May 25, 2015 0600 UTC Day 1 Convective Outlook

DAY 1 CONVECTIVE OUTLOOK  

   NWS STORM PREDICTION CENTER NORMAN OK
   1256 AM CDT MON MAY 25 2015

   VALID 251200Z - 261200Z

   ...THERE IS AN ENH RISK OF SVR TSTMS TODAY ACROSS PARTS OF CENTRAL
   INTO NORTHEAST TEXAS...

   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS SURROUNDING AREAS OF THE
   SOUTHERN PLAINS AND ADJACENT PORTIONS OF THE LOWER MISSISSIPPI
   VALLEY...

   ...THERE IS A SLGT RISK OF SVR TSTMS LATE THIS AFTERNOON AND EVENING
   ACROSS PARTS OF THE NORTH CENTRAL PLAINS AND MID MISSOURI VALLEY...

   ...THERE IS A MRGL RISK OF SVR TSTMS ACROSS MUCH OF THE REMAINDER OF
   THE SOUTHERN AND CENTRAL PLAINS...AND A CORRIDOR EXTENDING ACROSS
   THE MID MISSOURI VALLEY INTO THE GREAT LAKES REGION...

   ...SUMMARY...
   SEVERE THUNDERSTORMS ARE LIKELY TODAY INTO TONIGHT ACROSS MUCH OF
   CENTRAL AND EASTERN TEXAS INTO PARTS OF THE LOWER MISSISSIPPI
   VALLEY...AS WELL AS ACROSS PARTS OF THE CENTRAL PLAINS INTO THE
   MIDDLE MISSOURI VALLEY.  STRONGEST STORMS WILL BE CAPABLE OF
   PRODUCING LARGE HAIL AND POTENTIALLY DAMAGING WIND GUSTS.  A FEW
   TORNADOES ARE ALSO POSSIBLE.

   ...SYNOPSIS...
   SUBTROPICAL RIDGING APPEARS LIKELY TO REMAIN PROMINENT ALONG
   ATLANTIC COASTAL AREAS THROUGH THIS PERIOD.  MODELS DO INDICATE THAT
   UPPER FLOW ACROSS THE WESTERN INTO CENTRAL U.S. MAY BEGIN TO
   DEAMPLIFY A BIT...BUT BROAD UPPER TROUGHING IS FORECAST TO
   PERSIST...WITH A NUMBER OF SIGNIFICANT EMBEDDED SHORT WAVE
   PERTURBATIONS.  SEVERAL OF THESE WILL CONTINUE TO PROGRESS EAST OF
   THE ROCKIES...WITHIN SOUTHWESTERLY MID/UPPER FLOW ACROSS THE
   PLAINS...MISSISSIPPI/OHIO VALLEYS...AND GREAT LAKES REGION...ABOVE A
   PERSISTENT SOUTHERLY RETURN FLOW.

   THIS INCLUDES ONE IMPULSE WHICH IS EXPECTED TO PIVOT NORTHEAST OF
   THE MID/LOWER MISSOURI VALLEY...THROUGH THE UPPER MIDWEST EARLY
   TODAY...BEFORE BECOMING ABSORBED WITHIN INCREASINGLY CONFLUENT FLOW
   ACROSS AND NORTHEAST OF THE GREAT LAKES REGION.  UPSTREAM...THE
   REMNANTS OF A COMPACT...BUT SIGNIFICANT...MID-LEVEL CIRCULATION /NOW
   PROGRESSING INTO SOUTHWEST TEXAS/ ARE EXPECTED TO TURN NORTHEASTWARD
   ACROSS THE SOUTHERN PLAINS RED RIVER VALLEY DURING THE DAY TODAY. 
   GUIDANCE INDICATES THAT IT WILL THEN CONTINUE THROUGH THE LOWER
   MISSOURI VALLEY TONIGHT...JUST AHEAD OF THE REMNANTS OF THE CLOSED
   LOW NOW BEGINNING TO PROGRESS EAST OF THE FRONT RANGE OF THE
   ROCKIES.

