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000
FXUS66 KLOX 012207
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
207 PM PST SUN MAR 1 2015

.SYNOPSIS...

A MOIST AND UNSTABLE AIR MASS IN PLACE FROM A COLD UPPER LOW
PRESSURE SYSTEM WILL BRING SHOWERS AND A SLIGHT CHANCE OF
THUNDERSTORMS TO THE AREA THROUGH MONDAY. A WEAKER STORM SYSTEM
WILL FOLLOW ON ITS HEELS LATER MONDAY ALLOWING FOR LINGERING
SHOWERS INTO EARLY TUESDAY. DRY AND WARMER WEATHER IS EXPECTED
LATE TUESDAY THROUGH FRIDAY.

&&

.SHORT TERM (TONIGHT-WEDNESDAY)...

A COLD CUTOFF TROUGH OF LOW PRESSURE CENTERED NEAR POINT
CONCEPTION CONTINUES TO LINGER OVER THE AREA THIS AFTERNOON. THIS
TROUGH IS DRIFTING SLOWLY SOUTH AND EAST...AND WILL REMAIN OVER
THE REGION INTO MONDAY. A MOIST AND UNSTABLE AIR MASS WILL PERSIST
OVER THE AREA. RADAR AND SATELLITE IMAGERY INDICATE SHOWERY
ACTIVITY BECOMING MORE WIDESPREAD AND NUMEROUS AS PREVIOUSLY
SURMISED WITH DAYTIME HEATING. CONVECTIVE STORMS WILL CONTINUE
INTO THE EVENING HOURS AS CYCLOGENESIS OCCURS. WITH THE LOW
FREEZING AND SNOW LEVELS...THERE IS POTENTIAL FOR SMALL HAIL AND
GRAUPEL...POSSIBLY ACCUMULATING AT TIMES AS THE STORM CORES ARE
RATHER INTENSE THIS AFTERNOON. LOCALIZED FLOODING IS POSSIBLE TOO
ESPECIALLY IN LOW-LYING AREAS. RECENTLY BURN AREAS WILL BE
MONITORED CLOSELY AS RATES COULD REACH CRITICAL THRESHOLDS FOR
MUD AND DEBRIS FLOWS...SUCH AS THE COLBY...POWERHOUSE...AND
SPRINGS BURN AREAS.

AN UPSTREAM KICKER TROUGH ALONG THE BRITISH COLUMBIA COAST WILL
DROP SOUTH INTO THE REGION THROUGH MONDAY AND DISPLACE THE
SLOW-MOVING CUTOFF TROUGH BETWEEN MONDAY AND TUESDAY. GFS
SOLUTIONS HOLD ONTO THE IDEA THAT THE TROUGH MAY MOVE OFFSHORE
AND HAVE LITTLE IMPACT FOR THE AREA. NAM-WRF SOLUTIONS ARE
STARTING BUY INTO THIS IDEA. POPS HAVE BEEN DECREASED AND WEATHER
HAS BEEN SCALED BACK SOMEWHAT IN-LINE WITH THIS IDEA.

NORTHEAST FLOW ALOFT ON THE LEE SIDE OF THE KICKER TROUGH TUESDAY
WILL PERMIT AN OFFSHORE FLOW PATTERN TO DEVELOP AND BRING A WARMER
AND DRIER AIR MASS FOR LATE WEEK. RIDGING ALOFT WILL REENFORCE AND
BUILD IN BEHIND THE TROUGH WEDNESDAY...AND BRING ADDITIONAL
WARMING AND DRYING FOR THE REGION.

.LONG TERM (THURSDAY-SUNDAY)...

RIDGING ALOFT WILL REENFORCE AND BUILD IN BEHIND THE TROUGH
SOMETIME BETWEEN THURSDAY AND FRIDAY. ADDITIONAL WARMING AND
DRYING IS LIKELY FOR THE REGION...BUT IT COULD BE DELAYED BY A
DAY DEPENDING UPON WHAT HAPPENS WITH ANOTHER WEAK WAVE DROPPING
SOUTH IN THE NORTHERLY FLOW ALOFT. BY FRIDAY...AN OMEGA BLOCKING
RIDGE SHOULD ESTABLISH FOR THE WEEKEND. THE WARMEST DAY AT THIS
TIME APPEARS TO BE SATURDAY WHEN THE RIDGE CENTER IS OVERHEAD. THE
RIDGE SHOULD LINGER INTO EARLY NEXT WEEK.

&&

.AVIATION...01/1745Z.

AT 1745Z...THERE WAS NO MARINE INVERSION AT KLAX.

OVERALL...LOW CONFIDENCE IN 18Z TAF PACKAGE. UNSTABLE AIR MASS WILL
CONTINUE TO GENERATE SCATTERED SHOWERS AND EVEN THE POSSIBILITY OF
AN ISOLATED THUNDERSTORM JUST ABOUT AT ANY TAF SITE THROUGH THIS
EVENING. IN TERMS OF CIG/VSBY RESTRICTIONS...CONDS WILL LIKELY VARY
BETWEEN VFR AND MVFR...WITH A GOOD CHANCE OF MVFR CIGS BEING
PREDOMINATE THIS AFTERNOON/EVENING...EXCEPT 30 PERCENT CHANCE FOR
LIFR/IFR FOR KPRB THROUGH 19Z

KLAX...LOW CONFIDENCE IN 18Z TAF. CONFIDENCE IN TIMING OF ANY MVFR
CIGS THRU THE PERIOD IS LOW. THERE IS A SLIGHT CHANCE OF TSTMS
THROUGH THIS EVENING.

KBUR...LOW CONFIDENCE IN 18Z TAF. CONFIDENCE IN TIMING OF ANY MVFR
CIGS THRU THE PERIOD IS LOW. THERE IS A SLIGHT CHANCE OF TSTMS
THROUGH THIS EVENING.

&&

.MARINE...01/950 AM.

HIGH CONFIDENCE IN WINDS REMAINING BELOW SMALL CRAFT ADVISORY LEVELS
THROUGH EARLY TUESDAY MORNING. ON TUESDAY...THERE IS A CHANCE OF
NORTHWEST WINDS INCREASING TO SMALL CRAFT ADVISORY LEVELS ACROSS THE
OUTER WATERS. 30 PERCENT CHANCE FOR THE WESTERN PORTION OF THE SBA
CHANNEL TUESDAY AFTERNOON.

MAIN ISSUE IN THE SHORT TERM WILL BE THE CONTINUED THREAT OF
THUNDERSTORMS THROUGH MONDAY EVENING. WITH ANY THUNDERSTORMS THAT
DEVELOP...THERE WILL BE THE POTENTIAL FOR BRIEF GUSTY WINDS...SMALL
HAIL AND EVEN A WATERSPOUT.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXMWWLOX).

&&

$$

PUBLIC...HALL
AVIATION/MARINE...CK
SYNOPSIS...HALL

WWW.WEATHER.GOV/LOSANGELES






000
FXUS66 KLOX 012207
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
207 PM PST SUN MAR 1 2015

.SYNOPSIS...

A MOIST AND UNSTABLE AIR MASS IN PLACE FROM A COLD UPPER LOW
PRESSURE SYSTEM WILL BRING SHOWERS AND A SLIGHT CHANCE OF
THUNDERSTORMS TO THE AREA THROUGH MONDAY. A WEAKER STORM SYSTEM
WILL FOLLOW ON ITS HEELS LATER MONDAY ALLOWING FOR LINGERING
SHOWERS INTO EARLY TUESDAY. DRY AND WARMER WEATHER IS EXPECTED
LATE TUESDAY THROUGH FRIDAY.

&&

.SHORT TERM (TONIGHT-WEDNESDAY)...

A COLD CUTOFF TROUGH OF LOW PRESSURE CENTERED NEAR POINT
CONCEPTION CONTINUES TO LINGER OVER THE AREA THIS AFTERNOON. THIS
TROUGH IS DRIFTING SLOWLY SOUTH AND EAST...AND WILL REMAIN OVER
THE REGION INTO MONDAY. A MOIST AND UNSTABLE AIR MASS WILL PERSIST
OVER THE AREA. RADAR AND SATELLITE IMAGERY INDICATE SHOWERY
ACTIVITY BECOMING MORE WIDESPREAD AND NUMEROUS AS PREVIOUSLY
SURMISED WITH DAYTIME HEATING. CONVECTIVE STORMS WILL CONTINUE
INTO THE EVENING HOURS AS CYCLOGENESIS OCCURS. WITH THE LOW
FREEZING AND SNOW LEVELS...THERE IS POTENTIAL FOR SMALL HAIL AND
GRAUPEL...POSSIBLY ACCUMULATING AT TIMES AS THE STORM CORES ARE
RATHER INTENSE THIS AFTERNOON. LOCALIZED FLOODING IS POSSIBLE TOO
ESPECIALLY IN LOW-LYING AREAS. RECENTLY BURN AREAS WILL BE
MONITORED CLOSELY AS RATES COULD REACH CRITICAL THRESHOLDS FOR
MUD AND DEBRIS FLOWS...SUCH AS THE COLBY...POWERHOUSE...AND
SPRINGS BURN AREAS.

AN UPSTREAM KICKER TROUGH ALONG THE BRITISH COLUMBIA COAST WILL
DROP SOUTH INTO THE REGION THROUGH MONDAY AND DISPLACE THE
SLOW-MOVING CUTOFF TROUGH BETWEEN MONDAY AND TUESDAY. GFS
SOLUTIONS HOLD ONTO THE IDEA THAT THE TROUGH MAY MOVE OFFSHORE
AND HAVE LITTLE IMPACT FOR THE AREA. NAM-WRF SOLUTIONS ARE
STARTING BUY INTO THIS IDEA. POPS HAVE BEEN DECREASED AND WEATHER
HAS BEEN SCALED BACK SOMEWHAT IN-LINE WITH THIS IDEA.

NORTHEAST FLOW ALOFT ON THE LEE SIDE OF THE KICKER TROUGH TUESDAY
WILL PERMIT AN OFFSHORE FLOW PATTERN TO DEVELOP AND BRING A WARMER
AND DRIER AIR MASS FOR LATE WEEK. RIDGING ALOFT WILL REENFORCE AND
BUILD IN BEHIND THE TROUGH WEDNESDAY...AND BRING ADDITIONAL
WARMING AND DRYING FOR THE REGION.

.LONG TERM (THURSDAY-SUNDAY)...

RIDGING ALOFT WILL REENFORCE AND BUILD IN BEHIND THE TROUGH
SOMETIME BETWEEN THURSDAY AND FRIDAY. ADDITIONAL WARMING AND
DRYING IS LIKELY FOR THE REGION...BUT IT COULD BE DELAYED BY A
DAY DEPENDING UPON WHAT HAPPENS WITH ANOTHER WEAK WAVE DROPPING
SOUTH IN THE NORTHERLY FLOW ALOFT. BY FRIDAY...AN OMEGA BLOCKING
RIDGE SHOULD ESTABLISH FOR THE WEEKEND. THE WARMEST DAY AT THIS
TIME APPEARS TO BE SATURDAY WHEN THE RIDGE CENTER IS OVERHEAD. THE
RIDGE SHOULD LINGER INTO EARLY NEXT WEEK.

&&

.AVIATION...01/1745Z.

AT 1745Z...THERE WAS NO MARINE INVERSION AT KLAX.

OVERALL...LOW CONFIDENCE IN 18Z TAF PACKAGE. UNSTABLE AIR MASS WILL
CONTINUE TO GENERATE SCATTERED SHOWERS AND EVEN THE POSSIBILITY OF
AN ISOLATED THUNDERSTORM JUST ABOUT AT ANY TAF SITE THROUGH THIS
EVENING. IN TERMS OF CIG/VSBY RESTRICTIONS...CONDS WILL LIKELY VARY
BETWEEN VFR AND MVFR...WITH A GOOD CHANCE OF MVFR CIGS BEING
PREDOMINATE THIS AFTERNOON/EVENING...EXCEPT 30 PERCENT CHANCE FOR
LIFR/IFR FOR KPRB THROUGH 19Z

KLAX...LOW CONFIDENCE IN 18Z TAF. CONFIDENCE IN TIMING OF ANY MVFR
CIGS THRU THE PERIOD IS LOW. THERE IS A SLIGHT CHANCE OF TSTMS
THROUGH THIS EVENING.

KBUR...LOW CONFIDENCE IN 18Z TAF. CONFIDENCE IN TIMING OF ANY MVFR
CIGS THRU THE PERIOD IS LOW. THERE IS A SLIGHT CHANCE OF TSTMS
THROUGH THIS EVENING.

&&

.MARINE...01/950 AM.

HIGH CONFIDENCE IN WINDS REMAINING BELOW SMALL CRAFT ADVISORY LEVELS
THROUGH EARLY TUESDAY MORNING. ON TUESDAY...THERE IS A CHANCE OF
NORTHWEST WINDS INCREASING TO SMALL CRAFT ADVISORY LEVELS ACROSS THE
OUTER WATERS. 30 PERCENT CHANCE FOR THE WESTERN PORTION OF THE SBA
CHANNEL TUESDAY AFTERNOON.

MAIN ISSUE IN THE SHORT TERM WILL BE THE CONTINUED THREAT OF
THUNDERSTORMS THROUGH MONDAY EVENING. WITH ANY THUNDERSTORMS THAT
DEVELOP...THERE WILL BE THE POTENTIAL FOR BRIEF GUSTY WINDS...SMALL
HAIL AND EVEN A WATERSPOUT.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXMWWLOX).

&&

$$

PUBLIC...HALL
AVIATION/MARINE...CK
SYNOPSIS...HALL

WWW.WEATHER.GOV/LOSANGELES







000
FXUS66 KLOX 012207
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
207 PM PST SUN MAR 1 2015

.SYNOPSIS...

A MOIST AND UNSTABLE AIR MASS IN PLACE FROM A COLD UPPER LOW
PRESSURE SYSTEM WILL BRING SHOWERS AND A SLIGHT CHANCE OF
THUNDERSTORMS TO THE AREA THROUGH MONDAY. A WEAKER STORM SYSTEM
WILL FOLLOW ON ITS HEELS LATER MONDAY ALLOWING FOR LINGERING
SHOWERS INTO EARLY TUESDAY. DRY AND WARMER WEATHER IS EXPECTED
LATE TUESDAY THROUGH FRIDAY.

&&

.SHORT TERM (TONIGHT-WEDNESDAY)...

A COLD CUTOFF TROUGH OF LOW PRESSURE CENTERED NEAR POINT
CONCEPTION CONTINUES TO LINGER OVER THE AREA THIS AFTERNOON. THIS
TROUGH IS DRIFTING SLOWLY SOUTH AND EAST...AND WILL REMAIN OVER
THE REGION INTO MONDAY. A MOIST AND UNSTABLE AIR MASS WILL PERSIST
OVER THE AREA. RADAR AND SATELLITE IMAGERY INDICATE SHOWERY
ACTIVITY BECOMING MORE WIDESPREAD AND NUMEROUS AS PREVIOUSLY
SURMISED WITH DAYTIME HEATING. CONVECTIVE STORMS WILL CONTINUE
INTO THE EVENING HOURS AS CYCLOGENESIS OCCURS. WITH THE LOW
FREEZING AND SNOW LEVELS...THERE IS POTENTIAL FOR SMALL HAIL AND
GRAUPEL...POSSIBLY ACCUMULATING AT TIMES AS THE STORM CORES ARE
RATHER INTENSE THIS AFTERNOON. LOCALIZED FLOODING IS POSSIBLE TOO
ESPECIALLY IN LOW-LYING AREAS. RECENTLY BURN AREAS WILL BE
MONITORED CLOSELY AS RATES COULD REACH CRITICAL THRESHOLDS FOR
MUD AND DEBRIS FLOWS...SUCH AS THE COLBY...POWERHOUSE...AND
SPRINGS BURN AREAS.

AN UPSTREAM KICKER TROUGH ALONG THE BRITISH COLUMBIA COAST WILL
DROP SOUTH INTO THE REGION THROUGH MONDAY AND DISPLACE THE
SLOW-MOVING CUTOFF TROUGH BETWEEN MONDAY AND TUESDAY. GFS
SOLUTIONS HOLD ONTO THE IDEA THAT THE TROUGH MAY MOVE OFFSHORE
AND HAVE LITTLE IMPACT FOR THE AREA. NAM-WRF SOLUTIONS ARE
STARTING BUY INTO THIS IDEA. POPS HAVE BEEN DECREASED AND WEATHER
HAS BEEN SCALED BACK SOMEWHAT IN-LINE WITH THIS IDEA.

NORTHEAST FLOW ALOFT ON THE LEE SIDE OF THE KICKER TROUGH TUESDAY
WILL PERMIT AN OFFSHORE FLOW PATTERN TO DEVELOP AND BRING A WARMER
AND DRIER AIR MASS FOR LATE WEEK. RIDGING ALOFT WILL REENFORCE AND
BUILD IN BEHIND THE TROUGH WEDNESDAY...AND BRING ADDITIONAL
WARMING AND DRYING FOR THE REGION.

.LONG TERM (THURSDAY-SUNDAY)...

RIDGING ALOFT WILL REENFORCE AND BUILD IN BEHIND THE TROUGH
SOMETIME BETWEEN THURSDAY AND FRIDAY. ADDITIONAL WARMING AND
DRYING IS LIKELY FOR THE REGION...BUT IT COULD BE DELAYED BY A
DAY DEPENDING UPON WHAT HAPPENS WITH ANOTHER WEAK WAVE DROPPING
SOUTH IN THE NORTHERLY FLOW ALOFT. BY FRIDAY...AN OMEGA BLOCKING
RIDGE SHOULD ESTABLISH FOR THE WEEKEND. THE WARMEST DAY AT THIS
TIME APPEARS TO BE SATURDAY WHEN THE RIDGE CENTER IS OVERHEAD. THE
RIDGE SHOULD LINGER INTO EARLY NEXT WEEK.

&&

.AVIATION...01/1745Z.

AT 1745Z...THERE WAS NO MARINE INVERSION AT KLAX.

OVERALL...LOW CONFIDENCE IN 18Z TAF PACKAGE. UNSTABLE AIR MASS WILL
CONTINUE TO GENERATE SCATTERED SHOWERS AND EVEN THE POSSIBILITY OF
AN ISOLATED THUNDERSTORM JUST ABOUT AT ANY TAF SITE THROUGH THIS
EVENING. IN TERMS OF CIG/VSBY RESTRICTIONS...CONDS WILL LIKELY VARY
BETWEEN VFR AND MVFR...WITH A GOOD CHANCE OF MVFR CIGS BEING
PREDOMINATE THIS AFTERNOON/EVENING...EXCEPT 30 PERCENT CHANCE FOR
LIFR/IFR FOR KPRB THROUGH 19Z

KLAX...LOW CONFIDENCE IN 18Z TAF. CONFIDENCE IN TIMING OF ANY MVFR
CIGS THRU THE PERIOD IS LOW. THERE IS A SLIGHT CHANCE OF TSTMS
THROUGH THIS EVENING.

KBUR...LOW CONFIDENCE IN 18Z TAF. CONFIDENCE IN TIMING OF ANY MVFR
CIGS THRU THE PERIOD IS LOW. THERE IS A SLIGHT CHANCE OF TSTMS
THROUGH THIS EVENING.

&&

.MARINE...01/950 AM.

HIGH CONFIDENCE IN WINDS REMAINING BELOW SMALL CRAFT ADVISORY LEVELS
THROUGH EARLY TUESDAY MORNING. ON TUESDAY...THERE IS A CHANCE OF
NORTHWEST WINDS INCREASING TO SMALL CRAFT ADVISORY LEVELS ACROSS THE
OUTER WATERS. 30 PERCENT CHANCE FOR THE WESTERN PORTION OF THE SBA
CHANNEL TUESDAY AFTERNOON.

MAIN ISSUE IN THE SHORT TERM WILL BE THE CONTINUED THREAT OF
THUNDERSTORMS THROUGH MONDAY EVENING. WITH ANY THUNDERSTORMS THAT
DEVELOP...THERE WILL BE THE POTENTIAL FOR BRIEF GUSTY WINDS...SMALL
HAIL AND EVEN A WATERSPOUT.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXMWWLOX).

