Categorical Graphic
Probabilistic Graphic
Probability of severe weather within 25 miles of a point. Hatched Area: 10% or greater probability of significant severe within 25 miles of a point.

   SPC AC 271717
   
   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1217 PM CDT MON JUN 27 2011
   
   VALID 281200Z - 291200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE LOWER MS VALLEY AND TN
   VALLEY...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE CENTRAL HIGH PLAINS...
   
   ...SYNOPSIS...
   MODEL GUIDANCE INDICATES UPPER FLOW PATTERN WILL AMPLIFY TOMORROW AS
   THE UPPER LOW CURRENTLY DROPPING SWD OFF THE PACIFIC NW COAST TURNS
   SEWD TOWARD THE NRN/CENTRAL CA COAST.  THIS WILL RESULT IN THE
   DOWNSTREAM RIDGE BUILDING OVER THE ROCKIES AND PLAINS...WHILE THE
   UPPER LOW NOW NEARING THE UPPER MS VALLEY PROGRESSES EWD TOWARD THE
   ST LAWRENCE VALLEY.
   
   AT THE SURFACE...A LOW IS FORECAST TO MOVE FROM NRN LAKE HURON AT
   THE BEGINNING OF THE PERIOD NEWD TOWARD WRN QUEBEC...WITH TRAILING A
   COLD FRONT MOVING EWD/SEWD REACHING THE APPALACHIANS TO THE MID
   SOUTH BY LATE AFTERNOON...AND CONTINUING EWD/SEWD DURING THE NIGHT. 
   THE WRN PART OF THE FRONT WILL BEGIN TO LIFT NWD OVER THE SRN HIGH
   PLAINS TOMORROW AFTERNOON REACHING THE CENTRAL HIGH PLAINS DURING
   THE OVERNIGHT HOURS.
   
   ...LOWER MS VALLEY AND TN VALLEY...
   SCATTERED CONVECTION CONTINUING FROM LATE IN THE DAY 1 PERIOD MAY
   PERSIST DURING THE EARLY PART OF DAY 2 FROM AR INTO THE TN
   VALLEY...BUT THIS ACTIVITY IS EXPECTED TO DIMINISH DURING THE
   MORNING.  THIS WILL ALLOW SOME AREAS TO UNDERGO ENHANCED DIABATIC
   HEATING INTO THE AFTERNOON...AND WHEN COUPLED WITH PRE-EXISTING
   SURFACE DEW POINTS OF 70-75F...WILL RESULT IN CONSIDERABLE
   INSTABILITY WITH MLCAPE OF 2000-3000 J/KG.  THUNDERSTORMS ARE
   EXPECTED TO REDEVELOP DURING THE AFTERNOON ALONG THE COLD FRONT
   AND/OR EFFECTIVE OUTFLOW BOUNDARIES GENERATED BY EARLIER CONVECTION
   IN THE WARM SECTOR.  NWLY MID-LEVEL FLOW IS EXPECTED TO INCREASE TO
   25-35 KT AS THE UPSTREAM UPPER RIDGE AMPLIFIES...CONTRIBUTING TO
   SUFFICIENT DEEP LAYER SHEAR /30-35 KT IN THE LOWEST 6 KM/ TO ENHANCE
   STORM ORGANIZATION AND INTENSITY.  A FEW ORGANIZED MULTICELL
   CLUSTERS AND LINEAR SEGMENTS MAY DEVELOP DURING THE AFTERNOON AND
   EVENING WITH POTENTIAL TO PRODUCE LOCALLY DAMAGING WINDS AND
   OCCASIONAL HAIL AS THE ACTIVITY PROGRESSES SEWD.
   
