MESOSCALE DISCUSSION 1619
   NWS STORM PREDICTION CENTER NORMAN OK
   0905 PM CDT THU JUL 14 2011
   
   AREAS AFFECTED...SERN WY/NERN CO...WRN NEB AND NWRN KS
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 643...
   
   VALID 150205Z - 150300Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 643
   CONTINUES.
   
   UNTIL 03Z...THE GREATEST THREAT FOR SEVERE WEATHER IS EXPECTED
   ACROSS NERN CO...FAR SERN WY AND WRN NEB.  LOCAL WFO TEMPORAL
   EXTENSION OF WW 643 IS POSSIBLE ACROSS NERN CO AND PARTS OF WRN NEB.
   
   REGIONAL RADAR IMAGERY SHOWED AN OUTFLOW BOUNDARY...ATTENDANT TO A
   TSTM NOW MOVING THROUGH SHERIDAN COUNTY NEB...HAD MOVED SEWD/SWD. 
   AT 0145Z...THIS BOUNDARY EXTENDED SSWWD THROUGH GARDEN COUNTY NEB TO
   NEAR SNY INTO WELD COUNTY CO...AND THEN EXTENDED NWWD TO S AND W OF
   CYS.  THE AIR MASS FROM FAR SERN WY AND NERN CO INTO SRN/CENTRAL NEB
   REMAINS MODERATELY TO VERY UNSTABLE. THIS COMBINED WITH EFFECTIVE
   BULK SHEAR OF 30-35 KT CONTINUES TO SUPPORT A LIKELIHOOD FOR
   ORGANIZED STORMS PRODUCING LARGE HAIL AND DAMAGING WIND GUSTS.
   
   WSR-88D VADS INDICATED AN INCREASE IN SLY LOW LEVEL WINDS ACROSS WRN
   KS/WRN NEB WHICH CONFIRMS THE FORECAST FOR THIS EVENING BY THE 18Z
   GFS/NAM AND 12Z ECMWF.  LOW LEVEL WAA INVOF THE NOSE OF THIS JET AND
   MIDLEVEL IMPULSE TRACKING EWD ACROSS NERN CO/WRN NEB SHOULD SUPPORT
   CONTINUED TSTM DEVELOPMENT BEYOND 03Z. SHORT TERM HIGH RESOLUTION
   MODELS /12Z WRF-NMM AND 23Z WRF-HRRR/ SUGGEST THE TSTM COMPLEX OVER
   NERN CO/WRN NEB WILL PERSIST UNTIL 05-06Z.  GIVEN THE AVAILABLE
   INSTABILITY AND SUFFICIENT BULK SHEAR...A LOCAL TEMPORAL EXTENSION
   OF WW 643 MAY BE NEEDED ACROSS MAINLY NERN CO AND PARTS OF WRN NEB.
   
   ..PETERS.. 07/15/2011
   
   
   ATTN...WFO...GID...LBF...GLD...PUB...BOU...CYS...
   
   LAT...LON   38750146 38530359 38540395 38850393 39000364 39980367
               40230399 40540464 41140487 41600428 42030328 42480280
               42960270 42970018 40700020 40650068 39610069 39440130
               38750146