&&

$$

PUBLIC...HALL
AVIATION/MARINE...CK
SYNOPSIS...HALL

WWW.WEATHER.GOV/LOSANGELES







000
FXUS66 KLOX 012207
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
207 PM PST SUN MAR 1 2015

.SYNOPSIS...

A MOIST AND UNSTABLE AIR MASS IN PLACE FROM A COLD UPPER LOW
PRESSURE SYSTEM WILL BRING SHOWERS AND A SLIGHT CHANCE OF
THUNDERSTORMS TO THE AREA THROUGH MONDAY. A WEAKER STORM SYSTEM
WILL FOLLOW ON ITS HEELS LATER MONDAY ALLOWING FOR LINGERING
SHOWERS INTO EARLY TUESDAY. DRY AND WARMER WEATHER IS EXPECTED
LATE TUESDAY THROUGH FRIDAY.

&&

.SHORT TERM (TONIGHT-WEDNESDAY)...

A COLD CUTOFF TROUGH OF LOW PRESSURE CENTERED NEAR POINT
CONCEPTION CONTINUES TO LINGER OVER THE AREA THIS AFTERNOON. THIS
TROUGH IS DRIFTING SLOWLY SOUTH AND EAST...AND WILL REMAIN OVER
THE REGION INTO MONDAY. A MOIST AND UNSTABLE AIR MASS WILL PERSIST
OVER THE AREA. RADAR AND SATELLITE IMAGERY INDICATE SHOWERY
ACTIVITY BECOMING MORE WIDESPREAD AND NUMEROUS AS PREVIOUSLY
SURMISED WITH DAYTIME HEATING. CONVECTIVE STORMS WILL CONTINUE
INTO THE EVENING HOURS AS CYCLOGENESIS OCCURS. WITH THE LOW
FREEZING AND SNOW LEVELS...THERE IS POTENTIAL FOR SMALL HAIL AND
GRAUPEL...POSSIBLY ACCUMULATING AT TIMES AS THE STORM CORES ARE
RATHER INTENSE THIS AFTERNOON. LOCALIZED FLOODING IS POSSIBLE TOO
ESPECIALLY IN LOW-LYING AREAS. RECENTLY BURN AREAS WILL BE
MONITORED CLOSELY AS RATES COULD REACH CRITICAL THRESHOLDS FOR
MUD AND DEBRIS FLOWS...SUCH AS THE COLBY...POWERHOUSE...AND
SPRINGS BURN AREAS.

AN UPSTREAM KICKER TROUGH ALONG THE BRITISH COLUMBIA COAST WILL
DROP SOUTH INTO THE REGION THROUGH MONDAY AND DISPLACE THE
SLOW-MOVING CUTOFF TROUGH BETWEEN MONDAY AND TUESDAY. GFS
SOLUTIONS HOLD ONTO THE IDEA THAT THE TROUGH MAY MOVE OFFSHORE
AND HAVE LITTLE IMPACT FOR THE AREA. NAM-WRF SOLUTIONS ARE
STARTING BUY INTO THIS IDEA. POPS HAVE BEEN DECREASED AND WEATHER
HAS BEEN SCALED BACK SOMEWHAT IN-LINE WITH THIS IDEA.

NORTHEAST FLOW ALOFT ON THE LEE SIDE OF THE KICKER TROUGH TUESDAY
WILL PERMIT AN OFFSHORE FLOW PATTERN TO DEVELOP AND BRING A WARMER
AND DRIER AIR MASS FOR LATE WEEK. RIDGING ALOFT WILL REENFORCE AND
BUILD IN BEHIND THE TROUGH WEDNESDAY...AND BRING ADDITIONAL
WARMING AND DRYING FOR THE REGION.

.LONG TERM (THURSDAY-SUNDAY)...

RIDGING ALOFT WILL REENFORCE AND BUILD IN BEHIND THE TROUGH
SOMETIME BETWEEN THURSDAY AND FRIDAY. ADDITIONAL WARMING AND
DRYING IS LIKELY FOR THE REGION...BUT IT COULD BE DELAYED BY A
DAY DEPENDING UPON WHAT HAPPENS WITH ANOTHER WEAK WAVE DROPPING
SOUTH IN THE NORTHERLY FLOW ALOFT. BY FRIDAY...AN OMEGA BLOCKING
RIDGE SHOULD ESTABLISH FOR THE WEEKEND. THE WARMEST DAY AT THIS
TIME APPEARS TO BE SATURDAY WHEN THE RIDGE CENTER IS OVERHEAD. THE
RIDGE SHOULD LINGER INTO EARLY NEXT WEEK.

&&

.AVIATION...01/1745Z.

AT 1745Z...THERE WAS NO MARINE INVERSION AT KLAX.

OVERALL...LOW CONFIDENCE IN 18Z TAF PACKAGE. UNSTABLE AIR MASS WILL
CONTINUE TO GENERATE SCATTERED SHOWERS AND EVEN THE POSSIBILITY OF
AN ISOLATED THUNDERSTORM JUST ABOUT AT ANY TAF SITE THROUGH THIS
EVENING. IN TERMS OF CIG/VSBY RESTRICTIONS...CONDS WILL LIKELY VARY
BETWEEN VFR AND MVFR...WITH A GOOD CHANCE OF MVFR CIGS BEING
PREDOMINATE THIS AFTERNOON/EVENING...EXCEPT 30 PERCENT CHANCE FOR
LIFR/IFR FOR KPRB THROUGH 19Z

KLAX...LOW CONFIDENCE IN 18Z TAF. CONFIDENCE IN TIMING OF ANY MVFR
CIGS THRU THE PERIOD IS LOW. THERE IS A SLIGHT CHANCE OF TSTMS
THROUGH THIS EVENING.

KBUR...LOW CONFIDENCE IN 18Z TAF. CONFIDENCE IN TIMING OF ANY MVFR
CIGS THRU THE PERIOD IS LOW. THERE IS A SLIGHT CHANCE OF TSTMS
THROUGH THIS EVENING.

&&

.MARINE...01/950 AM.

HIGH CONFIDENCE IN WINDS REMAINING BELOW SMALL CRAFT ADVISORY LEVELS
THROUGH EARLY TUESDAY MORNING. ON TUESDAY...THERE IS A CHANCE OF
NORTHWEST WINDS INCREASING TO SMALL CRAFT ADVISORY LEVELS ACROSS THE
OUTER WATERS. 30 PERCENT CHANCE FOR THE WESTERN PORTION OF THE SBA
CHANNEL TUESDAY AFTERNOON.

MAIN ISSUE IN THE SHORT TERM WILL BE THE CONTINUED THREAT OF
THUNDERSTORMS THROUGH MONDAY EVENING. WITH ANY THUNDERSTORMS THAT
DEVELOP...THERE WILL BE THE POTENTIAL FOR BRIEF GUSTY WINDS...SMALL
HAIL AND EVEN A WATERSPOUT.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXMWWLOX).

&&

$$

PUBLIC...HALL
AVIATION/MARINE...CK
SYNOPSIS...HALL

WWW.WEATHER.GOV/LOSANGELES






000
FXUS66 KLOX 011800
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1000 AM PST SUN MAR 1 2015

.SYNOPSIS...

A MOIST AND UNSTABLE AIR MASS IN PLACE FROM A COLD UPPER LOW
PRESSURE SYSTEM WILL BRING SHOWERS AND A SLIGHT CHANCE OF
THUNDERSTORMS TO THE AREA THROUGH MONDAY. A WEAKER STORM SYSTEM
WILL FOLLOW ON ITS HEELS LATER MONDAY ALLOWING FOR LINGERING
SHOWERS INTO EARLY TUESDAY. DRY AND WARMER WEATHER IS EXPECTED
LATE TUESDAY THROUGH FRIDAY.

&&

.UPDATE...

SATELLITE IMAGERY INDICATES A COLD TROUGH OF LOW PRESSURE
SPINNING OFF OF THE CENTRAL COAST THIS MORNING. RADAR IMAGERY
INDICATES A STRATIFORM RAIN BAND SITTING SOUTH OF THE AREA OVER
SAN DIEGO COUNTY WITH SCATTERED SHOWERS MAINLY OVER LOS ANGELES
COUNTY THIS MORNING. A COLD AIR MASS ALOFT SHOULD PERMIT
CONVECTIVE STORMS TO DEVELOP LATER TODAY. SHOWER DEVELOPMENT IS
ALREADY STARTING TO OCCUR OVER INTERIOR SAN LUIS OBISPO COUNTY AS
SOLAR INSOLATION DESTABILIZES THE COLD ATMOSPHERE. POPS AND CLOUD
COVER WERE DECREASED THIS MORNING...BUT POPS AND CLOUD COVER LOOK
AGREEABLE FOR THE AFTERNOON TIME PERIOD.

THE TROUGH OF LOW PRESSURE WILL SLOWLY MOVE SOUTH AND EAST
THROUGH MONDAY MORNING...MOVING ASHORE NEAR SAN DIEGO LATE MONDAY
MORNING. WEAK RIDGING SHOULD DEVELOP FOR MONDAY AFTERNOON AND
BRING MORE SUN THAN CLOUDS.

MAIN PROBLEM FOR TODAY...BESIDES MONITORING SHOWER DEVELOPMENT
THIS AFTERNOON...WILL BE THE KICKER SYSTEM FOR MONDAY NIGHT AND
TUESDAY. NAM-WRF SOLUTIONS WANT TO HOLD ON TO THE IDEA OF THE
TROUGH MOVING CLOSER TO THE AREA...WHILE GFS SOLUTIONS MOVE THE
TROUGH FARTHER OFFSHORE. GFS MODEL TRENDS SUGGEST THE TROUGH
MOVING FARTHER OFFSHORE WITH EACH MODEL RUN. AS A RESULT...POPS
WILL LIKELY TRENDED DRIER FOR MONDAY NIGHT AND TUESDAY.

&&

.PREV DISCUSSION...

SHORT TERM...HOT ON THE HEALS OF THE CURRENT STORM A SECONDARY
SYSTEM WILL MOVE INTO THE AREA. THIS STORM IS NOW FORECAST TO TAKE
MORE WESTERLY TRACK OVER THE PACIFIC AND FARTHER AWAY FROM LAND.
THIS WILL REDUCE THE AMOUNT OF RAINFALL OVER THE LAND. THIS SYSTEM
NOW LOOKS LIKE IT WILL NOT PRODUCE MUCH RAINFALL FOR THE AREA.
LIKE TODAYS SYSTEM THE RAINFALL WILL BE SHOWERY AND RAINFALL WILL
VARY CONSIDERABLY FORM LOCATION TO LOCATION.

THE SECOND SYSTEM WILL SCOOT OUT FAIRLY QUICKLY MONDAY AND NIGHT AND
SKIES WILL CLEAR FOR TUESDAY.

MAX TEMPS WILL BE 4 TO 8 DEGREES BELOW NORMAL TODAY AND MONDAY WITH
ABOUT 3 DEGREES OF WARMING ON TUESDAY.

LONG TERM...HIGH PRESSURE WILL SET UP WEDNESDAY ALONG WITH WEAK
OFFSHORE FLOW. THIS WILL KICK OFF A ROUND OF DRY WEATHER WITH
CLEAR SKIES AND A WARMING TREND. MAX TEMPS WILL REACH NORMALS
WEDNESDAY AND THEN WILL BE ABOVE NORMAL FOR THE REST OF THE
PERIOD. RIGHT NOW FRIDAY LOOKS LIKE IT WILL BE THE WARMEST DAY
WITH PLENTY OF UPPER 70S AND A SMATTERING OF LOWER 80S FORECAST.

&&

.AVIATION...01/1745Z.

AT 1745Z...THERE WAS NO MARINE INVERSION AT KLAX.

OVERALL...LOW CONFIDENCE IN 18Z TAF PACKAGE. UNSTABLE AIR MASS WILL
CONTINUE TO GENERATE SCATTERED SHOWERS AND EVEN THE POSSIBILITY OF
AN ISOLATED THUNDERSTORM JUST ABOUT AT ANY TAF SITE THROUGH THIS
EVENING. IN TERMS OF CIG/VSBY RESTRICTIONS...CONDS WILL LIKELY VARY
BETWEEN VFR AND MVFR...WITH A GOOD CHANCE OF MVFR CIGS BEING
PREDOMINATE THIS AFTERNOON/EVENING...EXCEPT 30 PERCENT CHANCE FOR
LIFR/IFR FOR KPRB THROUGH 19Z

KLAX...LOW CONFIDENCE IN 18Z TAF. CONFIDENCE IN TIMING OF ANY MVFR
CIGS THRU THE PERIOD IS LOW. THERE IS A SLIGHT CHANCE OF TSTMS
THROUGH THIS EVENING.

KBUR...LOW CONFIDENCE IN 18Z TAF. CONFIDENCE IN TIMING OF ANY MVFR
CIGS THRU THE PERIOD IS LOW. THERE IS A SLIGHT CHANCE OF TSTMS
THROUGH THIS EVENING.

&&

.MARINE...01/950 AM.

HIGH CONFIDENCE IN WINDS REMAINING BELOW SMALL CRAFT ADVISORY LEVELS
THROUGH EARLY TUESDAY MORNING. ON TUESDAY...THERE IS A CHANCE OF
NORTHWEST WINDS INCREASING TO SMALL CRAFT ADVISORY LEVELS ACROSS THE
OUTER WATERS. 30 PERCENT CHANCE FOR THE WESTERN PORTION OF THE SBA
CHANNEL TUESDAY AFTERNOON.

MAIN ISSUE IN THE SHORT TERM WILL BE THE CONTINUED THREAT OF
THUNDERSTORMS THROUGH MONDAY EVENING. WITH ANY THUNDERSTORMS THAT
DEVELOP...THERE WILL BE THE POTENTIAL FOR BRIEF GUSTY WINDS...SMALL
HAIL AND EVEN A WATERSPOUT.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXMWWLOX).

&&

$$

PUBLIC...HALL/RORKE
AVIATION...CK
MARINE...CK
SYNOPSIS...HALL

WWW.WEATHER.GOV/LOSANGELES









000
FXUS66 KLOX 011800
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1000 AM PST SUN MAR 1 2015

.SYNOPSIS...

A MOIST AND UNSTABLE AIR MASS IN PLACE FROM A COLD UPPER LOW
PRESSURE SYSTEM WILL BRING SHOWERS AND A SLIGHT CHANCE OF
THUNDERSTORMS TO THE AREA THROUGH MONDAY. A WEAKER STORM SYSTEM
WILL FOLLOW ON ITS HEELS LATER MONDAY ALLOWING FOR LINGERING
SHOWERS INTO EARLY TUESDAY. DRY AND WARMER WEATHER IS EXPECTED
LATE TUESDAY THROUGH FRIDAY.

&&

.UPDATE...

SATELLITE IMAGERY INDICATES A COLD TROUGH OF LOW PRESSURE
SPINNING OFF OF THE CENTRAL COAST THIS MORNING. RADAR IMAGERY
INDICATES A STRATIFORM RAIN BAND SITTING SOUTH OF THE AREA OVER
SAN DIEGO COUNTY WITH SCATTERED SHOWERS MAINLY OVER LOS ANGELES
COUNTY THIS MORNING. A COLD AIR MASS ALOFT SHOULD PERMIT
CONVECTIVE STORMS TO DEVELOP LATER TODAY. SHOWER DEVELOPMENT IS
ALREADY STARTING TO OCCUR OVER INTERIOR SAN LUIS OBISPO COUNTY AS
SOLAR INSOLATION DESTABILIZES THE COLD ATMOSPHERE. POPS AND CLOUD
COVER WERE DECREASED THIS MORNING...BUT POPS AND CLOUD COVER LOOK
AGREEABLE FOR THE AFTERNOON TIME PERIOD.

THE TROUGH OF LOW PRESSURE WILL SLOWLY MOVE SOUTH AND EAST
THROUGH MONDAY MORNING...MOVING ASHORE NEAR SAN DIEGO LATE MONDAY
MORNING. WEAK RIDGING SHOULD DEVELOP FOR MONDAY AFTERNOON AND
BRING MORE SUN THAN CLOUDS.

MAIN PROBLEM FOR TODAY...BESIDES MONITORING SHOWER DEVELOPMENT
THIS AFTERNOON...WILL BE THE KICKER SYSTEM FOR MONDAY NIGHT AND
TUESDAY. NAM-WRF SOLUTIONS WANT TO HOLD ON TO THE IDEA OF THE
TROUGH MOVING CLOSER TO THE AREA...WHILE GFS SOLUTIONS MOVE THE
TROUGH FARTHER OFFSHORE. GFS MODEL TRENDS SUGGEST THE TROUGH
MOVING FARTHER OFFSHORE WITH EACH MODEL RUN. AS A RESULT...POPS
WILL LIKELY TRENDED DRIER FOR MONDAY NIGHT AND TUESDAY.

&&

.PREV DISCUSSION...

SHORT TERM...HOT ON THE HEALS OF THE CURRENT STORM A SECONDARY
SYSTEM WILL MOVE INTO THE AREA. THIS STORM IS NOW FORECAST TO TAKE
MORE WESTERLY TRACK OVER THE PACIFIC AND FARTHER AWAY FROM LAND.
THIS WILL REDUCE THE AMOUNT OF RAINFALL OVER THE LAND. THIS SYSTEM
NOW LOOKS LIKE IT WILL NOT PRODUCE MUCH RAINFALL FOR THE AREA.
LIKE TODAYS SYSTEM THE RAINFALL WILL BE SHOWERY AND RAINFALL WILL
VARY CONSIDERABLY FORM LOCATION TO LOCATION.

THE SECOND SYSTEM WILL SCOOT OUT FAIRLY QUICKLY MONDAY AND NIGHT AND
SKIES WILL CLEAR FOR TUESDAY.

MAX TEMPS WILL BE 4 TO 8 DEGREES BELOW NORMAL TODAY AND MONDAY WITH
ABOUT 3 DEGREES OF WARMING ON TUESDAY.

LONG TERM...HIGH PRESSURE WILL SET UP WEDNESDAY ALONG WITH WEAK
OFFSHORE FLOW. THIS WILL KICK OFF A ROUND OF DRY WEATHER WITH
CLEAR SKIES AND A WARMING TREND. MAX TEMPS WILL REACH NORMALS
WEDNESDAY AND THEN WILL BE ABOVE NORMAL FOR THE REST OF THE
PERIOD. RIGHT NOW FRIDAY LOOKS LIKE IT WILL BE THE WARMEST DAY
WITH PLENTY OF UPPER 70S AND A SMATTERING OF LOWER 80S FORECAST.

&&

.AVIATION...01/1745Z.

AT 1745Z...THERE WAS NO MARINE INVERSION AT KLAX.

OVERALL...LOW CONFIDENCE IN 18Z TAF PACKAGE. UNSTABLE AIR MASS WILL
CONTINUE TO GENERATE SCATTERED SHOWERS AND EVEN THE POSSIBILITY OF
AN ISOLATED THUNDERSTORM JUST ABOUT AT ANY TAF SITE THROUGH THIS
EVENING. IN TERMS OF CIG/VSBY RESTRICTIONS...CONDS WILL LIKELY VARY
BETWEEN VFR AND MVFR...WITH A GOOD CHANCE OF MVFR CIGS BEING
PREDOMINATE THIS AFTERNOON/EVENING...EXCEPT 30 PERCENT CHANCE FOR
LIFR/IFR FOR KPRB THROUGH 19Z

KLAX...LOW CONFIDENCE IN 18Z TAF. CONFIDENCE IN TIMING OF ANY MVFR
CIGS THRU THE PERIOD IS LOW. THERE IS A SLIGHT CHANCE OF TSTMS
THROUGH THIS EVENING.

KBUR...LOW CONFIDENCE IN 18Z TAF. CONFIDENCE IN TIMING OF ANY MVFR
CIGS THRU THE PERIOD IS LOW. THERE IS A SLIGHT CHANCE OF TSTMS
THROUGH THIS EVENING.

&&

.MARINE...01/950 AM.

HIGH CONFIDENCE IN WINDS REMAINING BELOW SMALL CRAFT ADVISORY LEVELS
THROUGH EARLY TUESDAY MORNING. ON TUESDAY...THERE IS A CHANCE OF
NORTHWEST WINDS INCREASING TO SMALL CRAFT ADVISORY LEVELS ACROSS THE
OUTER WATERS. 30 PERCENT CHANCE FOR THE WESTERN PORTION OF THE SBA
CHANNEL TUESDAY AFTERNOON.

