SPC AC 051622
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1122 AM CDT TUE MAY 05 2009
   
   VALID 051630Z - 061200Z
   
   ...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF NRN TX AND SRN
   OK...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM PORTIONS OF TX/OK ACROSS
   THE CENTRAL GULF COAST INTO THE CAROLINAS...
   
   ...SRN PLAINS...
   PRIMARY CHALLENGE WILL BE TIMING OF INITIATION OF SURFACE BASED
   SEVERE THUNDERSTORMS VICINITY OF THE E/W FRONTAL ZONE THAT STRETCHES
   FROM NRN LA ACROSS NRN TX TO ERN NM.  ONGOING OK STORMS  IN RESPONSE
   TO ASCENT ON NOSE OF 30-40KT LLJ AND ADVECTION OF ELEVATED
   MOISTURE/INSTABILITY. THESE SHOULD REMAIN PRIMARILY HAIL PRODUCERS
   DUE TO THEIR ELEVATED NATURE THRU MID AFTERNOON.
   
   UPSTREAM S/WV TROUGH CENTRAL ROCKIES WILL SPREAD INCREASING ASCENT
   AND SOME MID LEVEL COOLING WHICH COMBINED WITH THE WARM/MOIST
   ADVECTION ACROSS THE FRONTAL ZONE WILL PROVIDE A FERTILE ENVIRONMENT
   FOR SUPERCELL SEVERE THUNDERSTORM DEVELOPMENT LATER THIS AFTERNOON
   AND EVENING.  WITH EXTENSIVE LOW CLOUDINESS WITH THE GULF MOISTURE
   AND HIGH LEVEL CLOUDINESS SPREADING EWD AHEAD OF THE APPROACHING
   TROUGH...ALONG WITH INCONSISTENT MODEL SOLUTIONS...THE PRIMARY
   UNCERTAINTY IS WITH THE TIMING OF THE MOST INTENSE SURFACE/NEAR
   SURFACE BASED INITIATION.  THE DRY LINE WILL MIX EWD TO WCENTRAL TX
   S OF E/W FRONTAL ZONE PROVIDING POTENTIAL FOR INITIATION BY LATER
   THIS AFTERNOON WITH THE FRONTAL INTERSECTION. WITH MLCAPES CLIMBING
   TO AOA 3000 J/KG IN THE WARM SECTOR BY MID AFTERNOON E OF DRY
   LINE...ANY NEAR SURFACE BASED STORM WOULD QUICKLY BECOME SEVERE WITH
   POTENTIAL FOR VERY LARGE HAIL.
   
   AS LOW LEVEL JET INCREASES BY THIS EVENING SEVERE THUNDERSTORMS
   INCLUDING SUPERCELLS WILL BECOME MORE COMMON EWD ALONG AND S OF RED
   RIVER VALLEY VICINITY OF FRONTAL CONVERGENCE.  IN ADDITION TO VERY
   LARGE HAIL...VEERING SHEAR PROFILES WILL BE CONDUCIVE TO VERY LARGE
   HODOGRAPHS AND TORNADO POTENTIAL.  OVERNIGHT A SEVERE MCS SHOULD
   EVOLVE AND TRACK S OF E ACROSS NRN TX POSSIBLY INTO NRN LA BY 12Z
   WED. WIND DAMAGE POTENTIAL WOULD INCREASE AS THE MCS DEVELOPS DURING
   THE EVENING.
   
   ...ERN CAROLINAS...
   MOIST/UNSTABLE AND A WEAKLY CAPPED AIR MASS REMAINS ACROSS AREA TO E
   OF SRN APPALACHIANS AS A S/WV TROUGH PASSES BY TO THE N.
   THUNDERSTORMS ARE ALREADY INCREASING ERN CAROLINAS THIS AM WITHIN AN
   UNCAPPED ENVIRONMENT.  WITH 30-40KT OF SHEAR AND MLCAPES AOA 2000
   J/KG...STRONG/SEVERE STORMS WHICH HAVE DEVELOPED ERN CAROLINAS WILL
   INCREASE IN INTENSITY AS THEY MOVE TOWARD THE COAST...WITH POSSIBLE
   ENHANCEMENT OF CONVERGENCE WITH THE SEA BREEZE FRONT.  AFTERNOON
   HEATING SHOULD SUPPORT REDEVELOPMENT OF STORMS AGAIN ERN CAROLINAS. 
   STORMS WILL EVOLVE INTO SHORT LINE SEGMENTS/BOWS GIVEN THE AVAILABLE
   SHEAR WITH BOTH LARGE HAIL AND WIND DAMAGE THE PRIMARY THREAT.
   
   ...GULF COAST STATES...
   THE MORE DIFFUSE E/W STATIONARY FRONTAL ZONE FROM NRN GA TO CENTRAL
   MS WILL BE A FOCUS FOR PRIMARILY A DIURNAL LOWER END SEVERE
   POTENTIAL TODAY.  WITH SURFACE TEMPS INTO THE 80S AND DEWPOINTS NEAR
   70F ALONG AND S OF FRONT...MLCAPES AGAIN WILL BE QUITE UNSTABLE
   RANGING UPWARDS TO 3000 J/KG WHERE HEATING IS STRONGEST. GENERALLY
   30KT OR LESS OF DEEP LAYER SHEAR SUGGESTS MOST STORMS WILL BE
   MULTI-CELLULAR WITH A LARGE HAIL AND ISOLATED DAMAGING WIND THREAT
   FROM MID AFTERNOON UNTIL LATER THIS EVENING WHEN BOUNDARY LAYER
   STABILIZES.
   
   ..HALES/SMITH.. 05/05/2009
   
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