000 FXUS66 KLOX 271346 AFDLOX FXUS66 KLOX 271159 SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA 300 AM PST FRI DEC 27 2002 WEAK AND DIRTY RIDGE WAS CURRENTLY BLDG ACRS THE FCST AREA...AND ALTHOUGH SKIES WERE MOSTLY CLEAR ACRS L.A. AND VTU COUNTIES... PLENTY OF LOW AND MID LVL MSTR WAS CONTG TO STREAM ACRS SLO COUNTY AND MUCH OF SBA COUNTY. ALTHOUGH THIS MSTR MAY BEGIN TO LIFT NWD AND THIN OUT LATER TODAY...WL GO WITH MOSTLY CLOUDY SKIES N OF PT CONCEPTION...WHILE PTLY CLOUDY LOOKS GOOD S OF PT CONCEPTION. AGAIN TODAY...CAN NOT RULE OUT AN ISOLD SHOWER ACRS SLO AND NRN SBA COUNTY...BUT SINCE PRECIP WL BE SO LIGHT...WL USE SPRINKLES INSTEAD OF POPS IN THE ZONES. RISING THICKNESSES AND BOUNDARY LAYER TEMPS WL LEAD TO SEVERAL DEGS OF WARMING TODAY...ESPECIALLY ACRS L.A. AND VTU COUNTIES. A FAIRLY IMPRESSIVE TROUGH WL APCH THE W CST SAT. THIS SYSTEM WL WKN AS IT MOVES INTO CENTRAL CA SAT NIGHT...AND THE BEST DYNAMICS WL REMAIN TO THE N OF THE FCST AREA. HOWEVER...THE ASSOCD FRONTAL BAND WL PROBABLY HOLD TOGETHER SUFFICIENTLY TO BRING RAIN TO THE ENTIRE FCST AREA. MODELS HAVE TRENDED SLOWER WITH THE SYSTEM... WITH RAIN LIKELY TO HOLD OFF UNTIL LATE SAT ACRS SLO COUNTY...AND UNTIL AROUND OR AFTER MIDNIGHT ACROSS THE L.A. BASIN. XPCT A 6 TO 10 HOUR PERIOD OF STEADY RAIN IN AREAS N OF PT CONCEPTION... AND A 3 TO 6 HR PERIOD S OF PT CONCEPTION. RAIN WL TURN TO SHOWERS IN MOST AREAS EARLY SUNDAY MORNING. ANOTHER SHORT WAVE DROPPING SEWD ACRS THE PAC WILL HELP KEEP A TROUGH ACRS THE FCST AREA SUNDAY. THIS COULD KEEP A THREAT OF SHOWERS INTO THE AFTERNOON...ESPECIALLY IN THE MTNS. RAINFALL TOTALS SAT NIGHT AND SUNDAY WL BE ON THE LIGHT SIDE S OF PT CONCEPTION...GENERALLY ONE QUARTER TO ONE HALF INCH...WITH ONE HALF INCH TO ONE INCH POSSIBLE IN AREAS N OF PT CONCEPTION. THICKNESSESS AND FREEZING LVLS LOWER RATHER SHARPLY LATE SAT NIGHT...SO SNOW LVLS WL LIKELY DROP RATHER QUICKLY... POSSIBLY DOWN TO 4500 FEET ON INTERIOR SLOPES BY SUNDAY MORNING. EXACTLY HOW MUCH PRECIP IS LEFT AT THAT TIME IS STILL UNCERTAIN. THIS WILL CONT TO BE MONITORED CLOSELY...SINCE SUNDAY IS A VERY BUSY TRAVEL DAY...AND SNOW COULD AFFECT SOME OF THE MAJOR ROUTES THRU THE MTNS. XPCT DRY WEATHER ACRS THE AREA ON MON AS A WK RIDGE BRIEFLY BUILDS INTO THE FCST AREA. THEN...ANOTHER TROUGH WL APCH THE W CST LATE MONDAY INTO TUE. THE 06Z GFS MODEL WAS VERY DIFFERENT THAN PREVIOUS RUNS... TRENDING CONSIDERABLY WEAKER AND FLATTER WITH THIS SYSTEM. IF IT IS CORRECT...RAIN IS UNLIKELY TO PUSH S OF PT CONCEPTION AND MAY HAVE A TOUGH TIME MAKING IT INTO THE FCST AREA AT ALL. WL LET THE DAY SHIFT SEE FUTURE RUNS RATHER THAN MAKE ANY CHANGES BASED ON THAT ONE RUN. XPCT DRY WEATHER TO FOLLOW FOR NEW YEARS DAY AND THU...WITH A WARMUP LIKELY BY THE END OF THE WEEK. LAX 000. BRUNO. .LOX...NONE.