MESOSCALE DISCUSSION 1991
   NWS STORM PREDICTION CENTER NORMAN OK
   0125 PM CDT FRI AUG 13 2004
   
   AREAS AFFECTED...SRN CA...SRN/WRN AZ AND FAR SRN NV
   
   CONCERNING...SEVERE THUNDERSTORM POTENTIAL...HEAVY RAINFALL 
   
   VALID 131825Z - 132130Z
   
   ISOLATED DAMAGING WINDS GUSTS AND MARGINALLY SEVERE HAIL WILL BE
   POSSIBLE WITH THE STRONGEST STORMS OVER THE REGION THROUGH THE
   AFTERNOON. HOWEVER...THE GREATER THREAT WITH THE STORMS SHOULD BE
   HEAVY RAINFALL.
   
   SATELLITE IMAGERY INDICATED SEVERAL WEAK VORT CENTERS MOVING SLOWLY
   ENEWD OVER THE LOWER COLORADO RIVER VALLEY/MOJAVE DESERT. A VERY
   MOIST AIRMASS WAS IN PLACE WITH MID 60S DEWPTS AS FAR NORTH AS
   NEEDLES AND THE COACHELLA VALLEY. REMNANT CONVECTIVE BOUNDARY FROM
   YESTERDAY STORMS WILL CONTINUE TO ORGANIZE CONVECTION ACROSS FAR
   SERN CA INTO FAR SWRN AZ. ADDITIONAL STORMS WILL DEVELOP IN THE
   UPSLOPE FLOW OVER THE MTNS OF SRN CA INTO FAR SRN NV AND WRN AZ. A
   DEEPLY MIXED BOUNDARY LAYER WITH 30-40 DEG TEMPERATURE DEWPT SPREADS
   AT THE SFC WILL SUPPORT STRONG WINDS. IN HIGHER ELEVATIONS WHERE
   LESS MELTING WILL OCCUR...ISOLATED MARGINALLY SEVERE HAIL WILL BE
   POSSIBLE. 
   
   HOWEVER...THE GREATER THREAT APPEARS TO BE HEAVY RAINFALL DUE TO
   HIGH PRECIPITABLE WATER VALUES EVIDENT ON THE 18Z NKX AND DRA
   SOUNDINGS ALONG SLOW STORM MOTIONS OF 10 KTS OR LESS. WEAK WIND
   FIELDS...ALONG WITH FAVORABLE LOW LEVEL SELY UPSLOPE FLOW INTO THE
   LEE SIDE OF THE COASTAL RANGE MTNS OF SRN CA AND SLY FLOW INTO THE
   MTNS OF WRN AZ WILL ALLOW FOR CONVECTIVE TRAINING/BACKBUILDING
   ENHANCING RAINFALL RATES UP TO AND ABOVE 1 INCH/HR GIVEN SLOW STORM
   MOTIONS ANTICIPATED.
   
   ..CROSBIE.. 08/13/2004
   
   
   ATTN...WFO...TWC...FGZ...PSR...VEF...SGX...
   
   32681481 32661646 33611681 34231737 35181677 36031580
   36181468 33521165 32001165 32451334