MESOSCALE DISCUSSION 1118
   NWS STORM PREDICTION CENTER NORMAN OK
   0810 PM CDT MON JUN 06 2011
   
   AREAS AFFECTED...SD/FAR EASTERN WY/FAR NORTHERN NEB
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 433...
   
   VALID 070110Z - 070245Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 433
   CONTINUES.
   
   SEVERE TSTM WATCH 433 CONTINUES UNTIL 05Z...WITH CONTINUED POTENTIAL
   FOR ISOLATED BOUTS OF SEVERE HAIL/DAMAGING WINDS.
   
   TWO ISOLATED CLUSTERS OF STRONG/SEVERE TSTMS ARE ONGOING ALONG EARLY
   THIS EVENING ALONG I-90...ONE NEAR THE CHAMBERLAIN AREA AND THE
   OTHER NEAR RAPID CITY AS OF 0100Z. THE 00Z RAPID CITY OBSERVED RAOB
   REFLECTS THE RELATIVELY HOT/STEEP LAPSE RATE ENVIRONMENT THAT THESE
   STORMS DEVELOPED WITHIN ON THE SOUTHERN PERIPHERY OF STRONG
   WESTERLIES ALOFT. WHILE THE BOUNDARY LAYER WILL DECOUPLE AFTER DARK
   WITH CORRESPONDING ABATING OF LOW LEVEL LAPSE RATES...IT IS POSSIBLE
   THAT AN INCREASING SOUTHERLY LOW LEVEL JET THIS EVENING AND
   ASSOCIATED WARM ADVECTION...COUPLED WITH A GRAZING INFLUENCE OF A
   NORTHERN ROCKIES POTENT UPPER TROUGH...MAY SUSTAIN A NORTHEASTWARD
   EXPANSION/UPSCALE GROWTH AND/OR NEW DEVELOPMENT ACROSS SD THIS
   EVENING WITHIN A HIGHER MOISTURE CONTENT/INCREASINGLY SHEARED
   ENVIRONMENT /REFERENCE THE 00Z ABERDEEN OBSERVED RAOB/.
   
   ..GUYER.. 06/07/2011
   
   
   ATTN...WFO...FSD...ABR...LBF...UNR...CYS...
   
   LAT...LON   44370421 44850318 44919833 44009752 42989843 42810251
               43130417 44370421