SPC 1630Z Day 1 Outlook
DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1130 AM CDT THU APR 26 2012 VALID 261630Z - 271200Z ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON FOR NE NC AND SE VA... ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON INTO EARLY TONIGHT FOR THE KY/TN AREA... ...THERE IS A SLGT RISK OF SVR TSTMS LATE THIS AFTERNOON THROUGH TONIGHT FOR THE SRN/CENTRAL HIGH PLAINS... ...SRN/CENTRAL HIGH PLAINS THIS AFTERNOON TROUGH TONIGHT... A COMPACT SHORTWAVE TROUGH OVER SRN CA THIS MORNING WILL EJECT ENEWD TO THE FOUR CORNERS THIS EVENING AND SE CO-NRN TX PANHANDLE BY 27/12Z...IN RESPONSE TO THE INLAND MOVEMENT OF A LARGER-SCALE TROUGH OVER THE PAC NW. LEE CYCLOGENESIS WILL OCCUR ACROSS THE HIGH PLAINS OF E/SE CO LATER TODAY INTO TONIGHT IN ADVANCE OF THE MIDLEVEL TROUGH. THE LEE CYCLOGENESIS WILL INDUCE STRENGTHENING SELY LOW-LEVEL FLOW AND NWWD ADVECTION OF THE 55-65 F BOUNDARY LAYER DEWPOINTS NOW OBSERVED ACROSS WRN OK/ERN TX PANHANDLE... BENEATH A VERY WARM ELEVATED MIXED LAYER. GIVEN THE PRESENCE OF THE STRONG CAP...RELATIVELY LATE ARRIVAL OF THE SHORTWAVE TROUGH... AND A SUBSTANTIAL PLUME OF MID/HIGH-LEVEL MOISTURE/CLOUDS...THE MORE PROBABLE AREA FOR DAYTIME STORM INITIATION WILL BE ON THE HIGH PLAINS FROM NE NM INTO SE CO. HERE...AFTERNOON TEMPERATURES OF 80-85 F WILL BE SUFFICIENT TO REMOVE CONVECTIVE INHIBITION...AND STORM DEVELOPMENT IS EXPECTED ALONG THE SHARPENING LEE TROUGH. THE INITIAL STORMS WILL LIKELY BE HIGH-BASED SUPERCELLS CAPABLE OF PRODUCING LARGE HAIL/DAMAGING WINDS GIVEN SOMEWHAT LIMITED BOUNDARY LAYER MOISTURE THIS AFTERNOON...WHILE THE LOWER PLAINS REMAIN CAPPED. TONIGHT...FOCUSED ASCENT IN ADVANCE OF THE MIDLEVEL TROUGH WILL HELP ERODE THE CAP...AS A WARM FRONT MOVES NWD ACROSS THE TX PANHANDLE/WRN OK AND RICHER MOISTURE SURGES NWWD. LOW-LEVEL SHEAR WILL LIKEWISE INCREASE...RESULTING IN AN ENVIRONMENT THAT IS MORE FAVORABLE FOR A COUPLE OF NOCTURNAL TORNADIC SUPERCELLS FROM EXTREME SE CO INTO SW KS. THE SRN EXTENT OF THE OVERNIGHT SEVERE THREAT BECOMES MORE QUESTIONABLE DUE TO STRONGER CAPPING. ...ERN NC/SE VA THIS AFTERNOON... A WELL-DEVELOPED MCS FROM EARLIER THIS MORNING WEAKENED ACROSS UPSTATE SC AND CENTRAL NC AS IT ENCOUNTERED AT BEST MARGINAL INSTABILITY. THOUGH BOUNDARY LAYER DEWPOINTS WILL REMAIN IN THE MID-UPPER 50S AHEAD OF THE MCS REMNANTS...SURFACE HEATING AND THE WELL-DEVELOPED NATURE OF THE MCV COULD PROMOTE SOME REJUVENATION OF CONVECTION THIS AFTERNOON ALONG THE LEADING EDGE OF THE COLD POOL. ISOLATED DAMAGING GUSTS WILL BE THE MAIN CONCERN. ...KY/TN AREA THIS AFTERNOON INTO EARLY TONIGHT... LOW-LEVEL AIR MASS RECOVERY IS UNDERWAY ACROSS KY/TN IN THE WAKE OF EARLY MORNING CONVECTION. THE REMNANT COLD POOL WILL CONTINUE TO ERODE FROM W-E AS SURFACE TEMPERATURES WARM WELL INTO THE 70S AND BOUNDARY LAYER DEWPOINTS IN THE LOW-MID 60S SPREAD ENEWD FROM THE MS VALLEY. ADDITIONAL THUNDERSTORM DEVELOPMENT IS EXPECTED THIS AFTERNOON ALONG A SURFACE COLD FRONT THAT IS MOVING SEWD ACROSS THE OH RIVER AS OF 16Z...AS AN UPSTREAM SPEED MAX APPROACHES FROM NRN IL. ...FOUR CORNERS THIS AFTERNOON... A PRONOUNCED BELT OF ASCENT PRECEDING THE EJECTING MIDLEVEL TROUGH IS ALREADY SUPPORTING A BAND OF CONVECTION NEAR THE RIM IN CENTRAL AZ. THIS CONVECTION WILL SPREAD ENEWD THROUGH THE AFTERNOON/EVENING...WITH AN ACCOMPANYING RISK FOR ISOLATED STRONG GUSTS. ..THOMPSON/ROGERS.. 04/26/2012
via SPC Forecast Products http://www.spc.noaa.gov/products/outlook/day1otlk_1630.html
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