Area Forecast Discussion
Issued by NWS Los Angeles, CA

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000
FXUS66 KLOX 030357
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
855 PM PDT WED SEP 2 2015

.SYNOPSIS...

A LOW WILL CONTINUE THE OVERNIGHT LOW CLOUDS AND FOG AT THE COAST
AND VALLEYS WITH OVERNIGHT TEMPERATURES ABOVE NORMAL. THE CLOUDS
SHOULD RETREAT TO THE COAST BY THE AFTERNOON...AND TEMPERATURES WILL
BE BELOW NORMAL. EARLY NEXT WEEK THE LOW SHOULD WEAKEN FOR FAIR
SKIES AND WARMER CONDITIONS...WITH TEMPERATURES WARMING TO NEAR
NORMAL.

&&

.SHORT TERM (TODAY-SAT)...THE MARINE INVERSION AT KLAX EARLY THIS
EVENING WAS AROUND 1600 FEET DEEP...AND SHOULD DEEPEN OVERNIGHT
THANKS TO A WEAK EDDY DEVELOPING OVER THE SOCAL BIGHT. PATCHY LOW
CLOUDS WERE NOTED ALONG THE VTU COUNTY COAST...WITH MORE LOW CLOUDS
DEVELOPING OVER THE SOCAL BIGHT AND ALSO JUST OFF THE CENTRAL COAST.
THE LOW CLOUDS WILL EXPAND ALONG THE COAST THRU TONIGHT AND MOVE
INLAND TO THE ADJACENT VLYS AND LOWER COASTAL SLOPES LATER TONIGHT.
LOW CLOUDS SHOULD ALSO DEVELOP IN THE SALINAS RIVER VALLEY LATE
TONIGHT. OTHERWISE...MOSTLY CLEAR SKIES CAN BE EXPECTED ACROSS THE
FORECAST AREA THRU THE NIGHT. LINGERING GUSTY S TO W WINDS IN THE
FOOTHILLS...MTNS AND DESERTS THIS EVENING WILL DIMINISH OVERNIGHT.

AN UPPER LEVEL TROF ALONG THE CENTRAL COAST WILL WEAKEN AND MOVE
INLAND OVERNIGHT...WITH BROAD UPPER LEVEL TROFFINESS PERSISTING OVER
THE AREA THRU THU. DEEPER UPPER LEVEL TROFFINESS WILL COME DOWN FROM
THE N AND MOVE OVER SRN CA THU NIGHT AND FRI. THE UPPER TROF WILL
THEN MOVE E FRI NIGHT AND SAT...WITH A BROAD WLY FLOW ALOFT OVER SRN
CA ON SAT.

DRY AND COOLER THAN NORMAL WEATHER OVERALL WILL PREVAIL ACROSS THE
REGION THU THRU SAT. A RELATIVELY DEEP MARINE LAYER WILL KEEP
VARYING AMOUNTS OF NIGHT AND MORNING LOW CLOUDS AND FOG OVER THE
AREA DURING THE PERIOD...WITH SOME COASTAL LOCATIONS POSSIBLY
REMAINING MOSTLY CLOUDY IN THE AFTERNOON. HOWEVER...IT LOOKS LIKE
SOME OFFSHORE SHOW WILL AFFECT SLO/SBA COUNTIES FRI NIGHT INTO SAT
MORNING...WITH LOW CLOUD COVERAGE THERE A BIT LESS EXPECTED AT THAT
TIME. OTHERWISE...MOSTLY CLEAR SKIES WILL PREVAIL ACROSS THE REGION
THRU SAT. BREEZY AFTERNOON AND EVENING ONSHORE WINDS WILL AFFECT
PORTIONS OF THE CENTRAL COAST...AND FOOTHILLS...MTNS AND ANTELOPE
VLY EACH DAY AS WELL.

TEMPS WILL BE SEVERAL DEGREES BELOW NORMAL IN MOST AREAS THU THRU
SAT...EXCEPT NEAR NORMAL FOR THE MOST PART ALONG THE COASTAL PLAIN.