MAIN ISSUE IN THE SHORT TERM WILL BE THE CONTINUED THREAT OF
THUNDERSTORMS THROUGH MONDAY EVENING. WITH ANY THUNDERSTORMS THAT
DEVELOP...THERE WILL BE THE POTENTIAL FOR BRIEF GUSTY WINDS...SMALL
HAIL AND EVEN A WATERSPOUT.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXMWWLOX).

&&

$$

PUBLIC...HALL/RORKE
AVIATION...CK
MARINE...CK
SYNOPSIS...HALL

WWW.WEATHER.GOV/LOSANGELES








000
FXUS66 KLOX 011209
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
350 AM PST SUN MAR 1 2015

.SYNOPSIS...

A COLD UPPER LOW WILL SLOWLY MOVE OVER SOUTHERN CALIFORNIA BRINGING
PERIODS OF SHOWERS AND A SLIGHT CHANCE OF THUNDERSTORMS. SNOW WILL
FALL AS LOW AS 4000 FEET. THIS LOW WILL PERSIST OVER THE AREA
THROUGH EARLY MONDAY BEFORE EXITING. A WEAKER STORM SYSTEM WILL
FOLLOW ON ITS HEELS LATER MONDAY ALLOWING FOR LINGERING SHOWERS INTO
EARLY TUESDAY. DRY AND WARMER WEATHER IS EXPECTED LATE TUESDAY
THROUGH FRIDAY.

&&

.SHORT TERM (TODAY-TUE)...
THE UPPER LOW IS CURRENTLY OVER POINT CONCEPTION. IT IS SWINGING A
NICE VORT LOBE THROUGH THE AREA FROM SANTA BARBARA TO LOS ANGELES.
THIS VORT LOBE IS SPAWNING HEAVY SHOWERS AND SOME THUNDERSTORMS. A
FEW HEAVY SHOWERS ARE NOW OVER THE SPRINGS FIRE AND A FLASH FLOOD
WARNING WAS ISSUED DUE TO THE HEAVY RAINFALL. THE UPPER LOW WILL
MOVE VERY SLOWLY TO THE ESE AND WILL NOT EXIT THE AREA UNTIL MONDAY
MORNING. THIS UPPER LOW WILL SPIN LOBES OF PVA AND NVA OVER THE AREA
THROUGH MONDAY MORNING. THIS WILL MAKE FOR A VERY VARIABLE FORECAST
AT TIMES OF PVA THERE WILL BE PLENTY OF CLOUDS AND SHOWERS BUT WHEN
THE NVA IS MOVING THROUGH THERE WILL NO RAIN AND BREAKS IN THE
CLOUDS. MOST OF THE ACTION WILL BE SOUTH OF POINT CONCEPTION BUT SLO
AND SBA COUNTY WILL STILL SEE SOME BANDS OF SHOWERS MOVING THROUGH
AT TIMES. THE 500 MB TEMPS AT THE CORE OF THE UPPER LOW ARE ABOUT
-28 DEGREES C WHICH IS COOL ENOUGH TO DESTABILIZE THINGS ENOUGH TO
ALLOW FOR A SLIGHT CHC OF THUNDERSTORMS. ANY THUNDERSTORM THAT DOES
FORM COULD PRODUCE SOME SMALL HAIL.

THE COLD AIR WILL ALSO LOWER SNOW LEVELS TO 4000 FEET AND LOCALLY
DOWN TO 3500 FEET.

RAIN AND SNOWFALL AMOUNTS WITH THIS FIRST SYSTEM WILL BE HIGHLY
VARIABLE DUE TO THE SHOWERY NATURE. AN AREAL AVERAGE OF 0.10-0.25"
CAN BE EXPECTED FOR THE COASTAL AND VALLEY AREAS THROUGH MONDAY
MORNING. THERE WILL BE LOCALLY HEAVIER AMOUNTS UP TO AN INCH UNDER
HEAVIER SHOWERS OR THUNDERSTORMS. IN THE MOUNTAINS 0.50-1.00" OF
LIQUID EQUIVALENT IS LIKELY OVER MANY AREAS. THIS WILL LIKELY
TRANSLATE TO 8-12" OF SNOW IS ABOVE 6500 FEET...WITH 2-4" POSSIBLE
BETWEEN 4000 AND 5000 FEET.

HOT ON THE HEALS OF THE CURRENT STORM A SECONDARY SYSTEM WILL MOVE
INTO THE AREA. THIS STORM IS NOW FORECAST TO TAKE MORE WESTERLY
TRACK OVER THE PACIFIC AND FURTHER AWAY FROM LAND. THIS WILL REDUCE
THE AMOUNT OF RAINFALL OVER THE LAND. THIS SYSTEM NOW LOOKS LIKE IT
WILL NOT PRODUCE MUCH RAINFALL FOR THE AREA. LIKE TODAYS SYSTEM THE
RAINFALL WILL BE SHOWERY AND RAINFALL WILL VARY CONSIDERABLY FORM
LOCATION TO LOCATION.

THE SECOND SYSTEM WILL SCOOT OUT FAIRLY QUICKLY MONDAY AND NIGHT AND
SKIES WILL CLEAR FOR TUESDAY.

MAX TEMPS WILL BE 4 TO 8 DEGREES BELOW NORMAL TODAY AND MONDAY WITH
ABOUT 3 DEGREES OF WARMING ON TUESDAY.

.LONG TERM (WED-SAT)...
HIGH PRESSURE WILL SET UP WEDNESDAY ALONG WITH WEAK OFFSHORE FLOW.
THIS WILL KICK OFF A ROUND OF DRY WEATHER WITH CLEAR SKIES AND A
WARMING TREND. MAX TEMPS WILL REACH NORMALS WEDNESDAY AND THEN WILL
BE ABOVE NORMAL FOR THE REST OF THE PERIOD. RIGHT NOW FRIDAY LOOKS
LIKE IT WILL BE THE WARMEST DAY WITH PLENTY OF UPPER 70S AND A
SMATTERING OF LOWER 80S FORECAST.

&&

.AVIATION...

01/1115Z

AT 1100Z...THERE WAS NO MARINE INVERSION AT KLAX.

OVERALL...LOW CONFIDENCE IN 12Z TAF PACKAGE. UNSTABLE AIR MASS WILL
CONTINUE TO GENERATE SCATTERED SHOWERS AND EVEN THE POSSIBILITY OF
AN ISOLATED THUNDERSTORM JUST ABOUT AT ANY TAF SITE THROUGH THIS
EVENING. IN TERMS OF CIG/VSBY RESTRICTIONS...CONDS WILL LIKELY VARY
BETWEEN VFR AND MVFR...WITH A GOOD CHANCE OF MVFR CIGS BEING
PREDOMINATE THIS AFTERNOON/EVENING.

KLAX...LOW CONFIDENCE IN 12Z TAF. CONFIDENCE IN TIMING OF ANY MVFR
CIGS THRU THE PERIOD IS LOW. THERE IS A SLIGHT CHANCE OF TSTMS
THROUGH THIS EVENING.

KBUR...LOW CONFIDENCE IN 12Z TAF. CONFIDENCE IN TIMING OF ANY MVFR
CIGS THRU THE PERIOD IS LOW. THERE IS A SLIGHT CHANCE OF TSTMS
THROUGH THIS EVENING.

&&

.MARINE...01/200 AM...

HIGH CONFIDENCE IN WINDS REMAINING BELOW SMALL CRAFT ADVISORY LEVELS
THROUGH MONDAY NIGHT. ON TUESDAY...THERE IS A CHANCE OF NORTHWEST
WINDS INCREASING TO SMALL CRAFT ADVISORY LEVELS ACROSS THE OUTER
WATERS.

MAIN ISSUE IN THE SHORT TERM WILL BE THE CONTINUED THREAT OF
THUNDERSTORMS THROUGH MONDAY EVENING. WITH ANY THUNDERSTORMS THAT
DEVELOP...THERE WILL BE THE POTENTIAL FOR BRIEF GUSTY WINDS...SMALL
HAIL AND EVEN A WATERSPOUT.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...RORKE
AVIATION/MARINE...RAT
SYNOPSIS...CK

WWW.WEATHER.GOV/LOSANGELES







000
FXUS66 KLOX 011209
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
350 AM PST SUN MAR 1 2015

.SYNOPSIS...

A COLD UPPER LOW WILL SLOWLY MOVE OVER SOUTHERN CALIFORNIA BRINGING
PERIODS OF SHOWERS AND A SLIGHT CHANCE OF THUNDERSTORMS. SNOW WILL
FALL AS LOW AS 4000 FEET. THIS LOW WILL PERSIST OVER THE AREA
THROUGH EARLY MONDAY BEFORE EXITING. A WEAKER STORM SYSTEM WILL
FOLLOW ON ITS HEELS LATER MONDAY ALLOWING FOR LINGERING SHOWERS INTO
EARLY TUESDAY. DRY AND WARMER WEATHER IS EXPECTED LATE TUESDAY
THROUGH FRIDAY.

&&

.SHORT TERM (TODAY-TUE)...
THE UPPER LOW IS CURRENTLY OVER POINT CONCEPTION. IT IS SWINGING A
NICE VORT LOBE THROUGH THE AREA FROM SANTA BARBARA TO LOS ANGELES.
THIS VORT LOBE IS SPAWNING HEAVY SHOWERS AND SOME THUNDERSTORMS. A
FEW HEAVY SHOWERS ARE NOW OVER THE SPRINGS FIRE AND A FLASH FLOOD
WARNING WAS ISSUED DUE TO THE HEAVY RAINFALL. THE UPPER LOW WILL
MOVE VERY SLOWLY TO THE ESE AND WILL NOT EXIT THE AREA UNTIL MONDAY
MORNING. THIS UPPER LOW WILL SPIN LOBES OF PVA AND NVA OVER THE AREA
THROUGH MONDAY MORNING. THIS WILL MAKE FOR A VERY VARIABLE FORECAST
AT TIMES OF PVA THERE WILL BE PLENTY OF CLOUDS AND SHOWERS BUT WHEN
THE NVA IS MOVING THROUGH THERE WILL NO RAIN AND BREAKS IN THE
CLOUDS. MOST OF THE ACTION WILL BE SOUTH OF POINT CONCEPTION BUT SLO
AND SBA COUNTY WILL STILL SEE SOME BANDS OF SHOWERS MOVING THROUGH
AT TIMES. THE 500 MB TEMPS AT THE CORE OF THE UPPER LOW ARE ABOUT
-28 DEGREES C WHICH IS COOL ENOUGH TO DESTABILIZE THINGS ENOUGH TO
ALLOW FOR A SLIGHT CHC OF THUNDERSTORMS. ANY THUNDERSTORM THAT DOES
FORM COULD PRODUCE SOME SMALL HAIL.

THE COLD AIR WILL ALSO LOWER SNOW LEVELS TO 4000 FEET AND LOCALLY
DOWN TO 3500 FEET.

RAIN AND SNOWFALL AMOUNTS WITH THIS FIRST SYSTEM WILL BE HIGHLY
VARIABLE DUE TO THE SHOWERY NATURE. AN AREAL AVERAGE OF 0.10-0.25"
CAN BE EXPECTED FOR THE COASTAL AND VALLEY AREAS THROUGH MONDAY
MORNING. THERE WILL BE LOCALLY HEAVIER AMOUNTS UP TO AN INCH UNDER
HEAVIER SHOWERS OR THUNDERSTORMS. IN THE MOUNTAINS 0.50-1.00" OF
LIQUID EQUIVALENT IS LIKELY OVER MANY AREAS. THIS WILL LIKELY
TRANSLATE TO 8-12" OF SNOW IS ABOVE 6500 FEET...WITH 2-4" POSSIBLE
BETWEEN 4000 AND 5000 FEET.

HOT ON THE HEALS OF THE CURRENT STORM A SECONDARY SYSTEM WILL MOVE
INTO THE AREA. THIS STORM IS NOW FORECAST TO TAKE MORE WESTERLY
TRACK OVER THE PACIFIC AND FURTHER AWAY FROM LAND. THIS WILL REDUCE
THE AMOUNT OF RAINFALL OVER THE LAND. THIS SYSTEM NOW LOOKS LIKE IT
WILL NOT PRODUCE MUCH RAINFALL FOR THE AREA. LIKE TODAYS SYSTEM THE
RAINFALL WILL BE SHOWERY AND RAINFALL WILL VARY CONSIDERABLY FORM
LOCATION TO LOCATION.

THE SECOND SYSTEM WILL SCOOT OUT FAIRLY QUICKLY MONDAY AND NIGHT AND
SKIES WILL CLEAR FOR TUESDAY.

MAX TEMPS WILL BE 4 TO 8 DEGREES BELOW NORMAL TODAY AND MONDAY WITH
ABOUT 3 DEGREES OF WARMING ON TUESDAY.

.LONG TERM (WED-SAT)...
HIGH PRESSURE WILL SET UP WEDNESDAY ALONG WITH WEAK OFFSHORE FLOW.
THIS WILL KICK OFF A ROUND OF DRY WEATHER WITH CLEAR SKIES AND A
WARMING TREND. MAX TEMPS WILL REACH NORMALS WEDNESDAY AND THEN WILL
BE ABOVE NORMAL FOR THE REST OF THE PERIOD. RIGHT NOW FRIDAY LOOKS
LIKE IT WILL BE THE WARMEST DAY WITH PLENTY OF UPPER 70S AND A
SMATTERING OF LOWER 80S FORECAST.

&&

.AVIATION...

01/1115Z

AT 1100Z...THERE WAS NO MARINE INVERSION AT KLAX.

OVERALL...LOW CONFIDENCE IN 12Z TAF PACKAGE. UNSTABLE AIR MASS WILL
CONTINUE TO GENERATE SCATTERED SHOWERS AND EVEN THE POSSIBILITY OF
AN ISOLATED THUNDERSTORM JUST ABOUT AT ANY TAF SITE THROUGH THIS
EVENING. IN TERMS OF CIG/VSBY RESTRICTIONS...CONDS WILL LIKELY VARY
BETWEEN VFR AND MVFR...WITH A GOOD CHANCE OF MVFR CIGS BEING
PREDOMINATE THIS AFTERNOON/EVENING.

KLAX...LOW CONFIDENCE IN 12Z TAF. CONFIDENCE IN TIMING OF ANY MVFR
CIGS THRU THE PERIOD IS LOW. THERE IS A SLIGHT CHANCE OF TSTMS
THROUGH THIS EVENING.

KBUR...LOW CONFIDENCE IN 12Z TAF. CONFIDENCE IN TIMING OF ANY MVFR
CIGS THRU THE PERIOD IS LOW. THERE IS A SLIGHT CHANCE OF TSTMS
THROUGH THIS EVENING.

&&

.MARINE...01/200 AM...

HIGH CONFIDENCE IN WINDS REMAINING BELOW SMALL CRAFT ADVISORY LEVELS
THROUGH MONDAY NIGHT. ON TUESDAY...THERE IS A CHANCE OF NORTHWEST
WINDS INCREASING TO SMALL CRAFT ADVISORY LEVELS ACROSS THE OUTER
WATERS.

MAIN ISSUE IN THE SHORT TERM WILL BE THE CONTINUED THREAT OF
THUNDERSTORMS THROUGH MONDAY EVENING. WITH ANY THUNDERSTORMS THAT
DEVELOP...THERE WILL BE THE POTENTIAL FOR BRIEF GUSTY WINDS...SMALL
HAIL AND EVEN A WATERSPOUT.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...RORKE
AVIATION/MARINE...RAT
SYNOPSIS...CK

WWW.WEATHER.GOV/LOSANGELES






000
FXUS66 KLOX 010523
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
925 PM PST SAT FEB 28 2015

.SYNOPSIS...

A COLD UPPER LOW WILL SLOWLY MOVE INTO SOUTHERN CALIFORNIA BRINGING
PERIODS OF SHOWERS AND MOUNTAIN SNOW DOWN TO LOWER MOUNTAIN
ELEVATIONS. THIS LOW WILL PERSIST OVER THE AREA THROUGH EARLY MONDAY
BEFORE EXITING. ANOTHER QUICK MOVING WEAKER STORM SYSTEM WILL FOLLOW
ON ITS HEELS ALLOWING FOR LINGERING SHOWERS INTO EARLY TUESDAY. DRY
WEATHER IS EXPECTED LATE TUESDAY THROUGH FRIDAY. THERE WILL BE A
WARMING TREND...WITH DAYTIME TEMPERATURES NEAR OR ABOVE NORMAL BY
THURSDAY.

&&

.SHORT TERM (TONIGHT-TUE)...AN UPPER LEVEL LOW CENTERED AROUND
MONTEREY COUNTY THIS EVENING WILL CONTINUE TO DROP SOUTHWARD INTO
THE FORECAST AREA OVERNIGHT. SCATTERED SHOWERS OVER THE AREA THIS
EVENING WILL CONTINUE THRU THE NIGHT...AND WITH COLDER AIR ALOFT
MOVING IN...DOWN TO -28 DEG C LATER TONIGHT...A SLIGHT CHANCE OF
THUNDERSTORMS CAN BE EXPECTED ACROSS THE REGION. SNOW LEVELS WHICH
WERE NEAR 5000 FEET THIS EVENING WILL CONTINUE TO LOWER TO NEAR 4000
FEET TONIGHT AS COLDER AIR CONTINUES TO FILTER IN AT LOWER LEVELS.

THE UPPER LOW IS FORECAST TO LINGER NEAR SANTA BARBARA COUNTY ON SUN
THEN DRIFT SLOWLY E SUN NIGHT. ANOTHER UPPER LEVEL LOW IS FORECAST
TO MOVE OFF OF SBA COUNTY ON MON THEN MOVE SE MON NIGHT BEFORE
MOVING INTO NRN BAJA ON TUE. CYCLONIC FLOW ALOFT...DECENT CAPE
(200-600 J/KG) AND CONTINUED VERY COLD TEMPS AT 500 MB WILL KEEP THE
THREAT OF THUNDERSTORMS IN THE FORECAST FOR MUCH OF THE REGION THRU
SUN EVENING. IT LOOKS LIKE THE BEST CHANCE OF THUNDERSTORMS OVER THE
FOUR COUNTY AREA WILL BE ON SUN AFTERNOON...WHILE THE BEST CHANCE
FOR THE COASTAL WATERS SHOULD BE TONIGHT. ANY THUNDERSTORMS THAT
DEVELOP WOULD BE CAPABLE OF PRODUCING HEAVY RAIN...GUSTY WINDS AND
SMALL HAIL. OTHERWISE...PLENTY OF SHOWERS AND MOUNTAIN SNOW SHOWERS
WILL CONTINUE OVER THE FORECAST AREA THRU SUN AND INTO SUN NIGHT.
ADDITIONAL SHOWERS AND MOUNTAINS SNOW SHOWERS WITH THE SLIGHT CHANCE
OF THUNDERSTORMS CAN BE EXPECTED ON MON INTO MON EVENING AS THE
SECOND UPPER LOW PASSES BY THE REGION.

ADDITIONAL RAINFALL AMOUNTS ACROSS THE REGION THRU MON WILL BE
HIGHLY VARIABLE DUE TO THE SHOWERY NATURE OF THESE WEATHER SYSTEMS.
HOWEVER...IT APPEARS MOST AREAS SHOULD HAVE 0.15 TO 0.30 INCH FOR
THE COAST AND VALLEYS...AND 0.75 TO 1.25 INCH IN THE MOUNTAINS.
LOCALLY HIGHER AMOUNTS TO 1.00 INCH FOR THE COAST AND VLYS...AND UP
TO 2.00 INCHES IN THE MOUNTAINS WILL BE POSSIBLE.

SNOW LEVELS WILL BE AROUND 3500 TO 4000 FEET ON SUN THEN SLOWLY
INCREASE THRU MON TO 4000 TO 4500 FEET. THROUGH SUNDAY EVENING...
SNOWFALL AMOUNTS OF 8 TO 12 INCHES CAN BE EXPECTED ABOVE 6500
FEET...WITH 4 TO 8 INCHES BETWEEN 5000 AND 6500 FEET...AND 2 TO 4
INCHES BETWEEN 4000 AND 5000 FEET. LOCAL SNOW ACCUMULATIONS UP TO 18
INCHES ARE POSSIBLE...MAINLY ACROSS THE SAN GABRIEL MOUNTAINS AND
THE HIGHER TERRAIN OF VENTURA COUNTY. MUCH LIGHTER SNOW AMOUNTS
SHOULD FALL ON MON. WITH THE MOUNTAIN SNOWFALL...A WINTER WEATHER
ADVISORY IS IN EFFECT FOR THE L.A./VTU/SBA MTNS. PLEASE SEE THE
LATEST WINTER WEATHER MESSAGE (LAXWSWLOX) FOR FURTHER DETAILS.

