000
FXUS66 KLOX 230129
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
515 PM PDT WED MAY 22 2013

...UPDATED AVIATION DISCUSSION...

.SYNOPSIS...

ONSHORE FLOW WILL BRING COOLER TEMPERATURES...BREEZY WINDS...AND A
DEEPER MARINE LAYER TO SOUTHWESTERN CALIFORNIA THROUGH THE WEEKEND.
WINDS WILL BE STRONGEST IN THE MOUNTAINS THROUGH THURSDAY.  A
WARMING TREND WILL BEGIN NEXT WEEK.

&&

.SHORT TERM (TODAY-SAT)...STRONG NORTHWEST WINDS FOR THE NORTHERN
AND WESTERN PORTION OF OUR FORECAST AREA. STRONG (BY EDDY STANDARDS)
SOUTHEAST WINDS FOR SOUTHERN LA COUNTY AND ADJACENT WATERS. THAT`S
THE STORY FOR THE NEXT 18-24 HOURS OR SO. DRIZZLE IS A POSSIBILITY
ACROSS SOUTHEASTERN LA COUNTY LATER TONIGHT AS THOSE EDDY WINDS PUSH
UP AGAINST THE SAN GABRIELS. LOOKS LIKE A PRETTY DECENT SUNDOWNER
TONIGHT WITH WINDS UP TO 50 MPH.

NORTHWEST FLOW EXPECTED TO SLACKEN FRIDAY INTO SATURDAY, ALLOWING
THE MARINE LYR CLOUDS TO START MIGRATING NORTH UP THE COAST. NOT 100
PERCENT CONFIDENT THEY WILL FILL IN ALONG THE CENTRAL COAST BUT WILL
STICK WITH THAT FOR NOW. DAYTIME HIGHS EXPECTED TO DIP A FEW MORE
DEGREES THURSDAY WITH THE TROF AND MARINE LYR DEEPENING. STILL
RELATIVELY WARM ACROSS THE SBA COUNTY SOUTH COAST DUE TO SUBSIDENCE
FROM THE NORTH WINDS OVER THE SANTA YNEZ RANGE.

TROF LIFTS A TAD FRIDAY AND THE EDDY EXPECTED TO WEAKEN AS WELL SO
MOST AREAS SHOULD BE A COUPLE DEGREES WARMER. AGAIN THE OPPOSITE
TREND FOR SBA WITH NORTHERLY WINDS WEAKENING. THEN TURNING COOLER
WITH A DEEPER MARINE LYR SATURDAY AS THE TROF AGAIN DEEPENS ALONG
THE WEST COAST.

.LONG TERM (SUN-WED)...MODELS DIFFERING WITH THE DETAILS ON NEXT
WEEK BUT IMPACTS PRETTY MINIMAL EITHER WAY. MAIN THING TO WATCH FOR
IS THE POSSIBILITY FOR NORTHWEST WINDS INCREASING AGAIN ACROSS THE
WESTERN AND NORTHERN PORTION OF THE FORECAST AREA, POSSIBLY LEADING
TO MORE GALE FORCE WINDS OVER THE OUTER COASTAL WATERS AND GUSTY
SUNDOWNERS AND I5 CORRIDOR WINDS. TEMPERATURE TRENDS ALSO UNCLEAR AS
THE GFS IS TENDING TO SHIFT TOWARDS WEAK RIDGING BY TUESDAY WHILE
THE ECMWF SHOWS ANOTHER TROF COMING IN TUE AND WED.

&&

.AVIATION...22/0115Z...

SATELLITE IMAGERY SHOWS MOSTLY CLEAR SKIES ACROSS MUCH OF THE
FORECAST AREA LATE THIS AFTERNOON...WITH PATCHY LOW CLOUDS MOSTLY
CONFINED FROM COASTAL ORANGE COUNTY SOUTHWARD. THE STRONG NORTHWEST
WINDS ACROSS THE OUTER COASTAL WATERS WILL CONTINUE TO REINFORCE A
WELL DEVELOPED EDDY CIRCULATION OVERNIGHT. AS A RESULT...EXPECTING
WIDESPREAD COVERAGE OF LOW CLOUDS AND FOG TO DEVELOP ACROSS THE
LA BASIN OVERNIGHT...LIKELY SPREADING INTO PORTIONS OF VENTURA
COUNTY LATE TONIGHT AND THURSDAY MORNING. LOWER PROBABILTY OF
CIGS DEVELOPING ACROSS CENTRAL COAST TONIGHT. OTHERWISE GUSTY
WINDS WILL CONTINUE EACH AFTERNOON AND EVENING ACROSS KSMX...KSBP...
KPMD...AND KWJF. ALSO...HIGH CONFIDENCE OF LLWS AND STG UDDFS
AT KSBA TONIGHT.

KLAX...HIGH CONFIDENCE THAT MVFR CIGS WILL DEVELOP TONIGHT. EDDY
CIRCULATION WILL LIKELY BRING LIGHT EASTERLY WINDS TO KLAX BUT
WINDS EXPECTED TO REMAIN LESS THAN 10 KT.

KBUR... HIGH CONFIDENCE OF VFR CONDITIONS THROUGH THIS EVENING...WITH
HIGH CONFIDENCE THAT MVFR CIGS WILL DEVELOP OVERNIGHT. A 20 PERCENT
CHANCE OF BRIEF IFR CONDITIONS.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY (SEE LAXNPWLOX).
GALE WARNING (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH SURF ADVISORY (SEE LAXCFWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).

&&

$$

PUBLIC...MW
AVIATION...GOMBERG/SWEET
SYNOPSIS...KJ

WWW.WEATHER.GOV/LOSANGELES

000
FXUS66 KLOX 222105
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
205 PM PDT WED MAY 22 2013

.SYNOPSIS...

ONSHORE FLOW WILL BRING COOLER TEMPERATURES...BREEZY WINDS...AND A
DEEPER MARINE LAYER TO SOUTHWESTERN CALIFORNIA THROUGH THE WEEKEND.
WINDS WILL BE STRONGEST IN THE MOUNTAINS THROUGH THURSDAY.  A
WARMING TREND WILL BEGIN NEXT WEEK.

&&

.SHORT TERM (TODAY-SAT)...STRONG NORTHWEST WINDS FOR THE NORTHERN
AND WESTERN PORTION OF OUR FORECAST AREA. STRONG (BY EDDY STANDARDS)
SOUTHEAST WINDS FOR SOUTHERN LA COUNTY AND ADJACENT WATERS. THAT`S
THE STORY FOR THE NEXT 18-24 HOURS OR SO. DRIZZLE IS A POSSIBILITY
ACROSS SOUTHEASTERN LA COUNTY LATER TONIGHT AS THOSE EDDY WINDS PUSH
UP AGAINST THE SAN GABRIELS. LOOKS LIKE A PRETTY DECENT SUNDOWNER
TONIGHT WITH WINDS UP TO 50 MPH.

NORTHWEST FLOW EXPECTED TO SLACKEN FRIDAY INTO SATURDAY, ALLOWING
THE MARINE LYR CLOUDS TO START MIGRATING NORTH UP THE COAST. NOT 100
PERCENT CONFIDENT THEY WILL FILL IN ALONG THE CENTRAL COAST BUT WILL
STICK WITH THAT FOR NOW. DAYTIME HIGHS EXPECTED TO DIP A FEW MORE
DEGREES THURSDAY WITH THE TROF AND MARINE LYR DEEPENING. STILL
RELATIVELY WARM ACROSS THE SBA COUNTY SOUTH COAST DUE TO SUBSIDENCE
FROM THE NORTH WINDS OVER THE SANTA YNEZ RANGE.

TROF LIFTS A TAD FRIDAY AND THE EDDY EXPECTED TO WEAKEN AS WELL SO
MOST AREAS SHOULD BE A COUPLE DEGREES WARMER. AGAIN THE OPPOSITE
TREND FOR SBA WITH NORTHERLY WINDS WEAKENING. THEN TURNING COOLER
WITH A DEEPER MARINE LYR SATURDAY AS THE TROF AGAIN DEEPENS ALONG
THE WEST COAST.

.LONG TERM (SUN-WED)...MODELS DIFFERING WITH THE DETAILS ON NEXT
WEEK BUT IMPACTS PRETTY MINIMAL EITHER WAY. MAIN THING TO WATCH FOR
IS THE POSSIBILITY FOR NORTHWEST WINDS INCREASING AGAIN ACROSS THE
WESTERN AND NORTHERN PORTION OF THE FORECAST AREA, POSSIBLY LEADING
TO MORE GALE FORCE WINDS OVER THE OUTER COASTAL WATERS AND GUSTY
SUNDOWNERS AND I5 CORRIDOR WINDS. TEMPERATURE TRENDS ALSO UNCLEAR AS
THE GFS IS TENDING TO SHIFT TOWARDS WEAK RIDGING BY TUESDAY WHILE
THE ECMWF SHOWS ANOTHER TROF COMING IN TUE AND WED.

&&

.AVIATION...22/1800Z...

OVERALL CONFIDENCE IN THE 18Z TAF PACKAGE IS MODERATE. THE LARGE
SCALE WEATHER PATTERN WILL NOT CHANGE MUCH OVER THE NEXT 24 HOURS
AND MODELS ARE INDICATING A CATALINA EDDY WILL SPIN UP AGAIN LATE
TONIGHT AND TOMORROW MORNING. THIS SUGGESTS THE CLOUD PATTERN
TONIGHT AND TOMORROW MORNING WILL BE VERY SIMILAR TO WHAT WAS SEEN
LAST NIGHT AND THIS MORNING. THERE IS A 30% CHANCE THAT THE CIGS
FORECASTED AT KSMX WILL NOT DEVELOP. MODERATE TO HIGH CONFIDENCE
THAT ALL OTHER SITES NORTH OF KOXR WILL STAY VFR FOR THE NEXT 24
HOURS. THERE IS A 20% CHANCE THAT THE CIGS FORCASTED AT KOXR WILL
NOT HAPPEN LATE TONIGHT AND TOMORROW MORNING. THIS IS DUE TO THE
STRONG NORHTERLY FLOW ACROSS THE AREA...WHICH COULD KEEP THE EDDY
FROM BRINGING ANY LOW CLOUDS AS FAR NORTH AS KOXR.

KLAX...MODERATE TO HIGH CONFIDENCE THAT VFR CONDITIONS WILL CONTINUE
THROUGH THIS AFTERNOON. SKIES ARE CURRENTLY BROKEN AT ABOUT 3200
FEET...BUT CIGS SHOULD CONTINUE TO RISE THIS MORNING AND EVENTUALLY
SCATTER OUT BY ABOUT 19Z. THERE IS A 10% CHANCE THAT MVFR CONDITIONS
COULD BRIEFLY RETURN BEFORE THAT. HIGH CONFIDENCE THAT THE LOW
CLOUDS WILL RETURN THIS EVENING...BUT TIMING COULD BE +/- 3 HOURS.

KBUR...MODERATE TO HIGH CONFIDENCE THAT VFR CONDITIONS WILL CONTINUE
INTO EARLY THIS EVENING...AS THE CLEARING TREND CONTINUES THIS
MORNING. HIGH CONFIDENCE THAT LOW CLOUDS WILL RETURN TONIGHT...BUT
TIMING COULD BE +/- 2 HOURS.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY (SEE LAXNPWLOX).
GALE WARNING (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH SURF ADVISORY (SEE LAXCFWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).

&&

$$

PUBLIC...MW
AVIATION...SWEET
SYNOPSIS...KJ

WWW.WEATHER.GOV/LOSANGELES

000
FXUS66 KLOX 221820
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1120 AM PDT WED MAY 22 2013

...UPDATED AVIATION DISCUSSION...

.SYNOPSIS...
A COOLING TREND WILL CONTINUE THROUGH THURSDAY...AND THERE WILL BE
PLENTY OF NIGHT THROUGH MORNING LOW CLOUDS AND FOG...ESPECIALLY
ACROSS VENTURA AND LOS ANGELES COUNTIES. THERE MAY BE SOME SLIGHT
WARMING ON FRIDAY...THEN BELOW NORMAL DAYTIME TEMPERATURES ARE
EXPECTED THROUGH THE HOLIDAY WEEKEND WITH NIGHT THROUGH MORNING LOW
CLOUDS AND FOG IN COASTAL AND VALLEY AREAS. WARMING MAY BEGIN ACROSS
THE REGION TUESDAY.

&&

.SHORT TERM (TODAY-FRI)...MARINE LYR UP TO 3500 FT THIS MORNING.
INCREASING NORTHWEST WIND ACROSS THE WESTERN PORTION OF OUR FORECAST
AREA WILL BE BATTLING A SOUTHEAST EDDY WIND ACROSS THE SOUTHEASTERN
PORTION OF OUR FORECAST AREA THE NEXT COUPLE DAYS. SO FAR THIS HAS
RESULTED IN MINIMAL STRATUS FROM SBA COUNTY NORTH AND EARLY CLEARING
ACROSS VENTURA COUNTY. TONIGHT THE EDDY CIRCULATION IS EXPECTED TO
STRENGTHEN AS THE TROF DEEPENS ALONG THE WEST COAST. THIS MAY BE
ENOUGH TO GENERATE SOME PATCHY DRIZZLE, ESPECIALLY ACROSS THE ERN
PORTION OF LA COUNTY WHERE THE EDDY CIRCULATION WILL HAVE ITS
GREATEST INFLUENCE PUSHING UP AGAINST THE SAN GABRIELS.

GUSTY NORTHWEST WINDS EXPECTED ACROSS THE CENTRAL COAST, SRN SBA
COUNTY, I5 CORRIDOR AND THE ANTELOPE VALLEY, ESPECIALLY THIS
AFTERNOON AND EVENING. WINDS EXPECTED TO BE SLIGHTLY WEAKER THURSDAY
INTO THURSDAY EVENING.

COOLER TEMPS AGAIN TODAY WITH THE DEEPER MARINE LYR AND ONSHORE
FLOW. EXCEPT WARMER ACROSS SRN SBA COUNTY DUE TO THE NORTHERLY WINDS
THERE. A FEW MORE DEGREES OF COOLING THU.

***FROM PREVIOUS DISCUSSION***

THE UPPER LOW OVER THE PAC NW LIFTS INTO CANADA THU NIGHT AND
FRI...AND HEIGHTS ACROSS THE FCST AREA WILL BEGIN TO RISE. THIS MAY
ALLOW FOR SOME DECREASE IN MARINE LAYER DEPTH AND A REDUCTION IN
NIGHT THRU MORNING LOW CLOUDS AND FOG W OF THE MTNS. IT SHOULD ALSO
ALLOW FOR A FEW DEGREES OF WARMING ON FRI.

.LONG TERM (SAT-TUE)...ANOTHER UPPER LOW DROPS INTO THE PAC NW FRI
NIGHT AND SAT WITH RENEWED TROFFING ACROSS THE FCST AREA. WITH
DECREASING NW FLOW...EXPECT NIGHT THRU MORNING LOW CLOUDS/FOG TO
BECOME WIDESPREAD IN ALL COASTAL AND MOST VALLEY AREAS. THIS PATTERN
SHOULD CONTINUE THROUGH MONDAY...WITH LOCAL LATE NIGHT AND MORNING
DRIZZLE...AND POTENTIAL SLOW CLEARING NEAR THE BEACHES EACH DAY.
MAX TEMPS WILL LIKELY BE AT LEAST A FEW DEGREES BELOW NORMAL SAT
THRU MON. THE UPPER LOW AND ITS ASSOCD TROUGH WILL MOVE E LATE MON
AND TUE. HEIGHTS/THICKNESS WILL RISE ON TUE...AND SOME WARMING
SHOULD BEGIN.

&&

.FIRE WEATHER...
AS WINDS RAMP UP THIS AFTERNOON AND EVENING ACROSS THE SBA
SOUTH COAST AND MOUNTAINS...I-5 CORRIDOR OF THE LA/VTU COUNTY
MOUNTAINS...AND ANTELOPE VALLEY...THERE WILL BE ELEVATED FIRE DANGER
ACROSS ALL OF THESE AREAS. HUMDITIY LEVELS COULD BRIEFLY FALL BELOW
15 PERCENT ACROSS THE SBA SOUTH COAST ON THIS AFTERNOON.
SIMILAR LOW HUMIDITIES WILL LIKELY IMPACT THE I-5 CORRIDOR AND
ANTELOPE VALLEY DURING THE LATE AFTERNOON AND EVENING HOURS. AS A
RESULT...ALL OF THESE AREAS COULD EXPERIENCE BRIEF CRITICAL FIRE
WEATHER CONDITIONS...ESPECIALLY CONSIDERING THE VERY DRY FUELS FOR
THIS TIME OF YEAR. HOWEVER...IT DOES NOT APPEAR THAT DURATIONS OF
CRITICAL FIRE WEATHER CONDITIONS WILL BE MET TO ISSUE RED FLAG
WARNINGS FOR THIS EVENT.

&&

.AVIATION...22/1800Z...

OVERALL CONFIDENCE IN THE 18Z TAF PACKAGE IS MODERATE. THE LARGE
SCALE WEATHER PATTERN WILL NOT CHANGE MUCH OVER THE NEXT 24 HOURS
AND MODELS ARE INDICATING A CATALINA EDDY WILL SPIN UP AGAIN LATE
TONIGHT AND TOMORROW MORNING. THIS SUGGESTS THE CLOUD PATTERN
TONIGHT AND TOMORROW MORNING WILL BE VERY SIMILAR TO WHAT WAS SEEN
LAST NIGHT AND THIS MORNING. THERE IS A 30% CHANCE THAT THE CIGS
FORECASTED AT KSMX WILL NOT DEVELOP. MODERATE TO HIGH CONFIDENCE
THAT ALL OTHER SITES NORTH OF KOXR WILL STAY VFR FOR THE NEXT 24
HOURS. THERE IS A 20% CHANCE THAT THE CIGS FORCASTED AT KOXR WILL
NOT HAPPEN LATE TONIGHT AND TOMORROW MORNING. THIS IS DUE TO THE
STRONG NORHTERLY FLOW ACROSS THE AREA...WHICH COULD KEEP THE EDDY
FROM BRINGING ANY LOW CLOUDS AS FAR NORTH AS KOXR.

KLAX...MODERATE TO HIGH CONFIDENCE THAT VFR CONDITIONS WILL CONTINUE
THROUGH THIS AFTERNOON. SKIES ARE CURRENTLY BROKEN AT ABOUT 3200
FEET...BUT CIGS SHOULD CONTINUE TO RISE THIS MORNING AND EVENTUALLY
SCATTER OUT BY ABOUT 19Z. THERE IS A 10% CHANCE THAT MVFR CONDITIONS
COULD BRIEFLY RETURN BEFORE THAT. HIGH CONFIDENCE THAT THE LOW
CLOUDS WILL RETURN THIS EVENING...BUT TIMING COULD BE +/- 3 HOURS.

KBUR...MODERATE TO HIGH CONFIDENCE THAT VFR CONDITIONS WILL CONTINUE
INTO EARLY THIS EVENING...AS THE CLEARING TREND CONTINUES THIS
MORNING. HIGH CONFIDENCE THAT LOW CLOUDS WILL RETURN TONIGHT...BUT
TIMING COULD BE +/- 2 HOURS.

&&

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

&&

$$

PUBLIC...MW/DB
AVIATION...SUKUP/SWEET
FIRE...DG

WWW.WEATHER.GOV/LOSANGELES

000
FXUS66 KLOX 221634
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
935 AM PDT WED MAY 22 2013

.SYNOPSIS...
A COOLING TREND WILL CONTINUE THROUGH THURSDAY...AND THERE WILL BE
PLENTY OF NIGHT THROUGH MORNING LOW CLOUDS AND FOG...ESPECIALLY
ACROSS VENTURA AND LOS ANGELES COUNTIES. THERE MAY BE SOME SLIGHT
WARMING ON FRIDAY...THEN BELOW NORMAL DAYTIME TEMPERATURES ARE
EXPECTED THROUGH THE HOLIDAY WEEKEND WITH NIGHT THROUGH MORNING LOW
CLOUDS AND FOG IN COASTAL AND VALLEY AREAS. WARMING MAY BEGIN ACROSS
THE REGION TUESDAY.

&&

.SHORT TERM (TODAY-FRI)...MARINE LYR UP TO 3500 FT THIS MORNING.
INCREASING NORTHWEST WIND ACROSS THE WESTERN PORTION OF OUR FORECAST
AREA WILL BE BATTLING A SOUTHEAST EDDY WIND ACROSS THE SOUTHEASTERN
PORTION OF OUR FORECAST AREA THE NEXT COUPLE DAYS. SO FAR THIS HAS
RESULTED IN MINIMAL STRATUS FROM SBA COUNTY NORTH AND EARLY CLEARING
ACROSS VENTURA COUNTY. TONIGHT THE EDDY CIRCULATION IS EXPECTED TO
STRENGTHEN AS THE TROF DEEPENS ALONG THE WEST COAST. THIS MAY BE
ENOUGH TO GENERATE SOME PATCHY DRIZZLE, ESPECIALLY ACROSS THE ERN
PORTION OF LA COUNTY WHERE THE EDDY CIRCULATION WILL HAVE ITS
GREATEST INFLUENCE PUSHING UP AGAINST THE SAN GABRIELS.

GUSTY NORTHWEST WINDS EXPECTED ACROSS THE CENTRAL COAST, SRN SBA
COUNTY, I5 CORRIDOR AND THE ANTELOPE VALLEY, ESPECIALLY THIS
AFTERNOON AND EVENING. WINDS EXPECTED TO BE SLIGHTLY WEAKER THURSDAY
INTO THURSDAY EVENING.

COOLER TEMPS AGAIN TODAY WITH THE DEEPER MARINE LYR AND ONSHORE
FLOW. EXCEPT WARMER ACROSS SRN SBA COUNTY DUE TO THE NORTHERLY WINDS
THERE. A FEW MORE DEGREES OF COOLING THU.

