FXUS66 KLOX 192310

AFDLOX



SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
300 PM PST SAT FEB 19 2005

...VERY HEAVY RAIN EXPECTED LATE SUNDAY AND EARLY MONDAY...

.SHORT TERM...THE UPPER LEVEL STORM OFF THE WEST COAST THAT HAS PRODUCED SO MUCH RAIN OVER SOUTHERN CALIFORNIA THE LAST FEW DAYS IS STILL WITH US. IT IS CURRENTLY LOCATED 375 NM NW OF SAN FRANCISCO. SOUTH AND EAST OF THIS STORM...AN UPPER LEVEL TROUGH IS MOVING NORTHWARD THROUGH CENTRAL CALIFORNIA. IT WAS THIS TROUGH THAT PRODUCED MUCH OF THE HEAVIEST RAINS LAST NIGHT AND THIS MORNING. IN THE WAKE OF THIS TROUGH...SHOWERS AND SOME THUNDERSTORMS ARE CURRENTLY SCATTERED OVER THE MOUNTAINS...COASTAL SLOPES AND NEAR COASTAL WATERS. WITH THE LOW LEVEL FLOW TO REMAIN SOUTHERLY... LOOK FOR SHOWERS OR PERIODS OF MAINLY LIGHT RAIN TONIGHT AND SUNDAY.

IN THE NEXT 24 HOURS...THE STORM OFF THE COAST OF NORTHERN CALIFORNIA WILL BE REPLACED BY A NEW SYSTEM THAT IS CURRENTLY LOCATED ABOUT 850 NM WSW OF SAN FRANCISCO. BY THIS TIME TOMORROW...

THIS SECOND SYSTEM WILL BE LOCATED 600 NM SOUTHWEST OF SAN FRANCISCO...TAKING A BEAD ON SOUTHERN CALIFORNIA. IT WILL BE THIS SYSTEM THAT BRINGS IN THE SUBSTANTIAL RAIN EVENT NOW EXPECTED LATE SUNDAY INTO MONDAY.

BY SUNDAY EVENING...THE SURFACE LOW ASSOCIATED WITH THE SECOND STORM SYSTEM MOVES TO AROUND 300 NM OF POINT CONCEPTION. EVEN AT THAT DISTANCE...THE LEADING BANDS OF STRONG SOUTHERLY WINDS AND HEAVY RAINS WILL BEGIN MOVING ONSHORE OVER THE CENTRAL COAST OF SAN LUIS OBISPO AND SANTA BARBARA COUNTY. THE LOW WILL LINGER OFF THE COAST FROM SUNDAY NIGHT THROUGH TUESDAY...PRODUCING A SERIES OF BANDS OF VERY HEAVY RAIN AND THUNDERSTORMS...WITH INTERVALS OF LIGHT RAIN AND LESSER SHOWERS. DUE TO THE DURATION AND STRENGTH OF THE EVENT...VERY HEAVY RAIN IS EXPECTED WITH THIS SYSTEM...WITH THE HEAVIEST RAINS WE HAVE SEEN SINCE EARLY JANUARY LIKELY TO HIT LATE SUNDAY THROUGH NOON ON MONDAY. 24 HOUR RAINFALL AMOUNTS FROM LATE SUNDAY THROUGH LATE MONDAY WILL RUN 1 TO 3 INCHES COASTAL...3 TO 6 INCHES IN THE MOUNTAINS...WITH LOCALLY HIGHER AMOUNTS...AND RAIN STILL IN THE FORECAST THROUGH TUESDAY. IN ADDITON...LOOK FOR SOME THUNDERSTORMS WITH HIGHER INTENSITY RAINFALL AMOUNTS SUNDAY NIGHT AND MONDAY. WITH THE GROUNDS ALREADY SATURATED AND WITH NUMEROUS REPORTS OF FLOODING AND MUDSLIDES ALREADY COMING IN FROM JUST ABOUT EVERYWHERE...STILL...WE NEED TO BE PREPARED FOR EVEN WORSE FLOODING ONDITIONS THAN THESE FROM LATE SUNDAY THROUGH EARLY TUESDAY.

RIVER LEVELS ARE LOWERING THIS AFTERNOON AFTER THE HEAVY RAINS FROM THIS MORNING...BUT THE HEAVY RAINS EXPECTED SUNDAY AND MONDAY COULD RESULT IN RIVER FLOODING PROBLEMS ON MONDAY AND TUESDAY.

SNOW LEVELS WILL REMAIN MOSTLY ABOVE 5000 FEET THROUGH THE PERIOD...WITH EXPECTED SNOW ACCUMULATIONS MEASURED IN FEET ABOV 6000 FEET. THEREFORE...A WINTER WEATHER WARNING IS IN EFFECT THROUGH TUESDAY.

HIGH WINDS OF 25 TO 35 MPH WITH GUSTS TO ABOVE 50 MPH ARE EXPECTED...ALONG WITH SOME DENSE FOG. PEOPLE TRAVELING IN THE MOUNTAINS THIS WEEKEND ARE ADVISED TO KEEP ABREAST OF THE LATEST WINTER WEATHER CONDITIONS THROUGH THE EXTENDED WEEKEND.

EXTENDED...MEDIUM RANGE MODEL AGREEMENT LOOKS PRETTY GOOD THROUGH THE WEEK. ALL MODELS CALL FOR THE UPPER LEVEL LOW TO MOVE THROUGH SOUTHERN CALIFORNIA ON TUESDAY...AND EXIT SLOWLY ON WEDNESDAY. BY THURSDAY...A WEAK RIDGE IS EXPECTED TO BUILD INTO THE REGION AND LINGER THROUGH UNTIL NEXT WEEKEND. THEREFORE...LOOK FR THE HEAVIER RAINS TO END ON TUESDAY...WITH SHOWERS LINGER OVER MUCH OF THE REGION ON WEDNESDAY...SLOWLY DIMINISHING FROM THE WEST. AT THIS TIME...IT LOOKS LIKE PARTLY CLOUDY SKIES ARE IN THE FORECAST THURSDAY THROUGH THE WEEKEND WITH NO RAIN IN THE FORECAST...YET.



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.LOX WATCHES/WARNINGS/ADVISORIES...

FLOOD WATCH (SEE LAXFFALOX).

WINTER STORM WARNING (SEE LAXWSWLOX).

MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

SMALL CRAFT ADVISORY (SEE LAXCWFLOX).



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DANIELSON