Jun 27, 2014 0600 UTC Day 1 Convective Outlook

SPC AC 270548

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1248 AM CDT FRI JUN 27 2014

   VALID 271200Z - 281200Z

   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS MUCH OF THE CNTRL AND
   NRN PLAINS AND A SMALL PART OF THE SRN PLAINS...

   ...SUMMARY...
   SEVERE THUNDERSTORMS ARE EXPECTED ACROSS THE CENTRAL AND NORTHERN
   PLAINS ON FRIDAY. LARGE HAIL AND DAMAGING WIND WILL BE THE MAIN
   THREATS...BUT A COUPLE OF TORNADOES WILL ALSO BE POSSIBLE...MAINLY
   OVER A PORTION OF THE CENTRAL PLAINS.

   ...SYNOPSIS...

   PRIMARY FEATURE OF INTEREST FRIDAY IS AN UPPER TROUGH NOW LOCATED
   FROM THE NRN ROCKIES INTO THE GREAT BASIN. THIS FEATURE WILL MOVE
   EAST AND EMERGE OVER THE CNTRL THROUGH THE NRN HIGH PLAINS FRIDAY
   AFTERNOON AND EVENING. A VORTICITY MAXIMUM LOCATED WITHIN THE BASE
   OF THE TROUGH AND CURRENTLY OVER UT WILL REACH WRN NEB AND WRN KS BY
   LATE AFTERNOON. AT THE SFC A LEE TROUGH/DRYLINE WILL STRETCH FROM
   THE NRN THROUGH SRN HIGH PLAINS. DRYLINE SHOULD SHARPEN ACROSS WRN
   KS INTO THE TX PANHANDLE AS A LEE LOW DEEPENS IN RESPONSE TO THE
   EJECTING SHORTWAVE TROUGH. A WEAK PACIFIC COLD FRONT WILL ADVANCE
   EWD AND MERGE WITH THE LEE TROUGH/DRYLINE ACROSS THE CNTRL AND NRN
   HIGH PLAINS. 

   ...CNTRL PLAINS AREA...

   AN MCS OR TWO MAY STILL BE ONGOING EARLY FRIDAY OVER PORTIONS OF THE
   CNTRL PLAINS. AS EARLY MORNING STORMS SHIFT TOWARD THE MS
   VALLEY...STAGE WILL BE SET FOR THE ATMOSPHERE TO UNDERGO STRONG
   DESTABILIZATION AS STEEP LAPSE RATES ARE ADVECTED ABOVE THE VERY
   MOIST WARM SECTOR BY A BELT OF STRONGER WINDS ALOFT ACCOMPANYING THE
   UPPER TROUGH. MLCAPE SHOULD INCREASE TO 2500-3500 J/KG DURING THE
   AFTERNOON IN AN AXIS FROM WRN KS INTO WRN NEB. STORMS WILL LIKELY
   DEVELOP OVER THE HIGHER TERRAIN OF WY AND NERN CO. OTHER STORMS MAY
   INITIATE WITHIN ZONE OF DEEP MIXING ALONG SHARPENING DRYLINE ACROSS
   WRN KS AS WELL AS FARTHER NORTH ALONG WEAK COLD FRONT. BACKING
   LOW-LEVEL WINDS EAST OF LEE LOW AND STRENGTHENING 500-MB FLOW
   ACCOMPANYING MID-LEVEL JET ROTATING THROUGH UPPER TROUGH BASE WILL
   CONTRIBUTE TO 40+ KT 0-6 KM SHEAR. SUPERCELL MODES MAY OCCUR WITH
   INITIAL STORMS WITH A THREAT FOR VERY LARGE HAIL. A WINDOW WILL
   EXIST FOR A COUPLE OF TORNADOES AS LOW-LEVEL WINDS STRENGTHEN AND
   BACK AND AS STORMS APPROACH AXIS OF STRONG INSTABILITY DURING THE
   EARLY EVENING. WITH WEAK HIGH LEVEL FLOW EXPECTED...STORMS SHOULD
   TREND TOWARD HP AND OUTFLOW DOMINANCE SUGGESTING ANY TORNADOES
   SHOULD BE RELATIVELY BRIEF. ACTIVITY WILL EVENTUALLY CONSOLIDATE
   INTO CLUSTERS/LINES DURING THE EVENING. WHILE CONVECTIVE INHIBITION
   WILL BE STRONGER WITH EWD EXTENT INTO THE CNTRL PLAINS...STORM SCALE
   CONVERGENCE ASSOCIATED WITH INTENSIFYING LLJ INTERACTING WITH COLD
   POOLS SHOULD MAINTAIN ACTIVITY THROUGH THE EVENING ALONG WITH A
   THREAT FOR DAMAGING WIND AND HAIL.  

   ...NRN PLAINS...

   A FEW STORM CLUSTERS WILL BE ONGOING IN THIS REGION...BUT THE
   ATMOSPHERE IS EXPECTED TO BECOME AT LEAST MODERATELY UNSTABLE AS
   EARLY ACTIVITY SHIFTS EWD. ADDITIONAL STORMS WILL LIKELY DEVELOP
   OVER THE HIGHER TERRAIN AND ALONG LEE TROUGH/COLD FRONT AS THE
   BOUNDARY LAYER DESTABILIZES. THE STRONGER WINDS ALOFT ASSOCIATED
   WITH THE APPROACHING UPPER TROUGH WILL REMAIN SOUTH OF THIS REGION
   WITH WEAK TO MODEST VERTICAL SHEAR SUPPORTIVE OF MULTICELLS.
   ISOLATED DAMAGING WIND GUSTS AND HAIL WILL BE THE MAIN THREATS
   THROUGH EARLY EVENING. 

   ...WRN TX...

   THE ATMOSPHERE IS EXPECTED TO BECOME STRONGLY UNSTABLE /2500-3500
   J/KG MLCAPE/ ACROSS WRN TX...BUT WILL ALSO BE CAPPED BY A LAYER OF
   WARM AIR AT EML BASE. ISOLATED STORMS MAY INITIATE ACROSS WRN TX
   ALONG THE SHARPENING DRYLINE AS WELL AS OVER THE MOUNTAINS OF SWRN
   TX DURING THE LATE AFTERNOON. THIS REGION WILL REMAIN ON SRN FRINGE
   OF STRONGER WINDS ALOFT ACCOMPANYING THE PROGRESSIVE UPPER TROUGH.
   INITIAL WEAK VERTICAL SHEAR WILL UNDERGO SOME INCREASE AS THE UPPER
   TROUGH EMERGES OVER PLAINS AND AS THE LLJ STRENGTHENS. ANY STORMS
   THAT DEVELOP WILL BE CAPABLE OF LARGE HAIL AND DAMAGING WIND
   GUSTS...BUT UNCERTAINTY REGARDING STORM COVERAGE PRECLUDES MORE THAN
   5% SEVERE PROBABILITIES AT THIS TIME.  

   ...CAROLINAS...

   NUMEROUS MULTICELL STORMS ARE EXPECTED TO DEVELOP IN VICINITY OF
   STALLED BOUNDARY ACROSS THE CAROLINAS. A FEW OF THESE STORMS MAY
   BECOME CAPABLE OF PRODUCING ISOLATED STRONG WIND GUSTS THROUGH EARLY
   EVENING.