May 7, 2006 1300 UTC Day 1 Convective Outlook Updated: Sun May 7 12:52:11 UTC 2006 Probabilistic to Categorical Outlook Conversion Table (Effective Feb 14, 2006).
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SPC AC 071248 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0748 AM CDT SUN MAY 07 2006 VALID 071300Z - 081200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE CENTRAL GULF COAST AND SOUTHEAST... ...THERE IS A SLGT RISK OF SVR TSTMS INTO THE CENTRAL AND SRN HIGH PLAINS... ...THERE IS A SLGT RISK OF SVR TSTMS OVER SWRN TX... ...LOWER MS RIVER VALLEY ACROSS THE SOUTHEAST... BOUNDARY LAYER REMAINS QUITE MOIST AHEAD OF SHORTWAVE TROUGH NOW PROGRESSING EWD ACROSS THE CENTRAL GULF COAST STATES THIS MORNING WITH SURFACE DEW POINTS IN THE MID/UPPER 60S. WITH HEATING THIS SHOULD BE SUFFICIENT FOR MODERATE INSTABILITY EAST OF WEAK SURFACE LOW AND ASSOCIATED COLD FRONT FORECAST TO SHIFT EWD FROM CENTRAL AL INTO GA/SC TODAY. CONVERGENCE AND DEEP ASCENT ARE EXPECTED TO SUPPORT WIDESPREAD THUNDERSTORMS ACROSS THIS REGION THROUGH THE DAY...WITH SEVERE THREAT INCREASING IN BOTH INTENSITY AND COVERAGE WITH HEATING THIS MORNING. FORECAST SOUNDINGS INDICATE DEEP LAYER SHEAR WILL BE SUFFICIENT /I.E. EFFECTIVE SHEAR AROUND 40 KT/ FOR SUPERCELLS AND SMALL LINES...WITH PRIMARY SEVERE THREATS OF DAMAGING WINDS AND LARGE HAIL. ...PLAINS STATES... NARROW AXIS OF SURFACE-BASED INSTABILITY WILL DEVELOP TODAY OVER THE PLAINS ALONG WRN PERIPHERY OF LARGE SURFACE ANTICYCLONE CENTERED OVER THE NORTHEAST. FROM PORTIONS OF WRN TX INTO THE CENTRAL/ERN DAKOTAS...SLY LOW LEVEL FLOW WILL BECOME FOCUSED AHEAD OF A SURFACE TROUGH/COLD FRONT ADVANCING EWD OUT OF THE WRN PLAINS. MODELS HAVE BEEN CONSISTENT FOR SEVERAL RUNS IN INITIATING THUNDERSTORMS ALONG THIS FEATURE FROM CENTRAL/ERN ND INTO FAR ERN CO/WRN KS AND THE OK/TX PANHANDLES BY THE LATE AFTERNOON. ACTIVITY WILL INCREASE AHEAD OF A FAST MOVING SHORTWAVE TROUGH NOW SPREADING ACROSS THE NRN/CENTRAL ROCKIES WITH ASSOCIATED 25-35 KT WLY H5 FLOW INCREASING DEEP LAYER SHEAR AND SUPPORTING ORGANIZED CONVECTION. THOUGH AIR MASS IS NOT FORECAST TO DESTABILIZE SIGNIFICANTLY...BOUNDARY LAYER MOISTURE IS EXPECTED TO BE SUFFICIENT FOR MODEST MLCAPE NWD INTO PORTIONS OF WRN KS/NEB...WITH WEAKER INSTABILITY AND A DIMINISHED SEVERE THREAT NWD INTO THE DAKOTAS. SUPERCELLS AND MULTICELL CLUSTERS/LINES WILL EVOLVE EWD OUT OF THE CENTRAL/SRN HIGH PLAINS WITH THREATS OF ISOLATED LARGE HAIL/DAMAGING WINDS. SEVERE THREAT EXPECTED TO DIMINISH AFTER DARK...THOUGH THUNDERSTORM CLUSTERS WILL CONTINUE EWD FOR MUCH OF THE NIGHT. EXCEPTION MAY BE INTO PORTIONS OF WRN OK/NWRN TX ALONG NOSE OF 40 KT SLY LLJ WHICH IS FORECAST TO DEVELOP THIS EVENING. INTENSE STORMS/CLUSTERS OVER THE OK/TX PANHANDLE REGION AND SWRN KS/SERN CO MAY EVOLVE INTO A MCS WITH A MORE PERSISTENT SEVERE THREAT LINGERING SEWD INTO THE RED RIVER VALLEY THROUGH THE LATE EVENING. ...SWRN TX... STRONG HEATING WILL PROVIDE A VERY WEAK CAP ALONG NWRN EDGE OF RICH GULF MOISTURE EXPECTED TO NOSE INTO SWRN TX THIS AFTERNOON. 12Z SOUNDING AT DRT INDICATED ABUNDANT LOW LEVEL MOISTURE ALONG WITH A WEAK CAP. THOUGH CAPPING SHOULD INCREASE UNDER WLY FLOW ALOFT AS EVIDENCED BY 20C H85 TEMPS AT ELP THIS MORNING...SURFACE HEATING THROUGH THE 80S SHOULD WEAKEN CAP SUFFICIENTLY FOR A THREAT OF VIGOROUS UPDRAFTS LATER TODAY. SHEAR WILL REMAIN STRONG UNDER 40+ KT WLY MID LEVEL FLOW WITH FORECAST SOUNDINGS MAINTAINING EFFECTIVE SHEAR IN EXCESS OF 50 KT. THOUGH SEVERE THREAT IS MORE CONDITIONAL ACROSS THIS REGION GIVEN LACK OF LARGE SCALE ASCENT UNDER RIDGING ALOFT...FORECAST SOUNDINGS SUGGEST SUPERCELLS WOULD BE LIKELY SHOULD INITIATION OCCUR ALONG DRY LINE/WEAK LOW CENTER EXPECTED TO FORM OVER SWRN TX. LARGE HAIL WILL BE PRIMARY SEVERE THREAT...ALONG WITH ISOLATED DAMAGING WINDS. TORNADO POTENTIAL MAY BE MODULATED BY WEAK LOW LEVEL SHEAR FORECAST ACROSS THE AREA. ..EVANS/JEWELL.. 05/07/2006 CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z |