SOME CLOUDS WILL LINGER LATE MON NIGHT AND TUE...BUT DRY WEATHER
SHOULD RETURN TO ALL AREAS THRU THE DAY ON TUE. TEMPS ACROSS THE
REGION ARE FORECAST TO REMAIN SEVERAL DEGREES BELOW NORMAL SUN THRU
TUE...ALTHO THE WARMEST DAY DURING THE PERIOD SHOULD BE ON TUE.

***FROM PREVIOUS DISCUSSION***

.LONG TERM (WED-SAT)...

MODELS ARE IN GOOD AGREEMENT THAT A BUILDING RIDGE OF HIGH PRESSURE
WILL BRING SOME VERY NICE WEATHER IN THE LONG TERM. SKIES SHOULD
REMAIN MOSTLY CLEAR/SUNNY INTO THE WEEKEND. TEMPERATURES WILL CLIMB
ABOVE NORMAL BY THURSDAY AND REACH THE MID 70S TO LOW 80S FOR THE
COASTAL AND VALLEY AREAS BY FRIDAY AND SATURDAY.

&&

.AVIATION...01/0025Z.

AT 2355Z...THERE WAS NO MARINE INVERSION PRESENT AT KLAX.

MODERATE CONFIDENCE IN THE 00Z TAFS. MOSTLY VFR CIGS ARE EXPECTED AT
THE AIRFIELDS THRU SUN...HOWEVER THERE IS A 40 PERCENT CHANCE OF
INTERMITTENT MVFR CIGS AT TIMES DURING THE TAF PERIOD. THERE WILL
ALSO BE A CHANCE OF SHOWERS WITH SOME REDUCED VSBYS AT TIMES. A
SLIGHT CHANCE OF THUNDERSTORMS CAN BE EXPECTED AS WELL. GUSTY SW
WINDS WILL AFFECT KPMD AND KWJF THRU THIS EVENING.

KLAX...MODERATE CONFIDENCE IN THE 00Z TAF. MOSTLY VFR CIGS ARE
EXPECTED AT THE AIRFIELD THRU SUN EVENING. HOWEVER...THERE IS A 40
PERCENT CHANCE OF MVFR CIGS AT TIMES. THERE WILL ALSO BE A CHANCE OF
SHOWERS DURING THE PERIOD WITH A 20-30 PERCENT CHANCE OF MVFR VSBYS
AT TIMES. A SLIGHT CHANCE OF THUNDERSTORMS CAN BE EXPECTED AS WELL.

KBUR...MODERATE CONFIDENCE IN THE 00Z TAF. MOSTLY VFR CIGS ARE
EXPECTED AT THE AIRFIELD THRU SUN AFTERNOON. HOWEVER...THERE IS A 40
PERCENT CHANCE OF MVFR CIGS AT TIMES. THERE WILL ALSO BE A CHANCE OF
SHOWERS DURING THE PERIOD WITH A 20-30 PERCENT CHANCE OF MVFR VSBYS
AT TIMES. A SLIGHT CHANCE OF THUNDERSTORMS CAN BE EXPECTED AS WELL.


&&

.MARINE...28/800 PM...

SMALL CRAFT ADVISORY CONDITIONS ARE NOT EXPECTED THROUGH THE PERIOD.
OTHERWISE ISOLATED THUNDERSTORMS ARE EXPECTED THROUGH MON MORNING. A
SWELL GENERATED IN THE SOUTHERN HEMISPHERE WITHIN 190-210 DEGREES
RELATIVE TO VENTURA COUNTY LAST TUE IS EXPECTED TO ARRIVE NEXT WEEK
TUE THROUGH WED.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...SIRARD/SUKUP
AVIATION...SIRARD
MARINE...30/SIRARD
SYNOPSIS...KAPLAN

WWW.WEATHER.GOV/LOSANGELES







000
FXUS66 KLOX 010523
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
925 PM PST SAT FEB 28 2015

.SYNOPSIS...

A COLD UPPER LOW WILL SLOWLY MOVE INTO SOUTHERN CALIFORNIA BRINGING
PERIODS OF SHOWERS AND MOUNTAIN SNOW DOWN TO LOWER MOUNTAIN
ELEVATIONS. THIS LOW WILL PERSIST OVER THE AREA THROUGH EARLY MONDAY
BEFORE EXITING. ANOTHER QUICK MOVING WEAKER STORM SYSTEM WILL FOLLOW
ON ITS HEELS ALLOWING FOR LINGERING SHOWERS INTO EARLY TUESDAY. DRY
WEATHER IS EXPECTED LATE TUESDAY THROUGH FRIDAY. THERE WILL BE A
WARMING TREND...WITH DAYTIME TEMPERATURES NEAR OR ABOVE NORMAL BY
THURSDAY.

&&

.SHORT TERM (TONIGHT-TUE)...AN UPPER LEVEL LOW CENTERED AROUND
MONTEREY COUNTY THIS EVENING WILL CONTINUE TO DROP SOUTHWARD INTO
THE FORECAST AREA OVERNIGHT. SCATTERED SHOWERS OVER THE AREA THIS
EVENING WILL CONTINUE THRU THE NIGHT...AND WITH COLDER AIR ALOFT
MOVING IN...DOWN TO -28 DEG C LATER TONIGHT...A SLIGHT CHANCE OF
THUNDERSTORMS CAN BE EXPECTED ACROSS THE REGION. SNOW LEVELS WHICH
WERE NEAR 5000 FEET THIS EVENING WILL CONTINUE TO LOWER TO NEAR 4000
FEET TONIGHT AS COLDER AIR CONTINUES TO FILTER IN AT LOWER LEVELS.

THE UPPER LOW IS FORECAST TO LINGER NEAR SANTA BARBARA COUNTY ON SUN
THEN DRIFT SLOWLY E SUN NIGHT. ANOTHER UPPER LEVEL LOW IS FORECAST
TO MOVE OFF OF SBA COUNTY ON MON THEN MOVE SE MON NIGHT BEFORE
MOVING INTO NRN BAJA ON TUE. CYCLONIC FLOW ALOFT...DECENT CAPE
(200-600 J/KG) AND CONTINUED VERY COLD TEMPS AT 500 MB WILL KEEP THE
THREAT OF THUNDERSTORMS IN THE FORECAST FOR MUCH OF THE REGION THRU
SUN EVENING. IT LOOKS LIKE THE BEST CHANCE OF THUNDERSTORMS OVER THE
FOUR COUNTY AREA WILL BE ON SUN AFTERNOON...WHILE THE BEST CHANCE
FOR THE COASTAL WATERS SHOULD BE TONIGHT. ANY THUNDERSTORMS THAT
DEVELOP WOULD BE CAPABLE OF PRODUCING HEAVY RAIN...GUSTY WINDS AND
SMALL HAIL. OTHERWISE...PLENTY OF SHOWERS AND MOUNTAIN SNOW SHOWERS
WILL CONTINUE OVER THE FORECAST AREA THRU SUN AND INTO SUN NIGHT.
ADDITIONAL SHOWERS AND MOUNTAINS SNOW SHOWERS WITH THE SLIGHT CHANCE
OF THUNDERSTORMS CAN BE EXPECTED ON MON INTO MON EVENING AS THE
SECOND UPPER LOW PASSES BY THE REGION.

ADDITIONAL RAINFALL AMOUNTS ACROSS THE REGION THRU MON WILL BE
HIGHLY VARIABLE DUE TO THE SHOWERY NATURE OF THESE WEATHER SYSTEMS.
HOWEVER...IT APPEARS MOST AREAS SHOULD HAVE 0.15 TO 0.30 INCH FOR
THE COAST AND VALLEYS...AND 0.75 TO 1.25 INCH IN THE MOUNTAINS.
LOCALLY HIGHER AMOUNTS TO 1.00 INCH FOR THE COAST AND VLYS...AND UP
TO 2.00 INCHES IN THE MOUNTAINS WILL BE POSSIBLE.

SNOW LEVELS WILL BE AROUND 3500 TO 4000 FEET ON SUN THEN SLOWLY
INCREASE THRU MON TO 4000 TO 4500 FEET. THROUGH SUNDAY EVENING...
SNOWFALL AMOUNTS OF 8 TO 12 INCHES CAN BE EXPECTED ABOVE 6500
FEET...WITH 4 TO 8 INCHES BETWEEN 5000 AND 6500 FEET...AND 2 TO 4
INCHES BETWEEN 4000 AND 5000 FEET. LOCAL SNOW ACCUMULATIONS UP TO 18
INCHES ARE POSSIBLE...MAINLY ACROSS THE SAN GABRIEL MOUNTAINS AND
THE HIGHER TERRAIN OF VENTURA COUNTY. MUCH LIGHTER SNOW AMOUNTS
SHOULD FALL ON MON. WITH THE MOUNTAIN SNOWFALL...A WINTER WEATHER
ADVISORY IS IN EFFECT FOR THE L.A./VTU/SBA MTNS. PLEASE SEE THE
LATEST WINTER WEATHER MESSAGE (LAXWSWLOX) FOR FURTHER DETAILS.

SOME CLOUDS WILL LINGER LATE MON NIGHT AND TUE...BUT DRY WEATHER
SHOULD RETURN TO ALL AREAS THRU THE DAY ON TUE. TEMPS ACROSS THE
REGION ARE FORECAST TO REMAIN SEVERAL DEGREES BELOW NORMAL SUN THRU
TUE...ALTHO THE WARMEST DAY DURING THE PERIOD SHOULD BE ON TUE.

***FROM PREVIOUS DISCUSSION***

.LONG TERM (WED-SAT)...

MODELS ARE IN GOOD AGREEMENT THAT A BUILDING RIDGE OF HIGH PRESSURE
WILL BRING SOME VERY NICE WEATHER IN THE LONG TERM. SKIES SHOULD
REMAIN MOSTLY CLEAR/SUNNY INTO THE WEEKEND. TEMPERATURES WILL CLIMB
ABOVE NORMAL BY THURSDAY AND REACH THE MID 70S TO LOW 80S FOR THE
COASTAL AND VALLEY AREAS BY FRIDAY AND SATURDAY.

&&

.AVIATION...01/0025Z.

AT 2355Z...THERE WAS NO MARINE INVERSION PRESENT AT KLAX.

MODERATE CONFIDENCE IN THE 00Z TAFS. MOSTLY VFR CIGS ARE EXPECTED AT
THE AIRFIELDS THRU SUN...HOWEVER THERE IS A 40 PERCENT CHANCE OF
INTERMITTENT MVFR CIGS AT TIMES DURING THE TAF PERIOD. THERE WILL
ALSO BE A CHANCE OF SHOWERS WITH SOME REDUCED VSBYS AT TIMES. A
SLIGHT CHANCE OF THUNDERSTORMS CAN BE EXPECTED AS WELL. GUSTY SW
WINDS WILL AFFECT KPMD AND KWJF THRU THIS EVENING.

KLAX...MODERATE CONFIDENCE IN THE 00Z TAF. MOSTLY VFR CIGS ARE
EXPECTED AT THE AIRFIELD THRU SUN EVENING. HOWEVER...THERE IS A 40
PERCENT CHANCE OF MVFR CIGS AT TIMES. THERE WILL ALSO BE A CHANCE OF
SHOWERS DURING THE PERIOD WITH A 20-30 PERCENT CHANCE OF MVFR VSBYS
AT TIMES. A SLIGHT CHANCE OF THUNDERSTORMS CAN BE EXPECTED AS WELL.

KBUR...MODERATE CONFIDENCE IN THE 00Z TAF. MOSTLY VFR CIGS ARE
EXPECTED AT THE AIRFIELD THRU SUN AFTERNOON. HOWEVER...THERE IS A 40
PERCENT CHANCE OF MVFR CIGS AT TIMES. THERE WILL ALSO BE A CHANCE OF
SHOWERS DURING THE PERIOD WITH A 20-30 PERCENT CHANCE OF MVFR VSBYS
AT TIMES. A SLIGHT CHANCE OF THUNDERSTORMS CAN BE EXPECTED AS WELL.


&&

.MARINE...28/800 PM...

SMALL CRAFT ADVISORY CONDITIONS ARE NOT EXPECTED THROUGH THE PERIOD.
OTHERWISE ISOLATED THUNDERSTORMS ARE EXPECTED THROUGH MON MORNING. A
SWELL GENERATED IN THE SOUTHERN HEMISPHERE WITHIN 190-210 DEGREES
RELATIVE TO VENTURA COUNTY LAST TUE IS EXPECTED TO ARRIVE NEXT WEEK
TUE THROUGH WED.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...SIRARD/SUKUP
AVIATION...SIRARD
MARINE...30/SIRARD
SYNOPSIS...KAPLAN

WWW.WEATHER.GOV/LOSANGELES






000
FXUS66 KLOX 010032 AAA
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
435 PM PST SAT FEB 28 2015

...UPDATED AVIATION DISCUSSION...

.SYNOPSIS...

A COLD LOW PRESSURE SYSTEM WILL BRING SHOWERS AND MOUNTAIN SNOW THIS
WEEKEND...ALONG WITH A SLIGHT CHANCE OF THUNDERSTORMS. ANOTHER LOW
PRESSURE SYSTEM WILL BRING SIMILAR CONDITIONS TO THE AREA MONDAY AND
MONDAY NIGHT. DRY WEATHER IS EXPECTED STARTING TUESDAY. A BUILDING
RIDGE OF HIGH PRESSURE WILL RESULT IN A WARMING TREND FOR THE
REMAINDER OF NEXT WEEK.

&&

.SHORT TERM (TODAY-TUE)...

UNSETTLED WEATHER EXPECTED THROUGH MONDAY NIGHT...AS A COUPLE OF
COLD UPPER-LEVEL LOW PRESSURE SYSTEMS MOVES THROUGH THE AREA. AS OF
100 PM...THE FIRST UPPER LOW WHICH IS ASSOCIATED WITH A POSITIVELY
TILTED TROUGH...WAS CENTERED OVER CENTRAL CA. THIS UPPER LOW WILL
MOVE SOUTHWARD AND BECOME CENTERED OVER PT CONCEPTION BY SUNDAY
MORNING. THE UPPER LOW WILL SLOWLY DRIFT SOUTHWARD THROUGH THE
CALIFORNIA BIGHT THROUGH SUNDAY NIGHT...THEN OPEN UP AND MOVE INLAND
ON MONDAY AS THE SECOND UPPER-LOW STARTS TO DIVES SOUTH.

SO FAR TODAY...MOST OF THE SHOWER ACTIVITY HAS REMAINED FROM THE
VENTURA AND SANTA BARBARA COUNTY MOUNTAINS AND POINTS N. SHOWER
ACTIVITY SHOULD INCREASE FOR THE COASTAL AND VALLEY AREAS S OF THE
MOUNTAINS LATER THIS AFTERNOON AND THIS EVENING...AS THE UPPER-LOW
CONTINUES TO MOVE S. WHILE IT IS DIFFICULT TO PIN DOWN EXACTLY WHEN
AND HOW MUCH IT WILL RAIN DUE TO THE CONVECTIVE NATURE OF THE PRECIP
EXPECTED...IT LOOKS LIKE THE BEST CHANCE FOR RAIN IN VENTURA AND LA
COUNTY WILL BE TONIGHT AND SUNDAY MORNING...WHEN THE BEST SYNOPTIC
SCALE LIFT WILL OCCUR AHEAD OF THE APPROACHING UPPER LOW. SHOWERS
WILL LIKELY CONTINUE THROUGH MONDAY MORNING...BUT WILL BECOME LESS
NUMEROUS SUNDAY NIGHT INTO MONDAY MORNING...AS THE FIRST UPPER LOW
MOVES EAST.

A SLIGHT CHANCE OF TSTORMS IS IN THE FORECAST FOR THE ENTIRE AREA
STARTING TONIGHT. SO FAR THERE HAVE ONLY BEEN A COUPLE LIGHTNING
STRIKES WELL TO THE N OF OUR CWA...WHERE THE NAM IS SHOWING SOME
WEAK INSTABILITY WITH OVER 500 J/KG OF CAPE. NOT OVERLY CONFIDENT IN
TSTORMS FOR OUR AREA TONIGHT WITH CAPE VALUES GENERALLY LESS THAN
200 J/KG...BUT WILL KEEP A SLIGHT CHANCE IN THE FORECAST WITH THE
UPPER LOW APPROACHING. TSTORMS COULD BE MORE OF A PROBLEM DURING THE
DAY TOMORROW AS THE UPPER LOW MOVES DIRECTLY OVERHEAD AND CAPE
VALUES EXCEED 500 J/KG OVER SOME OF THE MOUNTAINS WITH THE ADDED
DAYTIME HEATING. ANY TSTORMS THAT DEVELOP TOMORROW WILL ALSO BE
SLOWER MOVING THAN TODAY...WITH MUCH WEAKER STEERING WINDS...SO
FLASH FLOODING AND DEBRIS FLOWS NEAR RECENT BURN AREAS COULD BE MORE
OF A CONCERN TOMORROW.

AREA AVERAGE RAINFALL AMOUNTS THROUGH MONDAY MORNING WILL GENERALLY
BE 0.10-0.25" FOR THE COAST AND VALLEY AREAS...AND 0.50-1.00" IN THE
MOUNTAINS. HOWEVER...AMOUNTS WILL BE HIGHLY VARIABLE AS PREVIOUSLY
MENTIONED DUE TO THE SHOWERY NATURE.

NO CHANGES ARE PLANNED FOR THE SNOWFALL AMOUNTS OR TIMING WITH THE
WINTER WEATHER ADVISORY...WHICH IS IN EFFECT FROM 4PM THIS AFTERNOON
THROUGH 4AM MONDAY FOR THE VENTURA AND LA COUNTY MOUNTAINS...AND 4PM
THIS AFTERNOON THROUGH 10PM SUNDAY FOR THE SANTA BARBARA COUNTY
MOUNTAINS. PLEASE SEE LAXWSWLOX FOR MORE DETAILS.

AFTER A LULL IN THE SHOWER ACTIVITY ON MONDAY MORNING...THE THREAT
OF SHOWERS AND ISOLATED TSTORMS WILL INCREASE AGAIN MONDAY AFTERNOON
THROUGH MONDAY EVENING...AS THE SECOND UPPER-LOW QUICKLY DIVES DOWN
FROM THE N. SHOWERS SHOULD QUICKLY TAPER OFF BY TUESDAY MORNING.
RAIN AND SNOW AMOUNTS WILL LIKELY BE LOWER WITH THE SECOND SYSTEM AS
IT WILL BE FASTER MOVING...BUT SNOW LEVELS WILL REMAIN AROUND 4000
FEET. SHOULD SEE MORE SUN THAN CLOUDS ON TUESDAY...BUT TEMPERATURES
WILL REMAIN SLIGHTLY BELOW NORMAL.

.LONG TERM (WED-SAT)...

MODELS ARE IN GOOD AGREEMENT THAT A BUILDING RIDGE OF HIGH PRESSURE
WILL BRING SOME VERY NICE WEATHER IN THE LONG TERM. SKIES SHOULD
REMAIN MOSTLY CLEAR/SUNNY INTO THE WEEKEND. TEMPERATURES WILL CLIMB
ABOVE NORMAL BY THURSDAY AND REACH THE MID 70S TO LOW 80S FOR THE
COASTAL AND VALLEY AREAS BY FRIDAY AND SATURDAY.

&&

.AVIATION...01/0025Z.

AT 2355Z...THERE WAS NO MARINE INVERSION PRESENT AT KLAX.

MODERATE CONFIDENCE IN THE 00Z TAFS. MOSTLY VFR CIGS ARE EXPECTED AT
THE AIRFIELDS THRU SUN...HOWEVER THERE IS A 40 PERCENT CHANCE OF
INTERMITTENT MVFR CIGS AT TIMES DURING THE TAF PERIOD. THERE WILL
ALSO BE A CHANCE OF SHOWERS WITH SOME REDUCED VSBYS AT TIMES. A
SLIGHT CHANCE OF THUNDERSTORMS CAN BE EXPECTED AS WELL. GUSTY SW
WINDS WILL AFFECT KPMD AND KWJF THRU THIS EVENING.

