Area Forecast Discussion
Issued by NWS Los Angeles, CA

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FXUS66 KLOX 280632
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1100 PM PDT WED MAY 27 2015

NEW AVIATION DISCUSSION

.SYNOPSIS...

BUILDING HIGH PRESSURE WILL RESULT IN A WARMING TREND AND A
SHRINKING MARINE LAYER INTO THE WEEKEND. ABOVE NORMAL TEMPERATURES
ARE EXPECTED FOR INLAND AREAS FRIDAY THROUGH SUNDAY. A MOISTURE
STARVED FRONTAL SYSTEM WILL APPROACH THE AREA BY LATE
SUNDAY...BRINGING SLIGHTLY COOLER WEATHER EARLY NEXT WEEK.

&&

.SHORT TERM (TONIGHT-SAT)...GENERALLY QUIET WX ACROSS THE FORECAST
AREA EARLY THIS EVENING. MOSTLY CLEAR SKIES PREVAILED FOR MOST
AREAS...ALTHO THERE WERE PATCHY LOW CLOUDS ALONG THE SBA COUNTY
CENTRAL COAST AND FROM SANTA CATALINA ISLAND TO PALOS VERDES. THE
LOW CLOUDS ARE EXPECTED TO EXPAND ALONG ALL COASTAL AREAS OVERNIGHT
AND MOVE INLAND TO THE ADJACENT VLYS...WITH MOSTLY CLEAR SKIES
ELSEWHERE. GUSTY S TO W WINDS FROM THE L.A. COUNTY MTNS TO THE
ANTELOPE VLY THIS EVENING WILL DIMINISH OVERNIGHT.

AN UPPER LEVEL RIDGE JUST OFF THE CA COAST THIS EVENING IS FORECAST
TO BUILD INTO THE AREA THU THRU FRI...THEN WEAKEN SLIGHTLY BUT
REMAIN OVER SRN CA THRU SAT. THE MAY GRAY PATTERN WILL CONTINUE FOR
MOST COASTAL AREAS INTO SOME OF THE ADJACENT VLYS THRU FRI...WITH
NIGHT AND MORNING LOW CLOUDS AND FOG. THE MARINE INVERSION SHOULD
LOWER DURING THE PERIOD...WITH LOW CLOUDS CONFINED MOSTLY TO THE
COASTAL PLAIN BY FRI NIGHT INTO SAT MORNING. OTHERWISE...MOSTLY
CLEAR SKIES WILL PREVAIL ACROSS THE REGION. BREEZY ONSHORE WINDS CAN
BE EXPECTED EACH AFTERNOON AND EARLY EVENING DURING THE PERIOD...
ALTHO GUSTY WINDS ARE EXPECTED IN THE ANTELOPE VLY. WITH THE UPPER
LEVEL RIDGE LOWERING THE MARINE INVERSION...TEMPS AWAY FROM THE
COAST WILL WARM UP NICELY. HIGHS ARE FORECAST TO BE NEAR NORMAL TO
SLIGHTLY ABOVE NORMAL ON THU...THEN WARM INLAND TO WELL ABOVE NORMAL
FRI AND SAT...WITH HIGHS IN THE LOWER 90S FOR THE WARMEST VLYS.
HIGHS FOR THE IMMEDIATE COAST WILL REMAIN NEAR NORMAL FOR THE MOST
PART.

***FROM PREVIOUS DISCUSSION***

.LONG TERM (SUN-WED)...TEMPS WILL PEAK SATURDAY BEFORE THE RIDGE
WEAKENS AND SHIFTS EAST AS A NEW TROF APPROACHES NRN CA AND THE PAC
NW. MAIN INFLUENCE LOCALLY WILL BE THE USUAL INCREASING MARINE LYR
COVERAGE, SLOWER CLEARING, AND COOLER TEMPS. SOME RECOVERY IN TEMPS
BY AROUND MID WEEK AS WEAK RIDGING DEVELOPS AGAIN.

&&

.AVIATION...

28/0600Z

AT 0544Z THE MARINE LAYER DEPTH AT KLAX WAS AROUND 1600 FT DEEP. THE
TOP OF THE INVERSION WAS NEAR 3400 FEET WITH A TEMPERATURE OF 18
DEGREES CELSIUS.

HIGH CONFIDENCE THAT STRATUS WILL AFFECT ALL COAST AND VLY TAFS BY
14Z. LOWER CONFIDENCE IN EXACT TIMING OF ARRIVAL OF LOW CLOUDS.
NORTH OF POINT CONCEPTION ONLY FAIR CONFIDENCE IN MVFR CIG HGT FCST
WITH A 30 PERCENT CHC OF IFR CIGS. GOOD CONFIDENCE IN IFR FCST NORTH
OF POINT CONCEPTION. FAIR CONFIDENCE IN BURN OFF TIME BUT 30 PERCENT
CHC FCST OF SCT CONDS IS OFF BY +/- ONE HOUR.

KLAX...GOOD CONFIDENCE IN CIGS ARRIVING BY 12Z BUT LOWER CONFIDENCE
IN EXACTLY WHEN. A 30 PERCENT CHC OF A 21Z BURN OFF AND A 20 PERCENT
CHC OF 5SM HZ CONDS AT THE TERMINAL FROM 16Z-23Z.

KBUR...FAIR CONFIDENCE IN TAF. THERE IS A 30 PERCENT CHC OF CIGS
ARRIVING AT 13Z. THERE IS A 30 PERCENT CHANCE THAT CIGS WILL BE
OVC008 WHEN THEY ARRIVE. A 20 PERCENT CHC OF A 19Z TRANSITION TO VFR
CONDS.

&&

.MARINE...

27/830 PM

OUTER WATERS... EXPECT NORTH WINDS GENERALLY 10 TO 20 KNOTS OVER THE
OUTER ZONES...WITH ISOLATED GUSTS TO 25 KNOTS. MODERATE CONFIDENCE
THAT GUSTS WILL REMAIN ISOLATED THIS EVENING THROUGH AROUND
MIDNIGHT. THERE WILL BE A BETTER CHANCE OF SCA CONDITIONS OVER THE
OUTER WATERS THURSDAY AFTERNOON AND EVENING AS NORTHWEST WINDS
INCREASE DUE TO BUILDING HIGH PRESSURE TO THE NORTHWEST.

INNER WATERS...WINDS ARE EXPECTED TO REMAIN WELL BELOW SMALL CRAFT
ADVISORY LEVELS THROUGH SATURDAY...EXCEPT FOR THE WESTERN PORTION OF
THE SANTA BARBARA CHANNEL WHERE GUSTS TO 20 KNOTS ARE EXPECTED THIS
EVENING.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
NONE

&&

$$

PUBLIC...SIRARD/MW
AVIATION...SIRARD
MARINE...SMITH/SIRARD
SYNOPSIS...SUKUP

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