MESOSCALE DISCUSSION 0641
   NWS STORM PREDICTION CENTER NORMAN OK
   0255 PM CDT TUE MAY 14 2013
   
   AREAS AFFECTED...NWRN KS NEWD ACROSS PORTIONS OF SRN/CNTRL/ERN
   NEB...FAR SERN SD...AND NWRN IA
   
   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 
   
   VALID 141955Z - 142230Z
   
   PROBABILITY OF WATCH ISSUANCE...5 PERCENT
   
   SUMMARY...ISOLATED HIGH-BASED THUNDERSTORMS MAY PRODUCE DMGG WIND
   GUSTS THROUGH THE AFTERNOON...BUT THE ISSUANCE OF A WW IS NOT
   NEEDED.
   
   DISCUSSION...A THERMAL RIDGE CHARACTERIZED BY SEASONALLY ANOMALOUSLY
   HOT SFC TEMPERATURES -- FROM THE 90S TO AROUND 105F -- LEADS A COLD
   FRONT THAT EXTENDS FROM S-CNTRL MN INTO SWRN NEB. SFC DEWPOINTS HAVE
   MIXED OUT INTO THE MIDDLE 30S TO THE LOWER 40S INVOF THIS AXIS...AND
   MODIFIED 12Z RAOBS INDICATE NEAR-ZERO CINH FOR A MIXED-LAYER PARCEL
   WITH MLCAPE VALUES OF AROUND 250-800 J/KG. DESPITE THE MEAGER
   INSTABILITY...FRONTAL ASCENT ALONG WITH CONVERGENCE ACCOMPANYING A
   WEAK CYCLONIC WIND-SHIFT AXIS ALIGNING WITH THE THERMAL RIDGE HAVE
   SUPPORTED HIGH-BASED CU DEVELOPMENT FROM NWRN KS INTO NWRN IA. THE
   MOST CONCENTRATED AREA OF CONVECTIVE DEVELOPMENT HAS THUS FAR BEEN
   ACROSS NWRN KS...WHERE MESOSCALE ASCENT IS BEING AUGMENTED OVER THE
   PERIPHERY OF A DEEPER DRY SLOT ACROSS CNTRL/SWRN KS.
   
   DEEP CONVECTION ACROSS THE MCD AREA WILL LIKELY BE ISOLATED AND OF A
   PULSE MODE OWING TO WEAK FORCING FOR ASCENT AND WEAK DEEP SHEAR.
   HOWEVER...WITH MODIFIED 12Z RAOBS INDICATING MIXED-LAYER DEPTHS IN
   EXCESS OF 14 KFT IN SOME INSTANCES...DEEP/STRONG SUB-CLOUD
   EVAPORATIVE COOLING WITH DCAPE VALUES OF AROUND 1000-2000 J/KG WILL
   SUPPORT DRY AND HYBRID WET/DRY MICROBURSTS...POTENTIALLY SUPPORTING
   SPORADIC/BRIEF DMGG WIND GUSTS. RELATIVELY STRONGER UPDRAFT MASS
   FLUXES WOULD BE CONFINED TO CNTRL NEB AND POINTS NEWD...WHERE
   SLIGHTLY HIGHER PW EXISTS -- I.E. 0.70-0.85 INCH PER GPS DATA --
   SUPPORTING MODESTLY ENHANCED WATER LOADING AND ENHANCED DOWNDRAFTS.
   STORMS SHOULD WEAKEN DURING THE EARLY EVENING AS NOCTURNAL
   STABILIZATION TAKES PLACE.
   
   ..COHEN/CARBIN.. 05/14/2013
   
   
   ATTN...WFO...DMX...FSD...OAX...GID...LBF...GLD...
   
   LAT...LON   38690162 39200195 40040193 40500114 41199949 41659865
               42659705 43459577 43349459 42489478 41659602 40489796
               39629967 38690162