SPC 1300Z Day 1 Outlook
DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0749 AM CDT MON JUN 03 2013 VALID 031300Z - 041200Z ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON/EVENING FOR PARTS OF THE CENTRAL AND SRN PLAINS... ...CENTRAL/SRN PLAINS LATE THIS AFTERNOON/EVENING... A MIDLEVEL SHORTWAVE TROUGH OVER THE NRN ROCKIES WILL PROGRESS EWD TO THE NRN PLAINS BY EARLY TUESDAY. IN RESPONSE TO WLY FLOW ON THE SRN PERIPHERY OF THE TROUGH...LEE CYCLOGENESIS WILL OCCUR SWD WITH TIME ACROSS THE CENTRAL HIGH PLAINS. THIS WILL INDUCE STRENGTHENING SLY LOW-LEVEL FLOW ACROSS THE SRN/CENTRAL PLAINS...AND WILL DRAW 50S BOUNDARY LAYER DEWPOINTS NWD IN A NARROW CORRIDOR...BENEATH A STEEP MIDLEVEL LAPSE RATE PLUME. SURFACE HEATING ALONG THE DEVELOPING SURFACE LEE TROUGH/DRYLINE WILL WEAKEN CONVECTIVE INHIBITION AND CONTRIBUTE TO THE DEVELOPMENT OF WEAK-MODERATE INSTABILITY /MLCAPE OF 1000-1500 J PER KG/ THIS AFTERNOON IN THE MOIST SECTOR IMMEDIATELY E OF THE DRYLINE. WIDELY-SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP BY 21-23Z FROM THE NRN TX PANHANDLE TO SW NEB...WITH SOME SUPERCELL STRUCTURES LIKELY GIVEN EFFECTIVE BULK SHEAR OF 35-45 KT AND CLOCKWISE TURNING OF THE HODOGRAPHS IN THE LOW LEVELS. TEMPERATURE-DEWPOINT SPREADS WILL BE RATHER LARGE IN THIS EARLY STAGE OF THE MOISTURE RETURN...WHICH WILL FAVOR LARGE HAIL AS THE PRIMARY THREAT THIS AFTERNOON IN THE STEEP LAPSE RATE ENVIRONMENT. THERE WILL ALSO BE SOME RISK FOR ISOLATED DAMAGING WINDS...ESPECIALLY WHERE ANY STORM MERGERS LEAD TO UPSCALE GROWTH INTO A SMALL CLUSTER OF STORMS. THOUGH WARM SECTOR BUOYANCY WILL WEAKEN AND CONVECTIVE INHIBITION WILL INCREASE QUICKLY NEAR AND AFTER SUNSET...SOME ELEVATED CONVECTION MAY PERSIST WELL INTO THE OVERNIGHT HOURS OVER OK/KS IN PRONOUNCED WAA REGIME ASSOCIATED WITH A 35-45 KT LLJ. ...NE GULF OF MEXICO AND THE ATLANTIC COAST STATES... A MIDLEVEL LOW WILL CONTINUE TO MOVE EWD OVER SRN QUEBEC...WITH A STRONGER BELT OF FLOW CONFINED TO AREAS FROM PA NWD INTO NEW ENGLAND. HOWEVER...THE STRONGER FLOW WILL TEND TO LAG THE SURFACE COLD FRONT WHICH WILL MOVE ACROSS SE NEW ENGLAND BY THIS EVENING. POOR LAPSE RATES AND LINGERING CLOUDS/RAIN WILL LIMIT INSTABILITY TODAY AHEAD OF THE FRONT...THUS SEVERE THUNDERSTORMS ARE NOT EXPECTED. FARTHER S...A WEAK MIDLEVEL TROUGH WILL DRIFT ACROSS THE APPALACHIANS TO THE SE ATLANTIC COAST BY EARLY TUESDAY. THOUGH A MOIST BOUNDARY LAYER IS PRESENT ACROSS THE ERN CAROLINAS...MODEST LAPSE RATES ALOFT AND RELATIVELY WEAK VERTICAL SHEAR SUGGEST THAT CONVECTION THIS AFTERNOON WILL REMAIN SUB-SEVERE. ..THOMPSON/GARNER.. 06/03/2013
via SPC Forecast Products http://www.spc.noaa.gov/products/outlook/day1otlk_1300.html
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