MESOSCALE DISCUSSION 0945
   NWS STORM PREDICTION CENTER NORMAN OK
   0100 PM CDT THU JUN 04 2009
   
   AREAS AFFECTED...CNTRL/ERN OR
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 041800Z - 042000Z
   
   TRENDS ARE BEING MONITORED FOR AN INCREASING SEVERE THREAT AND THE
   POSSIBILITY OF A WW.
   
   A SIGNIFICANT IMPULSE CONTINUES TO GRADUALLY PIVOT THROUGH THE
   NORTHEASTERN PERIPHERY OF THE CLOSED LOW....NOW CENTERED JUST WEST
   OF THE CALIFORNIA COAST...ACROSS PARTS OF THE GREAT BASIN INTO THE
   SOUTHERN CASCADES.  AS THIS OCCURS...MID-LEVEL COOLING IS
   CONTRIBUTING TO STEEPENING LAPSE RATES AS SURFACE HEATING PROGRESSES
   ACROSS AREAS WEST OF THE SOUTHERN CASCADES AND SOUTH OF THE
   MOUNTAINS OF NORTHEAST OREGON.  LATEST OBJECTIVE ANALYSIS SUGGESTS
   THAT THE DEEPENING MIXED BOUNDARY LAYER IS SUFFICIENTLY MOIST TO
   SUPPORT WEAK TO MODERATE POTENTIAL INSTABILITY...AS 500 MB FLOW
   STRENGTHENS IN EXCESS OF 50 KT...FROM SOUTHEAST TO NORTHWEST ACROSS
   THE REGION.  INHIBITION MAY BECOME SUFFICIENTLY WEAK FOR
   INTENSIFYING CONVECTIVE DEVELOPMENT AS EARLY AS MIDDAY...BEFORE
   PROBABILITY/COVERAGE OF STORMS INCREASES DURING AND SHORTLY AFTER
   THE PEAK HEATING HOURS.  DEEP LAYER SHEAR APPEARS LIKELY TO BECOME
   FAVORABLE...WHERE TERRAIN ALLOWS IN AT LEAST LOCALIZED AREAS...FOR
   ISOLATED SUPERCELLS...ENHANCING THE RISK FOR LARGE HAIL AND LOCALLY
   DAMAGING WIND GUSTS.
   
   ..KERR.. 06/04/2009
   
   
   ATTN...WFO...BOI...PDT...MFR...
   
   LAT...LON   44302163 44912066 45211883 45021746 43441705 42241795
               42191931 42072094 42572159 44302163