KLAX...MODERATE CONFIDENCE IN THE 00Z TAF. MOSTLY VFR CIGS ARE
EXPECTED AT THE AIRFIELD THRU SUN EVENING. HOWEVER...THERE IS A 40
PERCENT CHANCE OF MVFR CIGS AT TIMES. THERE WILL ALSO BE A CHANCE OF
SHOWERS DURING THE PERIOD WITH A 20-30 PERCENT CHANCE OF MVFR VSBYS
AT TIMES. A SLIGHT CHANCE OF THUNDERSTORMS CAN BE EXPECTED AS WELL.

KBUR...MODERATE CONFIDENCE IN THE 00Z TAF. MOSTLY VFR CIGS ARE
EXPECTED AT THE AIRFIELD THRU SUN AFTERNOON. HOWEVER...THERE IS A 40
PERCENT CHANCE OF MVFR CIGS AT TIMES. THERE WILL ALSO BE A CHANCE OF
SHOWERS DURING THE PERIOD WITH A 20-30 PERCENT CHANCE OF MVFR VSBYS
AT TIMES. A SLIGHT CHANCE OF THUNDERSTORMS CAN BE EXPECTED AS WELL.


&&

.MARINE...28/200 PM...

SMALL CRAFT ADVISORY CONDITIONS ARE NOT EXPECTED THROUGH THE PERIOD.
OTHERWISE ISOLATED THUNDERSTORMS ARE EXPECTED THROUGH MONDAY
MORNING. THE THUNDERSTORMS WILL MOVE WEST-SOUTHWEST AROUND 28 KT
TODAY THROUGH THIS AFTERNOON THEN AS THE TROUGH AXIS SETTLES OVER
THE AREA TONIGHT THROUGH SUNDAY NIGHT THE STORMS SOUTH OF POINT
CONCEPTION WILL MOVE NORTHEAST 25 KT AND MOVE SOUTHWEST AROUND 15 KT
NORTH OF POINT CONCEPTION. A SWELL GENERATED IN THE SOUTHERN
HEMISPHERE WITHIN 190-210 DEGREES RELATIVE TO VENTURA COUNTY LAST
TUESDAY IS EXPECTED TO ARRIVE NEXT WEEK TUE THROUGH WEDNESDAY.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...SUKUP
AVIATION...SIRARD
MARINE...30
SYNOPSIS...SMITH

WWW.WEATHER.GOV/LOSANGELES







000
FXUS66 KLOX 010032 AAA
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
435 PM PST SAT FEB 28 2015

...UPDATED AVIATION DISCUSSION...

.SYNOPSIS...

A COLD LOW PRESSURE SYSTEM WILL BRING SHOWERS AND MOUNTAIN SNOW THIS
WEEKEND...ALONG WITH A SLIGHT CHANCE OF THUNDERSTORMS. ANOTHER LOW
PRESSURE SYSTEM WILL BRING SIMILAR CONDITIONS TO THE AREA MONDAY AND
MONDAY NIGHT. DRY WEATHER IS EXPECTED STARTING TUESDAY. A BUILDING
RIDGE OF HIGH PRESSURE WILL RESULT IN A WARMING TREND FOR THE
REMAINDER OF NEXT WEEK.

&&

.SHORT TERM (TODAY-TUE)...

UNSETTLED WEATHER EXPECTED THROUGH MONDAY NIGHT...AS A COUPLE OF
COLD UPPER-LEVEL LOW PRESSURE SYSTEMS MOVES THROUGH THE AREA. AS OF
100 PM...THE FIRST UPPER LOW WHICH IS ASSOCIATED WITH A POSITIVELY
TILTED TROUGH...WAS CENTERED OVER CENTRAL CA. THIS UPPER LOW WILL
MOVE SOUTHWARD AND BECOME CENTERED OVER PT CONCEPTION BY SUNDAY
MORNING. THE UPPER LOW WILL SLOWLY DRIFT SOUTHWARD THROUGH THE
CALIFORNIA BIGHT THROUGH SUNDAY NIGHT...THEN OPEN UP AND MOVE INLAND
ON MONDAY AS THE SECOND UPPER-LOW STARTS TO DIVES SOUTH.

SO FAR TODAY...MOST OF THE SHOWER ACTIVITY HAS REMAINED FROM THE
VENTURA AND SANTA BARBARA COUNTY MOUNTAINS AND POINTS N. SHOWER
ACTIVITY SHOULD INCREASE FOR THE COASTAL AND VALLEY AREAS S OF THE
MOUNTAINS LATER THIS AFTERNOON AND THIS EVENING...AS THE UPPER-LOW
CONTINUES TO MOVE S. WHILE IT IS DIFFICULT TO PIN DOWN EXACTLY WHEN
AND HOW MUCH IT WILL RAIN DUE TO THE CONVECTIVE NATURE OF THE PRECIP
EXPECTED...IT LOOKS LIKE THE BEST CHANCE FOR RAIN IN VENTURA AND LA
COUNTY WILL BE TONIGHT AND SUNDAY MORNING...WHEN THE BEST SYNOPTIC
SCALE LIFT WILL OCCUR AHEAD OF THE APPROACHING UPPER LOW. SHOWERS
WILL LIKELY CONTINUE THROUGH MONDAY MORNING...BUT WILL BECOME LESS
NUMEROUS SUNDAY NIGHT INTO MONDAY MORNING...AS THE FIRST UPPER LOW
MOVES EAST.

A SLIGHT CHANCE OF TSTORMS IS IN THE FORECAST FOR THE ENTIRE AREA
STARTING TONIGHT. SO FAR THERE HAVE ONLY BEEN A COUPLE LIGHTNING
STRIKES WELL TO THE N OF OUR CWA...WHERE THE NAM IS SHOWING SOME
WEAK INSTABILITY WITH OVER 500 J/KG OF CAPE. NOT OVERLY CONFIDENT IN
TSTORMS FOR OUR AREA TONIGHT WITH CAPE VALUES GENERALLY LESS THAN
200 J/KG...BUT WILL KEEP A SLIGHT CHANCE IN THE FORECAST WITH THE
UPPER LOW APPROACHING. TSTORMS COULD BE MORE OF A PROBLEM DURING THE
DAY TOMORROW AS THE UPPER LOW MOVES DIRECTLY OVERHEAD AND CAPE
VALUES EXCEED 500 J/KG OVER SOME OF THE MOUNTAINS WITH THE ADDED
DAYTIME HEATING. ANY TSTORMS THAT DEVELOP TOMORROW WILL ALSO BE
SLOWER MOVING THAN TODAY...WITH MUCH WEAKER STEERING WINDS...SO
FLASH FLOODING AND DEBRIS FLOWS NEAR RECENT BURN AREAS COULD BE MORE
OF A CONCERN TOMORROW.

AREA AVERAGE RAINFALL AMOUNTS THROUGH MONDAY MORNING WILL GENERALLY
BE 0.10-0.25" FOR THE COAST AND VALLEY AREAS...AND 0.50-1.00" IN THE
MOUNTAINS. HOWEVER...AMOUNTS WILL BE HIGHLY VARIABLE AS PREVIOUSLY
MENTIONED DUE TO THE SHOWERY NATURE.

NO CHANGES ARE PLANNED FOR THE SNOWFALL AMOUNTS OR TIMING WITH THE
WINTER WEATHER ADVISORY...WHICH IS IN EFFECT FROM 4PM THIS AFTERNOON
THROUGH 4AM MONDAY FOR THE VENTURA AND LA COUNTY MOUNTAINS...AND 4PM
THIS AFTERNOON THROUGH 10PM SUNDAY FOR THE SANTA BARBARA COUNTY
MOUNTAINS. PLEASE SEE LAXWSWLOX FOR MORE DETAILS.

AFTER A LULL IN THE SHOWER ACTIVITY ON MONDAY MORNING...THE THREAT
OF SHOWERS AND ISOLATED TSTORMS WILL INCREASE AGAIN MONDAY AFTERNOON
THROUGH MONDAY EVENING...AS THE SECOND UPPER-LOW QUICKLY DIVES DOWN
FROM THE N. SHOWERS SHOULD QUICKLY TAPER OFF BY TUESDAY MORNING.
RAIN AND SNOW AMOUNTS WILL LIKELY BE LOWER WITH THE SECOND SYSTEM AS
IT WILL BE FASTER MOVING...BUT SNOW LEVELS WILL REMAIN AROUND 4000
FEET. SHOULD SEE MORE SUN THAN CLOUDS ON TUESDAY...BUT TEMPERATURES
WILL REMAIN SLIGHTLY BELOW NORMAL.

.LONG TERM (WED-SAT)...

MODELS ARE IN GOOD AGREEMENT THAT A BUILDING RIDGE OF HIGH PRESSURE
WILL BRING SOME VERY NICE WEATHER IN THE LONG TERM. SKIES SHOULD
REMAIN MOSTLY CLEAR/SUNNY INTO THE WEEKEND. TEMPERATURES WILL CLIMB
ABOVE NORMAL BY THURSDAY AND REACH THE MID 70S TO LOW 80S FOR THE
COASTAL AND VALLEY AREAS BY FRIDAY AND SATURDAY.

&&

.AVIATION...01/0025Z.

AT 2355Z...THERE WAS NO MARINE INVERSION PRESENT AT KLAX.

MODERATE CONFIDENCE IN THE 00Z TAFS. MOSTLY VFR CIGS ARE EXPECTED AT
THE AIRFIELDS THRU SUN...HOWEVER THERE IS A 40 PERCENT CHANCE OF
INTERMITTENT MVFR CIGS AT TIMES DURING THE TAF PERIOD. THERE WILL
ALSO BE A CHANCE OF SHOWERS WITH SOME REDUCED VSBYS AT TIMES. A
SLIGHT CHANCE OF THUNDERSTORMS CAN BE EXPECTED AS WELL. GUSTY SW
WINDS WILL AFFECT KPMD AND KWJF THRU THIS EVENING.

KLAX...MODERATE CONFIDENCE IN THE 00Z TAF. MOSTLY VFR CIGS ARE
EXPECTED AT THE AIRFIELD THRU SUN EVENING. HOWEVER...THERE IS A 40
PERCENT CHANCE OF MVFR CIGS AT TIMES. THERE WILL ALSO BE A CHANCE OF
SHOWERS DURING THE PERIOD WITH A 20-30 PERCENT CHANCE OF MVFR VSBYS
AT TIMES. A SLIGHT CHANCE OF THUNDERSTORMS CAN BE EXPECTED AS WELL.

KBUR...MODERATE CONFIDENCE IN THE 00Z TAF. MOSTLY VFR CIGS ARE
EXPECTED AT THE AIRFIELD THRU SUN AFTERNOON. HOWEVER...THERE IS A 40
PERCENT CHANCE OF MVFR CIGS AT TIMES. THERE WILL ALSO BE A CHANCE OF
SHOWERS DURING THE PERIOD WITH A 20-30 PERCENT CHANCE OF MVFR VSBYS
AT TIMES. A SLIGHT CHANCE OF THUNDERSTORMS CAN BE EXPECTED AS WELL.


&&

.MARINE...28/200 PM...

SMALL CRAFT ADVISORY CONDITIONS ARE NOT EXPECTED THROUGH THE PERIOD.
OTHERWISE ISOLATED THUNDERSTORMS ARE EXPECTED THROUGH MONDAY
MORNING. THE THUNDERSTORMS WILL MOVE WEST-SOUTHWEST AROUND 28 KT
TODAY THROUGH THIS AFTERNOON THEN AS THE TROUGH AXIS SETTLES OVER
THE AREA TONIGHT THROUGH SUNDAY NIGHT THE STORMS SOUTH OF POINT
CONCEPTION WILL MOVE NORTHEAST 25 KT AND MOVE SOUTHWEST AROUND 15 KT
NORTH OF POINT CONCEPTION. A SWELL GENERATED IN THE SOUTHERN
HEMISPHERE WITHIN 190-210 DEGREES RELATIVE TO VENTURA COUNTY LAST
TUESDAY IS EXPECTED TO ARRIVE NEXT WEEK TUE THROUGH WEDNESDAY.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...SUKUP
AVIATION...SIRARD
MARINE...30
SYNOPSIS...SMITH

WWW.WEATHER.GOV/LOSANGELES






000
FXUS66 KLOX 282223
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
220 PM PST SAT FEB 28 2015

.SYNOPSIS...

A COLD LOW PRESSURE SYSTEM WILL BRING SHOWERS AND MOUNTAIN SNOW THIS
WEEKEND...ALONG WITH A SLIGHT CHANCE OF THUNDERSTORMS. ANOTHER LOW
PRESSURE SYSTEM WILL BRING SIMILAR CONDITIONS TO THE AREA MONDAY AND
MONDAY NIGHT. DRY WEATHER IS EXPECTED STARTING TUESDAY. A BUILDING
RIDGE OF HIGH PRESSURE WILL RESULT IN A WARMING TREND FOR THE
REMAINDER OF NEXT WEEK.

&&

.SHORT TERM (TODAY-TUE)...

UNSETTLED WEATHER EXPECTED THROUGH MONDAY NIGHT...AS A COUPLE OF
COLD UPPER-LEVEL LOW PRESSURE SYSTEMS MOVES THROUGH THE AREA. AS OF
100 PM...THE FIRST UPPER LOW WHICH IS ASSOCIATED WITH A POSITIVELY
TILTED TROUGH...WAS CENTERED OVER CENTRAL CA. THIS UPPER LOW WILL
MOVE SOUTHWARD AND BECOME CENTERED OVER PT CONCEPTION BY SUNDAY
MORNING. THE UPPER LOW WILL SLOWLY DRIFT SOUTHWARD THROUGH THE
CALIFORNIA BIGHT THROUGH SUNDAY NIGHT...THEN OPEN UP AND MOVE INLAND
ON MONDAY AS THE SECOND UPPER-LOW STARTS TO DIVES SOUTH.

SO FAR TODAY...MOST OF THE SHOWER ACTIVITY HAS REMAINED FROM THE
VENTURA AND SANTA BARBARA COUNTY MOUNTAINS AND POINTS N. SHOWER
ACTIVITY SHOULD INCREASE FOR THE COASTAL AND VALLEY AREAS S OF THE
MOUNTAINS LATER THIS AFTERNOON AND THIS EVENING...AS THE UPPER-LOW
CONTINUES TO MOVE S. WHILE IT IS DIFFICULT TO PIN DOWN EXACTLY WHEN
AND HOW MUCH IT WILL RAIN DUE TO THE CONVECTIVE NATURE OF THE PRECIP
EXPECTED...IT LOOKS LIKE THE BEST CHANCE FOR RAIN IN VENTURA AND LA
COUNTY WILL BE TONIGHT AND SUNDAY MORNING...WHEN THE BEST SYNOPTIC
SCALE LIFT WILL OCCUR AHEAD OF THE APPROACHING UPPER LOW. SHOWERS
WILL LIKELY CONTINUE THROUGH MONDAY MORNING...BUT WILL BECOME LESS
NUMEROUS SUNDAY NIGHT INTO MONDAY MORNING...AS THE FIRST UPPER LOW
MOVES EAST.

A SLIGHT CHANCE OF TSTORMS IS IN THE FORECAST FOR THE ENTIRE AREA
STARTING TONIGHT. SO FAR THERE HAVE ONLY BEEN A COUPLE LIGHTNING
STRIKES WELL TO THE N OF OUR CWA...WHERE THE NAM IS SHOWING SOME
WEAK INSTABILITY WITH OVER 500 J/KG OF CAPE. NOT OVERLY CONFIDENT IN
TSTORMS FOR OUR AREA TONIGHT WITH CAPE VALUES GENERALLY LESS THAN
200 J/KG...BUT WILL KEEP A SLIGHT CHANCE IN THE FORECAST WITH THE
UPPER LOW APPROACHING. TSTORMS COULD BE MORE OF A PROBLEM DURING THE
DAY TOMORROW AS THE UPPER LOW MOVES DIRECTLY OVERHEAD AND CAPE
VALUES EXCEED 500 J/KG OVER SOME OF THE MOUNTAINS WITH THE ADDED
DAYTIME HEATING. ANY TSTORMS THAT DEVELOP TOMORROW WILL ALSO BE
SLOWER MOVING THAN TODAY...WITH MUCH WEAKER STEARING WINDS...SO
FLASH FLOODING AND DEBRIS FLOWS NEAR RECENT BURN AREAS COULD BE MORE
OF A CONCERN TOMORROW.

AREA AVERAGE RAINFALL AMOUNTS THROUGH MONDAY MORNING WILL GENERALLY
BE 0.10-0.25" FOR THE COAST AND VALLEY AREAS...AND 0.50-1.00" IN THE
MOUNTAINS. HOWEVER...AMOUNTS WILL BE HIGHLY VARIABLE AS PREVIOUSLY
MENTIONED DUE TO THE SHOWERY NATURE.

NO CHANGES ARE PLANNED FOR THE SNOWFALL AMOUNTS OR TIMING WITH THE
WINTER WEATHER ADVISORY...WHICH IS IN EFFECT FROM 4PM THIS AFTERNOON
THROUGH 4AM MONDAY FOR THE VENTURA AND LA COUNTY MOUNTAINS...AND 4PM
THIS AFTERNOON THROUGH 10PM SUNDAY FOR THE SANTA BARBARA COUNTY
MOUNTAINS. PLEASE SEE LAXWSWLOX FOR MORE DETAILS.

AFTER A LULL IN THE SHOWER ACTIVITY ON MONDAY MORNING...THE THREAT
OF SHOWERS AND ISOLATED TSTORMS WILL INCREASE AGAIN MONDAY AFTERNOON
THROUGH MONDAY EVENING...AS THE SECOND UPPER-LOW QUICKLY DIVES DOWN
FROM THE N. SHOWERS SHOULD QUICKLY TAPER OFF BY TUESAY MORNING. RAIN
AND SNOW AMOUNTS WILL LIKELY BE LOWER WITH THE SECOND SYSTEM AS IT
WILL BE FASTER MOVING...BUT SNOW LEVELS WILL REMAIN AROUND 4000
FEET. SHOULD SEE MORE SUN THAN CLOUDS ON TUESDAY...BUT TEMPERATURES
WILL REMAIN SLIGHTLY BELOW NORMAL.

.LONG TERM (WED-SAT)...

MODELS ARE IN GOOD AGREEMENT THAT A BUILDING RIDGE OF HIGH PRESSURE
WILL BRING SOME VERY NICE WEATHER IN THE LONG TERM. SKIES SHOULD
REMAIN MOSTLY CLEAR/SUNNY INTO THE WEEKEND. TEMPERATURES WILL CLIMB
ABOVE NORMAL BY THURSDAY AND REACH THE MID 70S TO LOW 80S FOR THE
COASTAL AND VALLEY AREAS BY FRIDAY AND SATURDAY.

&&

.AVIATION...28/1800Z...

MID/UPPER LEVEL TROUGH CENTER OVER CENTRAL/NORTHERN CALIFORNIA WILL
SHIFT SOUTH. UPPER LEVEL STRONG WEST-SOUTHWEST WINDS WILL BECOME
STRONG SOUTHWEST WHILE MID LEVEL MODERATE WEST WINDS BECOME LIGHT TO
MODERATE SOUTHWEST AFTER 01/05Z OVER THE AREA. FREEZING LEVEL WAS
APPROXIMATELY 6KFT THIS MORNING AND WILL DIFFER BY MINUS 1KFT SUNDAY
MORNING. ISOLATED THUNDERSTORMS WITH TOPS APPROXIMATELY 30KFT ARE
EXPECTED TO MOVE EAST-NORTHEAST AFTER 01/05Z.

MARINE LAYER AT LAX AT 1715Z IS NONE.

KLAX...CHANCE CIGS 030 AT TIMES THROUGH 28/20Z THEN CHANCE CIGS 030
AND -SHRA BETWEEN 01/03-01/11Z. CHANCE CIGS 030-035 AND -TSRA
BETWEEN 01/11-01/15Z THEN CHANCE CIGS 035-040 THEREAFTER.

