MESOSCALE DISCUSSION 1646
   NWS STORM PREDICTION CENTER NORMAN OK
   0216 PM CDT WED JUL 22 2009
   
   AREAS AFFECTED...PORTIONS OF SERN WY...NERN CO INTO WRN/CNTRL NEB
   AND WRN KS
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 221916Z - 222045Z
   
   THE THREAT FOR ISOLATED SEVERE STORMS CAPABLE OF HAIL AND LOCALLY
   DAMAGING WIND GUSTS WILL INCREASE THIS AFTERNOON INTO EVENING. 
   CONVECTIVE TRENDS ARE BEING MONITORED FOR A POSSIBLE WW.
   
   18Z MESOANALYSIS INDICATES A WEAK PRESSURE GRADIENT OVER THE REGION
   TODAY...THOUGH A WEAK BOUNDARY/CONVERGENCE ZONE HAS BECOME
   BETTER-DEFINED IN VISIBLE SATELLITE AND OBSERVATIONS DATA OVER
   NEB...GENERALLY ALONG A OFK-BBW-SNY LINE.  A SMALL CLUSTER OF TSTMS
   /LIKELY ELEVATED/ HAS PERSISTED ALONG THIS BOUNDARY TODAY OVER WRN
   INTO CNTRL PARTS OF NEB WITH ADDITIONAL DEEPENING CUMULUS OBSERVED
   TO THE W OVER THE SRN NEB PNHDL.  THIS ACTIVITY APPEARS TO BE
   ASSOCIATED WITH SHORT WAVE TROUGH DIGGING SEWD THROUGH WRN/CNTRL NEB
   INTO NRN KS PER WATER VAPOR IMAGERY.
   
   STRONGEST STORMS NEAR EAR AS OF 1850Z ARE LIKELY IN THE PROGRESS OF
   BECOMING SURFACE-BASED.  HOWEVER...ACTIVITY WILL CONTINUE TO
   MOVE/DEVELOP SEWD INTO LOW-LEVEL RIDGE AXIS WHERE BOUNDARY LAYER
   BECOMES PROGRESSIVELY MORE STABLE WITH SWD EXTENT.  HOWEVER...ANY
   STORMS THAT CAN DEVELOP ALONG BOUNDARY OVER THE NEB PNHDL INTO SWRN
   NEB WILL MOVE SWD/SEWD INTO A RELATIVELY HIGH THETA-E AIR MASS IN
   PLACE OVER ERN CO/WRN KS WHERE MLCAPE MAY APPROACH 1000-1500 J/KG
   LATER THIS AFTERNOON.  MOREOVER...ABOVE-MENTIONED SHORT WAVE TROUGH
   IS BEING ACCOMPANIED BY A BELT OF MODEST /30-35 KT/ NWLY FLOW IN THE
   MIDLEVELS...RESULTING IN 35-40 KT OF EFFECTIVE BULK SHEAR.
   THUS...SETUP WILL BE FAVORABLE FOR ORGANIZED/ROTATING STORMS CAPABLE
   OF HAIL/HIGH WINDS GIVEN SURFACE-BASED STORM INITIATION AND
   SUSTENANCE.
   
   FARTHER W OVER THE LARAMIE RANGE SWD ALONG THE CO FRONT
   RANGE...CUMULUS IS GRADUALLY DEEPENING AS BOUNDARY LAYER WARMS
   THROUGH THE 70S.  AIR MASS IS DRIER ALONG THE CHEYENNE RIDGE...BUT
   DEWPOINTS ARE LINGERING IN THE MID/UPPER 50S N OF THE PALMER DIVIDE.
   AREA PROFILERS INDICATE THAT VERTICAL SHEAR TENDS TO DECREASE WITH
   SWD EXTENT WITH THE GREATEST THREAT FOR A FEW ORGANIZED...SEVERE
   STORMS LIKELY REMAINING CONFINED TO N OF PUB.
   
   FINALLY...CUMULUS IS ALSO DEEPENING ALONG WEAK TROUGH/CONVERGENCE
   ZONE /ORIENTED N-S/ ALONG THE CO/KS BORDER.  SHOULD STORMS
   DEVELOP...THE COMBINATION OF MODEST CONVECTIVE INSTABILITY AND
   VERTICAL SHEAR INDICATE SOME THREAT FOR ISOLATED SEVERE STORMS.
   
   ..MEAD.. 07/22/2009
   
   
   ATTN...WFO...GID...LBF...DDC...GLD...PUB...BOU...CYS...
   
   LAT...LON   39410588 40930644 41870657 42330641 42160607 41690486
               41260428 41070349 41190237 41859994 41749922 40719881
               40299951 38620105 37420140 37420238 39490257 40090358
               40090419 39730449 39320471 38950518 38900573 39410588