***FROM PREVIOUS DISCUSSION***

THE UPPER LOW OVER THE PAC NW LIFTS INTO CANADA THU NIGHT AND
FRI...AND HEIGHTS ACROSS THE FCST AREA WILL BEGIN TO RISE. THIS MAY
ALLOW FOR SOME DECREASE IN MARINE LAYER DEPTH AND A REDUCTION IN
NIGHT THRU MORNING LOW CLOUDS AND FOG W OF THE MTNS. IT SHOULD ALSO
ALLOW FOR A FEW DEGREES OF WARMING ON FRI.

.LONG TERM (SAT-TUE)...ANOTHER UPPER LOW DROPS INTO THE PAC NW FRI
NIGHT AND SAT WITH RENEWED TROFFING ACROSS THE FCST AREA. WITH
DECREASING NW FLOW...EXPECT NIGHT THRU MORNING LOW CLOUDS/FOG TO
BECOME WIDESPREAD IN ALL COASTAL AND MOST VALLEY AREAS. THIS PATTERN
SHOULD CONTINUE THROUGH MONDAY...WITH LOCAL LATE NIGHT AND MORNING
DRIZZLE...AND POTENTIAL SLOW CLEARING NEAR THE BEACHES EACH DAY.
MAX TEMPS WILL LIKELY BE AT LEAST A FEW DEGREES BELOW NORMAL SAT
THRU MON. THE UPPER LOW AND ITS ASSOCD TROUGH WILL MOVE E LATE MON
AND TUE. HEIGHTS/THICKNESS WILL RISE ON TUE...AND SOME WARMING
SHOULD BEGIN.

&&

.FIRE WEATHER...
AS WINDS RAMP UP THIS AFTERNOON AND EVENING ACROSS THE SBA
SOUTH COAST AND MOUNTAINS...I-5 CORRIDOR OF THE LA/VTU COUNTY
MOUNTAINS...AND ANTELOPE VALLEY...THERE WILL BE ELEVATED FIRE DANGER
ACROSS ALL OF THESE AREAS. HUMDITIY LEVELS COULD BRIEFLY FALL BELOW
15 PERCENT ACROSS THE SBA SOUTH COAST ON THIS AFTERNOON.
SIMILAR LOW HUMIDITIES WILL LIKELY IMPACT THE I-5 CORRIDOR AND
ANTELOPE VALLEY DURING THE LATE AFTERNOON AND EVENING HOURS. AS A
RESULT...ALL OF THESE AREAS COULD EXPERIENCE BRIEF CRITICAL FIRE
WEATHER CONDITIONS...ESPECIALLY CONSIDERING THE VERY DRY FUELS FOR
THIS TIME OF YEAR. HOWEVER...IT DOES NOT APPEAR THAT DURATIONS OF
CRITICAL FIRE WEATHER CONDITIONS WILL BE MET TO ISSUE RED FLAG
WARNINGS FOR THIS EVENT.

&&

.AVIATION...22/1120Z...

OVERALL...MODERATE CONFIDENCE IN 12Z TAF PACKAGE. LATEST SATELLITE
SHOWS STRATUS SURGING ACROSS VENTURA/LA COUNTIES...WITH JUST SOME
PATCHY STRATUS ACROSS THE CENTRAL COAST. EXPECT MVFR CIGS ACROSS
VENTURA/LA COASTAL AND VALLEY TAFS THROUGH THE MORNING...WITH SOME
IFR/MVFR CIGS AT KSMX. THE STRATUS SHOULD BURN OFF DECENTLY BY EARLY
THIS AFTERNOON. FOR TONIGHT...EXPECT STRATUS TO RETURN TO THE SAME
SITES AS THIS MORNING WITH SIMILAR MVFR/IFR CIGS.

AS FOR WINDS...THERE WILL BE SOME GUSTY WEST TO NORTHWEST WINDS
ACROSS THE CENTRAL COAST...MOUNTAINS AND ANTELOPE VALLEY THIS
AFTERNOON AND TONIGHT. THE NORTHERLY WINDS WILL BE STRONG ENOUGH
ACROSS SOUTHERN SBA COUNTY TO PRODUCE SOME LLWS/TURBULENCE AT KSBA
THIS EVENING AND OVERNIGHT.

KLAX...MODERATE CONFIDENCE IN 12Z TAF. STRATUS CLEARING TODAY MAY
BE +/- 1-2 HOURS FROM CURRENT 19Z FORECAST.

KBUR...MODERATE CONFIDENCE IN 12Z TAF. STRATUS CLEARING TODAY MAY
BE +/- 1-2 HOURS OF CURRENT 18Z FORECAST.

&&

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

&&

$$

PUBLIC...MW/DB
AVIATION...RAT
FIRE...DG

WWW.WEATHER.GOV/LOSANGELES

000
FXUS66 KLOX 221131
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
420 AM PDT WED MAY 22 2013

...UPDATED AVIATION DISCUSSION...

.SYNOPSIS...
A COOLING TREND WILL CONTINUE THROUGH THURSDAY...AND THERE WILL BE
PLENTY OF NIGHT THROUGH MORNING LOW CLOUDS AND FOG...ESPECIALLY
ACROSS VENTURA AND LOS ANGELES COUNTIES. THERE MAY BE SOME SLIGHT
WARMING ON FRIDAY...THEN BELOW NORMAL DAYTIME TEMPERATURES ARE
EXPECTED THROUGH THE HOLIDAY WEEKEND WITH NIGHT THROUGH MORNING LOW
CLOUDS AND FOG IN COASTAL AND VALLEY AREAS. WARMING MAY BEGIN ACROSS
THE REGION TUESDAY.

&&

.SHORT TERM (TODAY-FRI)...MARINE LAYER HAS DEEPENED TO AROUND 2500
FEET EARLY THIS MORNING. SOLID EDDY CIRCULATION HAS DEVELOPED
ACROSS THE INNER WATERS. CLOUDS HAVE PUSHED INTO ALL COASTAL AND
VALLEY AREAS OF L.A. COUNTY WITH THE EXCEPTION OF THE SANTA CLARITA
VALLEY...BUT CLOUDS SHOULD REACH THAT AREA BY DAYBREAK. CLOUDS HAVE
OVERSPREAD MOST OF VTU COUNTY...AND MAY EVEN REACH THE EASTERN
PORTION OF THE S COAST OF SBA COUNTY BY MORNING. NORTH OF PT
CONCEPTION...SKIES WERE GENERALLY MOSTLY CLEAR...WITH ONLY SOME
PATCHY LOW CLOUDS ACROSS PORTIONS OF THE SANTA YNEZ VALLEY AND
SOUTHERN SECTIONS OF THE CENTRAL COAST. EXPECT SKIES TO CLEAR IN
MOST AREAS LATER THIS MORNING...BUT CLOUDS WILL LIKELY LINGER AT
SOME BEACHES OF L.A. COUNTY AND POSSIBLY VTU COUNTY INTO OR THROUGH
THE AFTERNOON. THE COOLING TREND WILL CONTINUE...AND MAX TEMPS WILL
DOWN ANOTHER SEVERAL DEGREES TODAY...ESPECIALLY ACROSS THE
INTERIOR.

THE EXCEPTION TO THE COOLING TREND WILL BE ACROSS THE SOUTH COAST OF
SBA COUNTY...WHERE GUSTY NW TO N WINDS THIS AFTERNOON WILL WARM AS
THEY DESCEND FROM THE SANTA YNEZ MOUNTAINS. EXPECT TEMPS TO RISE
INTO AT LEAST THE LOWER 80S ACROSS PORTIONS OF THE S COAST OF SBA
COUNTY LATE THIS AFTERNOON OR THIS EVENING AS THE NLY WINDS DEVELOP.

AN UPPER LOW WAS LOCATED ACROSS THE PAC NW THIS MORNING...WITH A
TROUGH EXTENDING SOUTHWARD INTO CA. A VORT LOBE WILL MOVE ACROSS THE
AREA THIS AFTERNOON AND EVENING. BEHIND IT...DECENT SUBSIDENCE WILL
OVERSPREAD THE AREA. AT THE SAME TIME N-S GRADIENTS WILL STRENGTHEN
AND NW TO N WINDS WILL INCREASE THROUGH THE ATMOSPHERE. THIS SHOULD
HELP TO PRODUCE HEALTHY SUNDOWNER WINDS THRU AND BELOW PASSES AND
CANYONS OF SRN SBA COUNTY. WINDS SHOULD FIRST DEVELOP THROUGH THE
GAVIOTA PASS THIS AFTERNOON...THEN ACROSS THE REMAINDER OF THAT AREA
THIS EVENING AS THE LOW LVL FLOW TURNS FROM WEST-NORTHWEST TO A MORE
NORTHERLY DIRECTION. GUSTY WINDS WILL ALSO AFFECT THE CENTRAL COAST
THIS AFTERNOON AND EVENING...AND THE ANTELOPE VALLEY AND MOUNTAINS
OF LOS ANGELES AND VENTURA COUNTIES THIS AFTERNOON THROUGH LATE
TONIGHT. WIND ADVISORIES HAVE BEEN ISSUED FOR THESE AREAS. PLEASE
ALSO SEE FIRE DISCUSSION BELOW FOR MORE DETAILS ON THE ELEVATED FIRE
DANGER.

THE TROUGH ACROSS CA WILL SHARPEN UP A BIT TONIGHT/THU. INCREASINGLY
CYCLONIC FLOW THROUGH THE ATMOSPHERE MAY PRODUCE ENOUGH LIFT FOR
SOME DRIZZLE LATE TONIGHT/THU...MAINLY IN COASTAL AND VALLEY
SECTIONS OF L.A. AND VTU COUNTIES. HOWEVER...THE LATEST RUN OF THE
WRF MODEL ACTUALLY SHOWS THE NLY WINDS SPREADING INTO THE SANTA
CLARITA VALLEY...AND SUGGESTS MUCH LESS INLAND EXTENT OF THE LOW
CLOUDS TONIGHT/THU MORNING...KEEPING CLOUDS MAINLY IN COASTAL AND
LOWER VALLEY LOCATIONS OF L.A. AND VTU COUNTIES...WITH PATCHY LOW
CLOUDS ON THE CENTRAL COAST. CLOUDS COULD AGAIN LINGER NEAR THE
BEACHES THU AFTERNOON...MAINLY ACROSS L.A. COUNTY. 950 MB TEMPS
SUPPORT A BIT OF ADDITIONAL COOLING IN MOST AREA THU. N-S GRADIENTS
WILL REMAIN RATHER STRONG...AND EXPECT ANOTHER ROUND OF GUSTY
WINDS...POSSIBLY TO ADVISORY LEVELS IN THE SAME AREAS THAT WILL BE
WINDY TODAY.

THE UPPER LOW OVER THE PAC NW LIFTS INTO CANADA THU NIGHT AND
FRI...AND HEIGHTS ACROSS THE FCST AREA WILL BEGIN TO RISE. THIS MAY
ALLOW FOR SOME DECREASE IN MARINE LAYER DEPTH AND A REDUCTION IN
NIGHT THRU MORNING LOW CLOUDS AND FOG W OF THE MTNS. IT SHOULD ALSO
ALLOW FOR A FEW DEGREES OF WARMING ON FRI.

.LONG TERM (SAT-TUE)...ANOTHER UPPER LOW DROPS INTO THE PAC NW FRI
NIGHT AND SAT WITH RENEWED TROFFING ACROSS THE FCST AREA. WITH
DECREASING NW FLOW...EXPECT NIGHT THRU MORNING LOW CLOUDS/FOG TO
BECOME WIDESPREAD IN ALL COASTAL AND MOST VALLEY AREAS. THIS PATTERN
SHOULD CONTINUE THROUGH MONDAY...WITH LOCAL LATE NIGHT AND MORNING
DRIZZLE...AND POTENTIAL SLOW CLEARING NEAR THE BEACHES EACH DAY.
MAX TEMPS WILL LIKELY BE AT LEAST A FEW DEGREES BELOW NORMAL SAT
THRU MON. THE UPPER LOW AND ITS ASSOCD TROUGH WILL MOVE E LATE MON
AND TUE. HEIGHTS/THICKNESS WILL RISE ON TUE...AND SOME WARMING
SHOULD BEGIN.

&&

.FIRE WEATHER...
AS WINDS RAMP UP THIS AFTERNOON AND EVENING ACROSS THE SBA
SOUTH COAST AND MOUNTAINS...I-5 CORRIDOR OF THE LA/VTU COUNTY
MOUNTAINS...AND ANTELOPE VALLEY...THERE WILL BE ELEVATED FIRE DANGER
ACROSS ALL OF THESE AREAS. HUMDITIY LEVELS COULD BRIEFLY FALL BELOW
15 PERCENT ACROSS THE SBA SOUTH COAST ON THIS AFTERNOON.
SIMILAR LOW HUMIDITIES WILL LIKELY IMPACT THE I-5 CORRIDOR AND
ANTELOPE VALLEY DURING THE LATE AFTERNOON AND EVENING HOURS. AS A
RESULT...ALL OF THESE AREAS COULD EXPERIENCE BRIEF CRITICAL FIRE
WEATHER CONDITIONS...ESPECIALLY CONSIDERING THE VERY DRY FUELS FOR
THIS TIME OF YEAR. HOWEVER...IT DOES NOT APPEAR THAT DURATIONS OF
CRITICAL FIRE WEATHER CONDITIONS WILL BE MET TO ISSUE RED FLAG
WARNINGS FOR THIS EVENT.

&&

.AVIATION...22/1120Z...

OVERALL...MODERATE CONFIDENCE IN 12Z TAF PACKAGE. LATEST SATELLITE
SHOWS STRATUS SURGING ACROSS VENTURA/LA COUNTIES...WITH JUST SOME
PATCHY STRATUS ACROSS THE CENTRAL COAST. EXPECT MVFR CIGS ACROSS
VENTURA/LA COASTAL AND VALLEY TAFS THROUGH THE MORNING...WITH SOME
IFR/MVFR CIGS AT KSMX. THE STRATUS SHOULD BURN OFF DECENTLY BY EARLY
THIS AFTERNOON. FOR TONIGHT...EXPECT STRATUS TO RETURN TO THE SAME
SITES AS THIS MORNING WITH SIMILAR MVFR/IFR CIGS.

AS FOR WINDS...THERE WILL BE SOME GUSTY WEST TO NORTHWEST WINDS
ACROSS THE CENTRAL COAST...MOUNTAINS AND ANTELOPE VALLEY THIS
AFTERNOON AND TONIGHT. THE NORTHERLY WINDS WILL BE STRONG ENOUGH
ACROSS SOUTHERN SBA COUNTY TO PRODUCE SOME LLWS/TURBULENCE AT KSBA
THIS EVENING AND OVERNIGHT.

KLAX...MODERATE CONFIDENCE IN 12Z TAF. STRATUS CLEARING TODAY MAY
BE +/- 1-2 HOURS FROM CURRENT 19Z FORECAST.

KBUR...MODERATE CONFIDENCE IN 12Z TAF. STRATUS CLEARING TODAY MAY
BE +/- 1-2 HOURS OF CURRENT 18Z FORECAST.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY (SEE LAXNPWLOX).
GALE WARNING (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH SURF ADVISORY (SEE LAXCFWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).

&&

$$

PUBLIC...DB
AVIATION...RAT
FIRE...DG

WWW.WEATHER.GOV/LOSANGELES

000
FXUS66 KLOX 221119
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
420 AM PDT WED MAY 22 2013

...UPDATED AVIATION DISCUSSION...

.SYNOPSIS...
A COOLING TREND WILL CONTINUE THROUGH THURSDAY...AND THERE WILL BE
PLENTY OF NIGHT THROUGH MORNING LOW CLOUDS AND FOG...ESPECIALLY
ACROSS VENTURA AND LOS ANGELES COUNTIES. THERE MAY BE SOME SLIGHT
WARMING ON FRIDAY...THEN BELOW NORMAL DAYTIME TEMPERATURES ARE
EXPECTED THROUGH THE HOLIDAY WEEKEND WITH NIGHT THROUGH MORNING LOW
CLOUDS AND FOG IN COASTAL AND VALLEY AREAS. WARMING MAY BEGIN ACROSS
THE REGION TUESDAY.

&&

.SHORT TERM (TODAY-FRI)...MARINE LAYER HAS DEEPENED TO AROUND 2500
FEET EARLY THIS MORNING. SOLID EDDY CIRCULATION HAS DEVELOPED
ACROSS THE INNER WATERS. CLOUDS HAVE PUSHED INTO ALL COASTAL AND
VALLEY AREAS OF L.A. COUNTY WITH THE EXCEPTION OF THE SANTA CLARITA
VALLEY...BUT CLOUDS SHOULD REACH THAT AREA BY DAYBREAK. CLOUDS HAVE
OVERSPREAD MOST OF VTU COUNTY...AND MAY EVEN REACH THE EASTERN
PORTION OF THE S COAST OF SBA COUNTY BY MORNING. NORTH OF PT
CONCEPTION...SKIES WERE GENERALLY MOSTLY CLEAR...WITH ONLY SOME
PATCHY LOW CLOUDS ACROSS PORTIONS OF THE SANTA YNEZ VALLEY AND
SOUTHERN SECTIONS OF THE CENTRAL COAST. EXPECT SKIES TO CLEAR IN
MOST AREAS LATER THIS MORNING...BUT CLOUDS WILL LIKELY LINGER AT
SOME BEACHES OF L.A. COUNTY AND POSSIBLY VTU COUNTY INTO OR THROUGH
THE AFTERNOON. THE COOLING TREND WILL CONTINUE...AND MAX TEMPS WILL
DOWN ANOTHER SEVERAL DEGREES TODAY...ESPECIALLY ACROSS THE
INTERIOR.

THE EXCEPTION TO THE COOLING TREND WILL BE ACROSS THE SOUTH COAST OF
SBA COUNTY...WHERE GUSTY NW TO N WINDS THIS AFTERNOON WILL WARM AS
THEY DESCEND FROM THE SANTA YNEZ MOUNTAINS. EXPECT HIGHS TO RISE
INTO AT LEAST THE LOWER 80S ACROSS PORTIONS OF THE S COAST OF SBA
COUNTY LATE THIS AFTERNOON OR THIS EVENING AS THERE NLY WINDS
DEVELOP.

AN UPPER LOW WAS LOCATED ACROSS THE PAC NW THIS MORNING...WITH A
TROUGH EXTENDING SOUTHWARD INTO CA. A VORT LOBE WILL MOVE ACROSS THE
AREA THIS AFTERNOON AND EVENING. BEHIND IT...DECENT SUBSIDENCE WILL
SPREAD ACROSS THE REGION. AT THE SAME TIME N-S GRADIENTS WILL
STRENGTHEN AND NW WINDS WILL INCREASE THROUGH THE ATMOSPHERE. THIS
SHOULD HELP TO PRODUCE HEALTHY SUNDOWNER WINDS THRU AND BELOW PASSES
AND CANYONS OF SRN SBA COUNTY. WINDS SHOULD FIRST DEVELOP IN THROUGH
THE GAVIOTA PASS THIS AFTERNOON...THEN ACROSS THE REMAINDER OF THAT
AREA THIS EVENING AS THE LOW LVL FLOW TURNS FROM WEST NORTHWEST TO A
MORE NORTHERLY DIRECTION. GUSTY WINDS WILL ALSO AFFECT THE CENTRAL
COAST THIS AFTERNOON AND EVENING...AND THE ANTELOPE VALLEY AND
MOUNTAINS OF LOS ANGELES AND VENTURA COUNTIES THIS AFTERNOON
THROUGH LATE TONIGHT. WIND ADVISORIES HAVE BEEN ISSUED FOR THESE
AREAS. PLEASE SEE FIRE DISCUSSION BELOW FOR MORE DETAILS ON ELEVATED
FIRE DANGER.

THE TROUGH ACROSS CA WILL SHARPEN UP A BIT TONIGHT AND THU.
INCREASINGLY CYCLONIC FLOW THROUGH THE ATMOSPHERE MAY PRODUCE
ENOUGH LIFT FOR SOME DRIZZLE LATE TONIGHT/THU...MAINLY IN COASTAL
AND VALLEY SECTIONS OF L.A. AND VTU COUNTIES. HOWEVER...THE LATEST
RUN OF THE WRF MODEL ACTUALLY SHOWS THE NLY WINDS SPREADING INTO
THE SANTA CLARITA VALLEY...AND SUGGEST MUCH LESS INLAND EXTENT OF
THE LOW CLOUDS TONIGHT/THU MORNING...KEEPING CLOUDS MAINLY IN
COASTAL AND LOWER VALLEY LOCATIONS OF L.A. AND VTU COUNTIES...WITH
PATCHY LOW CLOUDS ON THE CENTRAL COAST. CLOUDS COULD AGAIN LINGER
NEAR THE BEACHES THU AFTERNOON...MAINLY ACROSS L.A. COUNTY. 950 MB
TEMPS SUPPORT A BIT OF ADDITIONAL COOLING IN MOST AREA THU. N-S
GRADIENTS WILL REMAIN RATHER STRONG...AND EXPECT ANOTHER ROUND OF
GUSTY WINDS...POSSIBLY TO ADVISORY LEVELS IN THE SAME AREAS THAT
WILL BE WINDY TODAY.

THE UPPER LOW OVER THE PAC NW LIFTS INTO CANADA THU NIGHT AND
FRI...AND HEIGHTS ACROSS THE FCST AREA WILL BEGIN TO RISE. THIS MAY
ALLOW FOR SOME DECREASE IN MARINE LAYER DEPTH AND A REDUCTION IN
NIGHT THRU MORNING LOW CLOUDS AND FOG W OF THE MTNS. IT SHOULD ALSO
ALLOW FOR A FEW DEGREES OF WARMING ON FRI.

.LONG TERM (SAT-TUE)...ANOTHER UPPER LOW DROPS INTO THE PAC NW FRI
NIGHT AND SAT WITH RENEWED TROFFING ACROSS THE FCST AREA. WITH
DECREASING NW FLOW...EXPECT NIGHT THRU MORNING LOW CLOUDS/FOG TO
BECOME WIDESPREAD IN ALL COASTAL AND MOST VALLEY AREAS. THIS PATTERN
SHOULD CONTINUE THROUGH MONDAY...WITH POTENTIAL SLOW CLEARING NEAR
THE BEACHES EACH DAY. MAX TEMPS WILL LIKELY BE AT LEAST A FEW
DEGREES BELOW NORMAL SAT THRU MON. THE UPPER LOW AND ITS ASSOCD
TROUGH WILL MOVE E LATE MON AND TUE. HEIGHTS/THICKNESS WILL RISE ON
TUE...AND SOME WARMING SHOULD BEGIN.