KBUR...CHANCE CIGS 025 THROUGH 28/19Z THEN CHANCE CIGS 035 BETWEEN
29/19-01/11Z. CHANCE -TSRA CIGS 030 BETWEEN 01/11-01/15Z.

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


&&

.MARINE...28/200 PM...

SMALL CRAFT ADVISORY CONDITIONS ARE NOT EXPECTED THROUGH THE PERIOD.
OTHERWISE ISOLATED THUNDERSTORMS ARE EXPECTED THROUGH MONDAY
MORNING. THE THUNDERSTORMS WILL MOVE WEST-SOUTHWEST AROUND 28 KT
TODAY THROUGH THIS AFTERNOON THEN AS THE TROUGH AXIS SETTLES OVER
THE AREA TONIGHT THROUGH SUNDAY NIGHT THE STORMS SOUTH OF POINT
CONCEPTION WILL MOVE NORTHEAST 25 KT AND MOVE SOUTHWEST AROUND 15 KT
NORTH OF POINT CONCEPTION. A SWELL GENERATED IN THE SOUTHERN
HEMISPHERE WITHIN 190-210 DEGREES RELATIVE TO VENTURA COUNTY LAST
TUESDAY IS EXPECTED TO ARRIVE NEXT WEEK TUE THROUGH WEDNESDAY.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...SUKUP
AVIATION/MARINE...30
SYNOPSIS...SMITH

WWW.WEATHER.GOV/LOSANGELES






000
FXUS66 KLOX 282223
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
220 PM PST SAT FEB 28 2015

.SYNOPSIS...

A COLD LOW PRESSURE SYSTEM WILL BRING SHOWERS AND MOUNTAIN SNOW THIS
WEEKEND...ALONG WITH A SLIGHT CHANCE OF THUNDERSTORMS. ANOTHER LOW
PRESSURE SYSTEM WILL BRING SIMILAR CONDITIONS TO THE AREA MONDAY AND
MONDAY NIGHT. DRY WEATHER IS EXPECTED STARTING TUESDAY. A BUILDING
RIDGE OF HIGH PRESSURE WILL RESULT IN A WARMING TREND FOR THE
REMAINDER OF NEXT WEEK.

&&

.SHORT TERM (TODAY-TUE)...

UNSETTLED WEATHER EXPECTED THROUGH MONDAY NIGHT...AS A COUPLE OF
COLD UPPER-LEVEL LOW PRESSURE SYSTEMS MOVES THROUGH THE AREA. AS OF
100 PM...THE FIRST UPPER LOW WHICH IS ASSOCIATED WITH A POSITIVELY
TILTED TROUGH...WAS CENTERED OVER CENTRAL CA. THIS UPPER LOW WILL
MOVE SOUTHWARD AND BECOME CENTERED OVER PT CONCEPTION BY SUNDAY
MORNING. THE UPPER LOW WILL SLOWLY DRIFT SOUTHWARD THROUGH THE
CALIFORNIA BIGHT THROUGH SUNDAY NIGHT...THEN OPEN UP AND MOVE INLAND
ON MONDAY AS THE SECOND UPPER-LOW STARTS TO DIVES SOUTH.

SO FAR TODAY...MOST OF THE SHOWER ACTIVITY HAS REMAINED FROM THE
VENTURA AND SANTA BARBARA COUNTY MOUNTAINS AND POINTS N. SHOWER
ACTIVITY SHOULD INCREASE FOR THE COASTAL AND VALLEY AREAS S OF THE
MOUNTAINS LATER THIS AFTERNOON AND THIS EVENING...AS THE UPPER-LOW
CONTINUES TO MOVE S. WHILE IT IS DIFFICULT TO PIN DOWN EXACTLY WHEN
AND HOW MUCH IT WILL RAIN DUE TO THE CONVECTIVE NATURE OF THE PRECIP
EXPECTED...IT LOOKS LIKE THE BEST CHANCE FOR RAIN IN VENTURA AND LA
COUNTY WILL BE TONIGHT AND SUNDAY MORNING...WHEN THE BEST SYNOPTIC
SCALE LIFT WILL OCCUR AHEAD OF THE APPROACHING UPPER LOW. SHOWERS
WILL LIKELY CONTINUE THROUGH MONDAY MORNING...BUT WILL BECOME LESS
NUMEROUS SUNDAY NIGHT INTO MONDAY MORNING...AS THE FIRST UPPER LOW
MOVES EAST.

A SLIGHT CHANCE OF TSTORMS IS IN THE FORECAST FOR THE ENTIRE AREA
STARTING TONIGHT. SO FAR THERE HAVE ONLY BEEN A COUPLE LIGHTNING
STRIKES WELL TO THE N OF OUR CWA...WHERE THE NAM IS SHOWING SOME
WEAK INSTABILITY WITH OVER 500 J/KG OF CAPE. NOT OVERLY CONFIDENT IN
TSTORMS FOR OUR AREA TONIGHT WITH CAPE VALUES GENERALLY LESS THAN
200 J/KG...BUT WILL KEEP A SLIGHT CHANCE IN THE FORECAST WITH THE
UPPER LOW APPROACHING. TSTORMS COULD BE MORE OF A PROBLEM DURING THE
DAY TOMORROW AS THE UPPER LOW MOVES DIRECTLY OVERHEAD AND CAPE
VALUES EXCEED 500 J/KG OVER SOME OF THE MOUNTAINS WITH THE ADDED
DAYTIME HEATING. ANY TSTORMS THAT DEVELOP TOMORROW WILL ALSO BE
SLOWER MOVING THAN TODAY...WITH MUCH WEAKER STEARING WINDS...SO
FLASH FLOODING AND DEBRIS FLOWS NEAR RECENT BURN AREAS COULD BE MORE
OF A CONCERN TOMORROW.

AREA AVERAGE RAINFALL AMOUNTS THROUGH MONDAY MORNING WILL GENERALLY
BE 0.10-0.25" FOR THE COAST AND VALLEY AREAS...AND 0.50-1.00" IN THE
MOUNTAINS. HOWEVER...AMOUNTS WILL BE HIGHLY VARIABLE AS PREVIOUSLY
MENTIONED DUE TO THE SHOWERY NATURE.

NO CHANGES ARE PLANNED FOR THE SNOWFALL AMOUNTS OR TIMING WITH THE
WINTER WEATHER ADVISORY...WHICH IS IN EFFECT FROM 4PM THIS AFTERNOON
THROUGH 4AM MONDAY FOR THE VENTURA AND LA COUNTY MOUNTAINS...AND 4PM
THIS AFTERNOON THROUGH 10PM SUNDAY FOR THE SANTA BARBARA COUNTY
MOUNTAINS. PLEASE SEE LAXWSWLOX FOR MORE DETAILS.

AFTER A LULL IN THE SHOWER ACTIVITY ON MONDAY MORNING...THE THREAT
OF SHOWERS AND ISOLATED TSTORMS WILL INCREASE AGAIN MONDAY AFTERNOON
THROUGH MONDAY EVENING...AS THE SECOND UPPER-LOW QUICKLY DIVES DOWN
FROM THE N. SHOWERS SHOULD QUICKLY TAPER OFF BY TUESAY MORNING. RAIN
AND SNOW AMOUNTS WILL LIKELY BE LOWER WITH THE SECOND SYSTEM AS IT
WILL BE FASTER MOVING...BUT SNOW LEVELS WILL REMAIN AROUND 4000
FEET. SHOULD SEE MORE SUN THAN CLOUDS ON TUESDAY...BUT TEMPERATURES
WILL REMAIN SLIGHTLY BELOW NORMAL.

.LONG TERM (WED-SAT)...

MODELS ARE IN GOOD AGREEMENT THAT A BUILDING RIDGE OF HIGH PRESSURE
WILL BRING SOME VERY NICE WEATHER IN THE LONG TERM. SKIES SHOULD
REMAIN MOSTLY CLEAR/SUNNY INTO THE WEEKEND. TEMPERATURES WILL CLIMB
ABOVE NORMAL BY THURSDAY AND REACH THE MID 70S TO LOW 80S FOR THE
COASTAL AND VALLEY AREAS BY FRIDAY AND SATURDAY.

&&

.AVIATION...28/1800Z...

MID/UPPER LEVEL TROUGH CENTER OVER CENTRAL/NORTHERN CALIFORNIA WILL
SHIFT SOUTH. UPPER LEVEL STRONG WEST-SOUTHWEST WINDS WILL BECOME
STRONG SOUTHWEST WHILE MID LEVEL MODERATE WEST WINDS BECOME LIGHT TO
MODERATE SOUTHWEST AFTER 01/05Z OVER THE AREA. FREEZING LEVEL WAS
APPROXIMATELY 6KFT THIS MORNING AND WILL DIFFER BY MINUS 1KFT SUNDAY
MORNING. ISOLATED THUNDERSTORMS WITH TOPS APPROXIMATELY 30KFT ARE
EXPECTED TO MOVE EAST-NORTHEAST AFTER 01/05Z.

MARINE LAYER AT LAX AT 1715Z IS NONE.

KLAX...CHANCE CIGS 030 AT TIMES THROUGH 28/20Z THEN CHANCE CIGS 030
AND -SHRA BETWEEN 01/03-01/11Z. CHANCE CIGS 030-035 AND -TSRA
BETWEEN 01/11-01/15Z THEN CHANCE CIGS 035-040 THEREAFTER.

KBUR...CHANCE CIGS 025 THROUGH 28/19Z THEN CHANCE CIGS 035 BETWEEN
29/19-01/11Z. CHANCE -TSRA CIGS 030 BETWEEN 01/11-01/15Z.

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


&&

.MARINE...28/200 PM...

SMALL CRAFT ADVISORY CONDITIONS ARE NOT EXPECTED THROUGH THE PERIOD.
OTHERWISE ISOLATED THUNDERSTORMS ARE EXPECTED THROUGH MONDAY
MORNING. THE THUNDERSTORMS WILL MOVE WEST-SOUTHWEST AROUND 28 KT
TODAY THROUGH THIS AFTERNOON THEN AS THE TROUGH AXIS SETTLES OVER
THE AREA TONIGHT THROUGH SUNDAY NIGHT THE STORMS SOUTH OF POINT
CONCEPTION WILL MOVE NORTHEAST 25 KT AND MOVE SOUTHWEST AROUND 15 KT
NORTH OF POINT CONCEPTION. A SWELL GENERATED IN THE SOUTHERN
HEMISPHERE WITHIN 190-210 DEGREES RELATIVE TO VENTURA COUNTY LAST
TUESDAY IS EXPECTED TO ARRIVE NEXT WEEK TUE THROUGH WEDNESDAY.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...SUKUP
AVIATION/MARINE...30
SYNOPSIS...SMITH

WWW.WEATHER.GOV/LOSANGELES







000
FXUS66 KLOX 282223
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
220 PM PST SAT FEB 28 2015

.SYNOPSIS...

A COLD LOW PRESSURE SYSTEM WILL BRING SHOWERS AND MOUNTAIN SNOW THIS
WEEKEND...ALONG WITH A SLIGHT CHANCE OF THUNDERSTORMS. ANOTHER LOW
PRESSURE SYSTEM WILL BRING SIMILAR CONDITIONS TO THE AREA MONDAY AND
MONDAY NIGHT. DRY WEATHER IS EXPECTED STARTING TUESDAY. A BUILDING
RIDGE OF HIGH PRESSURE WILL RESULT IN A WARMING TREND FOR THE
REMAINDER OF NEXT WEEK.

&&

.SHORT TERM (TODAY-TUE)...

UNSETTLED WEATHER EXPECTED THROUGH MONDAY NIGHT...AS A COUPLE OF
COLD UPPER-LEVEL LOW PRESSURE SYSTEMS MOVES THROUGH THE AREA. AS OF
100 PM...THE FIRST UPPER LOW WHICH IS ASSOCIATED WITH A POSITIVELY
TILTED TROUGH...WAS CENTERED OVER CENTRAL CA. THIS UPPER LOW WILL
MOVE SOUTHWARD AND BECOME CENTERED OVER PT CONCEPTION BY SUNDAY
MORNING. THE UPPER LOW WILL SLOWLY DRIFT SOUTHWARD THROUGH THE
CALIFORNIA BIGHT THROUGH SUNDAY NIGHT...THEN OPEN UP AND MOVE INLAND
ON MONDAY AS THE SECOND UPPER-LOW STARTS TO DIVES SOUTH.

SO FAR TODAY...MOST OF THE SHOWER ACTIVITY HAS REMAINED FROM THE
VENTURA AND SANTA BARBARA COUNTY MOUNTAINS AND POINTS N. SHOWER
ACTIVITY SHOULD INCREASE FOR THE COASTAL AND VALLEY AREAS S OF THE
MOUNTAINS LATER THIS AFTERNOON AND THIS EVENING...AS THE UPPER-LOW
CONTINUES TO MOVE S. WHILE IT IS DIFFICULT TO PIN DOWN EXACTLY WHEN
AND HOW MUCH IT WILL RAIN DUE TO THE CONVECTIVE NATURE OF THE PRECIP
EXPECTED...IT LOOKS LIKE THE BEST CHANCE FOR RAIN IN VENTURA AND LA
COUNTY WILL BE TONIGHT AND SUNDAY MORNING...WHEN THE BEST SYNOPTIC
SCALE LIFT WILL OCCUR AHEAD OF THE APPROACHING UPPER LOW. SHOWERS
WILL LIKELY CONTINUE THROUGH MONDAY MORNING...BUT WILL BECOME LESS
NUMEROUS SUNDAY NIGHT INTO MONDAY MORNING...AS THE FIRST UPPER LOW
MOVES EAST.

A SLIGHT CHANCE OF TSTORMS IS IN THE FORECAST FOR THE ENTIRE AREA
STARTING TONIGHT. SO FAR THERE HAVE ONLY BEEN A COUPLE LIGHTNING
STRIKES WELL TO THE N OF OUR CWA...WHERE THE NAM IS SHOWING SOME
WEAK INSTABILITY WITH OVER 500 J/KG OF CAPE. NOT OVERLY CONFIDENT IN
TSTORMS FOR OUR AREA TONIGHT WITH CAPE VALUES GENERALLY LESS THAN
200 J/KG...BUT WILL KEEP A SLIGHT CHANCE IN THE FORECAST WITH THE
UPPER LOW APPROACHING. TSTORMS COULD BE MORE OF A PROBLEM DURING THE
DAY TOMORROW AS THE UPPER LOW MOVES DIRECTLY OVERHEAD AND CAPE
VALUES EXCEED 500 J/KG OVER SOME OF THE MOUNTAINS WITH THE ADDED
DAYTIME HEATING. ANY TSTORMS THAT DEVELOP TOMORROW WILL ALSO BE
SLOWER MOVING THAN TODAY...WITH MUCH WEAKER STEARING WINDS...SO
FLASH FLOODING AND DEBRIS FLOWS NEAR RECENT BURN AREAS COULD BE MORE
OF A CONCERN TOMORROW.

AREA AVERAGE RAINFALL AMOUNTS THROUGH MONDAY MORNING WILL GENERALLY
BE 0.10-0.25" FOR THE COAST AND VALLEY AREAS...AND 0.50-1.00" IN THE
MOUNTAINS. HOWEVER...AMOUNTS WILL BE HIGHLY VARIABLE AS PREVIOUSLY
MENTIONED DUE TO THE SHOWERY NATURE.

NO CHANGES ARE PLANNED FOR THE SNOWFALL AMOUNTS OR TIMING WITH THE
WINTER WEATHER ADVISORY...WHICH IS IN EFFECT FROM 4PM THIS AFTERNOON
THROUGH 4AM MONDAY FOR THE VENTURA AND LA COUNTY MOUNTAINS...AND 4PM
THIS AFTERNOON THROUGH 10PM SUNDAY FOR THE SANTA BARBARA COUNTY
MOUNTAINS. PLEASE SEE LAXWSWLOX FOR MORE DETAILS.

AFTER A LULL IN THE SHOWER ACTIVITY ON MONDAY MORNING...THE THREAT
OF SHOWERS AND ISOLATED TSTORMS WILL INCREASE AGAIN MONDAY AFTERNOON
THROUGH MONDAY EVENING...AS THE SECOND UPPER-LOW QUICKLY DIVES DOWN
FROM THE N. SHOWERS SHOULD QUICKLY TAPER OFF BY TUESAY MORNING. RAIN
AND SNOW AMOUNTS WILL LIKELY BE LOWER WITH THE SECOND SYSTEM AS IT
WILL BE FASTER MOVING...BUT SNOW LEVELS WILL REMAIN AROUND 4000
FEET. SHOULD SEE MORE SUN THAN CLOUDS ON TUESDAY...BUT TEMPERATURES
WILL REMAIN SLIGHTLY BELOW NORMAL.

.LONG TERM (WED-SAT)...

MODELS ARE IN GOOD AGREEMENT THAT A BUILDING RIDGE OF HIGH PRESSURE
WILL BRING SOME VERY NICE WEATHER IN THE LONG TERM. SKIES SHOULD
REMAIN MOSTLY CLEAR/SUNNY INTO THE WEEKEND. TEMPERATURES WILL CLIMB
ABOVE NORMAL BY THURSDAY AND REACH THE MID 70S TO LOW 80S FOR THE
COASTAL AND VALLEY AREAS BY FRIDAY AND SATURDAY.

&&

.AVIATION...28/1800Z...

MID/UPPER LEVEL TROUGH CENTER OVER CENTRAL/NORTHERN CALIFORNIA WILL
SHIFT SOUTH. UPPER LEVEL STRONG WEST-SOUTHWEST WINDS WILL BECOME
STRONG SOUTHWEST WHILE MID LEVEL MODERATE WEST WINDS BECOME LIGHT TO
MODERATE SOUTHWEST AFTER 01/05Z OVER THE AREA. FREEZING LEVEL WAS
APPROXIMATELY 6KFT THIS MORNING AND WILL DIFFER BY MINUS 1KFT SUNDAY
MORNING. ISOLATED THUNDERSTORMS WITH TOPS APPROXIMATELY 30KFT ARE
EXPECTED TO MOVE EAST-NORTHEAST AFTER 01/05Z.

MARINE LAYER AT LAX AT 1715Z IS NONE.

KLAX...CHANCE CIGS 030 AT TIMES THROUGH 28/20Z THEN CHANCE CIGS 030
AND -SHRA BETWEEN 01/03-01/11Z. CHANCE CIGS 030-035 AND -TSRA
BETWEEN 01/11-01/15Z THEN CHANCE CIGS 035-040 THEREAFTER.

KBUR...CHANCE CIGS 025 THROUGH 28/19Z THEN CHANCE CIGS 035 BETWEEN
29/19-01/11Z. CHANCE -TSRA CIGS 030 BETWEEN 01/11-01/15Z.

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


&&

.MARINE...28/200 PM...

SMALL CRAFT ADVISORY CONDITIONS ARE NOT EXPECTED THROUGH THE PERIOD.
OTHERWISE ISOLATED THUNDERSTORMS ARE EXPECTED THROUGH MONDAY
MORNING. THE THUNDERSTORMS WILL MOVE WEST-SOUTHWEST AROUND 28 KT
TODAY THROUGH THIS AFTERNOON THEN AS THE TROUGH AXIS SETTLES OVER
THE AREA TONIGHT THROUGH SUNDAY NIGHT THE STORMS SOUTH OF POINT
CONCEPTION WILL MOVE NORTHEAST 25 KT AND MOVE SOUTHWEST AROUND 15 KT
NORTH OF POINT CONCEPTION. A SWELL GENERATED IN THE SOUTHERN
HEMISPHERE WITHIN 190-210 DEGREES RELATIVE TO VENTURA COUNTY LAST
TUESDAY IS EXPECTED TO ARRIVE NEXT WEEK TUE THROUGH WEDNESDAY.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...SUKUP
AVIATION/MARINE...30
SYNOPSIS...SMITH

WWW.WEATHER.GOV/LOSANGELES







000
FXUS66 KLOX 282223
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
220 PM PST SAT FEB 28 2015

.SYNOPSIS...

A COLD LOW PRESSURE SYSTEM WILL BRING SHOWERS AND MOUNTAIN SNOW THIS
WEEKEND...ALONG WITH A SLIGHT CHANCE OF THUNDERSTORMS. ANOTHER LOW
PRESSURE SYSTEM WILL BRING SIMILAR CONDITIONS TO THE AREA MONDAY AND
MONDAY NIGHT. DRY WEATHER IS EXPECTED STARTING TUESDAY. A BUILDING
RIDGE OF HIGH PRESSURE WILL RESULT IN A WARMING TREND FOR THE
REMAINDER OF NEXT WEEK.

