618 
FXUS66 KLOX 050605
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA 
1040 PM PDT SUN OCT 4 2015

...AVIATION DISCUSSION UPDATED...

.SYNOPSIS... 

THE SLIGHT CHANCE OF SHOWERS WILL BECOME CONFINED TO THE MOUNTAINS 
AND DESERTS OF LOS ANGELES AND VENTURA COUNTIES MONDAY MORNING 
BEFORE CLEARING OUT BY THE AFTERNOON. HIGH PRESSURE ALOFT WILL  
BUILD INTO THE REGION THIS WEEK...SUPPORTING A WARMING TREND WITH 
WELL ABOVE NORMAL TEMPERATURES AND GUSTY OFFSHORE WINDS POSSIBLE BY 
THE WEEKEND.
 
&& 

.UPDATE...

A TROUGH OF LOW PRESSURE CONTINUES TO LINGER OVER THE REGION. THE 
TROUGH...NOW CENTERED OVER LOS ANGELES COUNTY...IS CONTINUING KEEP A 
MOIST AND UNSTABLE AIR MASS IN PLACE. SHOWERS REMAIN ON RADAR 
IMAGERY THIS EVENING. THE AIR MASS SHOULD START TO GRADUALLY 
STABILIZE AS THE TROUGH MOVES EAST THROUGH MONDAY MORNING. SHOWERS 
WILL BECOME LESS NUMEROUS AND MORE ISOLATED THROUGH MONDAY MORNING.  
A FEW TWEAK WERE TO POP FOR TIMING ISSUES...BUT THE CURRENT POP 
LOOKED AGREEABLE AT THIS TIME. A WARMING TREND WILL START TO TAKE 
SHAPE ON MONDAY AND BECOME MORE PRONOUNCED BY LATE WEEK AS A RIDGE 
OF HIGH PRESSURE NEAR 39N AND 132W BUILD IN OVER THE REGION. AN 
ISOLATED LIGHTNING STRIKE CANNOT BE RULED OUT OVER THE MOUNTAINS AND 
DESERT AND A SLIGHT CHANCE OF THUNDERSTORMS HAS BEEN LEFT IN THE 
PACKAGE FOR NOW.

&&

.PREV DISCUSSION...

LONG TERM...MODELS CONTINUE TO ADVERTISE A STRONG RIDGE AND WEAK TO 
MODERATE OFFSHORE FLOW FOR THE END OF THE WEEK AND PEAKING NEXT 
WEEKEND. BUMPED TEMPS UP A FEW DEGREES AS LOCAL GUIDANCE SUGGESTS 
100+ FOR THE VALLEYS OVER THE WEEKEND AND NEAR 100 FOR INTERIOR 
COASTAL PLAIN. THIS ASSUMES AT LEAST A 3 MB LAX-DAG GRADIENT AND 950 
TEMPS BETWEEN 30 AND 32C. THERE IS SOME UPPER LEVEL SUPPORT FOR 
SANTA ANA WINDS BUT THE PATTERN DOESN'T SEEM TO SUPPORT ADVISORY 
LEVEL WINDS AT THIS TIME. BUT VERY HOT AND DRY WITH SOME OFFSHORE 
BREEZES ARE A GOOD BET AT THIS TIME.

&&

.AVIATION...04/06Z.

AT 05Z AT KLAX... THERE WAS NO INVERSION.

OVERALL... MODERATE CONFIDENCE IN THE 06Z TAFS.  EVENING AND EARLY 
MORNING SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP PRIMARILY 
IN LOS ANGELES COUNTY AS THE LOW PRESSURE CENTER MOVES THROUGH THE 
REGION.  THIS WILL BRING LOCALLY HEAVY RAIN... GUSTY WINDS... AND 
PERIODS OF MVFR CONDITIONS THROUGH AT LEAST 12Z.  AWAY FROM THE 
CONVECTIVE DEVELOPMENT VFR CONDITIONS WILL PREVAIL.
 
KLAX... MODERATE CONFIDENCE IN THE 06Z TAF.  EVENING AND EARLY 
MORNING SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP IN THE AREA 
THROUGH AT LEAST 12Z AS THE LOW PRESSURE CENTER MOVES THROUGH THE 
REGION.  THERE IS A FIFTEEN PERCENT CHANCE THAT THE LOCALLY HEAVY 
RAIN... GUSTY WINDS... AND PERIODS OF MVFR CONDITIONS WILL MOVE 
DIRECTLY OVER KLAX.  OTHERWISE VFR CONDITIONS WILL PREVAIL.
 
KBUR... MODERATE CONFIDENCE IN THE 06Z TAF.  EVENING AND EARLY 
MORNING SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP IN THE AREA 
THROUGH AT LEAST 12Z AS THE LOW PRESSURE CENTER MOVES THROUGH THE 
REGION.  THERE IS A TWENTY FIVE PERCENT CHANCE THAT THE LOCALLY 
HEAVY RAIN... GUSTY WINDS... AND PERIODS OF MVFR CONDITIONS WILL 
MOVE DIRECTLY OVER KBUR.  OTHERWISE VFR CONDITIONS WILL PREVAIL.

&&

.MARINE...04/900 PM. 

SMALL CRAFT ADVISORY CONDITIONS ARE NOT EXPECTED THROUGH WEDNESDAY. 
NORTHWEST WINDS WILL INCREASE THURSDAY AND SMALL CRAFT CONDITIONS 
ARE EXPECTED FROM PIEDRAS BLANCAS TO SAN NICOLAS ISLAND. 

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
NONE.

&&
$$

PUBLIC...HALL/MW 
AVIATION...KJ
MARINE...HALL 
SYNOPSIS...MUNROE

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