&&

.FIRE WEATHER...
AS WINDS RAMP UP THIS AFTERNOON AND EVENING ACROSS THE SBA
SOUTH COAST AND MOUNTAINS...I-5 CORRIDOR OF THE LA/VTU COUNTY
MOUNTAINS...AND ANTELOPE VALLEY...THERE WILL BE ELEVATED FIRE DANGER
ACROSS ALL OF THESE AREAS. HUMDITIY LEVELS COULD BRIEFLY FALL BELOW
15 PERCENT ACROSS THE SBA SOUTH COAST ON THIS AFTERNOON.
SIMILAR LOW HUMIDITIES WILL LIKELY IMPACT THE I-5 CORRIDOR AND
ANTELOPE VALLEY DURING THE LATE AFTERNOON AND EVENING HOURS. AS A
RESULT...ALL OF THESE AREAS COULD EXPERIENCE BRIEF CRITICAL FIRE
WEATHER CONDITIONS...ESPECIALLY CONSIDERING THE VERY DRY FUELS FOR
THIS TIME OF YEAR. HOWEVER...IT DOES NOT APPEAR THAT DURATIONS OF
CRITICAL FIRE WEATHER CONDITIONS WILL BE MET TO ISSUE RED FLAG
WARNINGS FOR THIS EVENT.

&&

.AVIATION...22/1120Z...

OVERALL...MODERATE CONFIDENCE IN 12Z TAF PACKAGE. LATEST SATELLITE
SHOWS STRATUS SURGING ACROSS VENTURA/LA COUNTIES...WITH JUST SOME
PATCHY STRATUS ACROSS THE CENTRAL COAST. EXPECT MVFR CIGS ACROSS
VENTURA/LA COASTAL AND VALLEY TAFS THROUGH THE MORNING...WITH SOME
IFR/MVFR CIGS AT KSMX. THE STRATUS SHOULD BURN OFF DECENTLY BY EARLY
THIS AFTERNOON. FOR TONIGHT...EXPECT STRATUS TO RETURN TO THE SAME
SITES AS THIS MORNING WITH SIMILAR MVFR/IFR CIGS.

AS FOR WINDS...THERE WILL BE SOME GUSTY WEST TO NORTHWEST WINDS
ACROSS THE CENTRAL COAST...MOUNTAINS AND ANTELOPE VALLEY THIS
AFTERNOON AND TONIGHT. THE NORTHERLY WINDS WILL BE STRONG ENOUGH
ACROSS SOUTHERN SBA COUNTY TO PRODUCE SOME LLWS/TURBULENCE AT KSBA
THIS EVENING AND OVERNIGHT.

KLAX...MODERATE CONFIDENCE IN 12Z TAF. STRATUS CLEARING TODAY MAY
BE +/- 1-2 HOURS FROM CURRENT 19Z FORECAST.

KBUR...MODERATE CONFIDENCE IN 12Z TAF. STRATUS CLEARING TODAY MAY
BE +/- 1-2 HOURS OF CURRENT 18Z FORECAST.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY (SEE LAXNPWLOX).
GALE WARNING (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH SURF ADVISORY (SEE LAXCFWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).

&&

$$

PUBLIC...DB
AVIATION...RAT
FIRE...DG

WWW.WEATHER.GOV/LOSANGELES

000
FXUS66 KLOX 221117
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
339 AM PDT WED MAY 22 2013

.SYNOPSIS...
A COOLING TREND WILL CONTINUE THROUGH THURSDAY...AND THERE WILL BE
PLENTY OF NIGHT THROUGH MORNING LOW CLOUDS AND FOG...ESPECIALLY
ACROSS VENTURA AND LOS ANGELES COUNTIES. THERE MAY BE SOME SLIGHT
WARMING ON FRIDAY...THEN BELOW NORMAL DAYTIME TEMPERATURES ARE
EXPECTED THROUGH THE HOLIDAY WEEKEND WITH NIGHT THROUGH MORNING LOW
CLOUDS AND FOG IN COASTAL AND VALLEY AREAS. WARMING MAY BEGIN ACROSS
THE REGION TUESDAY.

&&

.SHORT TERM (TODAY-FRI)...MARINE LAYER HAS DEEPENED TO AROUND 2500
FEET EARLY THIS MORNING. SOLID EDDY CIRCULTATION HAS DEVELOPED
ACROSS THE INNER WATERS. CLOUDS HAVE PUSHED INTO ALL COASTAL AND
VALLEY AREAS OF L.A. COUNTY WITH THE EXCEPTION OF THE SANTA CLARITA
VALLEY...BUT CLOUDS SHOULD REACH THAT AREA BY DAYBREAK. CLOUDS HAVE
OVERSPREAD MOST OF VTU COUTNY...AND MAY EVEN REACH THE EASTERN
PORTION OF THE S COAST OF SBA COUNTY BY MORNING. NORTH OF PT
CONCEPTION...SKIES WERE GENERALLY MOSTLY CLEAR...WITH ONLY SOME
PATCHY LOW CLOUDS ACROSS PORTIONS OF THE SANTA YNEZ VALLEY AND
SOUTHERN SECTIONS OF THE CENTRAL COAST. EXPECT SKIES TO CLEAR IN
MOST AREAS LATER THIS MORNING...BUT CLOUDS WILL LIKELY LINGER AT
SOME BEACHES OF L.A. COUNTY AND POSSIBLY VTU COUNTY INTO OR THROUGH
THE AFTERNOON. THE COOLING TREND WILL CONTINE...AND MAX TEMPS WILL
DOWN ANOTHER SEVERAL DEGREES TODAY...ESPECIALLY ACROSS THE
INTERIOR.

THE EXCEPTION TO THE COOLING TREND WILL BE ACROSS THE SOUTH COAST OF
SBA COUNTY...WHERE GUSTY NW TO N WINDS THIS AFTERNOON WILL WARM AS
THEY DESCEND FROM THE SANTA YNEZ MOUNTAINS. EXPECT HIGHS TO RISE
INTO AT LEAST THE LOWER 80S ACROSS PORTIONS OF THE S COAST OF SBA
COUNTY LATE THIS AFTERNOON OR THIS EVENING AS THERE NLY WINDS
DEVELOP.

AN UPPER LOW WAS LOCATED ACROSS THE PAC NW THIS MORNING...WITH A
TROUGH EXTENDING SOUTHWARD INTO CA. A VORT LOBE WILL MOVE ACROSS THE
AREA THIS AFTERNOON AND EVENING. BEHIND IT...DECENT SUBSIDENCE WILL
SPREAD ACROSS THE REGION. AT THE SAME TIME N-S GRADIENTS WILL
STRENGTHEN AND NW WINDS WILL INCREASE THROUGH THE ATMOSPHERE. THIS
SHOULD HELP TO PRODUCE HEALTHY SUNDOWNER WINDS THRU AND BELOW PASSES
AND CANYONS OF SRN SBA COUNTY. WINDS SHOULD FIRST DEVELOP IN THROUGH
THE GAVIOTA PASS THIS AFTERNOON...THEN ACROSS THE REMAINDER OF THAT
AREA THIS EVENING AS THE LOW LVL FLOW TURNS FROM WEST NORTHWEST TO A
MORE NORTHERLY DIRECTION. GUSTY WINDS WILL ALSO AFFECT THE CENTRAL
COAST THIS AFTERNOON AND EVENING...AND THE ANTELOPE VALLEY AND
MOUTNAINS OF LOS ANGELES AND VENTURA COUNTIES THIS AFTEERNOON
THROUGH LATE TONIGHT. WIND ADVISORIES HAVE BEEN ISSUED FOR THESE
AREAS. PLEASE SEE FIRE DISCUSSION BELOW FOR MORE DETAILS ON ELEVATED
FIRE DANGER.

THE TROUGH ACROSS CA WILL SHARPEN UP A BIT TONIGHT AND THU.
INCREASINGLY CYCLONIC FLOW THROUGH THE ATMOSPHERE MAY PRODUCE
ENOUGHT LIFT FOR SOME DRIZZLE LATE TONIGHT/THU...MAINLY IN COASTAL
AND VALLEY SECTIONS OF L.A. AND VTU COUNTIES. HOWEVER...THE LATEST
RUN OF THE WRF MODEL ACTUALLY SHOWS THE NLY WINDS SPREADING INTO
THE SANTA CLARITA VALLEY...AND SUGGEST MUCH LESS INLAND EXTENT OF
THE LOW CLOUDS TONIGHT/THU MORNING...KEEPING CLOUDS MAINLY IN
COASTAL AND LOWER VALLEY LOCATIONS OF L.A. AND VTU COUNITES...WITH
PATCHY LOW CLOUDS ON THE CENTRAL COAST. CLOUDS COULD AGAIN LINGER
NEAR THE BEACHES THU AFTERNOON...MAINLY ACROSS L.A. COUNTY. 950 MB
TEMPS SUPPORT A BIT OF ADDITIONAL COOLING IN MOST AREA THU. N-S
GRADIENTS WILL REMAIN RATHER STRONG...AND EXPECT ANOTHER ROUND OF
GUSTY WINDS...POSSIBLY TO ADVISORY LEVELS IN THE SAME AREAS THAT
WILL BE WINDY TODAY.

THE UPPER LOW OVER THE PAC NW LIFTS INTO CANADA THU NIGHT AND
FRI...AND HEIGHTS ACROSS THE FCST AREA WILL BEGIN TO RISE. THIS MAY
ALLOW FOR SOME DECREASE IN MARINE LAYER DEPTH AND A REDUCTION IN
NIGHT THRU MORNING LOW CLOUDS AND FOG W OF THE MTNS. IT SHOULD ALSO
ALLOW FOR A FEW DEGREES OF WARMING ON FRI.

.LONG TERM (SAT-TUE)...ANOTHER UPPER LOW DROPS INTO THE PAC NW FRI
NIGHT AND SAT WITH RENEWED TROFFING ACROSS THE FCST AREA. WITH
DECREASING NW FLOW...EXPECT NIGHT THRU MORNING LOW CLOUDS/FOG TO
BECOME WIDESPREAD IN ALL COASTAL AND MOST VALLEY AREAS. THIS PATTERN
SHOULD CONTINUE THROUGH MONDAY...WITH POTENTIAL SLOW CLEARING NEAR
THE BEACHES EACH DAY. MAX TEMPS WILL LIKELY BE AT LEAST A FEW
DEGREES BELOW NORMAL SAT THRU MON. THE UPPER LOW AND ITS ASSOCD
TROUGH WILL MOVE E LATE MON AND TUE. HEIGHTS/THICKNESS WILL RISE ON
TUE...AND SOME WARMING SHOULD BEGIN.


&&

.FIRE WEATHER...
AS WINDS RAMP UP THIS AFTERNOON AND EVENING ACROSS THE SBA
SOUTH COAST AND MOUNTAINS...I-5 CORRIDOR OF THE LA/VTU COUNTY
MOUNTAINS...AND ANTELOPE VALLEY...THERE WILL BE ELEVATED FIRE DANGER
ACROSS ALL OF THESE AREAS. HUMDITIY LEVELS COULD BRIEFLY FALL BELOW
15 PERCENT ACROSS THE SBA SOUTH COAST ON THIS AFTERNOON.
SIMILAR LOW HUMIDITIES WILL LIKELY IMPACT THE I-5 CORRIDOR AND
ANTELOPE VALLEY DURING THE LATE AFTERNOON AND EVENING HOURS. AS A
RESULT...ALL OF THESE AREAS COULD EXPERIENCE BRIEF CRITICAL FIRE
WEATHER CONDITIONS...ESPECIALLY CONSIDERING THE VERY DRY FUELS FOR
THIS TIME OF YEAR. HOWEVER...IT DOES NOT APPEAR THAT DURATIONS OF
CRITICAL FIRE WEATHER CONDITIONS WILL BE MET TO ISSUE RED FLAG
WARNINGS FOR THIS EVENT.

&&

.AVIATION...21/1200Z.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY (SEE LAXNPWLOX).
GALE WARNING (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH SURF ADVISORY (SEE LAXCFWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).

&&

$$

PUBLIC...DB
AVIATION...RAT

WWW.WEATHER.GOV/LOSANGELES

000
FXUS66 KLOX 220528 AAA
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1030 PM PDT TUE MAY 21 2013

UPDATED AVIATION SECTION

.SYNOPSIS...

GUSTY WEST TO NORTHWEST WINDS WILL OCCUR IN THE
MOUNTAINS...DESERTS...AND PORTIONS OF THE COAST INTO THURSDAY. AN
AREA OF LOW PRESSURE WILL PERSIST ACROSS THE REGION...AND WILL GAIN
STRENGTH OVER THE WEEKEND TO DEEPEN THE MARINE LAYER AND BRING
DRIZZLE. THE AFTERNOON TEMPERATURES WILL STAY BELOW NORMAL THROUGH
NEXT TUESDAY...THEN A WARMING TREND STARTS WITH TEMPERATURES
REACHING ABOVE NORMAL BY MIDWEEK.

&&

.SHORT TERM (TONIGHT-FRI)...STRENGTHENING ONSHORE FLOW BROUGHT A
COOLING TREND TO MOST AREAS TODAY...WITH THE EXCEPTION OF THE
MOUNTAINS AND ANTELOPE VALLEY. LAX-DAGGETT GRADIENT PEAKED AT AROUND
+7 MB WHICH HELPED TO GENERATE GUSTY ONSHORE WINDS IN THE MOUNTAINS
AND ANTELOPE VALLEY. THE STRONGEST WINDS THIS EVENING HAVE BEEN
FOCUSED ACROSS THE FOOTHILLS OF THE ANTELOPE VALLEY...WITH LAKE
PALMDALE OBSERVING A GUST OF 47 MPH THIS PAST HOUR.
MEANWHILE...WIDESPREAD GALE FORCE WINDS ARE IMPACTING THE OUTER
COASTAL WATERS THIS EVENING. THE TIGHTENING NORTHWEST GRADIENT IS
ALSO REFLECTED ACROSS SBA COUNTY...WHERE THE CURRENT SBA-SMX GRADIENT
IS -4.2 MB. AS A RESULT...LOCALLY GUSTY SUNDOWNER WINDS ARE
IMPACTING THE WESTERN PORTIONS OF THE SBA COUNTY SOUTH COAST THIS
EVENING...WITH LOCAL GUSTS OVER 35 MPH.

AS THE UPPER TROUGH DEEPENS ACROSS THE REGION ON WEDNESDAY AND
THURSDAY...THE COOLING TREND WILL CONTINUE AND PUSH FURTHER INLAND.
GUSTY ONSHORE WINDS WILL CONTINUE ACROSS THE MOUNTAINS AND ANTELOPE
VALLEY...APPROACHING ADVISORY LEVELS EACH AFTERNOON AND EVENING. AS
THE NORTHWEST GRADIENT TIGHTENS ON WEDNESDAY ACROSS THE COASTAL
WATERS AND SBA COUNTY...THE GALE FORCE WINDS WILL BECOME MORE
WIDESPREAD EXTENDING INTO WESTERN PORTIONS OF THE SBA CHANNEL.
ALSO...WINDS ARE EXPECTED TO EXCEED ADVISORY LEVELS ACROSS THE
CENTRAL COAST AND SBA SOUTH COAST/MOUNTAINS ON WEDNESDAY AFTERNOON
AND EVENING. IN FACT...SBA-SMX GRADIENT IS EXPECTED TO JUMP TO
AROUND -5.5 MB ON WEDNESDAY EVENING. THIS IN COMBINATION WITH GOOD
THERMAL ADVECTION AND SOME UPPER LEVEL WIND SUPPORT WILL LIKELY
GENERATE WIND GUSTS UP TO 50 MPH ACROSS FAVORED PASSES AND CANYONS
OF SOUTHERN SBA COUNTY. WHILE THIS IS NOT A PARTICULARLY WARM
SUNDOWNER EVENT...COULD STILL SEE SOME FAVORED DOWNSLOPE LOCATIONS
EXCEED 80 DEGREES ON WEDNESDAY. PLEASE SEE FIRE DISCUSSION BELOW FOR
MORE DETAILS ON ELEVATED FIRE DANGER.

*** FROM PREVIOUS DISCUSSION ***

IF THE MODELS ARE TO BE BELIEVED, THE TROF BRIEFLY LIFTS ON FRIDAY,
RESULTING IN A VERY SLIGHT WARMING TREND FRIDAY, MAYBE A FEW DEGREES
AT MOST, AND EARLIER MARINE LYR CLEARING.

.LONG TERM (SAT-TUE)...TROF DEEPENS AGAIN OVER THE HOLIDAY WEEKEND.
DECREASING NORTHWEST FLOW SHOULD ALLOW THE LOW CLOUDS TO SPREAD UP
THE COAST THROUGH SLO COUNTY AND WE MAY SEE AREAS OF DRIZZLE AGAIN
EACH MORNING THROUGH MONDAY. LIMITED COASTAL CLEARING AND CLOUDS MAY
LINGER INTO EARLY AFTERNOON FOR SOME OF THE VALLEYS. DAYTIME TEMPS
EXPECTED TO RUN 2-4 DEGREES BELOW NORMAL. THE TROF IS EXPECTED TO
SHIFT EAST TUESDAY FOR A WARMING TREND GOING INTO THE MIDDLE OF NEXT
WEEK.

&&

.FIRE WEATHER...
AS WINDS RAMP UP WEDNESDAY AFTERNOON AND EVENING ACROSS THE SBA
SOUTH COAST AND MOUNTAINS...I-5 CORRIDOR OF THE LA/VTU COUNTY
MOUNTAINS...AND ANTELOPE VALLEY...THERE WILL BE ELEVATED FIRE DANGER
ACROSS ALL OF THESE AREAS. HUMDITIY LEVELS COULD BRIEFLY FALL BELOW
15 PERCENT ACROSS THE SBA SOUTH COAST ON WEDNESDAY AFTERNOON.
SIMILAR LOW HUMIDITIES WILL LIKELY IMPACT THE I-5 CORRIDOR AND
ANTELOPE VALLEY DURING THE LATE AFTERNOON AND EVENING HOURS. AS A
RESULT...ALL OF THESE AREAS COULD EXPERIENCE BRIEF CRITICAL FIRE
WEATHER CONDITIONS...ESPECIALLY CONSIDERING THE VERY DRY FUELS FOR
THIS TIME OF YEAR. HOWEVER...IT DOES NOT APPEAR THAT DURATIONS OF
CRITICAL FIRE WEATHER CONDITIONS WILL BE MET TO ISSUE RED FLAG
WARNINGS FOR THIS EVENT.

&&

.AVIATION...22/0530Z.
EXPECT LOW CLOUDS TO AFFECT MOST COASTAL AND VALLEY AREAS OF L.A.
AND VTU COUNTIES OVERNIGHT/THU MORNING...WITH CONDS MOSTLY IFR TO
LOW MVFR. EXPECT LOW CLOUDS TO BE MORE PATCHY IN NATURE N OF PT
CONCEPTION WITH CONDS MOSTLY LIFR TO IFR.

GUSTY WINDS ACROSS THE PASSES AND CANYONS OF SBA COUNTY THIS EVENING
AND SOMEWHAT STRONGER TOMORROW EVENING...BRINGING A GOOD CHANCE OF
LLWS BOTH EVENINGS. ALSO...GUSTY WEST TO NORTHWEST WINDS WILL BE
AFFECTING KSMX...KSBP...KPMD...AND KWJF WEDNESDAY AFTERNOON AND
EVENING.


KLAX...MODERATE CONFIDENCE IN TAF. THERE IS A 20 PERCENT CHANCE OF
IFR CONDS BETWEEN 06Z AND 12Z TODAY. THERE IS A 20 PERCENT CHANCE
THAT CIGS WILL LINGER THRU AS LATE AS 22Z.

KBUR...FAIRLY HIGH CONFIDENCE IN 06Z TAF. THERE IS A 20 PERCENT
CHANCE THAT CONDS WILL BE MVFR RATHER THAN IFR.


&&

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

&&

$$

PUBLIC...GOMBERG/MW
AVIATION...DB
FIRE...GOMBERG
SYNOPSIS...KJ

WWW.WEATHER.GOV/LOSANGELES

000
FXUS66 KLOX 220348
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
830 PM PDT TUE MAY 21 2013

.SYNOPSIS...

GUSTY WEST TO NORTHWEST WINDS WILL OCCUR IN THE MOUNTAINS...DESERTS...AND
PORTIONS OF THE COAST INTO THURSDAY. AN AREA OF LOW PRESSURE WILL PERSIST
ACROSS THE REGION...AND WILL GAIN STRENGTH OVER THE WEEKEND TO DEEPEN THE
MARINE LAYER AND BRING DRIZZLE. THE AFTERNOON TEMPERATURES WILL STAY BELOW
NORMAL THROUGH NEXT TUESDAY...THEN A WARMING TREND STARTS WITH TEMPERATURES
REACHING ABOVE NORMAL BY MIDWEEK.

&&

.SHORT TERM (TONIGHT-FRI)...STRENGTHENING ONSHORE FLOW BROUGHT A COOLING
TREND TO MOST AREAS TODAY...WITH THE EXCEPTION OF THE MOUNTAINS AND
ANTELOPE VALLEY. LAX-DAGGETT GRADIENT PEAKED AT AROUND +7 MB WHICH HELPED
TO GENERATE GUSTY ONSHORE WINDS IN THE MOUNTAINS AND ANTELOPE VALLEY.
THE STRONGEST WINDS THIS EVENING HAVE BEEN FOCUSED ACROSS THE FOOTHILLS
OF THE ANTELOPE VALLEY...WITH LAKE PALMDALE OBSERVING A GUST OF 47 MPH
THIS PAST HOUR. MEANWHILE...WIDESPREAD GALE FORCE WINDS ARE IMPACTING
THE OUTER COASTAL WATERS THIS EVENING. THE TIGHTENING NORTHWEST GRADIENT
IS ALSO REFLECTED ACROSS SBA COUNTY...WHERE THE CURRENT SBA-SMX GRADIENT
IS -4.2 MB. AS A RESULT...LOCALLY GUSTY SUNDOWNER WINDS ARE IMPACTING THE
WESTERN PORTIONS OF THE SBA COUNTY SOUTH COAST THIS EVENING...WITH LOCAL
GUSTS OVER 35 MPH.

