MESOSCALE DISCUSSION 1029
   NWS STORM PREDICTION CENTER NORMAN OK
   0140 PM CDT MON MAY 30 2011
   
   AREAS AFFECTED...CENTRAL NEB/EASTERN SD INTO SOUTHEAST ND/WESTERN MN
   
   CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 
   
   VALID 301840Z - 302015Z
   
   SEVERE/TORNADO THREAT IS EXPECTED TO INCREASE THROUGH LATE
   AFTERNOON/EARLY EVENING...PERHAPS INITIALLY ACROSS
   WEST-CENTRAL/NORTH-CENTRAL NEB INTO SOUTHEAST SD. ONE OR MORE
   TORNADO WATCHES WILL BE NEEDED BY MID AFTERNOON /LIKELY BY 20Z/.
   
   18Z SUBJECTIVE SURFACE ANALYSIS REFLECTS A 996 MB SURFACE LOW ACROSS
   EASTERN SD BETWEEN HURON AND ABERDEEN...WITH A COLD FRONT EXTENDING
   SOUTHWESTWARD FROM THE LOW INTO WESTERN NEB NEAR/WEST OF NORTH
   PLATTE...WITH EARLY AFTERNOON VISIBLE SATELLITE IMAGERY REFLECTING
   AN INCREASING SURFACE BASED CU FIELD NEAR/JUST EAST OF THE COLD
   FRONT /ESPECIALLY ACROSS NEB/. WITH STRONGER DPVA/IMPLIED ASCENT NOW
   BEGINNING TO OVERSPREAD THE NORTH-CENTRAL HIGH PLAINS...AN INCREASE
   IN DEEP CONVECTION IS EXPECTED IN VICINITY OF THE FRONTAL ZONE BY
   MID/LATE AFTERNOON...WITH AN ASSORTMENT OF NUMERICAL GUIDANCE
   /INCLUDING EXPERIMENTAL HRRR/ INDICATIVE OF DEEP CONVECTION AS EARLY
   AS 20-21Z.
   
   AFOREMENTIONED ASCENT COUPLED WITH AMPLE PRE-FRONTAL HEATING AND
   MIDDLE/UPPER 60S F SURFACE DEWPOINTS WILL CONTRIBUTE TO WEAKENING
   CINH AMID MODERATE INSTABILITY. IN CONJUNCTION WITH A
   STRENGTHENING/BUT LARGELY UNIDIRECTIONAL WIND FIELD...INITIAL MODAL
   SUPERCELLS CAPABLE OF SOME TORNADOES/LARGE HAIL ARE LIKELY. STORMS
   SHOULD ULTIMATELY CONGEAL THROUGH EARLY/MID EVENING...WITH MORE OF A
   WIDESPREAD DAMAGING WIND THREAT EVOLVING AS WELL.
   
   ..GUYER.. 05/30/2011
   
   
   ATTN...WFO...MPX...FGF...FSD...OAX...ABR...GID...LBF...
   
   LAT...LON   41320097 42809946 44969838 46039726 45889613 44649596
               43879632 43109680 41709790 41059836 40479916 40630076
               41320097