MESOSCALE DISCUSSION 1580
   NWS STORM PREDICTION CENTER NORMAN OK
   0353 PM CDT MON JUL 11 2011
   
   AREAS AFFECTED...PORTIONS OF ERN ID INTO SWRN MT
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 112053Z - 112230Z
   
   STORMS WILL CONTINUE TO DEVELOP THIS AFTERNOON WITH LARGE HAIL AND
   STRONG WINDS BEING THE PRIMARY THREAT THROUGH THIS EVENING.
   
   WHILE STORMS ARE NOT EXPECTED TO BE PARTICULARLY ORGANIZED THIS
   AFTERNOON...DAYTIME HEATING AND UPSLOPE FLOW IN A MOIST AIR MASS HAS
   LEAD TO SCATTERED THUNDERSTORM DEVELOPMENT THIS AFTERNOON.  A FEW
   STORMS HAVE SHOW RATHER ROBUST UPDRAFTS AS CINH HAS ERODED /PER 20Z
   MESOANALYSIS/ AND MLCAPE VALUE ARE NOW APPROACHING 1000-1500 J/KG.
   STEEP MID LEVEL LAPSE RATES AROUND 7-8 C/KM PER BOI AND TFX 12Z
   SOUNDINGS WITH 500 MB TEMPS AROUND -12 C TO -15 C WILL HELP AID IN
   THE DEVELOPMENT OF SEVERE HAIL. ADDITIONALLY...SFC
   TEMPERATURE-DEWPOINT SPREADS AROUND 30 DEGREES AND LOW LEVEL LAPSE
   RATES NEAR 9 C/KM INDICATED BY LATEST MESOANALYSIS WILL SUPPORT
   STRONG/GUSTY WINDS.
   
   STORMS MAY STRUGGLE TO MAINTAIN STRENGTH FOR LONG PERIODS OF TIME
   WITH NO FOCUS FOR ORGANIZATION OTHER THAN PERHAPS AROUND 30-40 KT
   EFFECTIVE BULK SHEAR. THEREFORE...BRIEF PERIODS OF SEVERE WEATHER
   MAY ACCOMPANY THESE STORMS.
   
   ..LEITMAN.. 07/11/2011
   
   
   ATTN...WFO...BYZ...RIW...TFX...SLC...PIH...MSO...BOI...LKN...
   
   LAT...LON   44611055 44331123 43641165 42761232 42111287 41981348
               41951433 42301514 44051495 44811468 45561413 46081340
               46291266 46461012 46020916 45380899 44970934 44721005
               44611055