   ...CENTRAL HIGH PLAINS...
   LOW LEVEL MOISTURE WITH SURFACE DEW POINTS OF 50-60F IS FORECAST TO
   GRADUALLY INCREASE NWD INTO THE REGION AS MODEST SSELY FLOW DEVELOPS
   NORTH OF THE RETREATING FRONTAL BOUNDARY.  STEEP LOW-MID LEVEL LAPSE
   RATES AND RESULTANT MLCAPE OF 1500-2500 J/KG COUPLED WITH WIND
   PROFILES THAT VEER STRONGLY WITH HEIGHT WILL PROVIDE A POTENTIALLY
   FAVORABLE ENVIRONMENT FOR STRONG/SEVERE STORM DEVELOPMENT.  PRIMARY
   LIMITING FACTOR IS THE LACK OF DYNAMIC FORCING FOR LARGE SCALE
   ASCENT WITHIN THE UPPER RIDGE WHICH SUGGESTS THAT WIDESPREAD
   CONVECTION IS UNLIKELY.  HOWEVER...MODEL GUIDANCE CONTINUES TO
   INDICATE ISOLATED/WIDELY SCATTERED STORMS FORMING DURING THE LATE
   AFTERNOON/EVENING HOURS OVER NERN/EAST CENTRAL CO...WITH STORMS THEN
   MOVING EWD INTO KS DURING THE OVERNIGHT HOURS AS THE LOW LEVEL JET
   STRENGTHENS AFTER DARK. STRONGER STORMS WILL HAVE POTENTIAL TO
   PRODUCE LARGE HAIL AND STRONG WIND GUSTS GIVEN STEEP LAPSE RATE AND
   DEEP PBL ENVIRONMENT...BEFORE ACTIVITY BECOMES PRIMARILY ELEVATED
   AFTER 03-06Z AS IT MOVES EWD ACROSS PARTS OF KS.
   
   ...MID ATLANTIC STATES INTO THE CAROLINAS...
   MODELS INDICATE MORNING STORMS WILL SPREAD EWD AHEAD OF THE COLD
   FRONT /ESPECIALLY OVER THE MID ATLANTIC REGION/ WITH WIDESPREAD
   AREAS OF CLOUD COVER/PRECIPITATION IMPACTING THE DEGREE OF
   SUBSEQUENT DESTABILIZATION PERHAPS INTO THE AFTERNOON. 
   HOWEVER...THERE WILL LIKELY BE REGIONS OF ENHANCED HEATING THAT DO
   OCCUR WITH MLCAPE OF 1500-2500 J/KG DEVELOPING WHICH WILL BE
   SUPPORTIVE OF STRONGER STORMS ALONG/AHEAD OF THE COLD FRONT. 
   ALTHOUGH THE STRENGTH OF FLOW ALOFT/VERTICAL SHEAR IS EXPECTED TO BE
   MARGINAL WITH 0-6 KM SHEAR GENERALLY LESS THAN 20-25 KT...THE THREAT
   FOR ISOLATED SEVERE STORMS WILL EXIST.
   
   ...NRN INTERMOUNTAIN REGION...
   UPPER FLOW IS FORECAST TO BACK AND INCREASE IN SPEED TOMORROW AS THE
   UPPER LOW MOVES SEWD TOWARD THE NRN/CENTRAL CA COAST.  THIS WILL
   RESULT IN THE DEVELOPMENT OF WIND PROFILES SUPPORTIVE OF ORGANIZED
   CONVECTION WITH DEEP LAYER SHEAR OF 40-50 KT IN THE LOWEST 6 KM. 
   SATELLITE IMAGERY/BLENDED TPW ANALYSES INDICATE MID LEVEL MOISTURE
   IS INCREASING INTO THE PACIFIC NW COASTAL AREA WITH GPS IPW GREATER
   THAN 1 INCH ATTM. THIS MOISTURE IS EXPECTED TO OVERSPREAD PARTS OF
   THE NRN INTERMOUNTAIN REGION TOMORROW AND INCREASE POTENTIAL FOR
   THUNDERSTORM DEVELOPMENT.  MODEL FORECAST SOUNDINGS INDICATE A
   MODERATELY DEEP PBL WILL DEVELOP DURING THE AFTERNOON AND EVENING
   WITH THREAT FOR HAIL AND STRONG WIND GUSTS WITH A FEW STORMS.
   
   ..WEISS.. 06/27/2011
   
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   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0600Z