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000
FXUS66 KLOX 251126
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
426 AM PDT SAT MAY 25 2013

.SYNOPSIS...

A LOW PRESSURE AREA OVER THE WEST COAST WILL KEEP ONSHORE FLOW
IN PLACE INTO EARLY NEXT WEEK. NIGHT THROUGH MORNING LOW CLOUDS
AND FOG WILL CONTINUE OVER THE COASTS AND VALLEY THROUGH THE
HOLIDAY WEEKEND WITH BREEZY CONDITIONS IN THE MOUNTAINS AND
DESERTS. LIGHT SHOWERS ARE POSSIBLE BETWEEN MONDAY AND TUESDAY AS
A WEAK WEATHER SYSTEM DIPS SOUTH. A COOLING TREND WILL PERSIST
INTO TUESDAY...THEN A WARMUP WILL BEGIN FOR THE MIDDLE OF NEXT
WEEK.

&&

.SHORT TERM (TODAY-MEMORIAL DAY)...

A WEAK MARINE INVERSION IN PLACE OVER THE AREA CONTINUES TO HINDER
MARINE LAYER STRATUS DEVELOPMENT THIS MORNING. THE LATEST
SOUNDINGS FROM KLAX INDICATE A MARINE LAYER DEPTH NEAR 2000
FEET...AND THINNER NORTH OF POINT CONCEPTION. AS THE MORNING
PROGRESSES...THE MARINE LAYER SHOULD BECOME A LITTLE MORE
EXPANSIVE AND FILL IN OVER THE SOUTH COAST BASIN AND THE CENTRAL
COAST AS THE LATEST FOG PRODUCT INDICATES.

A TROUGH OF LOW PRESSURE OVER THE PACIFIC NORTHWEST WILL
STRENGTHEN ONSHORE PRESSURE GRADIENTS OVER THE NEXT COUPLE OF DAYS
AND PERMIT A COOLING TREND TO DEVELOP. A SERIES OF WEAK WEATHER
SYSTEMS MOVING SOUTH WILL ALLOW FOR A MORE DEVELOPED MARINE LAYER
OVER THE NEXT COUPLE OF DAYS...AND THE POSSIBILITY OF NIGHT AND
MORNING DRIZZLE FROM THE MARINE LAYER STRATUS DECK. A VEERING
PROFILE WITH HEIGHT EXISTS IN THE MIXED LAYER TONIGHT AND INTO
SUNDAY...WHICH IS CLOSELY ALIGNED WITH A WEAK VORTICITY MAXIMUM
MOVING OVER THE AREA.

LOW-LEVEL NORTHWEST FLOW STRENGTHENING OVER THE COASTAL WATERS
WILL DEVELOP STRONG WINDS OVER THE ANTELOPE VALLEY...SOUTHERN
SANTA BARBARA COUNTY...AND THROUGH THE INTERSTATE 5 CORRIDOR.
LOCAL ADVISORY LEVEL WIND GUSTS ARE EXPECTED TODAY AND TONIGHT IN
THESE AREAS...BUT PERIODS OF WIDESPREAD GUSTY WINDS SHOULD DEVELOP
BETWEEN SUNDAY AFTERNOON AND SUNDAY NIGHT AND PERSIST INTO
TUESDAY. BLOWING DUST AND SAND WAS ADDED TO THE PACKAGE FOR THE
ANTELOPE VALLEY FOR SUNDAY AND MONDAY.

.LONG TERM (TUESDAY-FRIDAY)...

ANOTHER WEATHER SYSTEM WILL DROP SOUTH ON TUESDAY. WITH MORE
MOISTURE ASSOCIATED WITH THE SYSTEM AND BETTER INSTABILITY...A
CHANCE OF SHOWERS REMAINS FOR AREAS NORTH OF POINT CONCEPTION AND
A SLIGHT CHANCE OF SHOWERS REMAINS FOR MOST AREAS SOUTH OF POINT
CONCEPTION. AMOUNTS WITH SYSTEM WILL BE LIGHT WITH MOST AREAS
RECEIVING A TENTH OF AN INCH OR LESS.

A NORTHERLY SURFACE PRESSURE GRADIENT WILL REMAIN IN PLACE BEHIND
THE SYSTEMS FRONTAL BOUNDARY FOR THE LATTER HALF OF NEXT
WEEK...WHICH SHOULD PERMIT STRONG WINDS TO PERSIST FOR SOUTHERN
SANTA BARBARA COUNTY...AND THROUGH THE INTERSTATE 5 CORRIDOR
THROUGH THURSDAY. HIGH PRESSURE BUILDING IN ALOFT BEHIND THE
WEATHER SYSTEM SHOULD WARM THE AIR MASS FOR LATE NEXT WEEK...BUT
DOWNSLOPE EFFECTS AND COMPRESSIONAL HEATING MAY ENHANCE THE
WARMING TREND FOR THE SOUTH COAST BASIN FOR LATE WEEK.
TEMPERATURES HAVE BEEN WARMED FURTHER MOST COASTAL AND VALLEY
LOCATIONS SOUTH OF POINT CONCEPTION.

&&

.AVIATION...25/1100Z.

OVERALL...MODERATE CONFIDENCE IN 12Z TAF PACKAGE. STRATUS FILLING IN
NICELY ACROSS THE CENTRAL COAST AND THE LAX BASIN. OVERALL..EXPECT
MVFR CIGS TO PREVAIL AT ALL COASTAL/VALLEY TAF SITES EXCEPT FOR KSBA
THIS MORNING. STRATUS SHOULD DISSIPATE PRETTY WELL LATE THIS MORNING
AND EARLY AFTERNOON. FOR TONIGHT...WILL EXPECT A RATHER SIMILAR
STRATUS DEVELOPMENT PATTERN...ALTHOUGH STRATUS MAY TEND TO DEVELOP A
BIT SOONER THAN THIS MORNING.

KLAX...MODERATE CONFIDENCE IN 12Z TAF. THERE IS A 40% CHANCE THAT CIGS
MAY CLIMB TO VFR LEVELS AFTER SUNRISE. TIMING OF STRATUS RETURN
TONIGHT IS LOW CONFIDENCE...AND COULD BE +/- 2 HOURS OF CURRENT 07Z
FORECAST.

KBUR...MODERATE CONFIDENCE IN 12Z TAF. TIMING OF STRATUS RETURN
TONIGHT IS LOW CONFIDENCE...AND COULD BE +/- 2 HOURS OR CURRENT 09Z
FORECAST.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
GALE WATCH (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).

&&

$$

PUBLIC...HALL
AVIATION...RAT
SYNOPSIS...HALL

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