SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1030 AM PDT SAT SEP 13 2003

MORNING UPDATE RELEASED TO EXPIRE THE DENSE FOG ADVISORY IN ZONES 035 044 AND 045.

FOR THE NEXT 12 HOURS...WEATHER PATTERN NOW SETTLING INTO A TYPICAL NIGHT AND MORNING LOW CLOUDS AND FOG SITUATION WITH SOME CONCERN FOR DENSE FOG. AREAS MOST VULNERABLE TO DENSE FOG THROUGH SUNDAY MORNING INCLUDE THE CENTRAL COAST AND THE LA/VENTURA COUNTY VALLEYS. THE MARINE LAYER IS APPROXIMATELY 2 KFT AT KLAX THIS MORNING...AND ABOUT 1.2 KFT NEAR KVBG. OUTSIDE OF THE MARINE INFLUENCE...INTERIOR VALLEYS...MOUNTAINS AND DESERTS WILL AGAIN RISE INTO THE 80S AND 90S.

250 AM PDT SAT SEP 13 2003

QUIET WEATHER ACROSS THE DISTRICT. MARINE LAYER IS RUNNING AROUND 1000 TO 1500 FEET DEEP ACCORDING TO ACARS AND 00Z SOUNDINGS. DENSE FOG IS BEING REPORTED INTERMITTENTLY AT SOME OF THE CENTRAL COAST  METAR SITES...AND ALSO AN OFF-DUTY NWS EMPLOYEE JUST REPORTED WIDESPREAD DENSE FOG IN THE VENTURA COASTAL VALLEYS. WILL ISSUE DENSE FOG ADVISORY FOR ZONES 44/45 THIS MORNING...AND WILL HAVE TO MONITOR CENTRAL COAST FOR POSSIBLE DFA ISSUANCE AS WELL.

STAGNANT MARINE LAYER PATTERN WILL CONTINUE ACROSS THE DISTRICT THROUGH THE NEXT SEVERAL DAYS. UPPER LEVEL HIGH PRESSURE WILL REMAIN IN OVERALL CONTROL OF THE WX PICTURE...WITH DAY TO DAY VARIATIONS IN TEMPS AND CLOUD COVER CAUSED BY SMALL FLUCTUATIONS IN THE MARINE LAYER AND STRENGTH OF THE ONSHORE FLOW. FAIRLY WARM INLAND TEMPS SHOULD CONTINUE THROUGH THE WEEKEND...BUT THE BEACHES MAY HAVE TROUBLE CLEARING IN THE AFTERNOONS UNDER THE STRONG MARINE INVERSION. MARINE LAYER SHOULD BECOME A BIT MORE WIDESPREAD WITH SLIGHTLY COOLER MAX TEMPS INTO THE VALLEYS MONDAY AS AN UPPER TROF PASSES BY TO THE NORTH AND LOWERS HGTS SLIGHTLY ACROSS SO CAL.