MESOSCALE DISCUSSION 0856
   NWS STORM PREDICTION CENTER NORMAN OK
   0729 PM CDT FRI MAY 22 2009
   
   AREAS AFFECTED...SERN WY / NEB PNHDL INTO N-CNTRL NEB
   
   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 
   
   VALID 230029Z - 230230Z
   
   THE POTENTIAL FOR MARGINALLY SEVERE HAIL AND LOCALLY EXCESSIVE
   RAINFALL WILL CONTINUE INTO TONIGHT ACROSS DISCUSSION AREA.  A WW
   WILL NOT BE REQUIRED.
   
   SPORADIC TSTM ACTIVITY HAS PERSISTED THIS EVENING ALONG AND AHEAD OF
   SWD-MOVING COLD FRONT FROM NIOBRARA COUNTY SWD INTO PLATTE...GOSHEN
   AND LARAMIE COUNTIES IN E-CNTRL/SERN WY.  ENVIRONMENT IS NOT
   PARTICULARLY UNSTABLE...BUT CONTINUED SELY/ELY LOW-LEVEL FEED OF
   LOWER/MID 50S BOUNDARY LAYER DEWPOINTS BENEATH ERN EXTENSION OF
   EML/STEEP MIDLEVEL LAPSE RATE PLUME SHOULD BE SUFFICIENT TO MAINTAIN
   BRIEFLY STRONG UPDRAFTS CAPABLE OF SOME HAIL.  CURRENT CYS VWP AND
   MEDICINE BOW WY PROFILER INDICATE WEAK WIND FIELDS THROUGH THE LOW
   TO MID-TROPOSPHERE WITH STORM MOTIONS LARGELY GOVERNED BY
   PROPAGATION ALONG PRE-EXISTING OUTFLOW BOUNDARIES.
   
   STORMS MAY TEND TO INCREASE IN COVERAGE THROUGH 03-04Z EWD THROUGH
   THE NEB PNHDL INTO N-CNTRL NEB AS STRENGTHENING LLJ ENHANCES
   CONVERGENCE ALONG SWD-MOVING COLD FRONT.  SOME HAIL WILL BE POSSIBLE
   WITH THE STRONGER CORES...AS WILL LOCALLY HEAVY RAINFALL DUE TO
   TRAINING AND/OR BACKBUILDING TSTM ACTIVITY.
   
   ..MEAD.. 05/23/2009
   
   
   ATTN...WFO...LBF...CYS...
   
   LAT...LON   41770521 42500461 42850317 42930186 42670087 42060060
               41610099 41190311 41140470 41770521