AS THE UPPER TROUGH DEEPENS ACROSS THE REGION ON WEDNESDAY AND
THURSDAY...THE COOLING TREND WILL CONTINUE AND PUSH FURTHER INLAND.
GUSTY ONSHORE WINDS WILL CONTINUE ACROSS THE MOUNTAINS AND ANTELOPE
VALLEY...APPROACHING ADVISORY LEVELS EACH AFTERNOON AND EVENING. AS
THE NORTHWEST GRADIENT TIGHTENS ON WEDNESDAY ACROSS THE COASTAL
WATERS AND SBA COUNTY...THE GALE FORCE WINDS WILL BECOME MORE WIDESPREAD
EXTENDING INTO WESTERN PORTIONS OF THE SBA CHANNEL. ALSO...WINDS
ARE EXPECTED TO EXCEED ADVISORY LEVELS ACROSS THE CENTRAL COAST AND
SBA SOUTH COAST/MOUNTAINS ON WEDNESDAY AFTERNOON AND EVENING. IN
FACT...SBA-SMX GRADIENT IS EXPECTED TO JUMP TO AROUND -5.5 MB ON
WEDNESDAY EVENING. THIS IN COMBINATION WITH GOOD THERMAL ADVECTION
AND SOME UPPER LEVEL WIND SUPPORT WILL LIKELY GENERATE WIND GUSTS UP
TO 50 MPH ACROSS FAVORED PASSES AND CANYONS OF SOUTHERN SBA COUNTY.
WHILE THIS IS NOT A PARTICULARLY WARM SUNDOWNER EVENT...COULD STILL
SEE SOME FAVORED DOWNSLOPE LOCATIONS EXCEED 80 DEGREES ON WEDNESDAY.
PLEASE SEE FIRE DISCUSSION BELOW FOR MORE DETAILS ON ELEVATED FIRE DANGER.

*** FROM PREVIOUS DISCUSSION ***

IF THE MODELS ARE TO BE BELIEVED, THE TROF BRIEFLY LIFTS ON FRIDAY,
RESULTING IN A VERY SLIGHT WARMING TREND FRIDAY, MAYBE A FEW DEGREES
AT MOST, AND EARLIER MARINE LYR CLEARING.

.LONG TERM (SAT-TUE)...TROF DEEPENS AGAIN OVER THE HOLIDAY WEEKEND.
DECREASING NORTHWEST FLOW SHOULD ALLOW THE LOW CLOUDS TO SPREAD UP
THE COAST THROUGH SLO COUNTY AND WE MAY SEE AREAS OF DRIZZLE AGAIN
EACH MORNING THROUGH MONDAY. LIMITED COASTAL CLEARING AND CLOUDS MAY
LINGER INTO EARLY AFTERNOON FOR SOME OF THE VALLEYS. DAYTIME TEMPS
EXPECTED TO RUN 2-4 DEGREES BELOW NORMAL. THE TROF IS EXPECTED TO
SHIFT EAST TUESDAY FOR A WARMING TREND GOING INTO THE MIDDLE OF NEXT
WEEK.

&&

.FIRE WEATHER...
AS WINDS RAMP UP WEDNESDAY AFTERNOON AND EVENING ACROSS THE SBA
SOUTH COAST AND MOUNTAINS...I-5 CORRIDOR OF THE LA/VTU COUNTY MOUNTAINS...
AND ANTELOPE VALLEY...THERE WILL BE ELEVATED FIRE DANGER ACROSS ALL
OF THESE AREAS. HUMDITIY LEVELS COULD BRIEFLY FALL BELOW 15 PERCENT
ACROSS THE SBA SOUTH COAST ON WEDNESDAY AFTERNOON. SIMILAR LOW HUMIDITIES
WILL LIKELY IMPACT THE I-5 CORRIDOR AND ANTELOPE VALLEY DURING THE
LATE AFTERNOON AND EVENING HOURS. AS A RESULT...ALL OF THESE AREAS COULD
EXPERIENCE BRIEF CRITICAL FIRE WEATHER CONDITIONS...ESPECIALLY CONSIDERING
THE VERY DRY FUELS FOR THIS TIME OF YEAR. HOWEVER...IT DOES NOT APPEAR
THAT DURATIONS OF CRITICAL FIRE WEATHER CONDITIONS WILL BE MET TO ISSUE
RED FLAG WARNINGS FOR THIS EVENT.

&&

.AVIATION...21/2355Z.

SATELLITE IMAGERY SHOWING LOW CLOUDS SURGING QUICKLY INTO THE LA
COUNTY COASTAL AREAS LATE THIS AFTERNOON...INCLUDING KLAX. CLEARING
BEING OBSERVED TO THE NORTHWEST OF LA COUNTY. LOWER CONFIDENCE IN
LOW CLOUDS RETURNING TO COASTAL AREAS NORTH OF POINT CONCEPTION...WITH
HIGHER PROBABILITY OF CIGS ACROSS LA COUNTY COAST/VALLEYS TONIGHT.
APPEARS THAT EDDY WILL BE STRONG ENOUGH TO BRING LOW CLOUDS BACK
INTO KOXR EARLY WEDNESDAY MORNING. EDDY CIRCULATION EXPECTED TO MAINTAIN
CIGS IN MVFR CATEGORY FOR THE MOST PART...WITH THE EXCEPTION OF A 30 PERCENT
CHANCE OF IFR CONDITIONS IN THE VALLEYS (INCLUDING KBUR AND KVNY).
GUSTY WINDS ACROSS THE PASSES AND CANYONS OF SBA COUNTY THIS EVENING
AND SOMEWHAT STRONGER TOMORROW EVENING...BRINGING A GOOD CHANCE OF LLWS
BOTH EVENINGS. ALSO...GUSTY WEST TO NORTHWEST WINDS WILL BE AFFECTING
KSMX...KSBP...KPMD...AND KWJF THROUGH PERIOD.


KLAX...LOW CLOUDS SURGING IN QUICKLY AS OF 00Z WITH MVFR CIGS ALREADY
OBSERVED. CURRENT THINKING IS THAT LOW CLOUDS WILL LIKELY LINGER FOR
THE NIGHT...BUT THERE IS A 30 PERCENT CHANCE THAT LOW CLOUDS COULD SCOUR
OUT FOR A FEW HOURS LATER THIS EVENING BEFORE RETURNING. CIGS GENERALLY
EXPECTED TO REMAIN IN MVFR CATEGORY.


KBUR...FAIRLY HIGH CONFIDENCE THAT LOW CLOUDS WILL RETURN OVERNIGHT INTO
WEDNESDAY MORNING. LEANING TOWARDS MVFR CATEGORY...BUT A 30 PERCENT CHANCE
OF IFR CONDITIONS.

&&

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

&&

$$

PUBLIC...GOMBERG/MW
AVIATION...GOMBERG
FIRE...GOMBERG
SYNOPSIS...KJ

WWW.WEATHER.GOV/LOSANGELES

000
FXUS66 KLOX 220001
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
500 PM PDT TUE MAY 21 2013

...UPDATED AVIATION DISCUSSION...

.SYNOPSIS...

A COOLING TREND THAT BEGAN FOR MOST AREAS TODAY WILL CONTINUE
THROUGH THE WEEKEND ALONG WITH AN INCREASE IN NIGHT THROUGH MORNING
LOW CLOUDS AND FOG. BREEZY CONDITIONS ARE EXPECTED ALONG THE CENTRAL
COAST...SOUTHERN SANTA BARBARA COUNTY...INTERSTATE 5 CORRIDOR...AND
THE ANTELOPE VALLEY.

&&

.SHORT TERM (TODAY-FRI)...A STRONG ONSHORE PUSH TODAY BROUGHT
COOLING TO MOST AREAS EXCEPT SOME OF THE MTNS AND ANTELOPE VALLEY.
THIS WILL CONTINUE AND SPREAD FURTHER INLAND THROUGH THE WEEKEND AS
A PERSISTENT TROF SETS UP ALONG THE WEST COAST. SLIGHT DEEPENING OF
THE TROF IS EXPECTED WED AND THU, AND THIS COMBINED WITH A
STRENGTHENING EDDY CIRCULATION (THANKS TO INCREASING OUTER WATER
WINDS) WILL POSSIBLY BE ENOUGH TO GENERATE SOME DRIZZLE DURING THE
OVERNIGHT HOURS ACROSS VENTURA AND LA COUNTIES. THAT INCREASE IN
NORTHWEST FLOW AROUND PT CONCEPTION AND THROUGH THE SANTA YNEZ RANGE
WILL LIKELY KEEP LOW CLOUDS OUT OF SRN SBA COUNTY THE NEXT FEW DAYS
WITH WARMER TEMPS THERE. WINDS WILL BE CLOSE TO OR LOCALLY EXCEEDING
ADVISORY CRITERIA FOR SRN SBA COUNTY, THE I5 CORRIDOR AND THE
ANTELOPE VALLEY STARTING LATE WED.

IF THE MODELS ARE TO BE BELIEVED, THE TROF BRIEFLY LIFTS ON FRIDAY,
RESULTING IN A VERY SLIGHT WARMING TREND FRIDAY, MAYBE A FEW DEGREES
AT MOST, AND EARLIER MARINE LYR CLEARING.

.LONG TERM (SAT-TUE)...TROF DEEPENS AGAIN OVER THE HOLIDAY WEEKEND.
DECREASING NORTHWEST FLOW SHOULD ALLOW THE LOW CLOUDS TO SPREAD UP
THE COAST THROUGH SLO COUNTY AND WE MAY SEE AREAS OF DRIZZLE AGAIN
EACH MORNING THROUGH MONDAY. LIMITED COASTAL CLEARING AND CLOUDS MAY
LINGER INTO EARLY AFTERNOON FOR SOME OF THE VALLEYS. DAYTIME TEMPS
EXPECTED TO RUN 2-4 DEGREES BELOW NORMAL. THE TROF IS EXPECTED TO
SHIFT EAST TUESDAY FOR A WARMING TREND GOING INTO THE MIDDLE OF NEXT
WEEK.

&&

.AVIATION...21/2355Z.

SATELLITE IMAGERY SHOWING LOW CLOUDS SURGING QUICKLY INTO THE LA
COUNTY COASTAL AREAS LATE THIS AFTERNOON...INCLUDING KLAX. CLEARING
BEING OBSERVED TO THE NORTHWEST OF LA COUNTY. LOWER CONFIDENCE IN
LOW CLOUDS RETURNING TO COASTAL AREAS NORTH OF POINT CONCEPTION...WITH
HIGHER PROBABILITY OF CIGS ACROSS LA COUNTY COAST/VALLEYS TONIGHT.
APPEARS THAT EDDY WILL BE STRONG ENOUGH TO BRING LOW CLOUDS BACK
INTO KOXR EARLY WEDNESDAY MORNING. EDDY CIRCULATION EXPECTED TO MAINTAIN
CIGS IN MVFR CATEGORY FOR THE MOST PART...WITH THE EXCEPTION OF A 30 PERCENT
CHANCE OF IFR CONDITIONS IN THE VALLEYS (INCLUDING KBUR AND KVNY).
GUSTY WINDS ACROSS THE PASSES AND CANYONS OF SBA COUNTY THIS EVENING
AND SOMEWHAT STRONGER TOMORROW EVENING...BRINGING A GOOD CHANCE OF LLWS
BOTH EVENINGS. ALSO...GUSTY WEST TO NORTHWEST WINDS WILL BE AFFECTING
KSMX...KSBP...KPMD...AND KWJF THROUGH PERIOD.


KLAX...LOW CLOUDS SURGING IN QUICKLY AS OF 00Z WITH MVFR CIGS ALREADY
OBSERVED. CURRENT THINKING IS THAT LOW CLOUDS WILL LIKELY LINGER FOR
THE NIGHT...BUT THERE IS A 30 PERCENT CHANCE THAT LOW CLOUDS COULD SCOUR
OUT FOR A FEW HOURS LATER THIS EVENING BEFORE RETURNING. CIGS GENERALLY
EXPECTED TO REMAIN IN MVFR CATEGORY.


KBUR...FAIRLY HIGH CONFIDENCE THAT LOW CLOUDS WILL RETURN OVERNIGHT INTO
WEDNESDAY MORNING. LEANING TOWARDS MVFR CATEGORY...BUT A 30 PERCENT CHANCE
OF IFR CONDITIONS.

&&

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

&&

$$

PUBLIC...MW
AVIATION...GOMBERG
SYNOPSIS...KJ

WWW.WEATHER.GOV/LOSANGELES

000
FXUS66 KLOX 212041
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
142 PM PDT TUE MAY 21 2013

.SYNOPSIS...

A COOLING TREND THAT BEGAN FOR MOST AREAS TODAY WILL CONTINUE
THROUGH THE WEEKEND ALONG WITH AN INCREASE IN NIGHT THROUGH MORNING
LOW CLOUDS AND FOG. BREEZY CONDITIONS ARE EXPECTED ALONG THE CENTRAL
COAST...SOUTHERN SANTA BARBARA COUNTY...INTERSTATE 5 CORRIDOR...AND
THE ANTELOPE VALLEY.

&&

.SHORT TERM (TODAY-FRI)...A STRONG ONSHORE PUSH TODAY BROUGHT
COOLING TO MOST AREAS EXCEPT SOME OF THE MTNS AND ANTELOPE VALLEY.
THIS WILL CONTINUE AND SPREAD FURTHER INLAND THROUGH THE WEEKEND AS
A PERSISTENT TROF SETS UP ALONG THE WEST COAST. SLIGHT DEEPENING OF
THE TROF IS EXPECTED WED AND THU, AND THIS COMBINED WITH A
STRENGTHENING EDDY CIRCULATION (THANKS TO INCREASING OUTER WATER
WINDS) WILL POSSIBLY BE ENOUGH TO GENERATE SOME DRIZZLE DURING THE
OVERNIGHT HOURS ACROSS VENTURA AND LA COUNTIES. THAT INCREASE IN
NORTHWEST FLOW AROUND PT CONCEPTION AND THROUGH THE SANTA YNEZ RANGE
WILL LIKELY KEEP LOW CLOUDS OUT OF SRN SBA COUNTY THE NEXT FEW DAYS
WITH WARMER TEMPS THERE. WINDS WILL BE CLOSE TO OR LOCALLY EXCEEDING
ADVISORY CRITERIA FOR SRN SBA COUNTY, THE I5 CORRIDOR AND THE
ANTELOPE VALLEY STARTING LATE WED.

IF THE MODELS ARE TO BE BELIEVED, THE TROF BRIEFLY LIFTS ON FRIDAY,
RESULTING IN A VERY SLIGHT WARMING TREND FRIDAY, MAYBE A FEW DEGREES
AT MOST, AND EARLIER MARINE LYR CLEARING.

.LONG TERM (SAT-TUE)...TROF DEEPENS AGAIN OVER THE HOLIDAY WEEKEND.
DECREASING NORTHWEST FLOW SHOULD ALLOW THE LOW CLOUDS TO SPREAD UP
THE COAST THROUGH SLO COUNTY AND WE MAY SEE AREAS OF DRIZZLE AGAIN
EACH MORNING THROUGH MONDAY. LIMITED COASTAL CLEARING AND CLOUDS MAY
LINGER INTO EARLY AFTERNOON FOR SOME OF THE VALLEYS. DAYTIME TEMPS
EXPECTED TO RUN 2-4 DEGREES BELOW NORMAL. THE TROF IS EXPECTED TO
SHIFT EAST TUESDAY FOR A WARMING TREND GOING INTO THE MIDDLE OF NEXT
WEEK.

&&

.AVIATION...21/1800Z.

OVERALL CONFIDENCE IN THE 18Z TAF PACKAGE IS MODERATE. MODERATE TO
HIGH CONFIDENCE THAT ALL TAF SITES WILL REMAIN IN VFR CONDITIONS
THROUGH EARLY THIS EVENING. A TROUGH WILL MOVE THROUGH THE AREA
TODAY AND INCREASED NORTHERLY FLOW WILL HELP THIS. FOR TONIGHT AND
TOMORROW MORNING...MODERATE TO HIGH CONFIDENCE THAT MOST SITES NORTH
OF KOXR WILL REMAIN VFR DUE TO THE PREVIOUSLY MENTIONED STRONG
NORTHERLY FLOW AND EVEN SOME NORTHEAST FLOW ON THE CENTRAL COAST.
THERE IS A 30% CHANCE THAT KSMX WILL NOT SEE THE CEILINGS THAT ARE
CURRENTLY PREDICTED. A CATALINA EDDY WILL SPIN UP AGAIN TONIGHT AND
THE MARINE LAYER WILL DEEPEN FOR LOS ANGELES AND VENTURA
COUNTIES...SO A SIMILAR CLOUD PATTERN IS EXPECTED FOR THESE TAF
SITES TOMORROW MORNING AS TO WHAT WAS SEEN TODAY. LESS CONFIDENT IN
THE KOXR TAF AS THERE WILL BE STRONGER NORTHERLY FLOW TOMORROW
MORNING...WHICH MAY MAKE IT DIFFICULT FOR THE EDDY TO BRING LOW
CLOUDS THAT FAR NORTH. THERE IS A 30% CHANCE THAT THE FORECASTED
CEILINGS FOR KOXR TOMORROW MORNING WILL NOT DEVELOP.

KLAX...MODERATE TO HIGH CONFIDENCE IN VFR CONDITIONS THROUGH EARLY
THIS EVENING. HIGH CONFIDENCE THAT MVFR CONDITIONS WILL RETURN FOR
TONIGHT AND TOMORROW MORNING...HOWEVER LOW TO MODERATE CONFIDENCE IN
THE EXACT ARRIVAL TIME.

KBUR...HIGH CONFIDENCE IN VFR CONDITIONS THROUGH EARLY THIS EVENING.
MODERATE TO HIGH CONFIDENCE THAT AT LEAST MVFR CONDITIONS WILL
RETURN TONIGHT AND TOMORROW MORNING...HOWEVER LOW TO MODERATE
CONFIDENCE IN THE EXACT ARRIVAL TIME. THERE IS A 20% CHANCE THAT
CIGS COULD FALL INTO THE IFR CATEGORY.

&&

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

&&

$$

PUBLIC...MW
AVIATION...SWEET
SYNOPSIS...KJ

WWW.WEATHER.GOV/LOSANGELES

000
FXUS66 KLOX 211823
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1125 AM PDT TUE MAY 21 2013

...UPDATED AVIATION DISCUSSION...

.SYNOPSIS...
A COOLING TREND WILL BEGIN TODAY AND CONTINUE THROUGH
THURSDAY...ALONG WITH AN INCREASE IN NIGHT THROUGH MORNING LOW
CLOUDS AND FOG. COOL WEATHER WITH PLENTY OF NIGHT THROUGH MORNING
LOW CLOUDS AND FOG WILL LIKELY CONTINUE THROUGH THE HOLIDAY
WEEKEND.

&&

.SHORT TERM (TODAY-THU)...COOLING TREND STARTING TODAY WITH A STRONG
ONSHORE PUSH. MOST INLAND AREAS SHOULD BE COOLER BY 4-8 DEGREES FROM
YESTERDAY WHILE THE COAST RUNS A COUPLE DEGREES COOLER. MARINE LYR
MUCH MORE SOLID S OF PT CONCEPTION THIS MORNING UNDER A STRONGER
INVERSION AND WEAK EDDY CIRCULATION. THE FORECAST FOR THE REMAINDER
OF THE WEEK LOOKS LARGELY UNCHANGED FROM YESTERDAY AND AGAIN
EXPECTING MINIMAL CHANGES WITH THE AFTERNOON FORECAST.

***FROM PREVIOUS DISCUSSION***

AN UPPER LOW WILL MOVE INTO THE PAC NW TONIGHT AND WED...WITH A
SHARPENING TROUGH EXTENDING SOUTHWARD THRU CA. N-S GRADIENTS WILL
INCREASE ACROSS THE REGION TONIGHT...AND GUSTY NW TO N WINDS WILL
LIKELY AFFECT LOCATIONS THRU AND BELOW PASSES AND CANYONS OF THE
SANTA YNEZ RANGE IN SRN SBA COUNTY. EXPECT WINDS TO REMAIN JUST
BELOW ADVISORY LEVEL IN THESE AREAS AS WELL.

EXPECT LOW CLOUDS ACROSS MOST COASTAL AND VALLEY AREAS TONIGHT AND
WED MORNING. HOWEVER...ACROSS THE SBA COUNTY S COAST...NLY WINDS
WILL LIKELY ALLOW SKIES TO REMAIN CLEAR THERE. EXPECT CLOUDS TO
CLEAR FAIRLY WELL ON WED...ALTHOUGH THEY MAY LINGER INTO THE
AFTERNOON ONCE AGAIN NEAR SOME BEACHES OF L.A. AND VTU COUNTIES.
GUSTY WEST TO NORTHWEST WINDS WILL AFFECT THE INTERSTATE 5 CORRIDOR
TONIGHT AND WED...LIKELY STAYING BELOW ADVISORY LEVELS. MAX TEMPS
WILL BE DOWN A FEW MORE DEGREES IN MOST AREAS WED.

