SPC AC 280556

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1256 AM CDT SAT JUN 28 2014

   VALID 281200Z - 291200Z

   ...THERE IS A SLGT RISK OF SVR TSTMS FROM PORTIONS OF THE SRN AND
   CNTRL PLAINS THROUGH THE MIDDLE AND UPPER MS VALLEY...

   ...SUMMARY...
   CONSIDERABLE THUNDERSTORM ACTIVITY APPEARS LIKELY SATURDAY THROUGH
   SATURDAY NIGHT ACROSS PARTS OF THE CENTRAL AND SOUTHERN PLAINS INTO
   THE UPPER MISSISSIPPI VALLEY. SOME OF THESE STORMS WILL POSE A RISK
   FOR MAINLY STRONG TO DAMAGING WIND GUSTS AND HAIL.

   ...SYNOPSIS...

   NEGATIVE-TILT TROUGH WITH EMBEDDED VORTICITY MAXIMA WILL CONTINUE
   SLOWLY EAST THROUGH THE CNTRL AND NRN PLAINS INTO THE MIDDLE AND
   UPPER MS VALLEY REGION SATURDAY. A WEAK COLD FRONT ACCOMPANYING THIS
   FEATURE SHOULD EXTEND FROM THE ERN DAKOTAS SWWD THROUGH WRN KS EARLY
   SATURDAY. NRN PORTION OF THIS FRONT WILL REACH THE UPPER MS VALLEY
   BY 00Z SATURDAY WITH TRAILING PORTION EXTENDING INTO THE TX
   PANHANDLE WHERE IT WILL INTERSECT THE DRYLINE ACROSS WRN TX.  

   ...ERN NEB...ERN KS THROUGH OK AND THE MIDDLE MS VALLEY AREA...

   REMNANT OUTFLOW BOUNDARY AND RESIDUAL CONVECTION SHOULD PERSIST OVER
   CNTRL OR ERN KS 12Z SATURDAY. WIDESPREAD CLOUDS WILL PERSIST IN
   MOIST WARM SECTOR...LIMITING OR DELAYING BOUNDARY-LAYER WARMING. A
   RESERVOIR OF MODERATE INSTABILITY WILL EXIST SOUTH AND EAST OF THE
   ONGOING STORMS FROM OK THROUGH ERN KS AND WRN MO WHERE RESIDUAL EML
   PLUME RESIDES ABOVE THE MOIST BOUNDARY LAYER. HOWEVER...WARM SECTOR
   SHOULD BE CAPPED TO SURFACE BASED STORMS. AREAS OF DIABATIC HEATING
   WILL COMMENCE AS LOW CLOUDS MIX OUT...AND A SECONDARY VORTICITY
   MAXIMUM IS FORECAST TO ROTATE THROUGH BASE OF THE TROUGH AND INTO
   THE CNTRL PLAINS. THESE PROCESSES SHOULD SUPPORT THE REDEVELOPMENT
   OF STORMS ALONG RESIDUAL OUTFLOW BOUNDARIES FROM ERN/SRN KS INTO NRN
   OK AS WELL AS ALONG COLD FRONT ACROSS ERN NEB. WIND PROFILES WILL BE
   SUPPORTIVE OF A FEW ORGANIZED STORMS INCLUDING SOME SUPERCELL
   STRUCTURES...BUT THERE MAY BE A TENDENCY FOR ACTIVITY TO EVOLVE INTO
   CLUSTER AND LINES. ISOLATED LARGE HAIL AND DAMAGING WIND WILL BE THE
   MAIN THREATS FROM LATE AFTERNOON THROUGH EARLY EVENING.  

   ...ERN DAKOTAS THROUGH UPPER MS VALLEY REGION...

   A VIGOROUS PARTIALLY CONVECTIVELY ENHANCED VORTICITY MAXIMUM NOW
   OVER NEB WILL MOVE NEWD...REACHING THE ERN DAKOTAS EARLY SATURDAY
   BEFORE CONTINUING INTO WRN MN. CONSIDERABLE CLOUDS AND AREAS OF
   ONGOING CONVECTION WILL EXIST AT THE START OF THIS PERIOD WHICH
   LENDS UNCERTAINTY REGARDING OVERALL SEVERE POTENTIAL. STRONGER
   DEEP-LAYER WINDS ALONG SERN PERIPHERY OF VORTICITY MAXIMUM WILL
   SPREAD THROUGH THE UPPER MS VALLEY REGION DURING THE DAY. SHEAR
   PROFILES WILL REMAIN GENERALLY UNIDIRECTIONAL...BUT WITH SOME
   ENHANCEMENT OF LOW-LEVEL HODOGRAPHS ALONG THE LLJ AXIS. PRIMARY
   LIMITING FACTOR WILL BE THE MODEST THERMODYNAMIC ENVIRONMENT.
   DESPITE PRESENCE OF LOW-LEVEL MOISTURE...WIDESPREAD CLOUDS AND WEAK
   LAPSE RATES SHOULD LIMIT MLCAPE TO AOB 1000 J/KG. STORMS MAY UNDERGO
   SOME INTENSIFICATION WHERE BREAKS IN CLOUDS DESTABILIZE THE BOUNDARY
   LAYER. PRIMARY THREAT WILL BE ISOLATED STRONG WIND GUSTS AND MAYBE A
   BRIEF TORNADO OR TWO FROM MIDDLE TO LATE AFTERNOON INTO EARLY
   EVENING.  

   ...WRN TX...

   THE ATMOSPHERE WILL ONCE AGAIN BECOME STRONGLY UNSTABLE EAST OF
   DRYLINE ACROSS WRN TX. ISOLATED STORMS MAY ONCE AGAIN DEVELOP WITHIN
   ZONE OF DEEP MIXING AND CONVERGENCE AS GLANCING INFLUENCE OF DEEPER
   FORCING FOR ASCENT WITHIN BASE OF UPPER TROUGH INTERACTS WITH THE
   DRYLINE/OUTFLOW BOUNDARY INTERSECTION. LARGE HAIL AND LOCALLY STRONG
   WIND GUSTS WILL BE THE MAIN THREATS THROUGH EARLY EVENING.

   ..DIAL/DEAN.. 06/28/2014

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