Area Forecast Discussion
Issued by NWS Los Angeles, CA

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FXUS66 KLOX 010709
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1205 AM PDT FRI AUG 1 2014

.SYNOPSIS...
AN UPPER LEVEL HIGH EAST OF THE REGION WILL KEEP TEMPERATURES ABOVE
NORMAL THROUGH THE WEEKEND. NIGHT AND MORNING LOW CLOUDS WILL AFFECT
MUCH OF THE COAST LINE THROUGH THE PERIOD. MONSOONAL MOISTURE WILL
BRING A SLIGHT CHANCE OF THUNDERSTORMS TO THE MOUNTAINS AND DESERTS
ON SUNDAY...OTHERWISE DRY CONDITIONS ARE EXPECTED.

&&

.SHORT TERM (TONIGHT-SUN)...THE MARINE INVERSION REMAINED RATHER
SHALLOW AT LAX THIS EVENING AT AROUND 700 FEET. LOW CLOUDS AND FOG
WERE ALONG THE CENTRAL COAST AND HAVE STARTED TO PUSH INLAND WHICH
SHOULD CONTINUE OVERNIGHT AND INTO THE SANTA YNEZ VALLEY. S OF POINT
CONCEPTION...AN EDDY IS FORECAST TO DEVELOP OVERNIGHT WHICH SHOULD
HELP TO EXPAND LOW CLOUDS TO SOME COASTAL AREAS. OTHERWISE...MOSTLY
CLEAR SKIES WILL PREVAIL ACROSS THE FORECAST AREA THRU TONIGHT.
GUSTY SW WINDS IN THE ANTELOPE VLY WILL DIMINISH OVERNIGHT.

UPPER LEVEL RIDGING WILL PERSIST OVER THE FORECAST AREA THROUGH FRI
NIGHT THEN IT LOOKS LIKE AN INVERTED UPPER LEVEL TROF WILL APPROACH
THE AREA FROM THE SE ON SAT. THIS SYSTEM WILL LINGER OVER SERN CA
THRU SUN. THE UPPER LEVEL SYSTEM WILL BRING A SURGE OF MONSOONAL
MOISTURE INTO SWRN CA ESPECIALLY SAT NIGHT AND SUN. THE 00Z NAM
FORECASTS EXTENSIVE 600 MB MOISTURE OVER L.A. COUNTY INTO PORTIONS
OF VTU COUNTY SAT NIGHT AND SUN. THERE DOES APPEAR TO BE A REMOTE
CHANCE OF AN AFTERNOON THUNDERSTORM IN THE VTU/L.A. COUNTY MTNS AND
ANTELOPE VLY ON SAT...GENERALLY 10 PERCENT OR LESS. A SLIGHT CHANCE
OF THUNDERSTORMS IS EXPECTED FOR THESE AREAS SUN AFTERNOON AND
EVENING. THE FORECAST WILL BE A BIT TRICKY ON SUN DEPENDING ON WHERE
THE UPPER TROF SETS UP AND HOW MUCH SUNSHINE THE AREA RECEIVES. IF
THE NAM IS CORRECT...THERE MAY BE ENOUGH CLOUD COVER ON SUN TO
INHIBIT CONVECTION. THERE IS ALSO THE POSSIBILITY THAT SHOWERS AND
ANY HIGH-BASED THUNDERSTORMS COULD DRIFT TO THE COAST AND VLYS ON
SUN. FOR NOW WILL NOT CHANGE THE FORECAST FOR SUN FOR THE COAST AND
VLYS PENDING ADDITIONAL MODEL RUNS. SOME MARINE LAYER CLOUDS CAN BE
EXPECTED NIGHT AND MORNING HOURS FOR THE CENTRAL COAST AND MAINLY
L.A. COUNTY COAST...OTHERWISE MOSTLY CLEAR SKIES SHOULD PREVAIL THRU
SAT THEN BECOME PARTLY CLOUDY SAT NIGHT AND SUN...ALTHO AS MENTIONED
ABOVE THERE COULD BE MOSTLY CLOUDY SKIES FOR THE EASTERN PORTIONS OF
THE FORECAST AREA ON SUN. TEMPS ARE FORECAST TO REMAIN SEVERAL
DEGREES ABOVE NORMAL FOR MANY AREAS THRU SUN ALTHO HIGHS WILL COOL
OFF A COUPLE OF DEGREES EACH DAY.