THE UPPER LOW WILL CONTINUE TO SPIN ACROSS THE PAC NW WED NIGHT AND
THU...BUT THE TROUGH ACROSS CA WILL SHARPEN UP A BIT. THE MARINE
LAYER SHOULD DEEPEN A BIT MORE...AND NIGHT/MORNING LOW CLOUDS AND
FOG MAY HAVE TO BE ADDED TO THE SANTA CLARITA VALLEY AND POSSIBLY
EVEN THE COASTAL SLOPES. INCREASINGLY CYCLONIC HEIGHT PATTERN ALOFT
SUGGESTS THAT THERE MAY BE ENOUGH LIFT TO PRODUCE SOME DRIZZLE
LATE WED NIGHT/THU...MAINLY IN COASTAL SECTIONS OF L.A. AND VTU
COUNTIES. N-S GRADS WILL CONT TO INCREASE...AND ADVISORY LEVEL WINDS
ARE POSSIBLE ACROSS THE SBA COUNTY S COAST AND ACROSS THE INTERSTATE
5 CORRIDOR WED NIGHT. ON THE CENTRAL COAST...WINDS WILL APPROACH
WINDS ADVISORY LEVELS DURING THE AFTERNOON HOURS OF BOTH WED AND
THU. THU LOOKS TO BE THE DAY WITH THE GREATEST POTENTIAL FOR CLOUDS
LINGERING AT THE BEACHES OF L.A. AND VTU COUNTIES. TEMPS WILL BE
DOWN A COUPLE OF MORE DEGREES IN MOST AREAS ON THU...DOWN TO SEVERAL
DEGREES BELOW NORMAL IN MOST AREAS.

.LONG TERM (FRI-MON)...A LARGE UPPER LOW WILL CONTINUE TO SPIN
ACROSS THE PACIFIC NORTHWEST THROUGH THE HOLIDAY WEEKEND...WITH
TROFFING EXTENDING SOUTHWARD INTO THE FORECAST AREAS. FOR FRI
THROUGH MON..EXPECT PLENTY OF NIGHT THRU MORNING LOW CLOUDS AND FOG
IN COASTAL AND VALLEY AREAS. TEMPS WILL LIKELY BE AT LEAST A FEW
DEGREES NORMAL THROUGH THE PERIOD.

&&

.AVIATION...21/18Z.
OVERALL CONFIDENCE IN THE 18Z TAF PACKAGE IS MODERATE. MODERATE TO
HIGH CONFIDENCE THAT ALL TAF SITES WILL REMAIN IN VFR CONDITIONS
THROUGH EARLY THIS EVENING. A TROUGH WILL MOVE THROUGH THE AREA
TODAY AND INCREASED NORTHERLY FLOW WILL HELP THIS. FOR TONIGHT AND
TOMORROW MORNING...MODERATE TO HIGH CONFIDENCE THAT MOST SITES NORTH
OF KOXR WILL REMAIN VFR DUE TO THE PREVIOUSLY MENTIONED STRONG
NORTHERLY FLOW AND EVEN SOME NORTHEAST FLOW ON THE CENTRAL COAST.
THERE IS A 30% CHANCE THAT KSMX WILL NOT SEE THE CEILINGS THAT ARE
CURRENTLY PREDICTED. A CATALINA EDDY WILL SPIN UP AGAIN TONIGHT AND
THE MARINE LAYER WILL DEEPEN FOR LOS ANGELES AND VENTURA
COUNTIES...SO A SIMILAR CLOUD PATTERN IS EXPECTED FOR THESE TAF
SITES TOMORROW MORNING AS TO WHAT WAS SEEN TODAY. LESS CONFIDENT IN
THE KOXR TAF AS THERE WILL BE STRONGER NORTHERLY FLOW TOMORROW
MORNING...WHICH MAY MAKE IT DIFFICULT FOR THE EDDY TO BRING LOW
CLOUDS THAT FAR NORTH. THERE IS A 30% CHANCE THAT THE FORECASTED
CEILINGS FOR KOXR TOMORROW MORNING WILL NOT DEVELOP.

KLAX...MODERATE TO HIGH CONFIDENCE IN VFR CONDITIONS THROUGH EARLY
THIS EVENING. HIGH CONFIDENCE THAT MVFR CONDITIONS WILL RETURN FOR
TONIGHT AND TOMORROW MORNING...HOWEVER LOW TO MODERATE CONFIDENCE IN
THE EXACT ARRIVAL TIME.

KBUR...HIGH CONFIDENCE IN VFR CONDITIONS THROUGH EARLY THIS EVENING.
MODERATE TO HIGH CONFIDENCE THAT AT LEAST MVFR CONDITIONS WILL
RETURN TONIGHT AND TOMORROW MORNING...HOWEVER LOW TO MODERATE
CONFIDENCE IN THE EXACT ARRIVAL TIME. THERE IS A 20% CHANCE THAT
CIGS COULD FALL INTO THE IFR CATEGORY.

&&

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

&&

$$

PUBLIC...MW/DB
AVIATION...SS/DS

WWW.WEATHER.GOV/LOSANGELES

000
FXUS66 KLOX 211617
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
915 AM PDT TUE MAY 21 2013

.SYNOPSIS...
A COOLING TREND WILL BEGIN TODAY AND CONTINUE THROUGH
THURSDAY...ALONG WITH AN INCREASE IN NIGHT THROUGH MORNING LOW
CLOUDS AND FOG. COOL WEATHER WITH PLENTY OF NIGHT THROUGH MORNING
LOW CLOUDS AND FOG WILL LIKELY CONTINUE THROUGH THE HOLIDAY
WEEKEND.

&&

.SHORT TERM (TODAY-THU)...COOLING TREND STARTING TODAY WITH A STRONG
ONSHORE PUSH. MOST INLAND AREAS SHOULD BE COOLER BY 4-8 DEGREES FROM
YESTERDAY WHILE THE COAST RUNS A COUPLE DEGREES COOLER. MARINE LYR
MUCH MORE SOLID S OF PT CONCEPTION THIS MORNING UNDER A STRONGER
INVERSION AND WEAK EDDY CIRCULATION. THE FORECAST FOR THE REMAINDER
OF THE WEEK LOOKS LARGELY UNCHANGED FROM YESTERDAY AND AGAIN
EXPECTING MINIMAL CHANGES WITH THE AFTERNOON FORECAST.

***FROM PREVIOUS DISCUSSION***

AN UPPER LOW WILL MOVE INTO THE PAC NW TONIGHT AND WED...WITH A
SHARPENING TROUGH EXTENDING SOUTHWARD THRU CA. N-S GRADIENTS WILL
INCREASE ACROSS THE REGION TONIGHT...AND GUSTY NW TO N WINDS WILL
LIKELY AFFECT LOCATIONS THRU AND BELOW PASSES AND CANYONS OF THE
SANTA YNEZ RANGE IN SRN SBA COUNTY. EXPECT WINDS TO REMAIN JUST
BELOW ADVISORY LEVEL IN THESE AREAS AS WELL.

EXPECT LOW CLOUDS ACROSS MOST COASTAL AND VALLEY AREAS TONIGHT AND
WED MORNING. HOWEVER...ACROSS THE SBA COUNTY S COAST...NLY WINDS
WILL LIKELY ALLOW SKIES TO REMAIN CLEAR THERE. EXPECT CLOUDS TO
CLEAR FAIRLY WELL ON WED...ALTHOUGH THEY MAY LINGER INTO THE
AFTERNOON ONCE AGAIN NEAR SOME BEACHES OF L.A. AND VTU COUNTIES.
GUSTY WEST TO NORTHWEST WINDS WILL AFFECT THE INTERSTATE 5 CORRIDOR
TONIGHT AND WED...LIKELY STAYING BELOW ADVISORY LEVELS. MAX TEMPS
WILL BE DOWN A FEW MORE DEGREES IN MOST AREAS WED.

THE UPPER LOW WILL CONTINUE TO SPIN ACROSS THE PAC NW WED NIGHT AND
THU...BUT THE TROUGH ACROSS CA WILL SHARPEN UP A BIT. THE MARINE
LAYER SHOULD DEEPEN A BIT MORE...AND NIGHT/MORNING LOW CLOUDS AND
FOG MAY HAVE TO BE ADDED TO THE SANTA CLARITA VALLEY AND POSSIBLY
EVEN THE COASTAL SLOPES. INCREASINGLY CYCLONIC HEIGHT PATTERN ALOFT
SUGGESTS THAT THERE MAY BE ENOUGH LIFT TO PRODUCE SOME DRIZZLE
LATE WED NIGHT/THU...MAINLY IN COASTAL SECTIONS OF L.A. AND VTU
COUNTIES. N-S GRADS WILL CONT TO INCREASE...AND ADVISORY LEVEL WINDS
ARE POSSIBLE ACROSS THE SBA COUNTY S COAST AND ACROSS THE INTERSTATE
5 CORRIDOR WED NIGHT. ON THE CENTRAL COAST...WINDS WILL APPROACH
WINDS ADVISORY LEVELS DURING THE AFTERNOON HOURS OF BOTH WED AND
THU. THU LOOKS TO BE THE DAY WITH THE GREATEST POTENTIAL FOR CLOUDS
LINGERING AT THE BEACHES OF L.A. AND VTU COUNTIES. TEMPS WILL BE
DOWN A COUPLE OF MORE DEGREES IN MOST AREAS ON THU...DOWN TO SEVERAL
DEGREES BELOW NORMAL IN MOST AREAS.

.LONG TERM (FRI-MON)...A LARGE UPPER LOW WILL CONTINUE TO SPIN
ACROSS THE PACIFIC NORTHWEST THROUGH THE HOLIDAY WEEKEND...WITH
TROFFING EXTENDING SOUTHWARD INTO THE FORECAST AREAS. FOR FRI
THROUGH MON..EXPECT PLENTY OF NIGHT THRU MORNING LOW CLOUDS AND FOG
IN COASTAL AND VALLEY AREAS. TEMPS WILL LIKELY BE AT LEAST A FEW
DEGREES NORMAL THROUGH THE PERIOD.

&&

.AVIATION...21/12Z.
COASTAL LOW CLOUDS AND FOG WILL THIN AFTER DAYBREAK BUT SOME
LOCATIONS WILL NOT CLEAR PRIOR TO THE MARINE LAYER RETURNING AFTER
00Z.  FORTY PERCENT CHANCE OF GUSTY NORTHERLY WINDS ACROSS THE SANTA
BARBARA COASTAL MOUNTAINS AND SOUTH COAST 00Z-08Z.  VFR ELSEWHERE.

KLAX...IFR CONDITIONS WILL CONTINUE THROUGH 18Z-20Z THEN THE CLOUD
DECK WILL THIN DURING THE DAY.  IFR CONDITIONS RETURN 02Z-06Z
WITH A 40 PERCENT CHANCE OF LIFR.

KBUR...IFR CONDITIONS WILL CONTINUE THROUGH 17Z-19Z THEN THE CLOUD
DECK WILL THIN DURING THE DAY.  IFR CONDITIONS RETURN 06Z-10Z WITH
A 20 PERCENT CHANCE OF LIFR.

&&

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

&&

$$

PUBLIC...MW/DB
AVIATION...KJ

WWW.WEATHER.GOV/LOSANGELES

000
FXUS66 KLOX 211211
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
440 AM PDT TUE MAY 21 2013

...AVIATION DISCUSSION UPDATED...

.SYNOPSIS...
A COOLING TREND WILL BEGIN TODAY AND CONTINUE THROUGH
THURSDAY...ALONG WITH AN INCREASE IN NIGHT THROUGH MORNING LOW
CLOUDS AND FOG. COOL WEATHER WITH PLENTY OF NIGHT THROUGH MORNING
LOW CLOUDS AND FOG WILL LIKELY CONTINUE THROUGH THE HOLIDAY
WEEKEND.

&&

.SHORT TERM (TODAY-THU)...
EDDY CIRCULATION HAS DEVELOPED ACROSS THE INNER COASTAL WATERS THIS
MORNING. AMDAR SOUNDINGS OUT OF KLAX HAVE SHOWED A STEADY DEEPENING
OF THE MARINE LAYER LAST EVENING THROUGH EARLY THIS MORNING...WITH
ITS DEPTH NOW UP TO ABOUT 1800 FEET. LOW CLOUDS HAVE ALREADY
OVERSPREAD COASTAL AREAS OF L.A. AND VTU COUNTIES...AND THE VALLEYS
OF L.A. COUNTY WITH THE EXCEPTION OF THE SANTA CLARITA VALLEY. BY
DAYBREAK...EXPECT CLOUDS TO PUSH INTO THE VTU COUNTY VALLEYS AND
INTO COASTAL SECTIONS OF SOUTHERN SANTA BARBARA COUNTY. N OF PT
CONCEPTION...STRATUS WAS MORE PATCHY IN NATURE...POSSIBLY DISRUPTED
BY A THICK BAND OF HIGH CLOUDINESS PUSHING INTO THE COAST. EXPECT
THE LOW CLOUDS TO CLEAR IN MOST AREAS BY LATE MORNING...BUT WITH
INCREASINGLY STRONG ONSHORE GRADIENTS...THERE IS A CHANCE THAT SOME
CLOUDS COULD LINGER NEAR THE BEACHES...ESPECIALLY ACROSS VTU AND
L.A.COUNTIES. THERE WILL BE ENOUGH HIGH CLOUDINESS TO USE PARTLY
CLOUDY WORDING ACROSS THE REGION ASIDE FROM ANY LOW CLOUD ISSUES.
MAX TEMPS WILL BE DOWN SIGNIFICANTLY TODAY...ESPECIALLY IN THE
VALLEYS...WHERE HIGHS WILL LIKELY BE 8 TO 12 DEGREES LOWER THAN THEY
WERE YESTERDAY IN MOST AREAS. THE INCREASE IN ONSHORE FLOW WILL
BRING GUSTY WINDS TO THE MTNS...THE ANTELOPE VALLEY...THE SANTA
CLARITA VALLEY AND THE CENTRAL COAST THIS AFTERNOON. AT THIS
TIME...EXPECT WINDS TO REMAIN JUST BELOW ADVISORY LEVELS...WITH
GUSTS OF 30 TO 35 MPH EXPECTED...EXCEPT POSSIBLY TO 40 TO 45 MPH
ACROSS WESTERN PORTIONS OF THE ANTELOPE VALLEY.

AN UPPER LOW WILL MOVE INTO THE PAC NW TONIGHT AND WED...WITH A
SHARPENING TROUGH EXTENDING SOUTHWARD THRU CA. N-S GRADIENTS WILL
INCREASE ACROSS THE REGION TONIGHT...AND GUSTY NW TO N WINDS WILL
LIKELY AFFECT LOCATIONS THRU AND BELOW PASSES AND CANYONS OF THE
SANTA YNEZ RANGE IN SRN SBA COUNTY. EXPECT WINDS TO REMAIN JUST
BELOW ADVISORY LEVEL IN THESE AREAS AS WELL.

EXPECT LOW CLOUDS ACROSS MOST COASTAL AND VALLEY AREAS TONIGHT AND
WED MORNING. HOWEVER...ACROSS THE SBA COUNTY S COAST...NLY WINDS
WILL LIKELY ALLOW SKIES TO REMAIN CLEAR THERE. EXPECT CLOUDS TO
CLEAR FAIRLY WELL ON WED...ALTHOUGH THEY MAY LINGER INTO THE
AFTERNOON ONCE AGAIN NEAR SOME BEACHES OF L.A. AND VTU COUNTIES.
GUSTY WEST TO NORTHWEST WINDS WILL AFFECT THE INTERSTATE 5 CORRIDOR
TONIGHT AND WED...LIKELY STAYING BELOW ADVISORY LEVELS. MAX TEMPS
WILL BE DOWN A FEW MORE DEGREES IN MOST AREAS WED.

THE UPPER LOW WILL CONTINUE TO SPIN ACROSS THE PAC NW WED NIGHT AND
THU...BUT THE TROUGH ACROSS CA WILL SHARPEN UP A BIT. THE MARINE
LAYER SHOULD DEEPEN A BIT MORE...AND NIGHT/MORNING LOW CLOUDS AND
FOG MAY HAVE TO BE ADDED TO THE SANTA CLARITA VALLEY AND POSSIBLY
EVEN THE COASTAL SLOPES. INCREASINGLY CYCLONIC HEIGHT PATTERN ALOFT
SUGGESTS THAT THERE MAY BE ENOUGH LIFT TO PRODUCE SOME DRIZZLE
LATE WED NIGHT/THU...MAINLY IN COASTAL SECTIONS OF L.A. AND VTU
COUNTIES. N-S GRADS WILL CONT TO INCREASE...AND ADVISORY LEVEL WINDS
ARE POSSIBLE ACROSS THE SBA COUNTY S COAST AND ACROSS THE INTERSTATE
5 CORRIDOR WED NIGHT. ON THE CENTRAL COAST...WINDS WILL APPROACH
WINDS ADVISORY LEVELS DURING THE AFTERNOON HOURS OF BOTH WED AND
THU. THU LOOKS TO BE THE DAY WITH THE GREATEST POTENTIAL FOR CLOUDS
LINGERING AT THE BEACHES OF L.A. AND VTU COUNTIES. TEMPS WILL BE
DOWN A COUPLE OF MORE DEGREES IN MOST AREAS ON THU...DOWN TO SEVERAL
DEGREES BELOW NORMAL IN MOST AREAS.


.LONG TERM (FRI-MON)...A LARGE UPPER LOW WILL CONTINUE TO SPIN
ACROSS THE PACIFIC NORTHWEST THROUGH THE HOLIDAY WEEKEND...WITH
TROFFING EXTENDING SOUTHWARD INTO THE FORECAST AREAS. FOR FRI
THROUGH MON..EXPECT PLENTY OF NIGHT THRU MORNING LOW CLOUDS AND FOG
IN COASTAL AND VALLEY AREAS. TEMPS WILL LIKELY BE AT LEAST A FEW
DEGREES NORMAL THROUGH THE PERIOD.

&&

.AVIATION...21/12Z.
COASTAL LOW CLOUDS AND FOG WILL THIN AFTER DAYBREAK BUT SOME
LOCATIONS WILL NOT CLEAR PRIOR TO THE MARINE LAYER RETURNING AFTER
00Z.  FORTY PERCENT CHANCE OF GUSTY NORTHERLY WINDS ACROSS THE SANTA
BARBARA COASTAL MOUNTAINS AND SOUTH COAST 00Z-08Z.  VFR ELSEWHERE.

KLAX...IFR CONDITIONS WILL CONTINUE THROUGH 18Z-20Z THEN THE CLOUD
DECK WILL THIN DURING THE DAY.  IFR CONDITIONS RETURN 02Z-06Z
WITH A 40 PERCENT CHANCE OF LIFR.

KBUR...IFR CONDITIONS WILL CONTINUE THROUGH 17Z-19Z THEN THE CLOUD
DECK WILL THIN DURING THE DAY.  IFR CONDITIONS RETURN 06Z-10Z WITH
A 20 PERCENT CHANCE OF LIFR.

&&

$$

PUBLIC...DB
AVIATION...KJ


WWW.WEATHER.GOV/LOSANGELES

000
FXUS66 KLOX 211121
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
340 AM PDT TUE MAY 21 2013

.SYNOPSIS...
A COOLING TREND WILL BEGIN TODAY AND CONTINUE THROUGH
THURSDAY...ALONG WITH AN INCREASE IN NIGHT THROUGH MORNING LOW
CLOUDS AND FOG. COOL WEATHER WITH PLENTY OF NIGHT THROUGH MORNING
LOW CLOUDS AND FOG WILL LIKELY CONTINUE THROUGH THE HOLIDAY
WEEKEND.

&&

.SHORT TERM (TODAY-THU)...
EDDY CIRCULATION HAS DEVELOPED ACROSS THE INNER COASTAL WATERS THIS
MORNING. AMDAR SOUNDINGS OUT OF KLAX HAVE SHOWED A STEADY DEEPENING
OF THE MARINE LAYER LAST EVENING THROUGH EARLY THIS MORNING...WITH
ITS DEPTH NOW UP TO ABOUT 1800 FEET. LOW CLOUDS HAVE ALREADY
OVERSPREAD COASTAL AREAS OF L.A. AND VTU COUNTIES...AND THE VALLEYS
OF L.A. COUNTY WITH THE EXCEPTION OF THE SANTA CLARITA VALLEY. BY
DAYBREAK...EXPECT CLOUDS TO PUSH INTO THE VTU COUNTY VALLEYS AND
INTO COASTAL SECTIONS OF SOUTHERN SANTA BARBARA COUNTY. N OF PT
CONCEPTION...STRATUS WAS MORE PATCHY IN NATURE...POSSIBLY DISRUPTED
BY A THICK BAND OF HIGH CLOUDINESS PUSHING INTO THE COAST. EXPECT
THE LOW CLOUDS TO CLEAR IN MOST AREAS BY LATE MORNING...BUT WITH
INCREASINGLY STRONG ONSHORE GRADIENTS...THERE IS A CHANCE THAT SOME
CLOUDS COULD LINGER NEAR THE BEACHES...ESPECIALLY ACROSS VTU AND
L.A.COUNTIES. THERE WILL BE ENOUGH HIGH CLOUDINESS TO USE PARTLY
CLOUDY WORDING ACROSS THE REGION ASIDE FROM ANY LOW CLOUD ISSUES.
MAX TEMPS WILL BE DOWN SIGNIFICANTLY TODAY...ESPECIALLY IN THE
VALLEYS...WHERE HIGHS WILL LIKELY BE 8 TO 12 DEGREES LOWER THAN THEY
WERE YESTERDAY IN MOST AREAS. THE INCREASE IN ONSHORE FLOW WILL
BRING GUSTY WINDS TO THE MTNS...THE ANTELOPE VALLEY...THE SANTA
CLARITA VALLEY AND THE CENTRAL COAST THIS AFTERNOON. AT THIS
TIME...EXPECT WINDS TO REMAIN JUST BELOW ADVISORY LEVELS...WITH
GUSTS OF 30 TO 35 MPH EXPECTED...EXCEPT POSSIBLY TO 40 TO 45 MPH
ACROSS WESTERN PORTIONS OF THE ANTELOPE VALLEY.

AN UPPER LOW WILL MOVE INTO THE PAC NW TONIGHT AND WED...WITH A
SHARPENING TROUGH EXTENDING SOUTHWARD THRU CA. N-S GRADIENTS WILL
INCREASE ACROSS THE REGION TONIGHT...AND GUSTY NW TO N WINDS WILL
LIKELY AFFECT LOCATIONS THRU AND BELOW PASSES AND CANYONS OF THE
SANTA YNEZ RANGE IN SRN SBA COUNTY. EXPECT WINDS TO REMAIN JUST
BELOW ADVISORY LEVEL IN THESE AREAS AS WELL.

