Severe Thunderstorm Warning 14, NWS San Diego, CA

EXTREME SOUTHWESTERN CALIFORNIA AREA FORECAST DISCUSSION...CORRECTION
NATIONAL WEATHER SERVICE SAN DIEGO CA
200 PM PDT TUE AUG 29 2000

...CORRECTION TO POPS...

                              ...SYNOPSIS...
ABUNDANT MOISTURE WILL KEEP SOUTHWEST CALIFORNIA MOSTLY CLOUDY
TONIGHT WITH SCATTERED SHOWERS AND A CHANCE OF THUNDERSTORMS IN THE
MOUNTAINS AND DESERTS. SOME OF THE SHOWERS MAYBE HEAVY SO A FLASH
FLOOD WATCH IS IN EFFECT UNTIL 9 PM THIS EVENING FOR THE MOUNTAINS
AND DESERTS. MID LEVEL MOISTURE WILL REMAIN ON WEDNESDAY WITH A
GREATER CHANCE OF AFTERNOON THUNDERSTORMS IN THE MOUNTAINS AND
DESERTS. FOR THURSDAY THROUGH SATURDAY...A TROUGH OF LOW PRESSURE
WILL DEVELOP ALONG THE WEST COAST WITH DRIER AND A LITTLE COOLER
WEATHER IN THE MOUNTAINS AND DESERTS AND  EXTENSIVE NIGHT AND
MORNING COASTAL LOW CLOUDS.

                             ...DISCUSSION...
CHP REPORTED MUD AND ROCK SLIDE HIGHWAY 74 SOUTH AND UPGRADE FROM
PALM DESERT AND ALERT RAIN GAUGES IN AREA REPORTED AN INCH OF RAIN
IN A HALF HOUR. BASED ON THE MOISTURE ALREADY IN PLACE AND THE
LIKELYHOOD AREAS THAT HAVE RECEIVED MODERATE TO HEAVY AMOUNTS OF
PCPN OVER THE PAST SEVERAL DAYS...HAVE GONE AHEAD AND ISSUED A FLASH
FLOOD WATCH FOR THE MOUNTAINS AND DESERTS UNTIL 9 PM TONIGHT LOCAL
TIME. PROBABLY WILL NOT AS MUCH PCPN TO SET OFF FLASH FLOODING.

ETA STILL APPEARS TO BE THE MODEL OF CHOICE SO WILL FOLLOW THE ETA
SOLUTION. ETA BRINGS A S/WV NORTH ACROSS THE CWFA LATE TONIGHT AND
WEDNESDAY MORNING WHICH SHOULD CONTINUE THE SHOWERS AND
THUNDERSTORMS OVER THE MOUNTAINS AND DESERTS THROUGH WEDNESDAY.
BASED ON THE ETA...WITH SOME SUPPORT FROM THE AVN MODEL...IT APPEARS
THE S/WV THAT MOVES THROUGH ON WEDNESDAY SHOULD BE THE LAST AS BOTH
MODELS INDICATE DRYING BEHIND THE S/WV. CUT OFF LOW REMAINS IN PLACE
OFF THE WEST COAST WITH THE LOW WEST OF LOS ANGELES. THE MODELS
STILL INDICATE THE LOW WILL START LIFTING OUT ON THURSDAY BUT MODELS
DO HAVE A TENDENCY TO MOVE CUTOFF LOWS OUT TOO FAST. POSITION OF THE
LOW SHOULD PLACE A SOUTHWEST FLOW ALOFT OVER THE CWFA WEDNESDAY AND
THURSDAY WHICH SHOULD AID IN DRYING.

COASTAL AREAS SHOULD REMAIN IMPACTED BY A FAIRLY DEEP MARINE
LAYER...BETWEEN 3 AND 4 THOUSAND FEET DEEP...SO EXPECT MOSTLY CLOUDY
CONDITIONS SHOULD CONTINUE COASTAL AREAS ON WEDNESDAY. SHOULD HAVE
SOME AFTERNOON CLEARING COASTAL AREAS ON WEDNESDAY.

IN THE LONGER RANGE...MODELS BRING A FAIRLY SIGNIFICANT S/WV TROUGH
THROUGH NORTHERN AND CENTRAL CALIFORNIA ON FRIDAY WHICH SHOULD KEEP
A FAIRLY DEEP MARINE LAYER WEST OF THE MOUNTAINS AND A DRY SOUTHWEST
FLOW ALOFT. THE DEEP MARINE LAYER WILL KEEP TEMPERATURES IN THE
COASTAL AREAS BELOW NORMAL INTO THE WEEKEND WHILE THE SOUTHWEST.

SAN 2000

.SAN...FLASH FLOOD WATCH  (SEE LAXFFASAN).
       MARINE WEATHER STATEMENT FOR MINOR TIDAL OVERFLOW
       (SEE LAXMWSSAN).

HORTON