Area Forecast Discussion
Issued by NWS Los Angeles, CA

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000 FXUS66 KLOX 202331 AFDLOX SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA 435 PM PDT MON OCT 20 2014 .SYNOPSIS... A TROUGH OF LOW PRESSURE WILL BRING SLIGHTLY COOLER WEATHER TO THE AREA THROUGH TUESDAY. THERE WILL BE SOME LOCALLY GUSTY NORTHWEST WINDS LATE TONIGHT THROUGH TUESDAY NIGHT FOLLOWING THE PASSAGE OF THIS SYSTEM. A WARMING TREND WILL BEGIN ON WEDNESDAY AS WEAK OFFSHORE FLOW DEVELOPS...WITH ABOVE NORMAL TEMPERATURES EXPECTED THROUGH FRIDAY. COOLER WEATHER WILL LIKELY RETURN THIS WEEKEND WITH THE NEXT LOW PRESSURE SYSTEM. && .SHORT TERM (TODAY-WED)...LATEST SATELLITE IMAGES SHOWED A WEAKENING COLD FRONT WITH AN AREA OF CLOUDINESS APPROACHING THE CENTRAL COAST EARLY THIS AFTERNOON. MARINE LAYER CLOUDS THAT COVERED MUCH OF THE COAST AND VLYS THIS MORNING DISSIPATED IN MOST AREAS BY EARLY THIS AFTERNOON. THERE WERE SOME LINGERING CLOUDS ALONG THE VTU COAST AND PARTS OF THE CENTRAL COAST...OTHERWISE MOSTLY SUNNY SKIES WITH SOME HI CLOUDS COVERED THE REGION. GUSTY S TO W WINDS WERE NOTED IN THE L.A. COUNTY MTNS AND ANTELOPE VLY. AN UPPER LEVEL TROF WITH THE SURFACE COLD FRONT WILL APPROACH THE AREA FROM THE W THROUGH LATE TODAY. THE UPPER TROF WILL QUICKLY MOVE INLAND ACROSS MAINLY CENTRAL CA TONIGHT WHILE THE COLD FRONT DISSIPATES OVER SLO/SBA COUNTIES. THIS SYSTEM WILL BRING GUSTY NW WINDS TO THE L.A./VTU MTNS ALONG THE I-5 CORRIDOR TONIGHT AS WELL AS GUSTY NW TO N CANYON WINDS TO THE SBA COUNTY S COAST AND MTNS. IT LOOKS LIKE GUSTS WILL REMAIN JUST BELOW ADVISORY LEVELS EXCEPT SHOULD REACH THESE LEVELS AT TIMES BELOW AND THRU THE PASSES AND CANYONS OF THE SBA S COAST. A WIND ADVISORY HAS BEEN ISSUED FOR THIS AREA FOR THIS EVENING THRU LATE TONIGHT. THE DYING COLD FRONT WILL ALSO BRING MOISTURE TO THE N MTN SLOPES AND INTO THE FAR SERN VLYS OF SLO COUNTY AND THE CUYAMA VLY LATER TONIGHT INTO TUE MORNING...WITH CLOUDINESS AND POSSIBLY A FEW SHOWERS...AND ADDED POPS TO THESE AREAS FOR THAT PERIOD IN THE AFTERNOON ZONES. SOME LOW LEVEL OFFSHORE FLOW IS EXPECTED OVER MUCH OF THE REGION TONIGHT AND TUE MORNING WHICH SHOULD LIMIT MARINE LAYER CLOUDINESS TO THE L.A. COUNTY COAST AND PORTIONS OF THE SAN GABRIEL VLY. OTHERWISE...MOSTLY CLEAR TO PARTLY CLOUDY SKIES SHOULD PREVAIL ACROSS MUCH OF THE REGION THRU TUE. TEMPS ON TUE WILL TURN WARMER ALONG THE COAST AND ADJACENT VLYS TO NEAR NORMAL FOR THE MOST PART...WITH READINGS STILL A FEW DEGREES BELOW NORMAL ELSEWHERE. WEAK UPPER LEVEL RIDGING WHICH SHOULD START TO BUILD INTO SWRN CA ON TUE WILL BUILD FURTHER ACROSS SRN CA TUE NIGHT AND WED. OFFSHORE FLOW...LIKELY BELOW ADVISORY LEVELS...WILL COVER MUCH OF THE FORECAST AREA TUE NIGHT INTO WED MORNING. GUSTY N CANYON WINDS SHOULD ALSO AFFECT THE SBA S COAST AND MTNS AGAIN...BUT REMAIN BELOW ADVISORY LEVELS. THE NAM WAS FORECASTING A LINGERING EDDY OVER THE SRN CA BIGHT INTO WED MORNING WHICH MAY BRING A FEW LOW CLOUDS TO THE SRN L.A. COUNTY COAST. OVERALL... THOUGH...IT LOOKS LIKE MOSTLY CLEAR SKIES WITH NEAR TO SLIGHTLY ABOVE NORMAL TEMPS CAN BE EXPECTED TUE NIGHT AND WED. FLAT UPPER LEVEL RIDGING WILL PERSIST OVER SRN CA WED NIGHT AND THU. IT LOOKS LIKE MORE OFFSHORE FLOW BELOW ADVISORY LEVELS