EXPECT LOW CLOUDS ACROSS MOST COASTAL AND VALLEY AREAS TONIGHT AND
WED MORNING. HOWEVER...ACROSS THE SBA COUNTY S COAST...NLY WINDS
WILL LIKELY ALLOW SKIES TO REMAIN CLEAR THERE. EXPECT CLOUDS TO
CLEAR FAIRLY WELL ON WED...ALTHOUGH THEY MAY LINGER INTO THE
AFTERNOON ONCE AGAIN NEAR SOME BEACHES OF L.A. AND VTU COUNTIES.
GUSTY WEST TO NORTHWEST WINDS WILL AFFECT THE INTERSTATE 5 CORRIDOR
TONIGHT AND WED...LIKELY STAYING BELOW ADVISORY LEVELS. MAX TEMPS
WILL BE DOWN A FEW MORE DEGREES IN MOST AREAS WED.

THE UPPER LOW WILL CONTINUE TO SPIN ACROSS THE PAC NW WED NIGHT AND
THU...BUT THE TROUGH ACROSS CA WILL SHARPEN UP A BIT. THE MARINE
LAYER SHOULD DEEPEN A BIT MORE...AND NIGHT/MORNING LOW CLOUDS AND
FOG MAY HAVE TO BE ADDED TO THE SANTA CLARITA VALLEY AND POSSIBLY
EVEN THE COASTAL SLOPES. INCREASINGLY CYCLONIC HEIGHT PATTERN ALOFT
SUGGESTS THAT THERE MAY BE ENOUGH LIFT TO PRODUCE SOME DRIZZLE
LATE WED NIGHT/THU...MAINLY IN COASTAL SECTIONS OF L.A. AND VTU
COUNTIES. N-S GRADS WILL CONT TO INCREASE...AND ADVISORY LEVEL WINDS
ARE POSSIBLE ACROSS THE SBA COUNTY S COAST AND ACROSS THE INTERSTATE
5 CORRIDOR WED NIGHT. ON THE CENTRAL COAST...WINDS WILL APPROACH
WINDS ADVISORY LEVELS DURING THE AFTERNOON HOURS OF BOTH WED AND
THU. THU LOOKS TO BE THE DAY WITH THE GREATEST POTENTIAL FOR CLOUDS
LINGERING AT THE BEACHES OF L.A. AND VTU COUNTIES. TEMPS WILL BE
DOWN A COUPLE OF MORE DEGREES IN MOST AREAS ON THU...DOWN TO SEVERAL
DEGREES BELOW NORMAL IN MOST AREAS.


.LONG TERM (FRI-MON)...A LARGE UPPER LOW WILL CONTINUE TO SPIN
ACROSS THE PACIFIC NORTHWEST THROUGH THE HOLIDAY WEEKEND...WITH
TROFFING EXTENDING SOUTHWARD INTO THE FORECAST AREAS. FOR FRI
THROUGH MON..EXPECT PLENTY OF NIGHT THRU MORNING LOW CLOUDS AND FOG
IN COASTAL AND VALLEY AREAS. TEMPS WILL LIKELY BE AT LEAST A FEW
DEGREES NORMAL THROUGH THE PERIOD.

&&

.AVIATION...21/1200Z.

WILL BE ISSUED WITH THE 12Z TAFS.

&&

$$

PUBLIC...DB
AVIATION...KJ


WWW.WEATHER.GOV/LOSANGELES

000
FXUS66 KLOX 210332
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
830 PM PDT MON MAY 20 2013

.SYNOPSIS...

A COOLING TREND WILL BEGIN ON TUESDAY ALONG WITH AN INCREASE IN
NIGHT THROUGH MORNING LOW CLOUDS AND FOG. COOLER THAN NORMAL WEATHER
WITH A LATE CLEARING MARINE LAYER IS EXPECTED GOING INTO THE WEEKEND.

&&

.SHORT TERM (TONIGHT-THU)...AN UPPER LEVEL RIDGE OF HIGH PRESSURE
COMBINED WITH OFFSHORE WINDS BROUGHT VERY WARM AND DRY CONDITIONS TO
INLAND AREAS TODAY. SEVERAL VALLEY STATIONS SOARED INTO THE 90S...WITH
SAUGUS (IN THE SANTA CLARITA VALLEY) TOPPING OUT AT 98 DEGREES. PRESSURE
GRADIENTS HAVE NOW SWITCHED BACK TO WEAKLY ONSHORE THIS EVENING...ALLOWING
FOR A RETURN OF ONSHORE WINDS ACROSS COASTAL AND VALLEY AREAS. UPPER LEVEL
RIDGE OF HIGH PRESSURE WILL BEGIN TO WEAKEN AND SHIFT EASTWARD OVERNIGHT
INTO TUESDAY AS AN UPSTREAM TROUGH MOVES INTO NORTHERN AND CENTRAL
CALIFORNIA. THIS WILL CAUSE INCREASING ONSHORE PRESSURE GRADIENTS...ESPECIALLY
TUESDAY AFTERNOON. IN FACT...LATEST 00Z NAM MODEL HAS LAX-DAGGETT GRADIENT
PEAKING AT +8.5 ONSHORE BY LATE TUESDAY AFTERNOON.

THE INCREASING ONSHORE FLOW COMBINED WITH A WEAK EDDY CIRCULATION IS EXPECTED
TO SPIN UP SOME LOW CLOUDS AND FOG ACROSS COASTAL AREAS OF LOS ANGELES...VENTURA
AND SANTA BARBARA COUNTIES...AS WELL AS THE SAN GABRIEL VALLEY. LATEST
ACARS DATA HAS MARINE LAYER DEPTH AROUND 1000 FEET ACROSS THE LA BASIN...WITH
MODEL CROSS SECTIONS SHOWING A SLIGHT DEEPENING OF MARINE LAYER BY TUESDAY
MORNING. IN ADDITION...THERE WILL BE SOME HIGHER LEVEL CLOUDS THAT WILL PASS
THROUGH THE DISTRICT DURING THE NEXT 24 HOURS...MAINLY NORTH OF POINT
CONCEPTION. THE ONSHORE TRENDS AND INCREASED MARINE INFLUENCE WILL RESULT IN
A COOLING TREND ON TUESDAY...WITH MOST COASTAL AND VALLEY AREAS SEEING 5 TO
10 DEGREES OF COOLING. THERE WILL ALSO BE GUSTY ONSHORE WINDS ACROSS THE
MOUNTAINS...ANTELOPE VALLEY...AND SANTA CLARITA VALLEY. THESE AREAS WILL
GENERALLY SEE GUSTS IN THE 30 TO 35 MPH RANGE...EXCEPT ISOLATED GUSTS TO 45 MPH
IN THE FOOTHILLS OF THE ANTELOPE VALLEY. THE GUSTY ONSHORE WINDS COMBINED
WITH LINGERING LOW HUMIDITIES WILL BRING ELEVATED FIRE DANGER TO THESE AREAS
ON TUESDAY AFTERNOON AND EVENING.

UPPER TROUGH COMBINED WITH FAIRLY STRONG ONSHORE FLOW WILL CONTINUE TO
COOL TEMPERATURES WEDNESDAY THROUGH THURSDAY. THERE WILL BE A WIDESPREAD
GALE FORCE WIND EVENT ACROSS THE OUTER COASTAL WATERS DURING THIS TIME.
THIS INCREASED NORTHWEST FLOW PATTERN WILL ALSO GENERATE SOME GUSTY SUNDOWNER
WINDS EACH NIGHT ACROSS SOUTHERN SBA COUNTY.

&&

.LONG TERM (FRI-MON)...TROFFING TO CONTINUE THROUGH THE PERIOD,
THOUGH MODELS INDICATE SOME RISING OF HEIGHTS/THICKESSES FRIDAY
BEFORE THE TROF DEEPENS AGAIN OVER THE WEEKEND, ESPECIALLY SUNDAY.
GFS CONTINUES TO BE DEEPER AND COOLER BUT STILL DRY. COULD SEE SOME
NIGHT/MORNING DRIZZLE OVER THE WEEKEND BUT OTHERWISE REMAINING
COOLER THAN NORMAL WITH SLOW MARINE LYR CLEARING. CONTINUED BREEZY
IN THE ANTELOPE VALLEY AND CENTRAL COAST.

&&

.AVIATION...21/0030Z.

SATELLITE IMAGERY SHOWING MOSTLY CLEAR SKIES WITH LOW CLOUDS PUSHED
ALL THE WAY SOUTHWARD TO THE COAST OF SAN DIEGO COUNTY. WEAK EDDY
CIRCULATION IS EXPECTED TO BRING SOME OF THE LOW CLOUDS AND FOG NORTHWARD
ALONG THE COAST TO LA AND VENTURA COUNTIES LATER TONIGHT. WITH ACARS
SOUNDING SHOWING MARINE LAYER DEPTH AROUND 800 FEET ACROSS LA
BASIN...ANY CIGS THAT DO FORM ALONG THE COAST SHOULD BE IN IFR
CATEGORY...WITH A 20 PERCENT CHANCE OF LIFR CONDITIONS. OTHERWISE
INCREASING ONSHORE FLOW ON TUESDAY WILL BRING GUSTY WINDS TO
KPMD AND KWJF IN THE AFTERNOON.

KLAX...HIGH CONFIDENCE IN VFR CONDITIONS THIS EVENING. IFR CIGS
EXPECTED TO DEVELOP LATER TONIGHT...WITHIN +/- 2 HOURS OF 11Z.

KBUR...MOSTLY VFR CONDITIONS THROUGH PERIOD...WITH THE EXCEPTION
OF A CHANCE OF VSBYS BEING REDUCED IN HAZE ON TUESDAY MORNING. A
20 PERCENT CHANCE OF A BRIEF LIFR/IFR CIGS EARLY TUESDAY MORNING.

&&

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

&&

$$

PUBLIC...GOMBERG/MW
AVIATION...GOMBERG
SYNOPSIS...SWEET

WWW.WEATHER.GOV/LOSANGELES

000
FXUS66 KLOX 210036
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
525 PM PDT MON MAY 20 2013

...UPDATED AVIATION DISCUSSION...

.SYNOPSIS...

A COOLING TREND WILL BEGIN ON TUESDAY ALONG WITH AN INCREASE IN
NIGHT THROUGH MORNING LOW CLOUDS AND FOG. COOLER THAN NORMAL WEATHER
WITH A LATE CLEARING MARINE LAYER IS EXPECTED GOING INTO THE WEEKEND.

&&

.SHORT TERM (TODAY-THU)...NORTHEAST WINDS DIMINISHING THIS AFTERNOON
AFTER A BRIEF SURGE EARLIER ACROSS THE MOUNTAINS AND SANTA CLARITA
VALLEY. A SIZABLE WARMUP FOR INLAND AREAS TODAY BUT ONSHORE FLOW
KEEPING THINGS COOLER AT THE COAST. EXPECTING SOME CIRRUS CLOUDS TO
PASS OVERHEAD LATER TONIGHT BUT OTHERWISE MOSTLY CLEAR SKIES AWAY
FROM THE COAST.

RIDGE WILL BE A LITTLE SLOWER TO LEAVE THAN EXPECTED A COUPLE DAYS
AGO SO WHILE IT WILL BE COOLER TUESDAY WE`RE STILL EXPECTING TEMPS
WELL INTO THE 80S FOR THE VALLEYS. ONSHORE FLOW EXPECTED TO INCREASE
FROM 0-1MB TODAY TO OVER 7 MB TUESDAY SO A STRONG ONSHORE PUSH WILL
BRING GUSTY WEST WINDS TO THE ANTELOPE VALLEY. IN ADDITION,
INCREASING NORTHWEST WINDS ACROSS THE OUTER COASTAL WATERS TUESDAY
THROUGH THURSDAY WILL BRING ANOTHER FEW EVENINGS OF GUSTY NORTH
WINDS THROUGH THE SANTA YNEZ RANGE AS WELL AS WINDY CONDITIONS TO
THE CENTRAL COAST DURING THE AFTERNOONS.

MARINE LYR EXPECTED TO REMAIN CONFINED TO THE COAST OF VENTURA/LA
COUNTIES AND POSSIBLY SOME PATCHY CLOUDS FORMING ALONG THE CENTRAL
COAST AS WELL. WITH THE STRONG ONSHORE PUSH TUESDAY AFTERNOON AND
THE TROF DEEPENING ALONG THE COAST WE SHOULD THE MARINE LYR
DEEPENING AND SPREADING INTO THE VALLEYS BY WEDNESDAY MORNING, WITH
SIMILAR COVERAGE WEDNESDAY NIGHT AS WELL. SEVERAL DEGREES OF VALLEY
COOLING EXPECTED WED AND THU WITH CLOUDS EXPECTED TO HUG THE COAST
OF VENTURA AND LA COUNTIES THROUGH THE AFTERNOON.

.LONG TERM (FRI-MON)...TROFFING TO CONTINUE THROUGH THE PERIOD,
THOUGH MODELS INDICATE SOME RISING OF HEIGHTS/THICKESSES FRIDAY
BEFORE THE TROF DEEPENS AGAIN OVER THE WEEKEND, ESPECIALLY SUNDAY.
GFS CONTINUES TO BE DEEPER AND COOLER BUT STILL DRY. COULD SEE SOME
NIGHT/MORNING DRIZZLE OVER THE WEEKEND BUT OTHERWISE REMAINING
COOLER THAN NORMAL WITH SLOW MARINE LYR CLEARING. CONTINUED BREEZY
IN THE ANTELOPE VALLEY AND CENTRAL COAST.

&&

.AVIATION...21/0030Z.

SATELLITE IMAGERY SHOWING MOSTLY CLEAR SKIES WITH LOW CLOUDS PUSHED
ALL THE WAY SOUTHWARD TO THE COAST OF SAN DIEGO COUNTY. WEAK EDDY
CIRCULATION IS EXPECTED TO BRING SOME OF THE LOW CLOUDS AND FOG NORTHWARD
ALONG THE COAST TO LA AND VENTURA COUNTIES LATER TONIGHT. WITH ACARS
SOUNDING SHOWING MARINE LAYER DEPTH AROUND 800 FEET ACROSS LA
BASIN...ANY CIGS THAT DO FORM ALONG THE COAST SHOULD BE IN IFR
CATEGORY...WITH A 20 PERCENT CHANCE OF LIFR CONDITIONS. OTHERWISE
INCREASING ONSHORE FLOW ON TUESDAY WILL BRING GUSTY WINDS TO
KPMD AND KWJF IN THE AFTERNOON.

KLAX...HIGH CONFIDENCE IN VFR CONDITIONS THIS EVENING. IFR CIGS
EXPECTED TO DEVELOP LATER TONIGHT...WITHIN +/- 2 HOURS OF 11Z.

KBUR...MOSTLY VFR CONDITIONS THROUGH PERIOD...WITH THE EXCEPTION
OF A CHANCE OF VSBYS BEING REDUCED IN HAZE ON TUESDAY MORNING. A
20 PERCENT CHANCE OF A BRIEF LIFR/IFR CIGS EARLY TUESDAY MORNING.

&&

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

&&

$$

PUBLIC...MW
AVIATION...GOMBERG
SYNOPSIS...SWEET

WWW.WEATHER.GOV/LOSANGELES

000
FXUS66 KLOX 202149
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
248 PM PDT MON MAY 20 2013

.SYNOPSIS...

A COOLING TREND WILL BEGIN ON TUESDAY ALONG WITH AN INCREASE IN
NIGHT THROUGH MORNING LOW CLOUDS AND FOG. COOLER THAN NORMAL WEATHER
WITH A LATE CLEARING MARINE LAYER IS EXPECTED GOING INTO THE WEEKEND.

&&

.SHORT TERM (TODAY-THU)...NORTHEAST WINDS DIMINISHING THIS AFTERNOON
AFTER A BRIEF SURGE EARLIER ACROSS THE MOUNTAINS AND SANTA CLARITA
VALLEY. A SIZABLE WARMUP FOR INLAND AREAS TODAY BUT ONSHORE FLOW
KEEPING THINGS COOLER AT THE COAST. EXPECTING SOME CIRRUS CLOUDS TO
PASS OVERHEAD LATER TONIGHT BUT OTHERWISE MOSTLY CLEAR SKIES AWAY
FROM THE COAST.

RIDGE WILL BE A LITTLE SLOWER TO LEAVE THAN EXPECTED A COUPLE DAYS
AGO SO WHILE IT WILL BE COOLER TUESDAY WE`RE STILL EXPECTING TEMPS
WELL INTO THE 80S FOR THE VALLEYS. ONSHORE FLOW EXPECTED TO INCREASE
FROM 0-1MB TODAY TO OVER 7 MB TUESDAY SO A STRONG ONSHORE PUSH WILL
BRING GUSTY WEST WINDS TO THE ANTELOPE VALLEY. IN ADDITION,
INCREASING NORTHWEST WINDS ACROSS THE OUTER COASTAL WATERS TUESDAY
THROUGH THURSDAY WILL BRING ANOTHER FEW EVENINGS OF GUSTY NORTH
WINDS THROUGH THE SANTA YNEZ RANGE AS WELL AS WINDY CONDITIONS TO
THE CENTRAL COAST DURING THE AFTERNOONS.

MARINE LYR EXPECTED TO REMAIN CONFINED TO THE COAST OF VENTURA/LA
COUNTIES AND POSSIBLY SOME PATCHY CLOUDS FORMING ALONG THE CENTRAL
COAST AS WELL. WITH THE STRONG ONSHORE PUSH TUESDAY AFTERNOON AND
THE TROF DEEPENING ALONG THE COAST WE SHOULD THE MARINE LYR
DEEPENING AND SPREADING INTO THE VALLEYS BY WEDNESDAY MORNING, WITH
SIMILAR COVERAGE WEDNESDAY NIGHT AS WELL. SEVERAL DEGREES OF VALLEY
COOLING EXPECTED WED AND THU WITH CLOUDS EXPECTED TO HUG THE COAST
OF VENTURA AND LA COUNTIES THROUGH THE AFTERNOON.

.LONG TERM (FRI-MON)...TROFFING TO CONTINUE THROUGH THE PERIOD,
THOUGH MODELS INDICATE SOME RISING OF HEIGHTS/THICKESSES FRIDAY
BEFORE THE TROF DEEPENS AGAIN OVER THE WEEKEND, ESPECIALLY SUNDAY.
GFS CONTINUES TO BE DEEPER AND COOLER BUT STILL DRY. COULD SEE SOME
NIGHT/MORNING DRIZZLE OVER THE WEEKEND BUT OTHERWISE REMAINING
COOLER THAN NORMAL WITH SLOW MARINE LYR CLEARING. CONTINUED BREEZY
IN THE ANTELOPE VALLEY AND CENTRAL COAST.

&&

.AVIATION...20/1800Z.

MID/UPPER LEVEL RIDGE OF HIGH PRESSURE OVER THE AREA WILL SHIFT
SOUTH AND A MID/UPPER LEVEL TROUGH OF LOW PRESSURE WEST OF VANCOUVER
ISLAND WILL SHIFT SOUTHEAST. UPPER LEVEL MODERATE NORTHWEST WINDS
WILL BECOME MODERATE WEST AND RELATIVELY MOIST WHILE MID LEVEL LIGHT
NORTHEAST WINDS BECOME LIGHT WEST OVER THE AREA AFTER 21/12Z.
SCATTERED LOW LEVEL CLOUD TOPS APPROXIMATELY 1.8KFT THIS MORNING
WILL DIFFER LITTLE TUESDAY MORNING. WEAK TO MODERATE ONSHORE
PRESSURE GRADIENT THROUGH 21/05Z AND AFTER 21/18Z...OTHERWISE A
CATALINA EDDY WILL EXIST BETWEEN 21/05-21/18Z.

KLAX...CHANCE CIGS 011 VSBY 4SM BR BETWEEN 21/12-21/16Z AND VSBY 5SM
HZ BETWEEN 21/16-21/20Z.

KBUR...CHANCE VSBY 5SM HZ AFTER 21/12Z. OTHERWISE CURRENT SKY/VSBY
CONDITIONS LIKELY THROUGH PERIOD.

VIRTUALLY CERTAIN - 95-100%
VERY LIKELY       - 80-95%
LIKELY            - 60-80%
CHANCE            - 30-60%
VERY UNLIKELY     - 20% OR LESS

&&

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

&&

$$

PUBLIC...MW
AVIATION...30
SYNOPSIS...SWEET

WWW.WEATHER.GOV/LOSANGELES

000
FXUS66 KLOX 201805
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1104 AM PDT MON MAY 20 2013

.SYNOPSIS...

GUSTY NORTHEAST WINDS IN THE MOUNTAINS AND HIGHER VALLEYS ALONG WITH
WARMER TEMPERATURES ARE EXPECTED THROUGH THIS EVENING AS WEAK
OFFSHORE FLOW DEVELOPS. A COOLING TREND WILL BEGIN FOR COASTAL AREAS
ON TUESDAY ALONG WITH AN INCREASE IN NIGHT THROUGH MORNING LOW
CLOUDS AND FOG. COOLER THAN NORMAL WEATHER WITH A LATE CLEARING
MARINE LAYER IS EXPECTED GOING INTO THE WEEKEND.

&&

.SHORT TERM (TODAY-THU)...NORTHEAST FLOW ARRIVED ON SCHEDULE, SO FAR
CONFINED TO THE MOUNTAINS AND SANTA CLARITA VALLEY AND EASTERN
PORTION OF VENTURA COUNTY. MARINE LYR RUNNING 1600-1800 FT SO WINDS
WON`T LIKELY SURFACE MUCH LOWER THAN THAT, BUT IT WILL STILL WARM UP
NICELY WITH VALLEYS IN THE 90S AND COASTAL AREAS IN THE 70S AND 80S.
NOT PLANNING ANY FORECAST ADJUSTMENTS THIS MORNING AND PROBABLY JUST
MINIMAL CHANGES AT MOST FOR THE AFTERNOON FORECAST AS MODELS REALLY
HAVEN`T CHANGED MUCH THROUGH THE WEEKENED.