&&

.SHORT TERM (TODAY-TUE)...

UNSETTLED WEATHER EXPECTED THROUGH MONDAY NIGHT...AS A COUPLE OF
COLD UPPER-LEVEL LOW PRESSURE SYSTEMS MOVES THROUGH THE AREA. AS OF
100 PM...THE FIRST UPPER LOW WHICH IS ASSOCIATED WITH A POSITIVELY
TILTED TROUGH...WAS CENTERED OVER CENTRAL CA. THIS UPPER LOW WILL
MOVE SOUTHWARD AND BECOME CENTERED OVER PT CONCEPTION BY SUNDAY
MORNING. THE UPPER LOW WILL SLOWLY DRIFT SOUTHWARD THROUGH THE
CALIFORNIA BIGHT THROUGH SUNDAY NIGHT...THEN OPEN UP AND MOVE INLAND
ON MONDAY AS THE SECOND UPPER-LOW STARTS TO DIVES SOUTH.

SO FAR TODAY...MOST OF THE SHOWER ACTIVITY HAS REMAINED FROM THE
VENTURA AND SANTA BARBARA COUNTY MOUNTAINS AND POINTS N. SHOWER
ACTIVITY SHOULD INCREASE FOR THE COASTAL AND VALLEY AREAS S OF THE
MOUNTAINS LATER THIS AFTERNOON AND THIS EVENING...AS THE UPPER-LOW
CONTINUES TO MOVE S. WHILE IT IS DIFFICULT TO PIN DOWN EXACTLY WHEN
AND HOW MUCH IT WILL RAIN DUE TO THE CONVECTIVE NATURE OF THE PRECIP
EXPECTED...IT LOOKS LIKE THE BEST CHANCE FOR RAIN IN VENTURA AND LA
COUNTY WILL BE TONIGHT AND SUNDAY MORNING...WHEN THE BEST SYNOPTIC
SCALE LIFT WILL OCCUR AHEAD OF THE APPROACHING UPPER LOW. SHOWERS
WILL LIKELY CONTINUE THROUGH MONDAY MORNING...BUT WILL BECOME LESS
NUMEROUS SUNDAY NIGHT INTO MONDAY MORNING...AS THE FIRST UPPER LOW
MOVES EAST.

A SLIGHT CHANCE OF TSTORMS IS IN THE FORECAST FOR THE ENTIRE AREA
STARTING TONIGHT. SO FAR THERE HAVE ONLY BEEN A COUPLE LIGHTNING
STRIKES WELL TO THE N OF OUR CWA...WHERE THE NAM IS SHOWING SOME
WEAK INSTABILITY WITH OVER 500 J/KG OF CAPE. NOT OVERLY CONFIDENT IN
TSTORMS FOR OUR AREA TONIGHT WITH CAPE VALUES GENERALLY LESS THAN
200 J/KG...BUT WILL KEEP A SLIGHT CHANCE IN THE FORECAST WITH THE
UPPER LOW APPROACHING. TSTORMS COULD BE MORE OF A PROBLEM DURING THE
DAY TOMORROW AS THE UPPER LOW MOVES DIRECTLY OVERHEAD AND CAPE
VALUES EXCEED 500 J/KG OVER SOME OF THE MOUNTAINS WITH THE ADDED
DAYTIME HEATING. ANY TSTORMS THAT DEVELOP TOMORROW WILL ALSO BE
SLOWER MOVING THAN TODAY...WITH MUCH WEAKER STEARING WINDS...SO
FLASH FLOODING AND DEBRIS FLOWS NEAR RECENT BURN AREAS COULD BE MORE
OF A CONCERN TOMORROW.

AREA AVERAGE RAINFALL AMOUNTS THROUGH MONDAY MORNING WILL GENERALLY
BE 0.10-0.25" FOR THE COAST AND VALLEY AREAS...AND 0.50-1.00" IN THE
MOUNTAINS. HOWEVER...AMOUNTS WILL BE HIGHLY VARIABLE AS PREVIOUSLY
MENTIONED DUE TO THE SHOWERY NATURE.

NO CHANGES ARE PLANNED FOR THE SNOWFALL AMOUNTS OR TIMING WITH THE
WINTER WEATHER ADVISORY...WHICH IS IN EFFECT FROM 4PM THIS AFTERNOON
THROUGH 4AM MONDAY FOR THE VENTURA AND LA COUNTY MOUNTAINS...AND 4PM
THIS AFTERNOON THROUGH 10PM SUNDAY FOR THE SANTA BARBARA COUNTY
MOUNTAINS. PLEASE SEE LAXWSWLOX FOR MORE DETAILS.

AFTER A LULL IN THE SHOWER ACTIVITY ON MONDAY MORNING...THE THREAT
OF SHOWERS AND ISOLATED TSTORMS WILL INCREASE AGAIN MONDAY AFTERNOON
THROUGH MONDAY EVENING...AS THE SECOND UPPER-LOW QUICKLY DIVES DOWN
FROM THE N. SHOWERS SHOULD QUICKLY TAPER OFF BY TUESAY MORNING. RAIN
AND SNOW AMOUNTS WILL LIKELY BE LOWER WITH THE SECOND SYSTEM AS IT
WILL BE FASTER MOVING...BUT SNOW LEVELS WILL REMAIN AROUND 4000
FEET. SHOULD SEE MORE SUN THAN CLOUDS ON TUESDAY...BUT TEMPERATURES
WILL REMAIN SLIGHTLY BELOW NORMAL.

.LONG TERM (WED-SAT)...

MODELS ARE IN GOOD AGREEMENT THAT A BUILDING RIDGE OF HIGH PRESSURE
WILL BRING SOME VERY NICE WEATHER IN THE LONG TERM. SKIES SHOULD
REMAIN MOSTLY CLEAR/SUNNY INTO THE WEEKEND. TEMPERATURES WILL CLIMB
ABOVE NORMAL BY THURSDAY AND REACH THE MID 70S TO LOW 80S FOR THE
COASTAL AND VALLEY AREAS BY FRIDAY AND SATURDAY.

&&

.AVIATION...28/1800Z...

MID/UPPER LEVEL TROUGH CENTER OVER CENTRAL/NORTHERN CALIFORNIA WILL
SHIFT SOUTH. UPPER LEVEL STRONG WEST-SOUTHWEST WINDS WILL BECOME
STRONG SOUTHWEST WHILE MID LEVEL MODERATE WEST WINDS BECOME LIGHT TO
MODERATE SOUTHWEST AFTER 01/05Z OVER THE AREA. FREEZING LEVEL WAS
APPROXIMATELY 6KFT THIS MORNING AND WILL DIFFER BY MINUS 1KFT SUNDAY
MORNING. ISOLATED THUNDERSTORMS WITH TOPS APPROXIMATELY 30KFT ARE
EXPECTED TO MOVE EAST-NORTHEAST AFTER 01/05Z.

MARINE LAYER AT LAX AT 1715Z IS NONE.

KLAX...CHANCE CIGS 030 AT TIMES THROUGH 28/20Z THEN CHANCE CIGS 030
AND -SHRA BETWEEN 01/03-01/11Z. CHANCE CIGS 030-035 AND -TSRA
BETWEEN 01/11-01/15Z THEN CHANCE CIGS 035-040 THEREAFTER.

KBUR...CHANCE CIGS 025 THROUGH 28/19Z THEN CHANCE CIGS 035 BETWEEN
29/19-01/11Z. CHANCE -TSRA CIGS 030 BETWEEN 01/11-01/15Z.

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


&&

.MARINE...28/200 PM...

SMALL CRAFT ADVISORY CONDITIONS ARE NOT EXPECTED THROUGH THE PERIOD.
OTHERWISE ISOLATED THUNDERSTORMS ARE EXPECTED THROUGH MONDAY
MORNING. THE THUNDERSTORMS WILL MOVE WEST-SOUTHWEST AROUND 28 KT
TODAY THROUGH THIS AFTERNOON THEN AS THE TROUGH AXIS SETTLES OVER
THE AREA TONIGHT THROUGH SUNDAY NIGHT THE STORMS SOUTH OF POINT
CONCEPTION WILL MOVE NORTHEAST 25 KT AND MOVE SOUTHWEST AROUND 15 KT
NORTH OF POINT CONCEPTION. A SWELL GENERATED IN THE SOUTHERN
HEMISPHERE WITHIN 190-210 DEGREES RELATIVE TO VENTURA COUNTY LAST
TUESDAY IS EXPECTED TO ARRIVE NEXT WEEK TUE THROUGH WEDNESDAY.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...SUKUP
AVIATION/MARINE...30
SYNOPSIS...SMITH

WWW.WEATHER.GOV/LOSANGELES






000
FXUS66 KLOX 281841
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1041 AM PST SAT FEB 28 2015

.SYNOPSIS...

A COLD LOW PRESSURE SYSTEM WILL BRING SHOWERS AND MOUNTAIN SNOW TO
SOUTHWEST CALIFORNIA THIS WEEKEND...ALONG WITH A SLIGHT CHANCE OF
THUNDERSTORMS. AFTER A BRIEF BREAK...ANOTHER COLD SYSTEM WILL BRING
SIMILAR WEATHER TO THE AREA LATE MONDAY MORNING THROUGH EARLY
TUESDAY. DRY WEATHER IS EXPECTED LATE TUESDAY THROUGH FRIDAY. THERE
WILL BE A WARMING TREND...WITH DAYTIME TEMPERATURES NEAR OR ABOVE
NORMAL BY THURSDAY.

&&

.SHORT TERM (TODAY-MON)...

MAIN UPDATE THIS MORNING WAS TO DECREASE THE POPS AND CLOUD COVER
FOR THE MORNING HOURS BASED ON CURRENT SATELLITE AND RADAR TRENDS.
NOT EXPECTING MUCH SHOWER ACTIVITY FOR AREAS S OF THE MOUNTAINS THIS
MORNING DUE TO NW FLOW ALOFT. CLOUD COVERAGE AND RAIN CHANCES WILL
INCREASE THIS AFTERNOON AS THE UPPER LOW THAT IS CURRENTLY OVER
NORTHERN CA CONTINUES TO MOVE S. DAYTIME SURFACE HEATING WILL ALSO
HELP SHOWERS TO DEVELOP...AS THIS WILL BE A CONVECTIVE SCENARIO WITH
COLD AIR MOVING IN ALOFT. COULD EVEN BE SOME ISOLATED THUNDERSTORMS
N OF POINT CONCEPTION TODAY...WHERE THERE IS SOME WEAK INSTABILITY.

***FROM PREVIOUS DISCUSSION***

THE UPPER LOW WILL SLOWLY DROP SWD TO NEAR POINT CONCEPTION LATE
TONIGHT...MOVE VERY LITTLE ON SUNDAY...THEN PUSH SLOWLY INTO
LOS ANGELES COUNTY SUNDAY NIGHT. THIS WILL MAINTAIN A MOIST AND
UNSTABLE AIRMASS ACROSS THE REGION...SO EXPECT QUITE A BIT OF SHOWER
ACTIVITY OVERNIGHT THROUGH SUNDAY NIGHT...WITH A SLIGHT CHANCE OF
TSTMS. THE TEMPERATURE PROFILE THROUGH THE ATMOSPHERE WILL BE
FAVORABLE FOR SOME SMALL HAIL...AND INDEED...THIS HAS BEEN REPORTED
ACROSS NRN CA. ANY THUNDERSTORM THIS AFTERNOON THROUGH SUNDAY
EVENING WILL HAVE THE CAPABILITY OF PRODUCING SMALL HAIL AND HEAVY
DOWNPOURS. WHILE SHOWERS MAY OCCUR ANYWHERE AT ANY TIME...IT APPEARS
THAT THE BEST CHANCES OF ORGANIZED SHOWER ACTIVITY WILL BE TONIGHT
ACROSS L.A. COUNTY AND EASTERN VTU COUNTY AS SOME LOW LEVEL SWLY
FLOW DEVELOPS...AND SUNDAY AFTERNOON AND EVENING AS THE UPPER LOW
MOVES OVERHEAD. DUE TO THE SHOWERY NATURE OF THE PRECIPITATION...
RAINFALL TOTALS THROUGH SUNDAY NIGHT WILL BE HIGHLY VARIABLE...BUT
IN GENERAL...EXPECT TOTALS OF ONE QUARTER TO ONE HALF INCH...
EXCEPT ONE HALF INCH TO ONE INCH ACROSS THE MOUNTAINS...THE SAN
GABRIEL VALLEY...AND POSSIBLY PORTIONS OF THE REMAINDER OF THE L.A.
COUNTY VALLEYS AND THE VALLEYS OF ERN VTU COUNTY. LOCAL TOTALS UP TO
2 INCHES ARE POSSIBLE IN THE SAN GABRIEL MOUNTAINS AND FOOTHILLS.

SNOW WILL BE AN ISSUE FOR TRAVELERS THIS WEEKEND. SNOW LEVELS ARE
EXPECTED TO LOWER TO 5000 FEET LATE TODAY...THEN TO BETWEEN 3500 AND
4000 FEET LATE TONIGHT OR EARLY SUNDAY...THEN LINGER AT THOSE LEVELS
INTO SUNDAY NIGHT. SNOW MAY WELL AFFECT TRAVEL ACROSS HIGHER
PORTIONS OF INTERSTATE 5...HIGHWAY 14 AND HIGHWAY 33...ESPECIALLY
LATE TONIGHT THROUGH EARLY MONDAY. HAVE EXPANDED WINTER WEATHER
ADVISORIES TO INCLUDE THE MOUNTAINS OF SANTA BARBARA COUNTY. ON
AVERAGE...EXPECT A TOTAL OF 4 TO 8 INCHES OF SNOW BETWEEN 5000 AND
6500 FEET...WITH TOTALS OF 8 TO 12 INCHES ABOVE 6500 FEET...AND 2 TO
4 INCHES BETWEEN 4000 AND 5000 FEET. THERE COULD BE LOCAL TOTALS AS
HIGH AS 18 INCHES ACROSS PORTIONS OF THE SAN GABRIEL MOUNTAINS...OR
HIGHER ELEVATIONS IN VTU COUNTY. WAS STRONGLY CONSIDERING UPGRADING
TO A WINTER STORM WARNING...BUT HAVE DECIDED AGAINST IT...SINCE THE
SNOW ACCUMULATIONS MAY NOT MEET THE REQUIRED TOTALS IN ANY 12 OR 24
HOUR PERIOD. LATER SHIFTS MAY WELL HAVE TO UPGRADE DEPENDING UPON
SHOWER DEVELOPMENT.

SHOWERS WILL DECREASE ACROSS THE REGION SUNDAY NIGHT...AND MAY END
JUST ABOUT EVERYWHERE. HOWEVER...ANOTHER COLD UPPER LOW DROPPING
RAPIDLY SOUTHWARD WILL CAUSE SHOWERS TO BECOME LIKELY AGAIN MONDAY
AFTERNOON...WITH SHOWERS CONTINUING MONDAY NIGHT. THAT SYSTEM WILL
ALSO HAVE LOW SNOW LEVELS...AND PROBABLY ALSO A SLIGHT CHANCE OF
TSTMS. THAT SYSTEM WILL MOVE A BIT FASTER...BUT MAY ALSO TRACK A BIT
FARTHER OFF THE COAST...SO IT MAY PICK UP MORE MOISTURE. SHOWERS
SHOULD WIND DOWN IN MOST AREAS LATE MON NIGHT. MAX TEMPERATURES WILL
BE WELL BELOW NORMAL THROUGH MONDAY.

.LONG TERM (TUE-FRI)...THERE COULD BE A FEW LINGERING SHOWERS
TUE...BUT THAT IS LOOKING LESS AND LESS LIKELY. HEIGHTS WILL REBOUND
TUE AFTERNOON...AND WITH SOME SUNSHINE...EXPECT AT LEAST A BIT OR
WARMING. THE 06Z GFS NOW SHOWS A WEAK IMPULSE DROPPING SWD INTO THE
REGION ON WED...AND THAT WAS NOT ON THE PREVIOUS RUN. NO SHOWER
EXPECTED...BUT IT COULD KEEP MAX TEMPS ON THE COOL SIDE. AN UPPER
RIDGE AND HIGHER HEIGHTS WILL BRING WARMER WEATHER THU AND
FRI...WITH DAYTIME TEMPS LIKELY ABOVE NORMAL.


&&

.AVIATION...28/1800Z...

MID/UPPER LEVEL TROUGH CENTER OVER CENTRAL/NORTHERN CALIFORNIA WILL
SHIFT SOUTH. UPPER LEVEL STRONG WEST-SOUTHWEST WINDS WILL BECOME
STRONG SOUTHWEST WHILE MID LEVEL MODERATE WEST WINDS BECOME LIGHT TO
MODERATE SOUTHWEST AFTER 01/05Z OVER THE AREA. FREEZING LEVEL WAS
APPROXIMATELY 6KFT THIS MORNING AND WILL DIFFER BY MINUS 1KFT SUNDAY
MORNING. ISOLATED THUNDERSTORMS WITH TOPS APPROXIMATELY 30KFT ARE
EXPECTED TO MOVE EAST-NORTHEAST AFTER 01/05Z.

MARINE LAYER AT LAX AT 1715Z IS NONE.

KLAX...CHANCE CIGS 030 AT TIMES THROUGH 28/20Z THEN CHANCE CIGS 030
AND -SHRA BETWEEN 01/03-01/11Z. CHANCE CIGS 030-035 AND -TSRA
BETWEEN 01/11-01/15Z THEN CHANCE CIGS 035-040 THEREAFTER.

KBUR...CHANCE CIGS 025 THROUGH 28/19Z THEN CHANCE CIGS 035 BETWEEN
29/19-01/11Z. CHANCE -TSRA CIGS 030 BETWEEN 01/11-01/15Z.

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

&&

.MARINE...28/900 AM...

THERE IS A CHANCE SMALL CRAFT ADVISORY CONDITIONS WILL PERSIST
THROUGH EARLY THIS AFTERNOON IN THE INNER AND OUTER WATERS SOUTH OF
THE NORTHERN CHANNEL ISLANDS. OTHERWISE ISOLATED THUNDERSTORMS ARE
EXPECTED THROUGH MONDAY MORNING. THE THUNDERSTORMS WILL MOVE
WEST-SOUTHWEST AROUND 28 KT TODAY THROUGH THIS AFTERNOON THEN AS THE
TROUGH AXIS SETTLES OVER THE AREA TONIGHT THROUGH SUNDAY NIGHT THE
STORMS SOUTH OF POINT CONCEPTION WILL MOVE NORTHEAST 25 KT AND MOVE
SOUTHWEST AROUND 15 KT NORTH OF POINT CONCEPTION. A SWELL GENERATED
IN THE SOUTHERN HEMISPHERE WITHIN 190-210 DEGREES RELATIVE TO
VENTURA COUNTY LAST TUESDAY IS EXPECTED TO ARRIVE NEXT WEEK TUE
THROUGH WEDNESDAY.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...SUKUP/DB
AVIATION...30
MARINE...30
SYNOPSIS...SMITH

WWW.WEATHER.GOV/LOSANGELES












000
FXUS66 KLOX 281841
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1041 AM PST SAT FEB 28 2015

.SYNOPSIS...

A COLD LOW PRESSURE SYSTEM WILL BRING SHOWERS AND MOUNTAIN SNOW TO
SOUTHWEST CALIFORNIA THIS WEEKEND...ALONG WITH A SLIGHT CHANCE OF
THUNDERSTORMS. AFTER A BRIEF BREAK...ANOTHER COLD SYSTEM WILL BRING
SIMILAR WEATHER TO THE AREA LATE MONDAY MORNING THROUGH EARLY
TUESDAY. DRY WEATHER IS EXPECTED LATE TUESDAY THROUGH FRIDAY. THERE
WILL BE A WARMING TREND...WITH DAYTIME TEMPERATURES NEAR OR ABOVE
NORMAL BY THURSDAY.

&&

.SHORT TERM (TODAY-MON)...

