MESOSCALE DISCUSSION 1788
   NWS STORM PREDICTION CENTER NORMAN OK
   0540 PM CDT TUE JUL 27 2004
   
   AREAS AFFECTED...PORTIONS CENTRAL/SERN AZ
   
   CONCERNING...HEAVY RAINFALL...SEVERE THUNDERSTORM WATCH 670...
   
   VALID 272240Z - 280045Z
   
   BROKEN AND NW-SE ORIENTED BAND OF TSTMS SHOULD SHIFT SLOWLY SWD
   ACROSS WW AREA AND INTO LOWER DESERT ELEVATIONS...WITH POTENTIAL FOR
   SEVERE GUSTS AND OCCASIONAL HAIL.  INFLOW LAYER AIR MASS S OF RIM
   CONTAINS FAVORABLE INSTABILITY TO SUPPORT STRONG-SEVERE TSTMS.
   MODIFIED 18Z PHX RAOB IS TWICE AS BUOYANT AS RUC SOUNDING -- 1600
   J/KG MLCAPE COMPARED TO 800 -- BECAUSE OF APPARENT OVERMIXING OF RUC
   MOISTURE PROFILE.  PRIND FORMER IS MORE REPRESENTATIVE OF THAT AIR
   MASS...BUT IN EITHER CASE DEEPLY MIXED BOUNDARY LAGER WILL SUPPORT
   MAINTENANCE OF INTENSE DOWNDRAFTS TO SFC.  SLOW MOVEMENT AND
   TRAIN-ECHO CONFIGURATION OF SOME ACTIVITY -- PARTICULARLY OVER
   YAVAPAI COUNTY WHERE ACTIVITY IS ORIENTED MOST PARALLEL TO DEEP
   LAYER MEAN FLOW VECTOR -- WILL EXACERBATE LOCALIZED HEAVY RAIN
   THREAT...WITH SOME CORES PRODUCING 1-2 INCH/HOUR RATES FOR SHORT
   PERIODS.
   
   ..EDWARDS.. 07/27/2004
   
   
   ATTN...WFO...FGZ...PSR...VEF...EPZ...TWC...
   
   34021189 34411285 34891341 35201353 35291332 35151280
   34551172 34091156 
   
   31980904 33771329 35521329 33740906