252 FXUS66 KLOX 040237 AFDLOX SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA 730 PM PDT FRI JUL 3 2009 .SYNOPSIS... STRONG HIGH PRESSURE OVER THE AREA WILL PERSIST THROUGH THE WEEKEND...WITH CONTINUED SEASONABLY WARM TEMPERATURES ACROSS INLAND AREAS. LATE NIGHT AND MORNING LOW CLOUDS AND FOG WILL PERSIST WITH COOLER CONDITIONS ACROSS THE BEACHES. EXPECT A WEAK TROUGH TO BUILD INTO THE AREA BY TUESDAY...WITH A FEW DEGREES OF COOLING POSSIBLE. && .SHORT TERM (TONIGHT-MON)...LATEST SATELLITE IMAGERY INDICATED STRATUS ALREADY WELL POISED ACROSS THE CENTRAL COAST THIS EARLY EVENING...WHILE A PESKY PATCH OF STRATUS WAS AFFECTING KLAX LATE THIS AFTERNOON AND EARLY EVENING HOURS. LOW CLOUDS SHOULD CLEAR OUT AT LAX WITHIN THE NEXT HOUR. OTHERWISE...SKIES SHOULD REMAIN CLEAR FOR THE REMAINDER OF THE EARLY EVENING HOURS ACROSS THE SO CAL BIGHT AND ADJACENT COASTAL AREAS OF LA/VTU COUNTIES AS WELL AS THE SBA SOUTH COAST. HOWEVER...MODELS SUGGEST THAT THE MARINE LAYER WILL REDEVELOP BRINING LOW CLOUDS INTO COASTAL AND POSSIBLY COASTAL VALLEY OF LA/VTU COUNTY OVER THE NEXT FEW HOURS. LATEST AMDAR SOUNDINGS NEAR KLAX INDICATED THE MARINE LAYER NEAR 1200 FT THIS EVENING...VERY SIMILAR TO THE PAST FEW DAYS. HOWEVER...BASED ON LATEST SATELLITE IMAGERY...MODELS SEEM A BIT AGGRESSIVE WITH EARLY ARRIVAL OF LOW CLOUDS ACROSS LA/VTU COASTAL AREAS INCLUDING SBA SOUTH COAST. EXPECT STRATUS TO REDEVELOP IN MOST AREAS AFTER MIDNIGHT...WITH COASTAL VALLEYS RECEIVING SOME LOW CLOUDS AND FOG FOR ONLY A FEW HOURS BEFORE SUNRISE WITH A QUICK BURNOFF SATURDAY MORNING. COASTAL CLOUDS SHOULD BURN TO THE COAST BY LATE MORNING AS WELL. NOT MUCH CHANGE IN THE SYNOPTIC PATTERN OVER THE NEXT FEW DAYS. TEMPS SHOULD REMAIN SIMILAR FOR THE MOST PART ACROSS THE CWA WITH MAYBE A DEGREE OR TWO OF WARMING IF THE MARINE LAYER SHRINKS A FEW HUNDRED FEET AS THE UPPER RIDGE REMAINS IN PLACE THROUGH MONDAY. ALSO WITH SW FLOW ALOFT...NO CHANCE OF THUNDERSTORMS ACROSS THE REGION OVER THE WEEKEND. ...FROM PREVIOUS DISCUSSION... .LONG TERM (TUE-FRI)...MODELS HAVE BEEN ADVERTISING A TROF ALONG THE COAST FOR NEXT WEEK, AND WHILE THIS IS STILL THE CASE, 12Z GFS AND ECMWF WERE BOTH WEAKER WITH IT, ESPECIALLY THE ECMWF, WITH MORE EMPHASIS PLACED ON THE UPPER HIGH OVER SRN AZ/NRN MX. AS A RESULT, MOS GUIDANCE HIGHS FOR NEXT WEEK WERE 3-5 DEGREES WARMER THAN EARLIER RUNS. NUDGED UP HIGHS SLIGHTLY FOR NEXT WEEK, BUT OTHERWISE LEFT THE FORECAST LARGELY UNCHANGED. THE TROF WILL CERTAINLY MAINTAIN A DECENT MARINE LYR PRESENCE AT THE COAST WITH SOME INLAND PUSH EACH NIGHT. DRY WEST/SOUTHWEST FLOW ALOFT WILL KEEP ALL CONVECTION WELL TO THE EAST. OVERALL A VERY DULL FORECAST, BUT VERY PLEASANT CONDITIONS ACROSS OUR AREA. && .AVIATION...04/0100Z. MARINE LAYER NEAR 1200 FT DEEP THIS AFTERNOON. EXPECT MOSTLY VFR CONDITIONS THIS AFTERNOON...EXCEPT PESKY STRATUS AFFECTING KLAX THROUGH 02Z. SOME EARLIER THEN EXPECTED STRATUS NOW MOVING INTO THE CENTRAL COAST. GOOD CONFIDENCE FOR IFR CIGS TO AFFECT KSMX BY 02-04Z AND KSBY A FEW HOURS LATER. MODERATE CONFIDENCE FOR IFR/MVFR CIGS TO AFFECT COASTAL SITES IN LA/VTU/SBA COUNTIES BETWEEN 07-09Z. LOW CONFIDENCE FOR CIGS TO AFFECT KBUR/KVNY OVERNIGHT...IF IT DOES...AFTER 11Z AND SHORT LIVED. SKIES ACROSS COASTAL AREAS SHOULD BURNOFF BY 18Z IN MOST AREAS. KLAX...PATCHY IFR CIGS AFFECTING RUNWAYS THROUGH 02Z...THEN GOOD CONFIDENCE FOR VFR CONDS THROUGH 6Z...THEN GOOD CONFIDENCE FOR IFR/MVFR CIGS BETWEEN 08-09Z TONIGHT AND PERSIST THROUGH 16-18Z THEN BECOME VFR SATURDAY AFTERNOON. KBUR...HIGH CONFIDENCE IN VFR CONDITIONS THROUGH SATURDAY. && .LOX WATCHES/WARNINGS/ADVISORIES... NONE && $$ PUBLIC...KAPLAN/WOFFORD AVIATION...KAPLAN SYNOPSIS...MEIER WWW.WEATHER.GOV/LOSANGELES