MESOSCALE DISCUSSION 0483
   NWS STORM PREDICTION CENTER NORMAN OK
   0210 PM CDT THU APR 16 2009
   
   AREAS AFFECTED...ERN CO
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 161910Z - 162045Z
   
   SEVERE WEATHER THREAT WILL INCREASE THROUGH EARLY TO MID AFTERNOON
   AS THUNDERSTORM INITIATION TAKES PLACE ACROSS SERN CO DURING THE
   NEXT SEVERAL HOURS...AND THEN SPREADS NWD INTO E CENTRAL CO.
   ADDITIONAL STORMS MAY FORM E OF THE FRONT RANGE. AREA IS BEING
   MONITORED FOR A WW.
   
   18Z SUBJECTIVE SURFACE ANALYSIS SHOWS AN AREA OF LOW PRESSURE
   DEEPENING INVOF OF TAD...WITH A DRYLINE EXTENDING SEWD INTO THE TX
   PANHANDLE...AND A QUASI STATIONARY FRONTAL BOUNDARY LOCATED NWD
   ALONG/JUST E OF THE FRONT RANGE. PERSISTENT UPSLOPE FLOW OVER NERN
   CO IS RESULTING IN A BARRIER JET TYPE FEATURE...WHICH IS ACTING TO
   REINFORCE/STRENGTHEN CONVERGENCE ALONG THE STATIONARY BOUNDARY.
   AIRMASS OVER ERN CO IS CHARACTERIZED BY TEMPERATURES IN THE MID-UPR
   60S OVER SERN PORTIONS OF THE STATE...AND LOW 50S TOWARD THE NORTH
   WHERE CLOUD COVER IS MORE WIDESPREAD. DEEP BOUNDARY LAYER MIXING
   OVER SRN-SERN CO COMBINED WITH INCREASING LARGE SCALE ASCENT WITH
   THE APPROACH OF NM S/W TROUGH WILL RESULT IN SUFFICIENT
   DESTABILIZATION/CAP REMOVAL FOR THUNDERSTORM INITIATION BY MID
   AFTERNOON OVER SRN PORTION OF MCD.
   
   SURFACE DEWPOINTS CURRENTLY RESIDE IN THE LOW-MID 40S...WITH SOME
   ADDITIONAL MOISTENING POSSIBLE AS UPR 40S DEWPOINTS OVER WRN KS
   ATTEMPT TO MOVE W. THIS MOISTURE COMBINED WITH STEEP 700-500 MB
   LAPSE RATES /AOA 7-8 C PER KM/ WILL SUPPORT 500-1500 J/KG OF MLCAPE.
   DEEP LAYER FLOW WILL BE MAINLY UNI-DIRECTIONAL THROUGH MUCH OF THE
   AFTERNOON...BUT WINDS IN THE LOWEST FEW KM/S ARE FORECAST TO
   STRENGTHEN SIGNIFICANTLY IN RESPONSE TO APPROACHING UPR
   DISTURBANCE...LEADING TO SOME ENLARGEMENT IN LOW LVL HODOGRAPH
   STRUCTURE. DEEP LAYER AND LOW LVL SHEAR WILL SUPPORT ORGANIZED
   THUNDERSTORM DEVELOPMENT...INCLUDING BOTH SUPERCELLS AND FAST MOVING
   LINE SEGMENTS. THESE STORMS WILL POSE MAINLY A LARGE HAIL AND
   DAMAGING WIND THREAT...THOUGH STRENGTHENING LOW LVL WINDS DURING THE
   AFTERNOON /AND LOCALIZED BACKING OVER NERN CO...ALONG AND N OF A COS
   TO ITR LINE/ SUGGESTS SOME POTENTIAL FOR ISOLATED TORNADOES.
   
   ..GARNER.. 04/16/2009
   
   
   ATTN...WFO...DDC...GLD...PUB...BOU...
   
   LAT...LON   38830212 38210207 37370204 37060250 37150330 37480377
               38020414 39110456 40270412 40750342 39730254 38830212