVING QUICKLY SEWD THROUGH THE EARLY TO MID EVENING. ISOLATED DAMAGING WINDS ALONG WITH SOME HAIL WILL BE PRIMARY SEVERE THREATS.

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