WILL AFFECT THE AREA DURING THE NIGHT AND MORNING HOURS...EXCEPT THE L.A. COUNTY COAST WILL REMAIN UNDER THE INFLUENCE OF A WEAK EDDY WITH LATE NIGHT AND MORNING LOW CLOUDS AND FOG ONCE AGAIN EXPECTED. THE MOSTLY CLEAR SKIES WILL CONTINUE ELSEWHERE WITH TEMPS WARMING A LITTLE MORE TO SEVERAL DEGREES ABOVE NORMAL. .LONG TERM (FRI-MON)...ECMWF/GFS IN PRETTY GOOD AGREEMENT FRI THRU SAT WITH UPPER RIDGE LINGERING FRI THEN AN UPPER TROF APPROACHES THE AREA FROM THE E PAC ON SAT. THE GFS DOES BRING A DISSIPATING COLD FRONT INTO THE CENTRAL COAST ON SAT WITH A FEW SHOWERS POSSIBLE... WHILE THE EC IS NOT AS FAST AND HOLDS OFF TIL LATE SAT AND SAT EVENING. BIGGER DIFFERENCES SHOW UP SAT NIGHT INTO EARLY MON AS THE GFS PASSES THE PROGRESSIVE UPPER TROF QUICKLY E SUN WITH UPPER RIDGE BUILDING BACK IN BY LATE SUN...WHILE EC SLOWS UPPER TROF DOWN AND DEVELOPS AN UPPER LOW OVER CENTRAL CA EARLY SUN WITH A BETTER CHANCE OF RAIN OVER NORTHERN PARTS OF THE FORECAST AREA...THEN MOVES THIS SYSTEM AWAY SUN AFTERNOON THRU MON AS AN UPPER RIDGE BUILDS IN MON. TRENDED MORE TOWARD THE GFS SOLUTION AND TIMING OF DISSIPATING FRONT WITH POSSIBLE SHOWERS OVER PORTIONS OF SLO/SBA COUNTIES SUN. SOME MARINE LAYER CLOUDS MAY AFFECT THE L.A. COUNTY COAST NIGHT AND MORNING HOURS...OTHERWISE CLEAR TO PARTLY CLOUDY SKIES ARE EXPECTED. TEMPS SHOULD COOL SOME BACK TO NEAR NORMAL BY SAT THEN INCREASE TO NEAR NORMAL TO SLIGHTLY ABOVE NORMAL BY MON. && .AVIATION...20/2330Z. THE MARINE LAYER AT KLAX AT 2300Z IS 1600 FEET DEEP AND THE INVERSION TOP IS AT 3000 FEET WITH A TEMPERATURE OF 20 DEGREES C. WEAK COLD FRONT WASHING OUT ACROSS CENTRAL COAST LATE THIS AFTERNOON. AS SYSTEM MOVES THROUGH...MARINE INVERSION WILL LIKELY CONTINUE TO WEAKEN. AS A RESULT...NOT EXPECTING MUCH IN THE WAY OF ORGANIZED LOW CLOUD COVERAGE TONIGHT ACROSS COASTAL/VALLEY TAF LOCATIONS. BEST CHANCE OF ANY CIGS DEVELOPING WOULD BE AT KLAX AND KLGB LATER TONIGHT. KLAX...LOW CONFIDENCE IN THE 00Z TAF. THERE IS A 50 PERCENT CHANCE OF VFR CONDITIONS THROUGH THE NEXT 24 HOURS. KBUR...MODERATE CONFIDENCE IN THE 18Z TAF. THERE IS A 30 PERCENT CHANCE OF IFR CONDITIONS LATE TONIGHT INTO EARLY TUESDAY MORNING. && .MARINE...20/200 PM... MADE NUMEROUS CHANGES TO THE MARINE FORECAST AS PER THE LATEST GUIDANCE. GENERALLY GOOD CONFIDENCE IN THE MORNING FORECAST UNLESS OTHERWISE STATED. THE LATEST GUIDANCE SHOWS A PRETTY GOOD SHOT AT SMALL CRAFT ADVISORIES FOR THE OUTER WATERS LATE THIS AFTERNOON THROUGH TONIGHT. THERE IS FAIR CONFIDENCE IN SMALL CRAFT ADVISORIES FOR THE NEAR SHORE WATERS ON THE CENTRAL COAST AND WESTERN PORTIONS OF THE SANTA BARBARA CHANNEL AS WELL. MADE AREA AND TIMING CHANGES TO THE GALE WATCH FOR TUESDAY SINCE THE GALES ARE NOT LIKELY UNTIL LATE IN THE DAY AND THEY MAY NOT AFFECT THE NORTHERN OUTER WATERS. THERE IS ONLY FAIR CONFIDENCE AT BEST FOR THE GALE WATCH WITH MARINE ZONES 673 AND 676 HAVING THE BEST CHANCE OF SEEING FREQUENT GUSTS TO 35 KNOTS. && .LOX WATCHES/WARNINGS/ADVISORIES... HIGH SURF ADVISORY (SEE LAXCFWLOX). HIGH RIP CURRENT RISK (SEE LAXSRFLOX). SMALL CRAFT ADVISORY AND GALE WATCH (SEE LAXMWWLOX). && $$ PUBLIC...SIRARD AVIATION...GOMBERG MARINE...SWEET SYNOPSIS...SIRARD WWW.WEATHER.GOV/LOSANGELES

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