SPC 1730Z Day 2 Outlook
DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1219 PM CDT FRI AUG 24 2012 VALID 251200Z - 261200Z ...NO SVR TSTM AREAS FORECAST... ...SRN AND CNTRL PLAINS... A WELL-DEFINED CORRIDOR OF LOW-LEVEL MOISTURE WILL BE IN PLACE ACROSS THE SRN AND CNTRL PLAINS SATURDAY. AS SFC TEMPS WARM DURING THE DAY...MODERATE INSTABILITY IS FORECAST TO DEVELOP FROM THE ERN TX PANHANDLE AND WRN OK NWD INTO CNTRL KS. MODEL FORECASTS DEVELOP SCATTERED THUNDERSTORMS ON THE NWRN EDGE OF A LOW-LEVEL JET AND ON THE ERN EDGE OF AN ELEVATED MIXED LAYER FROM THE ERN TX PANHANDLE EXTENDING NEWD INTO CNTRL KS SATURDAY AFTERNOON. FORECAST SOUNDINGS ALONG THIS CORRIDOR AT 21 TO 00Z SHOW MLCAPE VALUES IN THE 1000 TO 1500 J/KG RANGE WITH ABOUT 20 KT OF DEEP LAYER SHEAR AND 850 TO 500 MB LAPSE RATES NEAR 7.5 C/KM. THIS ENVIRONMENT MAY SUPPORT A MARGINAL SEVERE THREAT WITH THE THREAT CONFINED TO AREAS WHERE CONVECTION INITIATES AND INSTABILITY BECOMES LOCALLY MAXIMIZED. HAIL AND STRONG GUSTY WINDS WILL LIKELY BE THE PRIMARY THREATS. ...NRN MS VALLEY... AN UPPER-LEVEL TROUGH WILL APPROACH THE NRN MS VALLEY ON SATURDAY AS A COLD FRONT ADVANCES SEWD INTO NRN AND CNTRL MN. THUNDERSTORMS ARE FORECAST TO DEVELOP ALONG THE FRONT EARLY SATURDAY AFTERNOON WITH THE CONVECTION MOVING EWD ACROSS THE NRN MS VALLEY. FORECAST SOUNDINGS JUST AHEAD OF THE FRONT AT 21Z SATURDAY SHOW MODERATE INSTABILITY...20 TO 25 KT OF LOW-LEVEL FLOW AND 30 TO 40 KT OF DEEP LAYER SHEAR. THIS ENVIRONMENT MAY SUPPORT AN ISOLATED SEVERE THREAT AS LOW-LEVEL LAPSE RATES BECOME STEEP. THE GREATEST SEVERE THREAT SHOULD OCCUR IN A NARROW WINDOW FROM 22Z TO 01Z WHEN THE COMBINATION OF INSTABILITY AND SHEAR IS FORECAST TO BE MAXIMIZED. THE MAGNITUDE OF THE THREAT SHOULD DEPEND UPON HOW MUCH THE AIRMASS CAN DESTABILIZE ALONG AND JUST AHEAD OF THE FRONT. ..BROYLES.. 08/24/2012
via SPC Forecast Products http://www.spc.noaa.gov/products/outlook/day2otlk_1730.html
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