SPC AC 250533

   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1233 AM CDT SAT MAY 25 2013

   VALID 261200Z - 271200Z

   ...THERE IS A SLGT RISK OF SVR TSTMS FOR PARTS OF THE NRN HIGH
   PLAINS INTO THE MID MO RIVER VALLEY...

   ...SYNOPSIS...
   A WRN U.S. UPPER TROUGH CENTRALLY LOCATED OVER THE PACIFIC NW WILL
   MOVE EWD DURING THE DAY 2 PERIOD AS THE UPPER AIR PATTERN BECOMES
   MORE PROGRESSIVE AS A MID LEVEL LOW DEPARTS FROM NEW ENGLAND INTO
   THE CANADIAN MARITIME PROVINCES.  MODEST BROAD SWLY MID LEVEL FLOW
   WILL SPILL DOWNSTREAM OVER THE HIGH PLAINS AS AN UPPER RIDGE WEAKENS
   OVER THE CNTRL U.S.  A RESIDUAL FRONTAL ZONE OVER THE MIDWEST SEWD
   TO THE SRN APPALACHIANS WILL SLOWLY ADVANCE NWD WHILE A SURFACE LOW
   AND ATTENDANT DRYLINE/SURFACE TROUGH EXTEND NORTH-SOUTH OVER THE
   HIGH PLAINS.

   ...MID MO RIVER VALLEY INTO THE N-CNTRL AND NRN HIGH PLAINS...
   A MODERATE WARM ADVECTION REGIME WILL LIKELY BE ONGOING SUNDAY
   MORNING OVER THE N-CNTRL PLAINS NEAR A FRONTAL ZONE LOCATED OVER THE
   MID MO RIVER VALLEY.  STEEP MID LEVEL LAPSE RATES IN EXCESS OF 8 DEG
   C PER KM MAY FACILITATE A MARGINAL HAIL THREAT WITH EARLY MORNING
   STORMS.  THE NWD ADVANCE OF THE FRONTAL ZONE OVER THE MID MO VALLEY
   MAY BE HAMPERED BY THE EARLY DAY CONVECTION ACTING TO REINFORCE THIS
   EFFECTIVE OUTFLOW/FRONT INVOF THE MID MO RIVER VALLEY.  

   LATER IN THE DAY...STRONG HEATING FARTHER W OVER THE HIGH PLAINS
   WILL LIKELY COINCIDE WITH GRADUAL MID LEVEL HEIGHT FALLS FROM KS/NEB
   NWD INTO ERN MT IN CONCERT WITH PERHAPS A FEW WEAK IMPULSES EJECTING
   INTO THE CNTRL-NRN HIGH PLAINS.  A PLUME OF LOW LEVEL MOISTURE
   CHARACTERIZED BY DEWPOINTS IN THE 50S SHOULD ADVECT NWWD INTO THE
   WRN DAKOTAS INTO CNTRL-ERN MT WHILE RICHER MOISTURE WITH DEWPOINTS
   RANGING THROUGH THE 60S REMAIN FARTHER SE OVER NEB SWD E OF THE
   DRYLINE.  FORECAST SOUNDINGS SHOW A MARGINAL TO MODERATELY UNSTABLE
   BOUNDARY LAYER OVER MT WITH MLCAPES RANGING FROM 500 J/KG W TO
   UPWARDS OF 2000 J/KG NEAR THE DAKOTAS BORDERS.  OROGRAPHIC
   LIFT/UPSLOPE FLOW AND GENERAL CYCLONIC SWLY UPPER FLOW WOULD
   SEEMINGLY BE SUPPORTIVE OF ISOLD-WIDELY SCTD STORMS BY THE LATE
   AFTERNOON/EVENING HOURS.  BACKED ELY FLOW N OF THE CNTRL HIGH PLAINS
   LOW FROM THE WRN DAKOTAS WWD INTO MT/WY WILL CONTRIBUTE SUFFICIENT
   DEEP LAYER SHEAR FOR ORGANIZED ISOLD STRONG-SEVERE
   STORMS...INCLUDING SUPERCELLS BY LATE AFTERNOON-EVENING...CAPABLE OF
   MAINLY A LARGE HAIL/SEVERE WIND GUST THREAT.  

   FARTHER S IN CLOSER PROXIMITY TO THE SURFACE LOW...GREATER HEATING
   WILL BE NECESSARY TO OVERCOME A CAP OVER NEB/KS.  MODEST SHEAR
   PROFILES WILL GENERALLY BE SUPPORTIVE OF ORGANIZED STRONG-SEVERE
   MULTICELLS AND PERHAPS A FEW SUPERCELLS BY THE AFTERNOON-EVENING. 
   STORM MERGERS/COLD POOL CONSOLIDATION AND A STRENGTHENING LLJ AFTER
   DARK MAY FAVOR UPSCALE GROWTH AND A LINGERING LARGE HAIL/DMGG WIND
   THREAT INTO THE EVENING.  

   ...WRN KS SWD INTO W TX...
   A SHARPENING DRYLINE DURING THE DAY MAY LEAD TO A FEW WIDELY-SPACED
   STORMS INVOF THE DRYLINE AS STRONG HEATING INTO THE 90S NEAR/WEST OF
   THE DRYLINE WEAKEN AND LOCALLY ERODE THE CAP BY LATE AFTERNOON. 
   FORECAST SOUNDINGS ALONG THE DRYLINE SHOW A VERY STEEP LAPSE RATE
   PROFILE WITH DEWPOINTS MIXING INTO THE 50S.  ALTHOUGH EFFECTIVE
   SHEAR VALUES WILL REMAIN MODEST /AOB 30 KT/...A FEW OF THE STRONGER
   STORMS WILL POTENTIALLY BE CAPABLE OF LARGE HAIL/DMGG WINDS BEFORE
   WEAKENING DURING THE EVENING.

   ..SMITH.. 05/25/2013

   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z