Area Forecast Discussion
Issued by NWS Los Angeles, CA

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000
FXUS66 KLOX 290410
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
910 PM PDT THU AUG 28 2014

.SYNOPSIS...

HIGH PRESSURE WILL CONTINUE THE ABOVE NORMAL TEMPERATURES THROUGH
SATURDAY. GUSTY NORTHWEST WINDS ARE EXPECTED TONIGHT THROUGH
SATURDAY NIGHT FOR THE SANTA BARBARA AREA. INCREASING ONSHORE FLOW
AND A WEAK TROUGH ARE EXPECTED TO BRING A COOLING TREND BY SUNDAY
AND CONTINUE THROUGH NEXT WEEK.

&&

.UPDATE...

HIGH PRESSURE ALOFT REMAINS IN PLACE OVER THE AREA THIS
EVENING...WITH THE RIDGE AXIS SITTING OVER THE OFFSHORE COASTAL
WATERS. IT IS KIND OF A MIXED BAG. THE LATEST MODELS SOLUTIONS
THIS EVENING INDICATE 1000-500 MB THICKNESS VALUES CLIMBING AND
500 MB HEIGHTS RISING...HOWEVER...950 MB TEMPERATURES COOL INTO
FRIDAY. WITH 00Z MODELS INITIALIZING 950 MB TEMPERATURES A DEGREE
CELSIUS TOO COOL AND 03Z 950 MB TEMPERATURES HAVING A COOL
BIAS...THE PACKAGE KEEPS A WARM FORECAST FOR THE AREA DESPITE MOS
GUIDANCE VALUES COOLING THE AIR MASS. THE ONLY WILD CARD WILL BE
MIDDLE AND HIGH LEVEL MOISTURE AND CLOUDINESS FROM MARIE FOR
FRIDAY. A FEW TWEAKS WERE PERFORMED TO THE PACKAGE FOR
TEMPERATURES...WITH MOST CHANGES ADDRESSING THE IMPENDING
SUNDOWNER WINDS EVENTS FOR LATE WEEK.

KSBA-KSMX SURFACE PRESSURE GRADIENTS HAVE TIGHTENED TO -3.5 MB AND
MARGINALLY SIT ON THE THRESHOLD FOR AN ADVISORY FOR SANTA
BARBARA SUNDOWNER WINDS. THE EVENTS ON FRIDAY AND SATURDAY DO
LOOK A TAD STRONGER...WITH THE POTENTIAL FOR FIRE WEATHER
CONDITIONS TO DETERIORATE. MINIMUM TEMPERATURES HAVE BEEN WARMED
SUBSTANTIALLY FOR THE FOOTHILLS OF THE SANTA BARBARA SOUTH COAST
AND MOUNTAINS OF SANTA BARBARA COUNTY FRIDAY NIGHT. LOCAL 4-KM WRF
SOLUTIONS SUGGEST TEMPERATURES STAYING IN THE 80S OVERNIGHT. WHILE
THIS MAY BE SLIGHTLY OVERDONE...TEMPERATURES WILL BE UPDATED TO
BRING THEM AROUND 80 FOR MOST LOCATIONS. WARM EVENINGS SHOULD
EXPECTED AND COMMON ALONG THE SANTA BARBARA SOUTH COAST EACH
NIGHT.

&&

.PREV DISCUSSION...

SHORT TERM...WARM WEATHER TO CONTINUE THROUGH SATURDAY AS HIGH
PRESSURE ALOFT REMAINS ANCHORED OVER SOUTHERN CALIFORNIA. THE HIGH
IS EXPECTED TO WEAKEN FRIDAY INTO SATURDAY AS A WEAK TROF PUSHES
INTO THE PAC NW. THIS SHOULD BRING A LITTLE BIT OF COOLING...MAINLY
TO COASTAL AREAS FRI/SAT (EXCEPT SBA) BUT STILL 3-6 DEGREES ABOVE
NORMAL FOR THE INTERIOR. MARINE LYR CLOUDS EXPECTED TO MAKE A
RETURN TO SRN LA COUNTY AS WELL...PERHAPS AS EARLY AS FRI MORNING
BUT BETTER CHANCE SATURDAY. LOW CLOUDS WILL RETURN TO THE CENTRAL
COAST TONIGHT AND REMAIN THERE THROUGH THE WEEKEND...CLEARING TO
NEAR OR JUST OFF THE BEACHES EACH DAY.

