Weather Service Report


604 
FXUS66 KSGX 232020
AFDSGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
200 PM PDT THU MAY 23 2013

.SYNOPSIS...
DAYTIME TEMPERATURES WILL REMAIN A LITTLE BELOW SEASONAL AVERAGES 
THROUGH MEMORIAL DAY...WITH AREAS OF NIGHT AND MORNING LOW CLOUDS 
EXTENDING INTO THE INLAND VALLEYS. STRONG ONSHORE FLOW WILL CONTINUE 
FOR GUSTY SOUTHWEST TO WEST WINDS IN THE MOUNTAINS AND DESERTS. 
STRONGER SOUTHWEST TO WEST WINDS WITH INCREASING CLOUDS AND A CHANCE 
FOR RAIN AND SHOWERS NEXT TUESDAY INTO EARLY WEDNESDAY...TAPERING 
OFF LATE WEDNESDAY. GRADUALLY WARMER AND DRY FOR THURSDAY.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

THIS AFTERNOON...SATELLITE IMAGERY SHOWS CLEARING OF THE LOW CLOUDS 
IN MOST AREAS...EXCEPT FOR A FEW PATCHES OVER ORANGE COUNTY AND THE 
INLAND EMPIRE. SFC PRESSURE GRADIENTS REMAIN STRONGLY ONSHORE...WITH 
+9 MB SAN-TPH.

THE LARGE-SCALE LOW/TROUGH OVER THE WESTERN U.S. IS EXPECTED TO 
REMAIN IN PLACE AND DOMINATE OUR WEATHER FOR THE FORESEEABLE FUTURE. 

THROUGH MEMORIAL DAY... A SERIES OF SHORTWAVES PROGRESSING THROUGH 
THE MEAN CYCLONIC FLOW ALOFT WILL CAUSE MINOR DAY-TO-DAY 
VARIATIONS...BUT WE CAN EXPECT GENERALLY COOLER CONDITIONS WITH 
EXTENSIVE NIGHT AND MORNING LOW CLOUDS WEST OF THE MTNS...AS WELL AS 
STRONG ONSHORE PRESSURE GRADIENTS FOR GUSTY SW TO W WINDS IN THE 
MTNS AND DESERTS. THE ONSHORE FLOW WILL PEAK THIS AFTERNOON/TONIGHT 
WITH WIND GUSTS AROUND 45 MPH IN FAVORED LOCATIONS. 

FOR LATE MONDAY THROUGH WEDNESDAY...FOR 2 CYCLES IN A ROW...THE 
GLOBAL DETERMINISTIC MODELS CONTINUE TO INDICATE PRECIP ASSOCIATED 
WITH A VIGOROUS SHORTWAVE MOVING IN FROM THE NW AND FORMING A CLOSED 
LOW OVER CENTRAL/SOUTHERN CALIFORNIA BY MON NIGHT. SOME DIFFERENCES 
IN THE TIMING AND POSITIONING OF THE LOW REMAIN...MAKING THE DETAILS 
SOMEWHAT UNCERTAIN. HOWEVER...IT IS LIKELY THAT WE WILL AT LEAST SEE 
INCREASING CLOUDS AND NOTICEABLY LOWER TEMPS. W TO SW WINDS WILL 
ALSO INCREASE...ESPECIALLY IN THE MTNS AND DESERTS...AND CONFIDENCE 
IS INCREASING THAT SOME PRECIP WILL MATERIALIZE. THIS WILL LIKELY BE 
FOLLOWED BY GRADUAL WARMING AND DRYING WED AND THU.

&&

.AVIATION...
232000Z...COAST/VALLEYS...LOW CLOUDS HAVE CLEARED IN MOST 
AREAS...BUT SCT-BKN CLOUDS WITH BASES 2500-3500FT MSL ARE LINGERING 
IN ORANGE COUNTY AND THE NORTHERN INLAND EMPIRE...AS WELL AS JUST 
OFFSHORE IN SOUTHERN SAN DIEGO COUNTY. EXPECT ANOTHER EARLY RETURN 
OF LOW CLOUDS TO KSAN AND KCRQ THIS EVENING BETWEEN 01-04Z. LOW 
CLOUDS WILL ARRIVE LATE AT KSNA...AROUND 06-10Z...IF AT ALL. THE 
SAME HOLDS FOR KONT...THOUGH CHANCES FOR LOW CLOUDS ARE EVEN SMALLER 
THERE. IN GENERAL...BASES WILL BE AROUND 2500-3000 FT MSL WITH 
PATCHY AND LESS EXTENSIVE COVERAGE TONIGHT. EARLIER CLEARING 
EXPECTED FRIDAY MORNING BETWEEN 15-17Z. 

MTS/DESERTS...MOSTLY CLEAR WITH UNRESTRICTED VIS THROUGH FRIDAY.

&&

.MARINE...
A SHORT PERIOD NORTHWEST SWELL AND AN INCREASE IN NORTHWEST WINDS 
WILL CREATE CHOPPY SEAS AROUND SAN CLEMENTE ISLAND LATE TODAY INTO 
EARLY FRIDAY. ISOLATED CONDITIONS MAY BE HAZARDOUS TO SMALL CRAFT IN 
THAT AREA. THE HIGHEST/LOWEST TIDES OF THE MONTH...WITH SWINGS OF 
8.9 FEET...WILL COMBINE WITH SURF FOR POTENTIAL MINOR COASTAL 
FLOODING FRIDAY THROUGH MEMORIAL DAY. STRONG RIP CURRENTS ARE 
EXPECTED THROUGH THE HOLIDAY WEEKEND.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...WIND ADVISORY FROM 3 PM THIS AFTERNOON TO 3 AM PDT FRIDAY FOR 
     THE COACHELLA VALLEY...RIVERSIDE COUNTY MOUNTAINS...SAN 
     DIEGO COUNTY DESERTS...SAN DIEGO COUNTY MOUNTAINS.

PZ...NONE.

&&

$$

PUBLIC...PG
AVIATION/MARINE...TS



Return to Home page


Western Regional Climate Center, wrcc@dri.edu