***FROM PREVIOUS DISCUSSION***

A FEW DAYS AGO TUESDAY LOOKED LIKE IT WAS GOING TO CLOUDIER AND MUCH
COOLER THAN TODAY...BUT IT LOOKS LIKE THE COOLING WILL BE DELAYED AS
THE RIDGE LINGERS INTO TUESDAY. THERE WILL ONLY BE MINIMAL MARINE
LAYER CLOUDS...MOSTLY ACROSS THE LA AND VTA COASTS AND WHILE MAX
TEMPS WILL COOL THEY WILL STILL BELOW NORMAL.

SYNOPTICALLY NOTHING HAS CHANGED MUCH FROM PREVIOUS THINKING. A BIG
COOL UPPER LOW WILL MOVE INTO THE PAC NW AND THEN SLIDE DOWN INTO
OREGON. ONSHORE FLOW AND AN EDDY WILL DEVELOP OVER THIS AREA. BUT
NEW NAM SHOWS THAT THE MARINE LAYER WILL BE MORE RELUCTANT TO FORM
ESP ACROSS THE SBA SOUTH COAST WHERE WEAK SUNDOWNERS WILL KEEP THE
CLOUDS PUSHED AWAY. DIALED THE CLOUD COVERAGE BACK A LITTLE DURING
THIS PERIOD. MAX TEMPS SHOULD STILL FALL AND WILL BE A FEW DEGREES
BLO NORMAL.

.LONG TERM (FRI-SUN)...
ALL MDLS AGREE THAT THE UPPER LOW WILL CONTINUE TO SPIN OVER THE PAC
NW DURING THE XTND PERIOD. THE RELENTLESS ONSHORE FLOW AND CYCLONIC
TURNING SHOULD BE ENOUGH CREATE A DEEP AND EXTENSIVE MARINE LAYER
THAT WILL HAVE TROUBLE CLEARING THE BEACHES IN THE AFTERNOON. MAX
TEMPS WILL REMAIN BELOW NORMAL THROUGH THE PERIOD.

&&

.AVIATION...20/1800Z.

MID/UPPER LEVEL RIDGE OF HIGH PRESSURE OVER THE AREA WILL SHIFT
SOUTH AND A MID/UPPER LEVEL TROUGH OF LOW PRESSURE WEST OF VANCOUVER
ISLAND WILL SHIFT SOUTHEAST. UPPER LEVEL MODERATE NORTHWEST WINDS
WILL BECOME MODERATE WEST AND RELATIVELY MOIST WHILE MID LEVEL LIGHT
NORTHEAST WINDS BECOME LIGHT WEST OVER THE AREA AFTER 21/12Z.
SCATTERED LOW LEVEL CLOUD TOPS APPROXIMATELY 1.8KFT THIS MORNING
WILL DIFFER LITTLE TUESDAY MORNING. WEAK TO MODERATE ONSHORE
PRESSURE GRADIENT THROUGH 21/05Z AND AFTER 21/18Z...OTHERWISE A
CATALINA EDDY WILL EXIST BETWEEN 21/05-21/18Z.

KLAX...CHANCE CIGS 011 VSBY 4SM BR BETWEEN 21/12-21/16Z AND VSBY 5SM
HZ BETWEEN 21/16-21/20Z.

KBUR...CHANCE VSBY 5SM HZ AFTER 21/12Z. OTHERWISE CURRENT SKY/VSBY
CONDITIONS LIKELY THROUGH PERIOD.

VIRTUALLY CERTAIN - 95-100%
VERY LIKELY       - 80-95%
LIKELY            - 60-80%
CHANCE            - 30-60%
VERY UNLIKELY     - 20% OR LESS

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY (SEE LAXNPWLOX).
GALE WATCH (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).

&&

$$

PUBLIC...MW/RORKE
SYNOPSIS...KJ

WWW.WEATHER.GOV/LOSANGELES

000
FXUS66 KLOX 201629
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
930 AM PDT MON MAY 20 2013

.SYNOPSIS...

GUSTY NORTHEAST WINDS IN THE MOUNTAINS AND HIGHER VALLEYS ALONG WITH
WARMER TEMPERATURES ARE EXPECTED THROUGH THIS EVENING AS WEAK
OFFSHORE FLOW DEVELOPS. A COOLING TREND WILL BEGIN FOR COASTAL AREAS
ON TUESDAY ALONG WITH AN INCREASE IN NIGHT THROUGH MORNING LOW
CLOUDS AND FOG. COOLER THAN NORMAL WEATHER WITH A LATE CLEARING
MARINE LAYER IS EXPECTED GOING INTO THE WEEKEND.

&&

.SHORT TERM (TODAY-THU)...NORTHEAST FLOW ARRIVED ON SCHEDULE, SO FAR
CONFINED TO THE MOUNTAINS AND SANTA CLARITA VALLEY AND EASTERN
PORTION OF VENTURA COUNTY. MARINE LYR RUNNING 1600-1800 FT SO WINDS
WON`T LIKELY SURFACE MUCH LOWER THAN THAT, BUT IT WILL STILL WARM UP
NICELY WITH VALLEYS IN THE 90S AND COASTAL AREAS IN THE 70S AND 80S.
NOT PLANNING ANY FORECAST ADJUSTMENTS THIS MORNING AND PROBABLY JUST
MINIMAL CHANGES AT MOST FOR THE AFTERNOON FORECAST AS MODELS REALLY
HAVEN`T CHANGED MUCH THROUGH THE WEEKENED.

***FROM PREVIOUS DISCUSSION***

A FEW DAYS AGO TUESDAY LOOKED LIKE IT WAS GOING TO CLOUDIER AND MUCH
COOLER THAN TODAY...BUT IT LOOKS LIKE THE COOLING WILL BE DELAYED AS
THE RIDGE LINGERS INTO TUESDAY. THERE WILL ONLY BE MINIMAL MARINE
LAYER CLOUDS...MOSTLY ACROSS THE LA AND VTA COASTS AND WHILE MAX
TEMPS WILL COOL THEY WILL STILL BELOW NORMAL.

SYNOPTICALLY NOTHING HAS CHANGED MUCH FROM PREVIOUS THINKING. A BIG
COOL UPPER LOW WILL MOVE INTO THE PAC NW AND THEN SLIDE DOWN INTO
OREGON. ONSHORE FLOW AND AN EDDY WILL DEVELOP OVER THIS AREA. BUT
NEW NAM SHOWS THAT THE MARINE LAYER WILL BE MORE RELUCTANT TO FORM
ESP ACROSS THE SBA SOUTH COAST WHERE WEAK SUNDOWNERS WILL KEEP THE
CLOUDS PUSHED AWAY. DIALED THE CLOUD COVERAGE BACK A LITTLE DURING
THIS PERIOD. MAX TEMPS SHOULD STILL FALL AND WILL BE A FEW DEGREES
BLO NORMAL.

.LONG TERM (FRI-SUN)...
ALL MDLS AGREE THAT THE UPPER LOW WILL CONTINUE TO SPIN OVER THE PAC
NW DURING THE XTND PERIOD. THE RELENTLESS ONSHORE FLOW AND CYCLONIC
TURNING SHOULD BE ENOUGH CREATE A DEEP AND EXTENSIVE MARINE LAYER
THAT WILL HAVE TROUBLE CLEARING THE BEACHES IN THE AFTERNOON. MAX
TEMPS WILL REMAIN BELOW NORMAL THROUGH THE PERIOD.

&&

.AVIATION...20/1140Z
EXPECT VFR CONDITIONS THROUGH THIS EVENING...EXCEPT FOR PATCHY IFR
CIGS THROUGH MID MORNING ACROSS PORTIONS OF THE CENTRAL COAST...THE
SANTA YNEZ VALLEY AND THE L.A. COUNTY COAST. EXPECT SOMEWHAT MORE
WIDESPREAD IFR CONDS IN COASTAL SECTIONS TONIGHT/EARLY TUE.

KLAX...LOW TO MODERATE CONFIDENCE IN 12Z TAF. THERE IS A 40 PERCENT
THAT IFR CONDS WILL NOT MATERIALIZE THIS MORNING.

KBUR...VERY HIGH CONFIDENCE IN 12Z TAF WITH VFR CONDS THRU THE
PERIOD.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY (SEE LAXNPWLOX).
GALE WATCH (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).

&&

$$

PUBLIC...MW/RORKE
AVIATION..DB
SYNOPSIS...KJ

WWW.WEATHER.GOV/LOSANGELES

000
FXUS66 KLOX 201139 AAA
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
440 AM PDT MON MAY 20 2013

UPDATED AVIATION SECTION

.SYNOPSIS...

GUSTY NORTH WINDS AND WARMING TEMPERATURES ARE EXPECTED TODAY AS
WEAK OFFSHORE FLOW DEVELOPS. A COOLING TREND WILL BEGIN ON TUESDAY
ALONG WITH AN INCREASE IN NIGHT THROUGH MORNING LOW CLOUDS AND FOG
AND WILL WILL LIKELY CONTINUE INTO NEXT WEEKEND.

&&

.SHORT TERM (TODAY-THU)...
MARINE LAYER IS 1400 FEET DEEP AND A WEAK EDDY IS SPINNING UP SOME
MARINE STRATUS INTO SOUTHERN L.A. COUNTY AND CATALINA ISLAND. AT THE
SAME TIME A COOL SFC HIGH WILL BUILD INTO NEVADA AND CREATE AN
OFFSHORE FLOW PATTERN BY MID MORNING. THIS OFFSHORE PUSH WILL HALT
THE PROGRESS OF THE LOW CLOUDS. IT WILL ALSO BE JUST STRONG ENOUGH
TO PRODUCE A BRIEF BURST OF WIND ADVISORY GUSTS IN THE MOUNTAINS AND
THE SANTA CLARITA VLY...ALTHOUGH THE SANTA CLARITA VLY WILL BE RIGHT
ON THE EDGE OF ADVISORY CRITERIA. THE OFFSHORE FLOW WILL THEN ALLOW
FOR A NICE WARM UP ACROSS THE AREA ESP ACROSS THE COASTS. THE
CENTRAL COAST WILL RISE 8 TO 12 DEGREES ABOVE NORMAL AND OTHER
COASTAL AREAS WILL BE 4 TO 8 DEGREES ABOVE NORMAL.

A FEW DAYS AGO TUESDAY LOOKED LIKE IT WAS GOING TO CLOUDIER AND MUCH
COOLER THAN TODAY...BUT IT LOOKS LIKE THE COOLING WILL BE DELAYED AS
THE RIDGE LINGERS INTO TUESDAY. THERE WILL ONLY BE MINIMAL MARINE
LAYER CLOUDS...MOSTLY ACROSS THE LA AND VTA COASTS AND WHILE MAX
TEMPS WILL COOL THEY WILL STILL BELOW NORMAL.

SYNOPTICALLY NOTHING HAS CHANGED MUCH FROM PREVIOUS THINKING. A BIG
COOL UPPER LOW WILL MOVE INTO THE PAC NW AND THEN SLIDE DOWN INTO
OREGON. ONSHORE FLOW AND AN EDDY WILL DEVELOP OVER THIS AREA. BUT
NEW NAM SHOWS THAT THE MARINE LAYER WILL BE MORE RELUCTANT TO FORM
ESP ACROSS THE SBA SOUTH COAST WHERE WEAK SUNDOWNERS WILL KEEP THE
CLOUDS PUSHED AWAY. DIALED THE CLOUD COVERAGE BACK A LITTLE DURING
THIS PERIOD. MAX TEMPS SHOULD STILL FALL AND WILL BE A FEW DEGREES
BLO NORMAL.

.LONG TERM (FRI-SUN)...
ALL MDLS AGREE THAT THE UPPER LOW WILL CONTINUE TO SPIN OVER THE PAC
NW DURING THE XTND PERIOD. THE RELENTLESS ONSHORE FLOW AND CYCLONIC
TURNING SHOULD BE ENOUGH CREATE A DEEP AND EXTENSIVE MARINE LAYER
THAT WILL HAVE TROUBLE CLEARING THE BEACHES IN THE AFTERNOON. MAX
TEMPS WILL REMAIN BELOW NORMAL THROUGH THE PERIOD.

&&

.AVIATION...20/1140Z
EXPECT VFR CONDITIONS THROUGH THIS EVENING...EXCEPT FOR PATCHY IFR
CIGS THROUGH MID MORNING ACROSS PORTIONS OF THE CENTRAL COAST...THE
SANTA YNEZ VALLEY AND THE L.A. COUNTY COAST. EXPECT SOMEWHAT MORE
WIDESPREAD IFR CONDS IN COASTAL SECTIONS TONIGHT/EARLY TUE.

KLAX...LOW TO MODERATE CONFIDENCE IN 12Z TAF. THERE IS A 40 PERCENT
THAT IFR CONDS WILL NOT MATERIALIZE THIS MORNING.

KBUR...VERY HIGH CONFIDENCE IN 12Z TAF WITH VFR CONDS THRU THE
PERIOD.

&&

.FIRE WEATHER...

(FROM PREVIOUS DISCUSSION)

GUSTY NORTHWEST TO NORTH WINDS WILL CONTINUE TO BRING LOWERING
HUMIDITIES AND ELEVATED FIRE DANGER THROUGH THIS EVENING ACROSS THE
MOUNTAINS...ANTELOPE VALLEY...SANTA CLARITA VALLEY...AND SBA SOUTH
COAST. THESE AREAS WILL GENERALLY SEE GUSTS IN THE 30 TO 40 MPH
RANGE. ALREADY SEEING HUMIDITIES LOWERING TO AROUND 10 PERCENT THIS
AFTERNOON ACROSS THE SANTA CLARITA VALLEY...ALONG WITH TEMPERATURES
CLIMBING INTO THE LOWER 90S.

BY LATE TONIGHT AND MONDAY...SURFACE HIGH PRESSURE BUILDS INTO THE
GREAT BASIN...SETTING THE STAGE FOR A BRIEF OFFSHORE WIND EVENT FOR
THE REGION. THE PROJECTED LAX-DAGGETT GRADIENT IS ONLY EXPECTED TO BE
AROUND -1.5 MB...WITH SOME UPPER LEVEL WIND SUPPORT. OFFSHORE
WINDS ARE EXPECTED TO DEVELOP ACROSS THE MOUNTAINS LATE
TONIGHT...THEN DESCEND INTO THE VALLEYS ON MONDAY MORNING. AT THIS
TIME...WIND GUSTS IN THE 35 TO 40 MPH RANGE CAN BE EXPECTED IN THE
MOUNTAINS ON MONDAY MORNING...WITH GUSTS IN THE 25 TO 35 MPH RANGE
ACROSS THE VALLEYS (MAINLY SANTA CLARITA AND EASTERN VENTURA
VALLEYS). THERE WILL LIKELY BE WIDESPREAD HUMIDITIES BETWEEN 10 AND
15 PERCENT ON MONDAY ACROSS THE MOUNTAINS AND VALLEYS OF LOS ANGELES
AND VENTURA COUNTIES...WITH ISOLATED SINGLE DIGIT READINGS LIKELY.
WHILE THIS OFFSHORE WIND EVENT DOES NOT APPEAR TO BE STRONG ENOUGH OR
HAVE SUFFICIENT DURATION TO WARRANT A RED FLAG WARNING...THERE WILL
BE ELEVATED FIRE DANGER ACROSS THE MOUNTAINS AND VALLEYS ON
MONDAY...ESPECIALLY CONSIDERING THE VERY DRY FUELS FOR THIS TIME OF
YEAR. THE OFFSHORE WINDS ARE EXPECTED TO DIMINISH FAIRLY RAPIDLY ON
MONDAY AFTERNOON...WITH ONSHORE WINDS GRADUALLY SPREADING ACROSS
COASTAL AND VALLEY AREAS THROUGH THE AFTERNOON AND EVENING HOURS.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY (SEE LAXNPWLOX).
GALE WARNING (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).

&&

$$

PUBLIC...RORKE
AVIATION..DB
SYNOPSIS...KJ

WWW.WEATHER.GOV/LOSANGELES

000
FXUS66 KLOX 201027
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
330 AM PDT MON MAY 20 2013

.SYNOPSIS...

GUSTY NORTH WINDS AND WARMING TEMPERATURES ARE EXPECTED TODAY AS
WEAK OFFSHORE FLOW DEVELOPS. A COOLING TREND WILL BEGIN ON TUESDAY
ALONG WITH AN INCREASE IN NIGHT THROUGH MORNING LOW CLOUDS AND FOG
AND WILL WILL LIKELY CONTINUE INTO NEXT WEEKEND.

&&

.SHORT TERM (TODAY-THU)...
MARINE LAYER IS 1400 FEET DEEP AND A WEAK EDDY IS SPINNING UP SOME
MARINE STRATUS INTO SOUTHERN L.A. COUNTY AND CATALINA ISLAND. AT THE
SAME TIME A COOL SFC HIGH WILL BUILD INTO NEVADA AND CREATE AN
OFFSHORE FLOW PATTERN BY MID MORNING. THIS OFFSHORE PUSH WILL HALT
THE PROGRESS OF THE LOW CLOUDS. IT WILL ALSO BE JUST STRONG ENOUGH
TO PRODUCE A BRIEF BURST OF WIND ADVISORY GUSTS IN THE MOUNTAINS AND
THE SANTA CLARITA VLY...ALTHOUGH THE SANTA CLARITA VLY WILL BE RIGHT
ON THE EDGE OF ADVISORY CRITERIA. THE OFFSHORE FLOW WILL THEN ALLOW
FOR A NICE WARM UP ACROSS THE AREA ESP ACROSS THE COASTS. THE
CENTRAL COAST WILL RISE 8 TO 12 DEGREES ABOVE NORMAL AND OTHER
COASTAL AREAS WILL BE 4 TO 8 DEGREES ABOVE NORMAL.

A FEW DAYS AGO TUESDAY LOOKED LIKE IT WAS GOING TO CLOUDIER AND MUCH
COOLER THAN TODAY...BUT IT LOOKS LIKE THE COOLING WILL BE DELAYED AS
THE RIDGE LINGERS INTO TUESDAY. THERE WILL ONLY BE MINIMAL MARINE
LAYER CLOUDS...MOSTLY ACROSS THE LA AND VTA COASTS AND WHILE MAX
TEMPS WILL COOL THEY WILL STILL BELOW NORMAL.

SYNOPTICALLY NOTHING HAS CHANGED MUCH FROM PREVIOUS THINKING. A BIG
COOL UPPER LOW WILL MOVE INTO THE PAC NW AND THEN SLIDE DOWN INTO
OREGON. ONSHORE FLOW AND AN EDDY WILL DEVELOP OVER THIS AREA. BUT
NEW NAM SHOWS THAT THE MARINE LAYER WILL BE MORE RELUCTANT TO FORM
ESP ACROSS THE SBA SOUTH COAST WHERE WEAK SUNDOWNERS WILL KEEP THE
CLOUDS PUSHED AWAY. DIALED THE CLOUD COVERAGE BACK A LITTLE DURING
THIS PERIOD. MAX TEMPS SHOULD STILL FALL AND WILL BE A FEW DEGREES
BLO NORMAL.

.LONG TERM (FRI-SUN)...
ALL MDLS AGREE THAT THE UPPER LOW WILL CONTINUE TO SPIN OVER THE PAC
NW DURING THE XTND PERIOD. THE RELENTLESS ONSHORE FLOW AND CYCLONIC
TURNING SHOULD BE ENOUGH CREATE A DEEP AND EXTENSIVE MARINE LAYER
THAT WILL HAVE TROUBLE CLEARING THE BEACHES IN THE AFTERNOON. MAX
TEMPS WILL REMAIN BELOW NORMAL THROUGH THE PERIOD.

&&

.AVIATION...

20/0620Z

EXPECT VFR CONDITIONS THROUGH THE PERIOD...ALTHOUGH THERE IS A
SLIGHT CHANCE OF IFR CONDS ACROSS PORTIONS OF THE CENTRAL
COAST...SANTA YNEZ VALLEY AND L.A. COUNTY COAST LATE TONIGHT THROUGH
EARLY MON MORNING.

KLAX...HIGH CONFIDENCE IN 06Z TAF. THERE IS A 20 PERCENT
CHANCE OF IFR CONDITIONS BETWEEN 09Z AND 16Z MON.

KBUR...VERY HIGH CONFIDENCE IN 06Z TAF WITH VFR CONDS THRU THE
PERIOD.

&&

.FIRE WEATHER...

(FROM PREVIOUS DISCUSSION)

GUSTY NORTHWEST TO NORTH WINDS WILL CONTINUE TO BRING LOWERING
HUMIDITIES AND ELEVATED FIRE DANGER THROUGH THIS EVENING ACROSS THE
MOUNTAINS...ANTELOPE VALLEY...SANTA CLARITA VALLEY...AND SBA SOUTH
COAST. THESE AREAS WILL GENERALLY SEE GUSTS IN THE 30 TO 40 MPH
RANGE. ALREADY SEEING HUMIDITIES LOWERING TO AROUND 10 PERCENT THIS
AFTERNOON ACROSS THE SANTA CLARITA VALLEY...ALONG WITH TEMPERATURES
CLIMBING INTO THE LOWER 90S.

