FXUS66 KSGX 092047
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
230 PM PDT SAT MAY 9 2009
.SYNOPSIS...A SHALLOW MARINE LAYER AND ONSHORE FLOW WILL CAUSE 
COASTAL LOW CLOUDS AND FOG DURING THE NIGHTS AND MORNINGS... 
EXTENDING LOCALLY INLAND. TEMPERATURES WILL REMAIN NEAR SEASONAL 
AVERAGES.
&&
.DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO... 
ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES.
ONSHORE FLOW AND THE MARINE LAYER CONTINUE TO DOMINATE OUR WEATHER. 
LOW CLOUDS AND FOG WERE SLOW TO CLEAR THIS MORNING DUE TO A SLIGHTLY 
DEEPER MARINE LAYER AND A STRONG EDDY. WIDESPREAD CLEARING TO NEAR 
THE COAST EVENTUALLY OCCURRED DESPITE THE LONGER BURN OFF TIME. SOME 
PARTIAL CLEARING IS OCCURRING AT THE BEACHES EARLY THIS AFTERNOON AS 
THE EDDY CIRCULATION HELPS TO PULL THE STRATUS OFFSHORE...HOWEVER 
THIS CLEARING WILL BE SHORT LIVED AS ONSHORE FLOW INCREASES AND 
EXERTS A STRONGER PULL THAN THE EDDY.
AN INTERMITTENT COASTAL EDDY AND ONSHORE FLOW WILL CAUSE COAST AND 
VALLEY LOW CLOUDS AND FOG DURING THE NIGHTS AND MORNINGS. LITTLE 
CHANGE IN TEMPS NEAR THE COAST...BUT SLIGHTLY COOLER INLAND AS UPPER 
LEVEL HIGH PRESSURE SLOWLY WEAKENS THROUGH AT LEAST THE BEGINNING OF 
NEXT WEEK. ONSHORE FLOW WILL CAUSE LOCALLY BREEZY CONDITIONS IN THE 
MOUNTAINS AND DESERTS DURING THE AFTERNOONS AND EVENINGS.
LONG RANGE MODELS INDICATE THAT HIGH PRESSURE WILL SLOWLY REBUILD 
ALOFT AS WEAK UPPER LEVEL LOW PRESSURE DEVELOPS TO OUR SOUTH. BOTH 
MODELS HAVE EVEN BEEN HINTING AT THE POSSIBILITY OF SOUTHEAST FLOW 
BRINGING AN INCREASE IN MID LEVEL MOISTURE TO THE AREA. THIS SEEMS A 
BIT TOO EARLY GIVEN THE TIME OF THE YEAR. SO FOR NOW...WILL GO WITH 
A PERSISTENCE FORECAST OF LOW CLOUDS AND FOG WEST OF THE MOUNTAINS 
WITH SLIGHTLY WARMER TEMPS.
&&
.AVIATION...
092030Z...COASTAL CLOUDS WILL STICK TO THE COAST AND BEGIN TO SPREAD 
INLAND IN SPOTS LATE THIS AFTERNOON AND EARLY EVENING. COASTAL 
AIRPORTS WILL BE UNDER CEILINGS BETWEEN 00-03Z. BASES AND VISBY WILL 
BE SIMILAR TONIGHT AS THEY WERE THIS MORNING...AROUND 800 FEET ASL 
AND AROUND 3-5SM. THE COASTAL EDDY AND STRONG INVERSION WILL 
CONTINUE SUNDAY AND SCATTER OUT TIMES WILL BE ABOUT THE SAME AS THEY 
WERE TODAY. CLEARING AT THE COAST WILL BE ONLY PARTIAL AGAIN.  
ABOVE AND BEYOND THE MARINE LAYER...A MOSTLY CLEAR SKY WITH 
UNRESTRICTED VISIBILITIES WILL CONTINUE THROUGH SUNDAY.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...NONE
&&
$$
PUBLIC...SCV
AVIATION...MM