SUNDOWNER WINDS EXPECTED IN THE SBA AREA NEXT FEW EVENINGS, PEAKING
FRI/SAT. TONIGHT LOOKS LIKE A SUB-ADVISORY EVENT WITH ISOLATED WINDS
AROUND 35 MPH FOR WESTERN CANYONS/PASSES. 5-10 MPH STRONGER AND A
LITTLE LATE FRI/SAT AND A LITTLE MORE WIDESPREAD SO A LOW END
ADVISORY LIKELY THEN. THE NW FLOW WILL KEEP TEMPS IN THE SBA AREA
WELL ABOVE NORMAL THE NEXT FEW DAYS WITH HIGHS LOCALLY TOPPING 90.

INCREASING ONSHORE FLOW SUNDAY SHOULD PUSH THE COOLING TREND WELL
INLAND BRINGING HIGHS BACK DOWN CLOSER TO NORMAL LEVELS. MARINE LYR
WILL BE SPREADING FURTHER NORTH INTO VENTURA AND POSSIBLY SERN SBA
COUNTY AS NW FLOW WEAKENS ACROSS SRN SBA COUNTY.

LONG TERM...A WEAK TROF WILL PERSIST ALONG THE WEST COAST MOST OF
NEXT WEEK...THOUGH MODELS...ESPECIALLY THE GFS...HAVE TRENDED
WEAKER WITH THIS FEATURE THE LAST FEW RUNS. IF CURRENT MODELS HOLD
THEN OUR COOLING TREND WILL LIKELY LEVEL OFF SUNDAY OR MONDAY WITH
MINIMAL CHANGES THROUGH AT LEAST WED. FURTHER DEEPENING OF THE
TROF LATER IN THE WEEK WOULD LEAD TO ADDITIONAL COOLING THU/FRI.
DRY SOUTHWEST FLOW ALOFT WILL KEEP MONSOON FLOW WELL EAST ALL OF
NEXT WEEK.

&&

.AVIATION...29/0043Z.

NORTH OF POINT CONCEPTION...VFR CONDITIONS ARE EXPECTED THROUGH AT
LEAST 03Z. THEN...VLIFR TO LIFR CONDITIONS WILL LIKELY DEVELOP
THROUGH 10Z. VFR CONDITIONS WILL REDEVELOP BY 17Z AT THE LATEST.

SOUTH OF POINT CONCEPTION...VFR CONDITIONS ARE EXPECTED THROUGHOUT
THE PERIOD...EXCEPT FOR A CHANCE OF VLIFR TO LIFR CONDITIONS AT
COASTAL TERMINALS BETWEEN 10Z AND 16Z. PERIODS OF MODERATE WIND
SHEAR AND TURBULENCE IS EXPECTED AT KSBA BETWEEN 02Z AND 09Z.

KLAX...VFR CONDITIONS ARE EXPECTED THROUGH AT LEAST 10Z...THEN THERE
IS A 50 PERCENT CHANCE OF VLIFR TO LIFR CONDITIONS BETWEEN 10Z AND
16Z.

KBUR...VFR CONDITIONS ARE EXPECTED THROUGHOUT THE PERIOD.

&&

.MARINE...28/900 PM.