***FROM PREVIOUS DISCUSSION***

.LONG TERM (SUN-WED)...A FEW DEGREES OF ADDITIONAL WARMING SUNDAY
BRINGING TEMPS BACK TO NEAR NORMAL LEVELS BUT THEN LIKELY LEVELING
OFF THROUGH THE EARLY PART OF NEXT WEEK AS HEIGHT RISES CEASE WITH
SOME ADDITIONAL TROUGH ENERGY COMING IN FROM THE NORTH. OVERALL A
PRETTY BLAND WEATHER PATTERN THROUGH THE LABOR DAY WEEKEND. MORE
WARMING LIKELY TOWARDS THE LATTER HALF OF NEXT WEEK AS THE RIDGE
TRIES TO BUILD BACK NORTH AGAIN.

&&

.AVIATION...02/2355Z.

AT 2314Z...THE MARINE INVERSION AT KLAX WAS AROUND 1350 FT DEEP. THE
TOP OF THE INVERSION WAS AROUND 2900 FEET WITH A TEMPERATURE OF 21
DEGREES CELSIUS.

GENERALLY HI CONFIDENCE IN THE 00Z TAFS WITH REGARD TO LOW CLOUD AND
MOSTLY IFR/MVFR DEVELOPMENT TONIGHT AT ALL COASTAL AND VLY AIRFIELDS
WHICH WILL PERSIST INTO LATE THU MORNING TO EARLY THU AFTERNOON.
THERE IS MODERATE CONFIDENCE IN THE TIMING OF THE ONSET OF THE LOW
CLOUDS WHICH COULD BE OFF PLUS/MINUS AN HOUR OR TWO. FOR KWJF AND
KPMD...HI CONFIDENCE IN THE 00Z TAFS WITH VFR CONDITIONS EXPECTED
THRU THU. GUSTY W TO SW WINDS AT THESE AIRFIELDS THIS EVENING WILL
DIMINISH TONIGHT AND INCREASE AGAIN WED AFTERNOON. GUSTY NW WINDS
ARE ALSO EXPECTED AT KSBP AND KSMX THU AFTERNOON.

KLAX...GENERALLY HI CONFIDENCE IN THE 00Z TAF. LOW CLOUDS AND MVFR
CIGS ARE FORECAST TO DEVELOP BY 05Z AND PERSIST THRU 21Z THU WITH
VFR CONDITIONS THRU 03Z BEFORE MVFR CIGS DEVELOP AGAIN THU EVENING.
THE TIMING OF THE ONSET OF THE LOW CLOUDS TONIGHT COULD BE TOO EARLY
BY AN HOUR OR TWO.

KBUR...GENERALLY HI CONFIDENCE IN THE 00Z TAF. LOW CLOUDS AND MVFR
CIGS ARE FORECAST TO DEVELOP BY 07Z AND PERSIST THRU 18Z THU WITH
VFR CONDITIONS THE REST OF THE DAY. THE TIMING OF THE ONSET OF THE
LOW CLOUDS TONIGHT COULD BE OFF PLUS/MINUS AN HOUR OR TWO.

&&

.MARINE...02/800 PM.

LOCALLY MODERATE NORTHWEST WINDS ARE EXPECTED TO PERSIST OVER THE
OUTER WATERS THROUGH THURSDAY...WITH LOCAL GUSTS TO 25 KNOTS DURING
THE AFTERNOON AND EVENING HOURS EACH DAY. THURSDAY NIGHT THE WINDS
WILL INCREASE TO SCA SPEEDS AND ARE LIKELY TO PERSIST THROUGH THE
WEEKEND. SCA GUSTS ARE ALSO LIKELY OVER THE NEAR SHORE WATERS NORTH
OF POINT SAL. MODERATE TO HIGH CONFIDENCE IN THIS FORECAST.
MEANWHILE...STORM FORCE WINDS IN THE SOUTH PACIFIC GENERATED A SWELL
THAT WILL AFFECT THE COASTAL WATERS OF SOUTHWEST CALIFORNIA OVER THE
WEEKEND. SWELL HEIGHTS WILL BE 2 TO 4 FEET WITH INTERVALS NEAR 20
SECONDS. MARINERS SHOULD BE PREPARED FOR LONG PERIOD SWELLS THAT
WILL LIKELY HAVE EXTRA SURGING AND CURRENTS. SHOALING WILL BE LIKELY
IN SHALLOWER WATER AND IN SOME HARBOR ENTRANCES.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
BEACH HAZARD STATEMENT (SEE LAXCFWLOX).

&&

$$

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

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