BY LATE TONIGHT AND MONDAY...SURFACE HIGH PRESSURE BUILDS INTO THE
GREAT BASIN...SETTING THE STAGE FOR A BRIEF OFFSHORE WIND EVENT FOR
THE REGION. THE PROJECTED LAX-DAGGETT GRADIENT IS ONLY EXPECTED TO BE
AROUND -1.5 MB...WITH SOME UPPER LEVEL WIND SUPPORT. OFFSHORE
WINDS ARE EXPECTED TO DEVELOP ACROSS THE MOUNTAINS LATE
TONIGHT...THEN DESCEND INTO THE VALLEYS ON MONDAY MORNING. AT THIS
TIME...WIND GUSTS IN THE 35 TO 40 MPH RANGE CAN BE EXPECTED IN THE
MOUNTAINS ON MONDAY MORNING...WITH GUSTS IN THE 25 TO 35 MPH RANGE
ACROSS THE VALLEYS (MAINLY SANTA CLARITA AND EASTERN VENTURA
VALLEYS). THERE WILL LIKELY BE WIDESPREAD HUMIDITIES BETWEEN 10 AND
15 PERCENT ON MONDAY ACROSS THE MOUNTAINS AND VALLEYS OF LOS ANGELES
AND VENTURA COUNTIES...WITH ISOLATED SINGLE DIGIT READINGS LIKELY.
WHILE THIS OFFSHORE WIND EVENT DOES NOT APPEAR TO BE STRONG ENOUGH OR
HAVE SUFFICIENT DURATION TO WARRANT A RED FLAG WARNING...THERE WILL
BE ELEVATED FIRE DANGER ACROSS THE MOUNTAINS AND VALLEYS ON
MONDAY...ESPECIALLY CONSIDERING THE VERY DRY FUELS FOR THIS TIME OF
YEAR. THE OFFSHORE WINDS ARE EXPECTED TO DIMINISH FAIRLY RAPIDLY ON
MONDAY AFTERNOON...WITH ONSHORE WINDS GRADUALLY SPREADING ACROSS
COASTAL AND VALLEY AREAS THROUGH THE AFTERNOON AND EVENING HOURS.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY (SEE LAXNPWLOX).
GALE WARNING (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).

&&

$$

PUBLIC...RORKE
AVIATION...BRUNO
SYNOPSIS...KJ

WWW.WEATHER.GOV/LOSANGELES

000
FXUS66 KLOX 200523 AAA
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1020 PM PDT SUN MAY 19 2013

UPDATED AVIATION DISCUSSION

.SYNOPSIS...

BREEZY TO LOCALLY GUSTY SANTA ANA WINDS AND WARMING TEMPERATURES
ARE EXPECTED THROUGH MONDAY EVENING AS WEAK OFFSHORE FLOW
DEVELOPS. A COOLING TREND WILL BEGIN ON TUESDAY ALONG WITH AN
INCREASE IN NIGHT THROUGH MORNING LOW CLOUDS AND FOG. COOL WEATHER
AND PARTLY TO MOSTLY CLOUDY CONDITIONS WILL LIKELY CONTINUE INTO
NEXT WEEKEND.

&&

.UPDATE...

A RIDGE OF HIGH PRESSURE ALOFT CONTINUES TO NOSE INTO THE REGION
THIS EVENING FROM THE WEST. A COLD AIR MASS...IN THE WAKE OF A
TROUGH MOVING THROUGH THE INTERMOUNTAIN WEST...WILL SETTLE INTO
THE GREAT BASIN AND ALLOW SURFACE HIGH PRESSURE TO ESTABLISH. AN
OFFSHORE FLOW PATTERN WILL DEVELOP ACROSS THE AREA AS SURFACE
PRESSURE HIGH PRESSURE BUILDS INTO THE GREAT BASIN. THE AIR MASS
WILL WARM AND DRY...ESPECIALLY ACROSS THE COASTAL AND VALLEY AREAS
DUE TO COMPRESSIONAL HEATING ON MONDAY MORNING. THE LATEST MODELS
ARE SUGGESTING A MARGINAL ADVISORY LEVEL BURST OF WINDS
DEVELOPING ON MONDAY MORNING WITH THE HIGHEST CONFIDENCE PLACED
IN THE LOS ANGELES AND VENTURA COUNTY MOUNTAINS AND THE SANTA
CLARITA VALLEY. TEMPERATURES HAVE BEEN WARMED SLIGHTLY FOR THE
FOOTHILLS AND MOUNTAINS TONIGHT AS THE OFFSHORE WINDS DEVELOP AND
INCREASE MIXING...AND COOLED SLIGHTLY FOR THE INTERIOR SECTIONS
ON MONDAY AS A COOLER AIR MASS FILTERS INTO THE DESERT.

&&

.PREV DISCUSSION...

SHORT TERM...A DEEP UPPER LOW WILL BEGIN TO MOVE SOUTH ALONG THE
EASTERN GULF OF ALASKA MONDAY INTO TUESDAY. FOR SOUTHWEST
CALIFORNIA...WINDS WILL SHIFT BACK TO ONSHORE ALLOWING A MORE
WIDESPREAD MARINE LAYER TO FORM MONDAY NIGHT. THE NAM12 SHOWS A
COASTAL EDDY FORMING NEAR CATALINA ISLAND BUT HEIGHTS ALOFT WILL
STILL BE HIGH ENOUGH TO KEEP THE MARINE LAYER SHALLOW...SO THAT
LOW CLOUDS AND FOG WILL LIKELY BE LIMITED TO NEAR-COASTAL AREAS.

THE UPPER CLOSED LOW WILL CONTINUE TO SINK SOUTH ALONG THE WEST
COAST TUESDAY INTO WEDNESDAY...RESULTING IN A COOLING TREND AND A
DEEPENING MARINE LAYER FOR SW CALIFORNIA. BY TUESDAY NIGHT MARINE
LAYER CLOUDS SHOULD ADVANCE INLAND THROUGH ALL BUT THE MOST INTERIOR
VALLEYS...AND WEDNESDAY`S HIGHS WILL BE CAPPED NEAR 80 DEGREES.

LONG TERM...THE MEDIUM RANGE MODELS AGREE FAIRLY WELL IN PLACING
THE CLOSED UPPER LOW OVER OREGON EARLY THURSDAY...WHERE IT IS
FORECAST TO REMAIN NEARLY STATIONARY INTO FRIDAY. THE PROXIMITY OF
THE UPPER CLOSED LOW WILL PRODUCE CYCLONIC CURVATURE ALOFT AND
ONSHORE FLOW OVER THE CALIFORNIA COAST. THIS SCENARIO WILL CREATE
A DEEP MARINE LAYER OVER SOUTHWEST CALIFORNIA...WITH LOW CLOUDS
MOVING WELL INLAND TO THE INTERIOR VALLEYS THURSDAY AND FRIDAY
NIGHTS. THE UPPER LOW IS FORECAST TO LIFT NORTHEAST OUT OF THE
AREA LATE FRIDAY INTO SATURDAY AS AN UPPER TROUGH FORMS ALONG THE
CALIFORNIA COAST. THIS SCENARIO WILL LIKELY PRODUCE LITTLE CHANGE
THROUGH LATE IN THE EXTENDED...WITH A DEEP MARINE LAYER AND
EXTENSIVE LOW CLOUDS FORMING EACH NIGHT TO MORNING PERIOD...ALONG
WITH LOWER THAN NORMAL DAYTIME HIGH TEMPERATURES.

&&

.AVIATION...20/0520Z.

EXPECT VFR CONDITIONS THROUGH THE PERIOD...ALTHOUGH THERE IS A
SLIGHT CHANCE OF IFR CONDS ACROSS PORTIONS OF THE CENTRAL
COAST...SANTA YNEZ VALLEY AND L.A. COUNTY COAST LATE TONIGHT THROUGH
EARLY MON MORNING.

KLAX...HIGH CONFIDENCE IN 06Z TAF. THERE IS A 20 PERCENT
CHANCE OF IFR CONDITIONS BETWEEN 09Z AND 16Z MON.

KBUR...VERY HIGH CONFIDENCE IN 06Z TAF WITH VFR CONDS THRU THE
PERIOD.


&&

.FIRE WEATHER...

GUSTY NORTHWEST TO NORTH WINDS WILL CONTINUE TO BRING LOWERING
HUMIDITIES AND ELEVATED FIRE DANGER THROUGH THIS EVENING ACROSS THE
MOUNTAINS...ANTELOPE VALLEY...SANTA CLARITA VALLEY...AND SBA SOUTH
COAST. THESE AREAS WILL GENERALLY SEE GUSTS IN THE 30 TO 40 MPH
RANGE. ALREADY SEEING HUMIDITIES LOWERING TO AROUND 10 PERCENT THIS
AFTERNOON ACROSS THE SANTA CLARITA VALLEY...ALONG WITH TEMPERATURES
CLIMBING INTO THE LOWER 90S.

BY LATE TONIGHT AND MONDAY...SURFACE HIGH PRESSURE BUILDS INTO THE
GREAT BASIN...SETTING THE STAGE FOR A BRIEF OFFSHORE WIND EVENT FOR
THE REGION. THE PROJECTED LAX-DAGGETT GRADIENT IS ONLY EXPECTED TO BE
AROUND -1.5 MB...WITH SOME UPPER LEVEL WIND SUPPORT. OFFSHORE
WINDS ARE EXPECTED TO DEVELOP ACROSS THE MOUNTAINS LATE
TONIGHT...THEN DESCEND INTO THE VALLEYS ON MONDAY MORNING. AT THIS
TIME...WIND GUSTS IN THE 35 TO 40 MPH RANGE CAN BE EXPECTED IN THE
MOUNTAINS ON MONDAY MORNING...WITH GUSTS IN THE 25 TO 35 MPH RANGE
ACROSS THE VALLEYS (MAINLY SANTA CLARITA AND EASTERN VENTURA
VALLEYS). THERE WILL LIKELY BE WIDESPREAD HUMIDITIES BETWEEN 10 AND
15 PERCENT ON MONDAY ACROSS THE MOUNTAINS AND VALLEYS OF LOS ANGELES
AND VENTURA COUNTIES...WITH ISOLATED SINGLE DIGIT READINGS LIKELY.
WHILE THIS OFFSHORE WIND EVENT DOES NOT APPEAR TO BE STRONG ENOUGH OR
HAVE SUFFICIENT DURATION TO WARRANT A RED FLAG WARNING...THERE WILL
BE ELEVATED FIRE DANGER ACROSS THE MOUNTAINS AND VALLEYS ON
MONDAY...ESPECIALLY CONSIDERING THE VERY DRY FUELS FOR THIS TIME OF
YEAR. THE OFFSHORE WINDS ARE EXPECTED TO DIMINISH FAIRLY RAPIDLY ON
MONDAY AFTERNOON...WITH ONSHORE WINDS GRADUALLY SPREADING ACROSS
COASTAL AND VALLEY AREAS THROUGH THE AFTERNOON AND EVENING HOURS.

&&

.MARINE...A THERMAL TROUGH OF LOW PRESSURE WILL INTENSIFY NEAR SHORE
WHILE HIGH PRESSURE PERSISTS OVER THE EASTERN PACIFIC THROUGH EARLY
MONDAY AND A GALE WARNING IS IN EFFECT OVER THE OUTER WATERS FROM
SAN CLEMENTE ISLAND TO POINT PIEDRAS BLANCAS AND INCLUDING THE INNER
WATERS FROM POINT PIEDRAS BLANCAS TO POINT SAL THROUGH LATE TONIGHT.
THE RIDGE OF HIGH PRESSURE OVER THE EASTERN PACIFIC WILL WEAKEN
MONDAY. A TROUGH OF LOW PRESSURE IS THEN EXPECTED TO MOVE SOUTHEAST
OVER THE OFFSHORE AND COASTAL WATERS EARLY TUESDAY THROUGH EARLY
WEDNESDAY WHILE A RIDGE OF HIGH PRESSURE STRENGTHENS OVER THE
EASTERN PACIFIC. NORTHWEST WINDS WILL LIKELY INCREASE NEAR SHORE
NORTH OF POINT CONCEPTION AND OVER THE OUTER WATERS SOUTH OF POINT
CONCEPTION TUESDAY EVENING THROUGH WEDNESDAY. A GALE WATCH WILL BE
ISSUED WHEN THE RISK OF GALE FORCE WINDS HAS SIGNIFICANTLY
INCREASED.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
GALE WARNING (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
WIND ADVISORY (SEE LAXNPWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...HALL
AVIATION...HALL
MARINE...30
FIRE WEATHER...GOMBERG
SYNOPSIS...KJ/HALL

WWW.WEATHER.GOV/LOSANGELES

000
FXUS66 KLOX 200343
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
843 PM PDT SUN MAY 19 2013

.SYNOPSIS...

BREEZY TO LOCALLY GUSTY SANTA ANA WINDS AND WARMING TEMPERATURES
ARE EXPECTED THROUGH MONDAY EVENING AS WEAK OFFSHORE FLOW
DEVELOPS. A COOLING TREND WILL BEGIN ON TUESDAY ALONG WITH AN
INCREASE IN NIGHT THROUGH MORNING LOW CLOUDS AND FOG. COOL WEATHER
AND PARTLY TO MOSTLY CLOUDY CONDITIONS WILL LIKELY CONTINUE INTO
NEXT WEEKEND.

&&

.UPDATE...

A RIDGE OF HIGH PRESSURE ALOFT CONTINUES TO NOSE INTO THE REGION
THIS EVENING FROM THE WEST. A COLD AIR MASS...IN THE WAKE OF A
TROUGH MOVING THROUGH THE INTERMOUNTAIN WEST...WILL SETTLE INTO
THE GREAT BASIN AND ALLOW SURFACE HIGH PRESSURE TO ESTABLISH. AN
OFFSHORE FLOW PATTERN WILL DEVELOP ACROSS THE AREA AS SURFACE
PRESSURE HIGH PRESSURE BUILDS INTO THE GREAT BASIN. THE AIR MASS
WILL WARM AND DRY...ESPECIALLY ACROSS THE COASTAL AND VALLEY AREAS
DUE TO COMPRESSIONAL HEATING ON MONDAY MORNING. THE LATEST MODELS
ARE SUGGESTING A MARGINAL ADVISORY LEVEL BURST OF WINDS
DEVELOPING ON MONDAY MORNING WITH THE HIGHEST CONFIDENCE PLACED
IN THE LOS ANGELES AND VENTURA COUNTY MOUNTAINS AND THE SANTA
CLARITA VALLEY. TEMPERATURES HAVE BEEN WARMED SLIGHTLY FOR THE
FOOTHILLS AND MOUNTAINS TONIGHT AS THE OFFSHORE WINDS DEVELOP AND
INCREASE MIXING...AND COOLED SLIGHTLY FOR THE INTERIOR SECTIONS
ON MONDAY AS A COOLER AIR MASS FILTERS INTO THE DESERT.

&&

.PREV DISCUSSION...

SHORT TERM...A DEEP UPPER LOW WILL BEGIN TO MOVE SOUTH ALONG THE
EASTERN GULF OF ALASKA MONDAY INTO TUESDAY. FOR SOUTHWEST
CALIFORNIA...WINDS WILL SHIFT BACK TO ONSHORE ALLOWING A MORE
WIDESPREAD MARINE LAYER TO FORM MONDAY NIGHT. THE NAM12 SHOWS A
COASTAL EDDY FORMING NEAR CATALINA ISLAND BUT HEIGHTS ALOFT WILL
STILL BE HIGH ENOUGH TO KEEP THE MARINE LAYER SHALLOW...SO THAT
LOW CLOUDS AND FOG WILL LIKELY BE LIMITED TO NEAR-COASTAL AREAS.

THE UPPER CLOSED LOW WILL CONTINUE TO SINK SOUTH ALONG THE WEST
COAST TUESDAY INTO WEDNESDAY...RESULTING IN A COOLING TREND AND A
DEEPENING MARINE LAYER FOR SW CALIFORNIA. BY TUESDAY NIGHT MARINE
LAYER CLOUDS SHOULD ADVANCE INLAND THROUGH ALL BUT THE MOST INTERIOR
VALLEYS...AND WEDNESDAY`S HIGHS WILL BE CAPPED NEAR 80 DEGREES.

LONG TERM...THE MEDIUM RANGE MODELS AGREE FAIRLY WELL IN PLACING
THE CLOSED UPPER LOW OVER OREGON EARLY THURSDAY...WHERE IT IS
FORECAST TO REMAIN NEARLY STATIONARY INTO FRIDAY. THE PROXIMITY OF
THE UPPER CLOSED LOW WILL PRODUCE CYCLONIC CURVATURE ALOFT AND
ONSHORE FLOW OVER THE CALIFORNIA COAST. THIS SCENARIO WILL CREATE
A DEEP MARINE LAYER OVER SOUTHWEST CALIFORNIA...WITH LOW CLOUDS
MOVING WELL INLAND TO THE INTERIOR VALLEYS THURSDAY AND FRIDAY
NIGHTS. THE UPPER LOW IS FORECAST TO LIFT NORTHEAST OUT OF THE
AREA LATE FRIDAY INTO SATURDAY AS AN UPPER TROUGH FORMS ALONG THE
CALIFORNIA COAST. THIS SCENARIO WILL LIKELY PRODUCE LITTLE CHANGE
THROUGH LATE IN THE EXTENDED...WITH A DEEP MARINE LAYER AND
EXTENSIVE LOW CLOUDS FORMING EACH NIGHT TO MORNING PERIOD...ALONG
WITH LOWER THAN NORMAL DAYTIME HIGH TEMPERATURES.

&&

.AVIATION...19/2350Z.

VFR CONDITIONS ARE EXPECTED THROUGHOUT THE PERIOD EXCEPT FOR A
CHANCE OF LIFR TO IFR CONDITIONS AT LOS ANGELES COUNTY COAST AND
CENTRAL COAST TERMINALS BETWEEN 08Z AND 16Z. PERIOD OF MODERATE TO
STRONG WIND SHEAR AND TURBULENCE ARE POSSIBLE AT KSBA THROUGH 08Z
AND VENTURA COUNTY TERMINALS BETWEEN 10Z AND 18Z.

KLAX...VFR CONDITIONS ARE EXPECTED THROUGHOUT THE PERIOD EXCEPT FOR
A 30 PERCENT CHANCE OF LIFR TO IFR CONDITIONS.

KBUR...VFR CONDITIONS ARE EXPECTED THROUGHOUT THE PERIOD WITH A 20
PERCENT CHANCE OF MODERATE LOW-LEVEL WIND SHEAR AND TURBULENCE
BETWEEN 10Z AND 16Z.

&&

.FIRE WEATHER...

GUSTY NORTHWEST TO NORTH WINDS WILL CONTINUE TO BRING LOWERING
HUMIDITIES AND ELEVATED FIRE DANGER THROUGH THIS EVENING ACROSS THE
MOUNTAINS...ANTELOPE VALLEY...SANTA CLARITA VALLEY...AND SBA SOUTH
COAST. THESE AREAS WILL GENERALLY SEE GUSTS IN THE 30 TO 40 MPH
RANGE. ALREADY SEEING HUMIDITIES LOWERING TO AROUND 10 PERCENT THIS
AFTERNOON ACROSS THE SANTA CLARITA VALLEY...ALONG WITH TEMPERATURES
CLIMBING INTO THE LOWER 90S.

BY LATE TONIGHT AND MONDAY...SURFACE HIGH PRESSURE BUILDS INTO THE
GREAT BASIN...SETTING THE STAGE FOR A BRIEF OFFSHORE WIND EVENT FOR
THE REGION. THE PROJECTED LAX-DAGGETT GRADIENT IS ONLY EXPECTED TO BE
AROUND -1.5 MB...WITH SOME UPPER LEVEL WIND SUPPORT. OFFSHORE
WINDS ARE EXPECTED TO DEVELOP ACROSS THE MOUNTAINS LATE
TONIGHT...THEN DESCEND INTO THE VALLEYS ON MONDAY MORNING. AT THIS
TIME...WIND GUSTS IN THE 35 TO 40 MPH RANGE CAN BE EXPECTED IN THE
MOUNTAINS ON MONDAY MORNING...WITH GUSTS IN THE 25 TO 35 MPH RANGE
ACROSS THE VALLEYS (MAINLY SANTA CLARITA AND EASTERN VENTURA
VALLEYS). THERE WILL LIKELY BE WIDESPREAD HUMIDITIES BETWEEN 10 AND
15 PERCENT ON MONDAY ACROSS THE MOUNTAINS AND VALLEYS OF LOS ANGELES
AND VENTURA COUNTIES...WITH ISOLATED SINGLE DIGIT READINGS LIKELY.
WHILE THIS OFFSHORE WIND EVENT DOES NOT APPEAR TO BE STRONG ENOUGH OR
HAVE SUFFICIENT DURATION TO WARRANT A RED FLAG WARNING...THERE WILL
BE ELEVATED FIRE DANGER ACROSS THE MOUNTAINS AND VALLEYS ON
MONDAY...ESPECIALLY CONSIDERING THE VERY DRY FUELS FOR THIS TIME OF
YEAR. THE OFFSHORE WINDS ARE EXPECTED TO DIMINISH FAIRLY RAPIDLY ON
MONDAY AFTERNOON...WITH ONSHORE WINDS GRADUALLY SPREADING ACROSS
COASTAL AND VALLEY AREAS THROUGH THE AFTERNOON AND EVENING HOURS.

&&

.MARINE...A THERMAL TROUGH OF LOW PRESSURE WILL INTENSIFY NEAR SHORE
WHILE HIGH PRESSURE PERSISTS OVER THE EASTERN PACIFIC THROUGH EARLY
MONDAY AND A GALE WARNING IS IN EFFECT OVER THE OUTER WATERS FROM
SAN CLEMENTE ISLAND TO POINT PIEDRAS BLANCAS AND INCLUDING THE INNER
WATERS FROM POINT PIEDRAS BLANCAS TO POINT SAL THROUGH LATE TONIGHT.
THE RIDGE OF HIGH PRESSURE OVER THE EASTERN PACIFIC WILL WEAKEN
MONDAY. A TROUGH OF LOW PRESSURE IS THEN EXPECTED TO MOVE SOUTHEAST
OVER THE OFFSHORE AND COASTAL WATERS EARLY TUESDAY THROUGH EARLY
WEDNESDAY WHILE A RIDGE OF HIGH PRESSURE STRENGTHENS OVER THE
EASTERN PACIFIC. NORTHWEST WINDS WILL LIKELY INCREASE NEAR SHORE
NORTH OF POINT CONCEPTION AND OVER THE OUTER WATERS SOUTH OF POINT
CONCEPTION TUESDAY EVENING THROUGH WEDNESDAY. A GALE WATCH WILL BE
ISSUED WHEN THE RISK OF GALE FORCE WINDS HAS SIGNIFICANTLY
INCREASED.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
GALE WARNING (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
WIND ADVISORY (SEE LAXNPWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...HALL
AVIATION...HALL
MARINE...30
FIRE WEATHER...GOMBERG
SYNOPSIS...KJ/HALL

WWW.WEATHER.GOV/LOSANGELES