SMALL CRAFT ADVISORY CONDITIONS LIMITED TO THE VICINITY OF THE
NORTHERN CHANNEL ISLANDS WILL LIKELY EXPAND EACH AFTERNOON AND
PERSIST THROUGH THE EVENING HOURS FRIDAY THROUGH SUNDAY. THERE IS
A CHANCE THAT GALE FORCE WIND GUSTS WILL DEVELOP IN THE VICINITY
OF THE NORTHERN CHANNEL ISLAND SATURDAY NIGHT AND SUNDAY. THE
SWELL FROM MARIE WILL CONTINUE TO SUBSIDE THROUGH SATURDAY. A
SMALL SWELL FROM THE SOUTHERN HEMISPHERE IS LIKELY TO ARRIVE
FRIDAY AND PERSIST THROUGH THE PERIOD. OTHERWISE...A LOCALLY
GENERATED NORTHWEST SWELL WILL BUILD TO POSSIBLY TO 10 FEET IN
THE OUTER WATERS SOUTH OF POINT CONCEPTION FRIDAY THROUGH FRIDAY
NIGHT AND PERSIST THROUGH MONDAY.

&&

.BEACHES...28/900 PM.

THE SURF WILL CONTINUE TO SUBSIDE...BUT THE RISK OF STRONG RIP
CURRENTS WILL REMAIN HIGH ALONG ALL EXPOSED SOUTH FACING SHORES
THROUGH FRIDAY. A LOW PRESSURE SYSTEM SOUTHEAST OF NEW ZEALAND
YESTERDAY AND TODAY WITH STORM FORCE WINDS HAD GENERATED SEAS OVER
40 FEET IN AN AREA BETWEEN 200-215 DEGREES RELATIVE TO SOUTHERN
CALIFORNIA. THE SWELLS FROM THE STORM WILL LIKELY BEGIN TO ARRIVE
LATE NEXT WEEK THURSDAY.

&&

.FIRE WEATHER...28/900 PM.

GUSTY SUNDOWNER WINDS ARE EXPECTED TO DEVELOP ACROSS THE PASSES
AND CANYONS OF SOUTHERN SANTA BARBARA COUNTY FROM THE LATE
AFTERNOON THROUGH NIGHTTIME HOURS BEGINNING TONIGHT AND PERSISTING
THROUGH SATURDAY NIGHT. THE STRONGEST EVENT AND THE POTENTIAL FOR
CRITICAL FIRE WEATHER CONDITIONS COULD OCCUR BETWEEN SATURDAY
AFTERNOON AND LATE SATURDAY NIGHT. A MARGINAL EVENT HAS DEVELOPED
TONIGHT...WITH GUSTS TO AROUND 35 MPH MAINLY WEST OF GOLETA.
SINGLE DIGIT HUMIDITIES HAVE DEVELOPED IN THE HIGHER PORTIONS OF
THE FOOTHILLS. WIND EXPOSED LOCATIONS AND FOOTHILLS WILL
GENERALLY SEE HUMIDITIES BETWEEN 10 AND 20 PERCENT RANGE FOR THE
EVENTS ON FRIDAY AND SATURDAY. IN ADDITION...OVERNIGHT LOW
TEMPERATURES IN THE FOOTHILLS WILL LIKELY ONLY COOL TO UPPER 70S
TO LOWER 80S FRIDAY NIGHT AND SATURDAY NIGHT. THE COMBINATION OF
GUSTY SUNDOWNER WINDS AND LOW HUMIDITIES WILL LIKELY BRING BRIEF
PERIODS OF CRITICAL FIRE WEATHER CONDITIONS TO THE SANTA BARBARA
SOUTH COAST AND FOOTHILLS EACH EVENING...HOWEVER...DURATIONS ARE
NOT EXPECTED TO BE LONG ENOUGH TO WARRANT A RED FLAG WARNING AT
THIS TIME.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH SURF ADVISORY (SEE LAXCFWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
BEACH HAZARDS STATEMENT (SEE LAXCFWLOX).


&&

$$

PUBLIC...HALL
AVIATION...HALL
MARINE/BEACHES...HALL
FIRE WEATHER...HALL
SYNOPSIS...B

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