***FROM PREVIOUS DISCUSSION***

.LONG TERM (MON-THU)...IF SUNDAY ENDS UP BEING ACTIVE THEN IT`S
LIKELY THAT MONDAY WILL HAVE SOME THUNDERSTORMS OVER THE MTNS AND
DESERTS, THOUGH MOISTURE IS DEFINITELY ON THE DECREASE BY THAT TIME.
KEEPING IT DRY FOR NOW. OTHERWISE, NOT MUCH CHANGE IN
HEIGHTS/THICKNESSES THROUGH WED WITH A WEAK TROF LINGERING JUST OFF
THE COAST. BY THU THE TROF IS EXPECTED TO PUSH INLAND LEADING TO A
FEW DEGREES OF COOLING MOST AREAS.

&&

.AVIATION...01/0620Z...
N OF POINT CONCEPTION...MODERATE CONFIDENCE WITH LIFR CONDS ALONG
CENTRAL COAST 00Z TAFS. 30 PERCENT CHANCE THAT LIFR CIGS COULD REACH
KPRB BY 11Z THIS MORNING. 30 PERCENT CHANCE FOR CIGS TO SCOUR OUT
+/- 1 HOURS FROM TAF. SIMILAR TIMING FOR STRATUS ONCE AGAIN FRI
NIGHT WITH SIMILAR CIGS.

S OF POINT CONCEPTION...LOW CONFIDENCE WITH COASTAL TAFS. EXPECT LOW
MVFR TAFS FOR LA COASTAL TAFS I.E. KLAX/KLGB...WITH IFR CONDS FOR
KOXR/KCMA/KSBA. 30 PERCENT CHANCE THAT CIGS WILL BE INCONSISTENT IN
RESPECT TO CLEARING PERIODICALLY ALONG COASTAL AREAS THROUGH THE
OVERNIGHT HOURS. LESS CONFIDENCE WITH STRATUS FOR TONIGHT ALTHOUGH
MODELS INDICATE A DEEPER MARINE LAYER INFLUENCE WITH LOW MVFR CIGS
AFTER MIDNIGHT. HOWEVER...INCREASING  MID TO HIGH CLOUDS EXPECTED
ACROSS THE SOUTHERN PORTION OF THE REGION MIGHT CAUSE LOW CLOUD
REGIME TO BECOME CHAOTIC FRIDAY NIGHT INTO SAT MORNING.

KLAX...LOW TO MODERATE CONFIDENCE IN THE 06Z TAF...HI IFR TO LOW
MVFR CIGS WILL DEVELOP BETWEEN 08Z-10Z...AND SCOUR OUT BETWEEN
15Z-17Z TODAY. LOWER CONFIDENCE WITH RETURN TIMING OF MVFR STRATUS.
HIGH CLOUDS WILL BEGIN TO MOVE ACROSS THE AREA BY EARLY SAT MORNING.

KBUR...HI CONFIDENCE IN THE 06Z TAF WITH VFR CONDITIONS EXPECTED
THRU THROUGH THIS EVE. 20 PERCENT CHANCE FOR LIFR/IFR CIGS BETWEEN
12Z-15Z TODAY. MODERATE CONFIDENCE THAT JUST MID TO HIGH LEVEL
CLOUDS WILL AFFECT THE TERMINAL. 20 PERCENT FOR IFR CIGS AFTER 10Z
SAT MORNING.

&&

.MARINE...31/830 PM PDT...
LOCAL GUSTS TO 25 KT ARE EXPECTED OVER PZZ655 THROUGH LATE THIS
EVENING...OTHERWISE SMALL CRAFT ADVISORY CONDITIONS ARE NO LONGER
EXPECTED IN THAT PORTION OF THE WATERS. GUSTY NW WINDS WILL PERSIST
OVER THE SOUTHERN OUTER WATERS THROUGH LATE TONIGHT. LITTLE CHANGE
IS EXPECTED IN THE FORECAST THROUGH THE WEEKEND...WITH NW WINDS
INCREASING OVER THE OUTER WATERS EACH AFTERNOON TO EVENING PERIOD
THROUGH SUNDAY. THE STRONGEST WINDS WILL BE OVER PZZ673-676...WITH
SOMEWHAT LIGHTER SPEEDS OVER PZZ670. MAINLY LIGHT TO LOCALLY
MODERATE WINDS ARE ALSO EXPECTED FOR ALL NEARSHORE WATERS THROUGH
THE PERIOD.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).

&&
$$

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

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