808 
FXUS66 KLOX 011651
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
945 AM PDT SUN APR 1 2012

.SYNOPSIS...
LOW PRESSURE AND LAST NIGHTS FRONT ARE QUICKLY MOVING OFF TO THE
EAST...LEAVING BEHIND GUSTY NORTHWEST TO NORTH WINDS ALONG WITH 
CLOUDS AND SNOW SHOWERS ON OUR NORTHERN MOUNTAIN SLOPES FOR TODAY. 
HIGH PRESSURE WILL BUILD INTO THE AREA TO START THE UPCOMING WEEK 
WHICH WILL BRING MUCH WARMER AND DRY CONDITIONS MONDAY AND TUESDAY. 
LOW PRESSURE WILL MOVE ACROSS CALIFORNIA FOR THE SECOND HALF OF THE 
WEEK BRINGING COOLER CONDITIONS TO ALL AREAS.
 
&&

.UPDATE...
SATELLITE PICTURES SHOW CONSIDERABLE AMOUNT OF CLOUDS PUSHING UP 
AGAINST NORTHERN SLOPES THIS MORNING. WEBCAMS SHOW LIGHT SNOW 
FALLING THROUGHOUT THE REGION FROM NORTHERN VENTURA COUNTY TO THE 
GRAPEVINE. LOCAL MESO MODEL FORECASTS MEASUREABLE PRECIPITATION 
THROUGH 03Z. CURRENT SNOW ADVISORY RUNS THRU 12 NOON AND WOULD NOT 
BE SURPRISED IF I HAVE TO EXTEND TO 6 PM. OTHERWISE...A BLUSTERY DAY 
ON TAP IN ALL AREAS WITH A STRONG GRADIENT SETTING UP OVER THE 
REGION. WINDS ALREADY UP IN MANY AREAS BUT YET TO SURFACE IN VALLEYS 
FROM VENTURA TO LA. EXPECT THIS TO HAPPEN BEFORE NOON. WINDS OUT IN 
THE ANTELOPE VALLEY ARE ALREADY GUSTING INTO THE 50S SO WARNINGS 
LOOK GOOD. ON THE MARINE SIDE...WINDS AND WAVES SUPPORT CURRENT 
WARNINGS AND ADVISORIES WITH BUOY 28 AND 11 BOTH REPORTING 23 FEET 
AND GUSTS TO 33 KTS. 

.PREV DISCUSSION...
A HUGE PATTERN CHANGE OCCURS MONDAY AND LASTS INTO TUESDAY AS A 
LARGE RIDGE BUILDS IN OVERHEAD AND OFFSHORE FLOW SETS UP AT THE 
SURFACE. LOOK FOR TEMPS TO JUMP TO WELL ABOVE NORMAL WITH MANY 
MAX TEMPS IN THE 80S ACROSS THE VLYS. THERE WILL BE GUSTY CANYON 
WINDS EACH MORNING...RIGHT NOW IT LOOKS BELOW ADVISORY CRITERIA BUT 
IT WILL BE CLOSE.

.LONG TERM (WED-SAT)...
A LARGE LOW PRESSURE SYSTEM BEACH BALLS ITS WAY INTO THE PAC NW 
TUESDAY NIGHT AND WEDNESDAY AND PUSHES THE RIDGE ASIDE AND SETS UP 
COOL CYCLONIC FLOW OVER THE AREA ALONG WITH ONSHORE FLOW. IT DOES 
NOT BRING ANY FRONTS WITH IT SO THERE WILL BE NO RAIN JUST A DEEP 
MARINE LAYER THAT WILL BRING NIGHT THROUGH MORNING LOW CLOUDS AND 
FOG TO THE COASTS AND MOST VLYS WEDNESDAY AND THURSDAY...THERE 
SHOULD BE ENOUGH COLD AIR ADVECTION TO WIPE OUT MOST OF THE LOW 
CLOUDS BY FRIDAY. IT WILL ALSO BRING MAX TEMPS TUMBLING DOWN 15 TO 
20 DEGREES ACROSS MOST AREAS ESP THE VLYS.

BY SATURDAY THE LOW MOVES EASTWARD INTO IDAHO AND ALLOWS A WEAK 
RIDGE TO BUILD INTO SOUTHERN CALIFORNIA THIS WILL REDUCE THE MARINE 
LAYER AND ALLOW FOR SOME WARMING.

&&

.AVIATION...01/1140Z.
LOCAL MVFR CIGS ON THE CENTRAL COAST WILL BREAK UP BY MID 
MORNING...WHILE IFR CONDS IN THE MTNS...PARTICULARLY ON THE INTERIOR 
SLOPES WILL IMPROVE THIS AFTERNOON. OTHERWISE...EXPECT VFR CONDS 
THRU THE PD. STRONG AND GUSTY WEST TO NORTHWEST WINDS WILL AFFECT
MUCH OF THE REGION TODAY INTO TONIGHT. 

KLAX...MODERATE TO HIGH CONFIDENCE IN TAF. THERE IS A 20 PERCENT 
CHANCE THAT WIND GUSTS WILL REACH 40 KNOTS FROM THE WEST OR 
NORTHWEST BETWEEN 18Z THIS MORNING AND 02Z THIS EVENING. THERE IS A 
10 TO 20 PERCENT CHANCE THAT WINDS WILL BE MORE OR A CROSSWIND THAN 
CURRENTLY INDICATED THROUGH THIS EVENING. SOME LLWS IS POSSIBLE. 
THERE IS A 10 TO 20 PERCENT CHANCE THAT WINDS FROM 040-060 WILL 
REACH 10 KNOTS BETWEEN 12Z AND 16Z MON.  

KBUR...MODERATE TO HIGH CONFIDENCE IN TAF. THERE IS A 20 PERCENT 
CHANCE THAT WIND GUSTS WILL REACH 35 KNOTS FROM THE WEST OR 
NORTHWEST BETWEEN 18Z THIS MORNING AND 02Z THIS EVENING...WITH
POSSIBLE LLWS CONCERNS. 

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING (SEE LAXNPWLOX).
WIND ADVISORY (SEE LAXNPWLOX).
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
GALE WARNING (SEE LAXMWWLOX).
HIGH SURF ADVISORY (SEE LAXCFWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).

&&

$$

PUBLIC...TRM
AVIATION...DB
SYNOPSIS...RAT/TRM

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