MESOSCALE DISCUSSION 0722
   NWS STORM PREDICTION CENTER NORMAN OK
   0930 PM CDT WED MAY 26 2010
   
   AREAS AFFECTED...SERN MT...NERN WY AND WRN SD
   
   CONCERNING...TORNADO WATCH 224...
   
   VALID 270230Z - 270330Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 224 CONTINUES.
   
   THROUGH 05-06Z...EXPECT THAT THE PRIMARY SEVERE WEATHER THREAT AREA
   WILL BECOME CONFINED TO SERN MT PORTION OF WW AREA.
   
   SYNTHESIS OF LATEST MESOANALYSIS AND 00Z PLAN VIEW UPPER-AIR DATA
   INDICATE THE PRESENCE OF A DEEPER BAROCLINIC ZONE IN PLACE ACROSS
   SRN MT INTO FAR NWRN SD...TO THE NE OF A SURFACE LOW NEAR OR N OF
   WRL.  IR SATELLITE AND LIGHTNING TRENDS SHOW TSTMS INCREASING IN
   COVERAGE ALONG AND TO THE N OF THIS BOUNDARY /NW OF 4BQ/ WHERE
   LOW-LEVEL ASCENT IS BEING ENHANCED BY A STRENGTHENING 30-40
   KT...SELY LLJ.
   
   WHILE THE AIR MASS IS NOT PARTICULARLY MOIST /PW VALUES OF .8 INCH
   OR LESS/...THE PRESENCE OF STEEP LAPSE RATES AND STRONG LOW-LEVEL
   ASCENT SHOULD CONTINUE TO FOSTER AN INCREASING NUMBER OF TSTMS OVER
   ERN MT IN THE 03-06Z TIME FRAME.  BOUNDARY LAYER COOLING AND A
   RESULTANT INCREASE IN CONVECTIVE INHIBITION SUGGEST A DECREASING
   THREAT FOR TORNADOES.  NONETHELESS...SEVERE HAIL WILL STILL REMAIN
   POSSIBLE WITH THE STRONGEST STORMS.
   
   FARTHER S INTO NERN WY AND WRN SD...COMPARATIVELY WEAKER FORCING FOR
   ASCENT AND THE MARGINAL CONVECTIVE INSTABILITY /REF. 00Z RAP
   SOUNDING/ SHOULD RESULT IN A GRADUAL DECREASE IN TSTM ACTIVITY AND
   ASSOCIATED SEVERE WEATHER THREAT THROUGH 06Z.
   
   ..MEAD.. 05/27/2010
   
   
   ATTN...WFO...UNR...BYZ...
   
   LAT...LON   43730563 44720595 44840711 45460811 46160807 46540679
               46350463 45650386 44570283 44120271 43620284 43520359
               43730563