   ...SOUTHERN PLAINS...
   MODELS GENERALLY INDICATE THAT A 30-50 KT LOWER/MID TROPOSPHERIC JET
   WILL ACCOMPANY THE IMPULSE EMERGING FROM THE SOUTHWEST.  THIS
   FEATURE APPEARS LIKELY TO NOSE NORTH/NORTHEAST OF THE BIG BEND
   REGION AFTER 12Z THIS MORNING.  ASSOCIATED FORCING FOR
   ASCENT...COUPLED WITH RETURNING MOISTURE BENEATH AT LEAST MODESTLY
   STEEP MID-LEVEL LAPSE RATES...MAY ALREADY BE IN THE PROCESS OF
   SUPPORTING VIGOROUS CONVECTIVE DEVELOPMENT ACROSS PARTS OF THE TEXAS
   SOUTH PLAINS AND EDWARDS PLATEAU.  THIS ACTIVITY IS EXPECTED TO
   CONTINUE...GRADUALLY INCREASING IN COVERAGE AND INTENSITY WHILE
   DEVELOPING EAST NORTHEASTWARD THROUGH EARLY AFTERNOON...AS INFLOW
   BECOMES INCREASINGLY ROOTED IN A DESTABILIZING BOUNDARY LAYER.

   THE RISK FOR LARGE HAIL APPEARS THE PRIMARY SEVERE THREAT INITIALLY.
    EVENTUALLY...A GRADUAL CONSOLIDATION OF CONVECTION AND ASSOCIATED
   OUTFLOW IS EXPECTED TO LEAD TO EVOLUTION OF AN INCREASINGLY
   ORGANIZED FORWARD PROPAGATING CONVECTIVE SYSTEM.  ALTHOUGH AMBIENT
   LOW-LEVEL WIND FIELDS MAY BE INITIALLY MODEST...AT LEAST SOME
   INTENSIFICATION DURING THE DAY...COUPLED WITH COLD POOL
   STRENGTHENING...MAY CONTRIBUTE TO AN INCREASING RISK FOR POTENTIALLY
   DAMAGING WIND GUSTS.  GIVEN THE SEASONABLY MOIST BOUNDARY LAYER
   /CHARACTERIZED BY SURFACE DEW POINTS NEAR 70F/...MESOVORTICES
   DEVELOPING ALONG THE GUST FRONT MAY BE ACCOMPANIED BY THE RISK FOR
   TORNADOES OR LOCALLY ENHANCED SURFACE GUSTS AS ACTIVITY SPREADS
   TOWARD THE ARKLATEX REGION AND SABINE VALLEY THROUGH EARLY EVENING.

   IN THE WAKE OF THIS INITIAL CONVECTIVE ACTIVITY...ADDITIONAL
   STRONG/SEVERE STORM DEVELOPMENT APPEARS POSSIBLE DURING THE LATE
   AFTERNOON AND EVENING ALONG THE DRYLINE ACROSS THE PANHANDLE REGION
   INTO WEST CENTRAL TEXAS.  THIS SHOULD BE MORE WIDELY SCATTERED IN
   NATURE...BUT MAY INCLUDE DISCRETE SUPERCELLS.

   ...CENTRAL PLAINS INTO THE MID MISSOURI VALLEY...
   LOW-LEVEL MOISTURE ALONG/AHEAD OF AN INCREASINGLY BETTER DEFINED
   SURFACE FRONTAL ZONE WILL BE MORE LIMITED THAN ACROSS THE SOUTHERN
   PLAINS.  BUT...THE NORTHEASTWARD ADVECTION OF A PLUME OF STEEP
   MID-LEVEL LAPSE RATES IS EXPECTED TO CONTRIBUTE TO MODERATELY LARGE
   CAPE BY LATE AFTERNOON.  STORMS MAY INITIATE FIRST NEAR THE
   DRYLINE...ON THE NOSE OF STRONGER SURFACE HEATING  ACROSS NORTH
   CENTRAL KANSAS...WHERE VERTICAL SHEAR SHOULD BE SUFFICIENT FOR
   SUPERCELLS.  THEREAFTER...A MORE SUBSTANTIVE INCREASE IN STORM
   DEVELOPMENT ALONG THE FRONT...EAST NORTHEASTWARD ACROSS THE MIDDLE
   MISSOURI VALLEY...IS EXPECTED TO AWAIT BETTER FORCING ASSOCIATED
   WITH IMPULSE PROGRESSING EAST OF THE FRONT RANGE.  THIS MAY NOT BE
   UNTIL THE 26/00-03Z TIME FRAME...BUT THE ENVIRONMENT SHOULD STILL BE
   CONDUCIVE TO THE DEVELOPMENT OF SUPERCELLS...PERHAPS AN ORGANIZING
   STORM CLUSTER OR TWO.  LARGE HAIL...DAMAGING WIND GUSTS AND A COUPLE
   OF TORNADOES ALL APPEAR POSSIBLE.