MESOSCALE DISCUSSION 1974
   NWS STORM PREDICTION CENTER NORMAN OK
   1246 PM CDT SUN AUG 14 2011
   
   AREAS AFFECTED...N-CNTRL SD...S-CNTRL ND
   
   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 
   
   VALID 141746Z - 141845Z
   
   A SMALL THREAT FOR MARGINALLY SVR HAIL MAY OCCUR THROUGH
   MID-AFTERNOON. THE MARGINAL/ISOLATED NATURE OF THE THREAT SHOULD
   PRECLUDE THE NEED FOR A WW.
   
   MASS CONVERGENCE AND MOISTURE TRANSPORT INVOF THE NOSE OF A
   SLY/SSWLY LOW-LEVEL JET -- 20-25 KT WITHIN THE 0.5-1.5-KM-AGL LAYER
   PER NORTH PLATTE NEB VWP DATA -- WILL CONTINUE SUPPORTING CLUSTERS
   OF ELEVATED CONVECTION ACROSS N-CNTRL SD AND S-CNTRL ND INTO THE
   MID-AFTERNOON HOURS. MID-LEVEL LAPSE RATES AROUND ONGOING CONVECTION
   ARE RATHER MEAGER TO SUSTAIN VIGOROUS CONVECTION...WITH THE 12Z
   OBSERVED SOUNDING FROM ABERDEEN DEPICTING AN H7-H5 LAPSE RATE OF 6.3
   C/KM. THE EWD ADVECTION OF AN EML FROM THE HIGH PLAINS COULD
   TEMPORARILY INCREASE ELEVATED INSTABILITY AND SUPPORT A BRIEF UPTICK
   IN ONGOING ACTIVITY.  ALSO...MODEST WLY MID-LEVEL FLOW IS SUPPORTING
   A 0-6-KM BULK SHEAR MAGNITUDE OF 37 KT PER ABERDEEN VWP DATA...WHICH
   COULD SUPPORT BRIEF ATTEMPTS AT WEAKLY ORGANIZED CONVECTION. AN
   INSTANCE OR TWO OF MARGINALLY SVR HAIL CANNOT BE RULED OUT.
   HOWEVER...UPSTREAM OBSERVED/RUC FORECAST SOUNDINGS SUGGEST INCREASED
   CAPPING IN ASSOCIATION WITH THE EML TO POTENTIALLY SUPPRESS
   CONVECTION IN THE ABSENCE OF STRONGER DEEP-LAYER FORCING FOR ASCENT.
   
   ..COHEN.. 08/14/2011
   
   
   ATTN...WFO...FGF...ABR...BIS...
   
   LAT...LON   46539902 46439824 45929753 45299759 45169897 45360001
               45780055 46300051 46509990 46539902