SPC AC 140629
   
   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1229 AM CST TUE FEB 14 2012
   
   VALID 151200Z - 161200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS WED AND WED  NIGHT ACROSS PARTS
   OF SOUTHEAST TEXAS EASTWARD THROUGH THE CNTRL GULF STATES...
   
   ...SYNOPSIS...
   LITTLE CHANGE TO THE GENERAL LARGE SCALE PATTERN IS EXPECTED THROUGH
   THIS FORECAST PERIOD.  MODELS INDICATE THAT A SERIES OF SHORT WAVE
   IMPULSES WILL CONTINUE TO EMERGE FROM A STRONG MID LATITUDE PACIFIC
   JET AND PROGRESS AROUND BROADER SCALE EASTERN PACIFIC UPPER
   RIDGING...BEFORE SPLITTING OFF INTO AT LEAST A COUPLE OF LINGERING
   BRANCHES OF STRONGER FLOW ACROSS NORTH AMERICA.  AS A RESULT...THE
   VIGOROUS CLOSED LOW/SHORT WAVE TROUGH...NOW DIGGING INTO THE
   SOUTHERN PLATEAU...IS EXPECTED TO REMAIN PROGRESSIVE...AND LIKELY BE
   IN THE PROCESS OF ACCELERATING EAST NORTHEAST OF THE ROCKIES BY
   EARLY WEDNESDAY.  GUIDANCE STILL INDICATES THAT THIS WILL BE
   PRECEDED BY THE NORTHWARD EXPANSION OF SUBTROPICAL RIDGING INTO THE
   LOWER MISSISSIPPI VALLEY AND SOUTHEAST STATES.  BUT THE UPSTREAM
   IMPULSE MAY RESULT IN SOME SUPPRESSION OF THE RIDGE ACROSS THE NORTH
   CENTRAL GULF STATES INTO THE TENNESSEE VALLEY...AS IT LIFTS
   NORTHEAST OF THE SOUTH CENTRAL PLAINS THROUGH THE MIDDLE MISSISSIPPI
   VALLEY LATE WEDNESDAY AND WEDNESDAY NIGHT.
   
   CONSIDERABLE SPREAD PERSISTS AMONG THE VARIOUS MODELS CONCERNING THE
   ASSOCIATED LOW-LEVEL CYCLOGENESIS...WHICH WILL SUBSTANTIALLY IMPACT
   POTENTIAL FOR INLAND BOUNDARY LAYER DESTABILIZATION ACROSS THE LOWER
   MISSISSIPPI VALLEY/CENTRAL GULF STATES...AS WELL AS THE LOW-LEVEL
   SHEAR.  HOWEVER...A SUBSTANTIVE INLAND RETURN FLOW OF MOISTURE OFF
   THE WESTERN GULF OF MEXICO SEEMS PROBABLE...WITH A TONGUE OF
   PRECIPITABLE WATER ON THE ORDER OF 1 TO 1.5+ INCHES ADVECTING
   NORTHWARD ACROSS AND EAST OF THE LOWER MISSISSIPPI VALLEY WEDNESDAY
   NIGHT.  THIS IS EXPECTED TO CONTRIBUTE TO THE RISK FOR THUNDERSTORM
   ACTIVITY ACROSS A LARGE PORTION OF THE SOUTH CENTRAL STATES...WITH
   POTENTIAL FOR AT LEAST A FEW SEVERE STORMS.
   
   ...SOUTHEAST TEXAS EASTWARD THROUGH THE CENTRAL GULF STATES...
   ALTHOUGH MUCH MODEL VARIABILITY PERSISTS...THE NAM/SREF...GFS AND
   ECMWF ARE FAIRLY CLOSE WITH A FOCUSED AREA OF DIFLUENT UPPER
   FLOW...BETWEEN THE SHORT WAVE TROUGH AND SUBTROPICAL RIDGE...
   SHIFTING FROM PARTS OF SOUTHEAST TEXAS THROUGH NORTHERN AND CENTRAL
   LOUISIANA/MISSISSIPPI AND ALABAMA DURING THE LATE AFTERNOON AND
   EVENING.  THIS MAY PROVE FAVORABLE FOR AN ASSOCIATED REGION OF
   STRONG AND FOCUSED ASCENT...AIDED BY LOW-LEVEL WARM ADVECTION...TO
   INTERCEPT RICHER MOISTURE RETURN.  AND THE ENVIRONMENT PROBABLY WILL
   BECOME CONDUCIVE TO THE EVOLUTION OF AN ORGANIZED STORM CLUSTER...OR
   CLUSTERS...AND PERHAPS DISCRETE SUPERCELLS...AS WEST SOUTHWESTERLY
   500 MB FLOW STRENGTHENS TO 50-70+ KT.
   
   THE ECMWF HAS BEEN MORE SUGGESTIVE THAN THE OTHER MODELS OF
   POTENTIAL FOR SIGNIFICANT SURFACE CYCLONE DEEPENING ACROSS THE
   MIDDLE MISSISSIPPI VALLEY WEDNESDAY NIGHT...PERHAPS AIDED BY PHASING
   OF THE SOUTHERN BRANCH IMPULSE WITH A DIGGING NORTHERN BRANCH
   TROUGH.  IF THIS OCCURS...STRONGER SURFACE PRESSURE FALLS COULD AID
   BOUNDARY LAYER DESTABILIZATION ACROSS MISSISSIPPI AND ALABAMA...WITH
   STRONGER SOUTHERLY 850 MB FLOW ALSO CONTRIBUTING TO LARGE AND
   CLOCKWISE CURVED LOW-LEVEL HODOGRAPHS.  THIS WOULD PROVIDE POTENTIAL
   FOR A GREATER SEVERE RISK THAN CURRENTLY INDICATED...INCLUDING THE
   POSSIBILITY OF A STRONG TORNADO OR TWO.
   
   ..KERR.. 02/14/2012
   
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   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z