351 FXUS66 KLOX 171552 AAA AFDLOX SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA 850 AM PDT FRI OCT 17 2014 .SYNOPSIS... A TROUGH WILL MOVE OVER THE REGION THROUGH SATURDAY...BRINGING AN INCREASE IN CLOUDS. LOW CLOUDS AND FOG WILL AFFECT COAST AND VALLEYS THROUGH EARLY NEXT WEEK. TEMPERATURES WILL BE SLIGHTLY COOLER INTO SATURDAY WITH A BRIEF WARM UP ON SUNDAY. ANOTHER TROUGH WILL BRING CLOUDY AND COOLER CONDITIONS TO THE REGION THROUGH TUESDAY. A SIGNIFICANT WARM UP IS EXPECTED BY MID WEEK WITH THE RETURN OF WEAK OFFSHORE WINDS. && .SHORT TERM (TODAY-SUN)... FORECAST LOOKS TO BE IN GOOD SHAPE SO NOT ANTICIPATING ANY MAJOR CHANGES. THE LOW CLOUD FORECAST SEEMS TO HAVE WORKED OUT PRETTY WELL THIS MORNING...WITH MOST OF THE ORGANIZED LOW CLOUDS CONFINED TO LA COUNTY. MARINE LAYER WAS AROUND 4000 FEET DEEP. WATER VAPOR IMAGERY SHOWS A TROUGH OF LOW PRESSURE APPROACHING THE WEST COAST THIS MORNING...WITH MID AN HIGH CLOUDS OUT AHEAD OF IT. SKIES WILL BE PARTLY CLOUDY TODAY AS THIS TROUGH APPROACHES...POSSIBLY MOSTLY CLOUDY AT TIMES...ESPECIALLY NORTH OF PT CONCEPTION. NOT EXPECTING ANY MEASURABLE RAINFALL WITH THIS SYSTEM THROUGH TONIGHT...AS IT NOW APPEARS THE SURFACE FRONT WILL FIZZLE OUT BEFORE REACHING THE CENTRAL COAST. MOST PLACES WILL BE A FEW DEGREES COOLER TODAY DUE TO THE INCREASE AND HIGH CLOUDS AND APPROACHING TROUGH. ***FROM PREVIOUS DISCUSSION*** HIGH TEMPS WILL TREND A DEGREE OR TWO COOLER TODAY WITH SIMILAR TEMPS EXPECTED FOR SATURDAY. LOW CLOUDS SHOULD BE MORE ORGANIZED YET REMAIN FAIRLY DEEP AFFECTING ALL VALLEYS. CLOUDS MIGHT HAVE A TOUGHER TIME SCOURING OUT ALONG THE IMMEDIATE COAST OF LA/VTU/SBA SOUTH COAST SAT MORNING AS THE INVERSION SHOULD BE A BIT STRONGER. FOR SUNDAY...A BRIEF RIDGE AXIS BEHIND THE EXITING TROUGH WILL ALLOW A COUPLE DEGREES OF WARMING BUT NO MAJOR CHANGES OTHERWISE. HIGH TEMPS WILL REMAIN MOSTLY IN THE MID TO UPPER 70S...WITH A COUPLE VALLEY SITES REACHING 80. THERE WILL BE A RETURN OF LOW CLOUDS AND PATCHY FOG TO COAST AND COASTAL VALLEYS. .LONG TERM (MON-THU)... FOR MONDAY...ANOTHER UPPER LEVEL TROUGH WILL DIG SOUTH AND BECOME ELONGATED JUST OFF THE COAST OF SAN FRANCISCO. AT THIS TIME HAVE LEFT SLIGHT CHANCE POPS OUT OF THE NORTHERN PORTION OF SLO COUNTY ON MONDAY...BUT LATER SHIFTS MIGHT NEED TO ADD. OTHERWISE...SKIES WILL BECOME MOSTLY CLOUDY NORTH OF POINT CONCEPTION WITH PARTLY CLOUDY SKIES TO THE SOUTH MON/TUE. BEHIND THE TROUGH A SURFACE HIGH WILL DEVELOP ACROSS THE GREAT BASIN WHICH WILL SET UP WEAK OFFSHORE BY WED MORNING...WITH THE POSSIBILITY OF STRONGER OFFSHORE WINDS THU. THERE WILL BE A NICE WARM UP ACROSS THE COAST AND VALLEYS AS IS TYPICAL WITH OFFSHORE FLOW FOR WED/THU. EXPECT OFFSHORE FLOW AND WARM TEMPS TO CONTINUE INTO FRIDAY. && .AVIATION...17/1200Z... AT 1125Z THE BASE OF THE VERY WEAK MARINE INVERSION AROUND 3100 FEET. THE TOP OF THE INVERSION WAS AROUND 6700 FEET AT 15 C. PATCHY MVFR CIGS ACRS PORTIONS OF L.A. COUNTY AND THE CENTRAL COAST THIS MORNING. OTHERWISE...SOME HIGH CLOUDS ACROSS THE REGION. EXPECT WIDESPREAD MVFR CONDS IN COASTAL AND MOST VALLEY AREAS TONIGHT...WITH LOCAL IFR CONDS ON THE CENTRAL CST. KLAX...LOW TO MODERATE CONFIDENCE IN THE 12Z TAF. THERE IS A 30 TO 40 PERCENT CHANCE OF MVFR CIGS BETWEEN 13Z AND 17Z. BUR...LOW TO MODERATE CONFIDENCE IN THE 12Z TAF. THERE IS A 30 TO 40 PERCENT CHANCE OF MVFR CIGS BETWEEN 13Z AND 17Z. && .MARINE...17/300 AM. NO SCA LEVEL WINDS OR SEAS EXPECTED THROUGH AT LEAST SUNDAY. && .LOX WATCHES/WARNINGS/ADVISORIES... HIGH RIP CURRENT RISK (SEE LAXSRFLOX). && $$ PUBLIC...SUKUP/KAPLAN AVIATION/MARINE...DB WWW.WEATHER.GOV/LOSANGELES