MAIN UPDATE THIS MORNING WAS TO DECREASE THE POPS AND CLOUD COVER
FOR THE MORNING HOURS BASED ON CURRENT SATELLITE AND RADAR TRENDS.
NOT EXPECTING MUCH SHOWER ACTIVITY FOR AREAS S OF THE MOUNTAINS THIS
MORNING DUE TO NW FLOW ALOFT. CLOUD COVERAGE AND RAIN CHANCES WILL
INCREASE THIS AFTERNOON AS THE UPPER LOW THAT IS CURRENTLY OVER
NORTHERN CA CONTINUES TO MOVE S. DAYTIME SURFACE HEATING WILL ALSO
HELP SHOWERS TO DEVELOP...AS THIS WILL BE A CONVECTIVE SCENARIO WITH
COLD AIR MOVING IN ALOFT. COULD EVEN BE SOME ISOLATED THUNDERSTORMS
N OF POINT CONCEPTION TODAY...WHERE THERE IS SOME WEAK INSTABILITY.

***FROM PREVIOUS DISCUSSION***

THE UPPER LOW WILL SLOWLY DROP SWD TO NEAR POINT CONCEPTION LATE
TONIGHT...MOVE VERY LITTLE ON SUNDAY...THEN PUSH SLOWLY INTO
LOS ANGELES COUNTY SUNDAY NIGHT. THIS WILL MAINTAIN A MOIST AND
UNSTABLE AIRMASS ACROSS THE REGION...SO EXPECT QUITE A BIT OF SHOWER
ACTIVITY OVERNIGHT THROUGH SUNDAY NIGHT...WITH A SLIGHT CHANCE OF
TSTMS. THE TEMPERATURE PROFILE THROUGH THE ATMOSPHERE WILL BE
FAVORABLE FOR SOME SMALL HAIL...AND INDEED...THIS HAS BEEN REPORTED
ACROSS NRN CA. ANY THUNDERSTORM THIS AFTERNOON THROUGH SUNDAY
EVENING WILL HAVE THE CAPABILITY OF PRODUCING SMALL HAIL AND HEAVY
DOWNPOURS. WHILE SHOWERS MAY OCCUR ANYWHERE AT ANY TIME...IT APPEARS
THAT THE BEST CHANCES OF ORGANIZED SHOWER ACTIVITY WILL BE TONIGHT
ACROSS L.A. COUNTY AND EASTERN VTU COUNTY AS SOME LOW LEVEL SWLY
FLOW DEVELOPS...AND SUNDAY AFTERNOON AND EVENING AS THE UPPER LOW
MOVES OVERHEAD. DUE TO THE SHOWERY NATURE OF THE PRECIPITATION...
RAINFALL TOTALS THROUGH SUNDAY NIGHT WILL BE HIGHLY VARIABLE...BUT
IN GENERAL...EXPECT TOTALS OF ONE QUARTER TO ONE HALF INCH...
EXCEPT ONE HALF INCH TO ONE INCH ACROSS THE MOUNTAINS...THE SAN
GABRIEL VALLEY...AND POSSIBLY PORTIONS OF THE REMAINDER OF THE L.A.
COUNTY VALLEYS AND THE VALLEYS OF ERN VTU COUNTY. LOCAL TOTALS UP TO
2 INCHES ARE POSSIBLE IN THE SAN GABRIEL MOUNTAINS AND FOOTHILLS.

SNOW WILL BE AN ISSUE FOR TRAVELERS THIS WEEKEND. SNOW LEVELS ARE
EXPECTED TO LOWER TO 5000 FEET LATE TODAY...THEN TO BETWEEN 3500 AND
4000 FEET LATE TONIGHT OR EARLY SUNDAY...THEN LINGER AT THOSE LEVELS
INTO SUNDAY NIGHT. SNOW MAY WELL AFFECT TRAVEL ACROSS HIGHER
PORTIONS OF INTERSTATE 5...HIGHWAY 14 AND HIGHWAY 33...ESPECIALLY
LATE TONIGHT THROUGH EARLY MONDAY. HAVE EXPANDED WINTER WEATHER
ADVISORIES TO INCLUDE THE MOUNTAINS OF SANTA BARBARA COUNTY. ON
AVERAGE...EXPECT A TOTAL OF 4 TO 8 INCHES OF SNOW BETWEEN 5000 AND
6500 FEET...WITH TOTALS OF 8 TO 12 INCHES ABOVE 6500 FEET...AND 2 TO
4 INCHES BETWEEN 4000 AND 5000 FEET. THERE COULD BE LOCAL TOTALS AS
HIGH AS 18 INCHES ACROSS PORTIONS OF THE SAN GABRIEL MOUNTAINS...OR
HIGHER ELEVATIONS IN VTU COUNTY. WAS STRONGLY CONSIDERING UPGRADING
TO A WINTER STORM WARNING...BUT HAVE DECIDED AGAINST IT...SINCE THE
SNOW ACCUMULATIONS MAY NOT MEET THE REQUIRED TOTALS IN ANY 12 OR 24
HOUR PERIOD. LATER SHIFTS MAY WELL HAVE TO UPGRADE DEPENDING UPON
SHOWER DEVELOPMENT.

SHOWERS WILL DECREASE ACROSS THE REGION SUNDAY NIGHT...AND MAY END
JUST ABOUT EVERYWHERE. HOWEVER...ANOTHER COLD UPPER LOW DROPPING
RAPIDLY SOUTHWARD WILL CAUSE SHOWERS TO BECOME LIKELY AGAIN MONDAY
AFTERNOON...WITH SHOWERS CONTINUING MONDAY NIGHT. THAT SYSTEM WILL
ALSO HAVE LOW SNOW LEVELS...AND PROBABLY ALSO A SLIGHT CHANCE OF
TSTMS. THAT SYSTEM WILL MOVE A BIT FASTER...BUT MAY ALSO TRACK A BIT
FARTHER OFF THE COAST...SO IT MAY PICK UP MORE MOISTURE. SHOWERS
SHOULD WIND DOWN IN MOST AREAS LATE MON NIGHT. MAX TEMPERATURES WILL
BE WELL BELOW NORMAL THROUGH MONDAY.

.LONG TERM (TUE-FRI)...THERE COULD BE A FEW LINGERING SHOWERS
TUE...BUT THAT IS LOOKING LESS AND LESS LIKELY. HEIGHTS WILL REBOUND
TUE AFTERNOON...AND WITH SOME SUNSHINE...EXPECT AT LEAST A BIT OR
WARMING. THE 06Z GFS NOW SHOWS A WEAK IMPULSE DROPPING SWD INTO THE
REGION ON WED...AND THAT WAS NOT ON THE PREVIOUS RUN. NO SHOWER
EXPECTED...BUT IT COULD KEEP MAX TEMPS ON THE COOL SIDE. AN UPPER
RIDGE AND HIGHER HEIGHTS WILL BRING WARMER WEATHER THU AND
FRI...WITH DAYTIME TEMPS LIKELY ABOVE NORMAL.


&&

.AVIATION...28/1800Z...

MID/UPPER LEVEL TROUGH CENTER OVER CENTRAL/NORTHERN CALIFORNIA WILL
SHIFT SOUTH. UPPER LEVEL STRONG WEST-SOUTHWEST WINDS WILL BECOME
STRONG SOUTHWEST WHILE MID LEVEL MODERATE WEST WINDS BECOME LIGHT TO
MODERATE SOUTHWEST AFTER 01/05Z OVER THE AREA. FREEZING LEVEL WAS
APPROXIMATELY 6KFT THIS MORNING AND WILL DIFFER BY MINUS 1KFT SUNDAY
MORNING. ISOLATED THUNDERSTORMS WITH TOPS APPROXIMATELY 30KFT ARE
EXPECTED TO MOVE EAST-NORTHEAST AFTER 01/05Z.

MARINE LAYER AT LAX AT 1715Z IS NONE.

KLAX...CHANCE CIGS 030 AT TIMES THROUGH 28/20Z THEN CHANCE CIGS 030
AND -SHRA BETWEEN 01/03-01/11Z. CHANCE CIGS 030-035 AND -TSRA
BETWEEN 01/11-01/15Z THEN CHANCE CIGS 035-040 THEREAFTER.

KBUR...CHANCE CIGS 025 THROUGH 28/19Z THEN CHANCE CIGS 035 BETWEEN
29/19-01/11Z. CHANCE -TSRA CIGS 030 BETWEEN 01/11-01/15Z.

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

&&

.MARINE...28/900 AM...

THERE IS A CHANCE SMALL CRAFT ADVISORY CONDITIONS WILL PERSIST
THROUGH EARLY THIS AFTERNOON IN THE INNER AND OUTER WATERS SOUTH OF
THE NORTHERN CHANNEL ISLANDS. OTHERWISE ISOLATED THUNDERSTORMS ARE
EXPECTED THROUGH MONDAY MORNING. THE THUNDERSTORMS WILL MOVE
WEST-SOUTHWEST AROUND 28 KT TODAY THROUGH THIS AFTERNOON THEN AS THE
TROUGH AXIS SETTLES OVER THE AREA TONIGHT THROUGH SUNDAY NIGHT THE
STORMS SOUTH OF POINT CONCEPTION WILL MOVE NORTHEAST 25 KT AND MOVE
SOUTHWEST AROUND 15 KT NORTH OF POINT CONCEPTION. A SWELL GENERATED
IN THE SOUTHERN HEMISPHERE WITHIN 190-210 DEGREES RELATIVE TO
VENTURA COUNTY LAST TUESDAY IS EXPECTED TO ARRIVE NEXT WEEK TUE
THROUGH WEDNESDAY.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...SUKUP/DB
AVIATION...30
MARINE...30
SYNOPSIS...SMITH

WWW.WEATHER.GOV/LOSANGELES













000
FXUS66 KLOX 281841
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1041 AM PST SAT FEB 28 2015

.SYNOPSIS...

A COLD LOW PRESSURE SYSTEM WILL BRING SHOWERS AND MOUNTAIN SNOW TO
SOUTHWEST CALIFORNIA THIS WEEKEND...ALONG WITH A SLIGHT CHANCE OF
THUNDERSTORMS. AFTER A BRIEF BREAK...ANOTHER COLD SYSTEM WILL BRING
SIMILAR WEATHER TO THE AREA LATE MONDAY MORNING THROUGH EARLY
TUESDAY. DRY WEATHER IS EXPECTED LATE TUESDAY THROUGH FRIDAY. THERE
WILL BE A WARMING TREND...WITH DAYTIME TEMPERATURES NEAR OR ABOVE
NORMAL BY THURSDAY.

&&

.SHORT TERM (TODAY-MON)...

MAIN UPDATE THIS MORNING WAS TO DECREASE THE POPS AND CLOUD COVER
FOR THE MORNING HOURS BASED ON CURRENT SATELLITE AND RADAR TRENDS.
NOT EXPECTING MUCH SHOWER ACTIVITY FOR AREAS S OF THE MOUNTAINS THIS
MORNING DUE TO NW FLOW ALOFT. CLOUD COVERAGE AND RAIN CHANCES WILL
INCREASE THIS AFTERNOON AS THE UPPER LOW THAT IS CURRENTLY OVER
NORTHERN CA CONTINUES TO MOVE S. DAYTIME SURFACE HEATING WILL ALSO
HELP SHOWERS TO DEVELOP...AS THIS WILL BE A CONVECTIVE SCENARIO WITH
COLD AIR MOVING IN ALOFT. COULD EVEN BE SOME ISOLATED THUNDERSTORMS
N OF POINT CONCEPTION TODAY...WHERE THERE IS SOME WEAK INSTABILITY.

***FROM PREVIOUS DISCUSSION***

THE UPPER LOW WILL SLOWLY DROP SWD TO NEAR POINT CONCEPTION LATE
TONIGHT...MOVE VERY LITTLE ON SUNDAY...THEN PUSH SLOWLY INTO
LOS ANGELES COUNTY SUNDAY NIGHT. THIS WILL MAINTAIN A MOIST AND
UNSTABLE AIRMASS ACROSS THE REGION...SO EXPECT QUITE A BIT OF SHOWER
ACTIVITY OVERNIGHT THROUGH SUNDAY NIGHT...WITH A SLIGHT CHANCE OF
TSTMS. THE TEMPERATURE PROFILE THROUGH THE ATMOSPHERE WILL BE
FAVORABLE FOR SOME SMALL HAIL...AND INDEED...THIS HAS BEEN REPORTED
ACROSS NRN CA. ANY THUNDERSTORM THIS AFTERNOON THROUGH SUNDAY
EVENING WILL HAVE THE CAPABILITY OF PRODUCING SMALL HAIL AND HEAVY
DOWNPOURS. WHILE SHOWERS MAY OCCUR ANYWHERE AT ANY TIME...IT APPEARS
THAT THE BEST CHANCES OF ORGANIZED SHOWER ACTIVITY WILL BE TONIGHT
ACROSS L.A. COUNTY AND EASTERN VTU COUNTY AS SOME LOW LEVEL SWLY
FLOW DEVELOPS...AND SUNDAY AFTERNOON AND EVENING AS THE UPPER LOW
MOVES OVERHEAD. DUE TO THE SHOWERY NATURE OF THE PRECIPITATION...
RAINFALL TOTALS THROUGH SUNDAY NIGHT WILL BE HIGHLY VARIABLE...BUT
IN GENERAL...EXPECT TOTALS OF ONE QUARTER TO ONE HALF INCH...
EXCEPT ONE HALF INCH TO ONE INCH ACROSS THE MOUNTAINS...THE SAN
GABRIEL VALLEY...AND POSSIBLY PORTIONS OF THE REMAINDER OF THE L.A.
COUNTY VALLEYS AND THE VALLEYS OF ERN VTU COUNTY. LOCAL TOTALS UP TO
2 INCHES ARE POSSIBLE IN THE SAN GABRIEL MOUNTAINS AND FOOTHILLS.

SNOW WILL BE AN ISSUE FOR TRAVELERS THIS WEEKEND. SNOW LEVELS ARE
EXPECTED TO LOWER TO 5000 FEET LATE TODAY...THEN TO BETWEEN 3500 AND
4000 FEET LATE TONIGHT OR EARLY SUNDAY...THEN LINGER AT THOSE LEVELS
INTO SUNDAY NIGHT. SNOW MAY WELL AFFECT TRAVEL ACROSS HIGHER
PORTIONS OF INTERSTATE 5...HIGHWAY 14 AND HIGHWAY 33...ESPECIALLY
LATE TONIGHT THROUGH EARLY MONDAY. HAVE EXPANDED WINTER WEATHER
ADVISORIES TO INCLUDE THE MOUNTAINS OF SANTA BARBARA COUNTY. ON
AVERAGE...EXPECT A TOTAL OF 4 TO 8 INCHES OF SNOW BETWEEN 5000 AND
6500 FEET...WITH TOTALS OF 8 TO 12 INCHES ABOVE 6500 FEET...AND 2 TO
4 INCHES BETWEEN 4000 AND 5000 FEET. THERE COULD BE LOCAL TOTALS AS
HIGH AS 18 INCHES ACROSS PORTIONS OF THE SAN GABRIEL MOUNTAINS...OR
HIGHER ELEVATIONS IN VTU COUNTY. WAS STRONGLY CONSIDERING UPGRADING
TO A WINTER STORM WARNING...BUT HAVE DECIDED AGAINST IT...SINCE THE
SNOW ACCUMULATIONS MAY NOT MEET THE REQUIRED TOTALS IN ANY 12 OR 24
HOUR PERIOD. LATER SHIFTS MAY WELL HAVE TO UPGRADE DEPENDING UPON
SHOWER DEVELOPMENT.

SHOWERS WILL DECREASE ACROSS THE REGION SUNDAY NIGHT...AND MAY END
JUST ABOUT EVERYWHERE. HOWEVER...ANOTHER COLD UPPER LOW DROPPING
RAPIDLY SOUTHWARD WILL CAUSE SHOWERS TO BECOME LIKELY AGAIN MONDAY
AFTERNOON...WITH SHOWERS CONTINUING MONDAY NIGHT. THAT SYSTEM WILL
ALSO HAVE LOW SNOW LEVELS...AND PROBABLY ALSO A SLIGHT CHANCE OF
TSTMS. THAT SYSTEM WILL MOVE A BIT FASTER...BUT MAY ALSO TRACK A BIT
FARTHER OFF THE COAST...SO IT MAY PICK UP MORE MOISTURE. SHOWERS
SHOULD WIND DOWN IN MOST AREAS LATE MON NIGHT. MAX TEMPERATURES WILL
BE WELL BELOW NORMAL THROUGH MONDAY.

.LONG TERM (TUE-FRI)...THERE COULD BE A FEW LINGERING SHOWERS
TUE...BUT THAT IS LOOKING LESS AND LESS LIKELY. HEIGHTS WILL REBOUND
TUE AFTERNOON...AND WITH SOME SUNSHINE...EXPECT AT LEAST A BIT OR
WARMING. THE 06Z GFS NOW SHOWS A WEAK IMPULSE DROPPING SWD INTO THE
REGION ON WED...AND THAT WAS NOT ON THE PREVIOUS RUN. NO SHOWER
EXPECTED...BUT IT COULD KEEP MAX TEMPS ON THE COOL SIDE. AN UPPER
RIDGE AND HIGHER HEIGHTS WILL BRING WARMER WEATHER THU AND
FRI...WITH DAYTIME TEMPS LIKELY ABOVE NORMAL.


&&

.AVIATION...28/1800Z...

MID/UPPER LEVEL TROUGH CENTER OVER CENTRAL/NORTHERN CALIFORNIA WILL
SHIFT SOUTH. UPPER LEVEL STRONG WEST-SOUTHWEST WINDS WILL BECOME
STRONG SOUTHWEST WHILE MID LEVEL MODERATE WEST WINDS BECOME LIGHT TO
MODERATE SOUTHWEST AFTER 01/05Z OVER THE AREA. FREEZING LEVEL WAS
APPROXIMATELY 6KFT THIS MORNING AND WILL DIFFER BY MINUS 1KFT SUNDAY
MORNING. ISOLATED THUNDERSTORMS WITH TOPS APPROXIMATELY 30KFT ARE
EXPECTED TO MOVE EAST-NORTHEAST AFTER 01/05Z.

MARINE LAYER AT LAX AT 1715Z IS NONE.

KLAX...CHANCE CIGS 030 AT TIMES THROUGH 28/20Z THEN CHANCE CIGS 030
AND -SHRA BETWEEN 01/03-01/11Z. CHANCE CIGS 030-035 AND -TSRA
BETWEEN 01/11-01/15Z THEN CHANCE CIGS 035-040 THEREAFTER.

KBUR...CHANCE CIGS 025 THROUGH 28/19Z THEN CHANCE CIGS 035 BETWEEN
29/19-01/11Z. CHANCE -TSRA CIGS 030 BETWEEN 01/11-01/15Z.

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

&&

.MARINE...28/900 AM...

THERE IS A CHANCE SMALL CRAFT ADVISORY CONDITIONS WILL PERSIST
THROUGH EARLY THIS AFTERNOON IN THE INNER AND OUTER WATERS SOUTH OF
THE NORTHERN CHANNEL ISLANDS. OTHERWISE ISOLATED THUNDERSTORMS ARE
EXPECTED THROUGH MONDAY MORNING. THE THUNDERSTORMS WILL MOVE
WEST-SOUTHWEST AROUND 28 KT TODAY THROUGH THIS AFTERNOON THEN AS THE
TROUGH AXIS SETTLES OVER THE AREA TONIGHT THROUGH SUNDAY NIGHT THE
STORMS SOUTH OF POINT CONCEPTION WILL MOVE NORTHEAST 25 KT AND MOVE
SOUTHWEST AROUND 15 KT NORTH OF POINT CONCEPTION. A SWELL GENERATED
IN THE SOUTHERN HEMISPHERE WITHIN 190-210 DEGREES RELATIVE TO
VENTURA COUNTY LAST TUESDAY IS EXPECTED TO ARRIVE NEXT WEEK TUE
THROUGH WEDNESDAY.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...SUKUP/DB
AVIATION...30
MARINE...30
SYNOPSIS...SMITH

WWW.WEATHER.GOV/LOSANGELES












000
FXUS66 KLOX 281812
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1011 AM PST SAT FEB 28 2015

.SYNOPSIS...

A COLD LOW PRESSURE SYSTEM WILL BRING SHOWERS AND MOUNTAIN SNOW TO
SOUTHWEST CALIFORNIA THIS WEEKEND...ALONG WITH A SLIGHT CHANCE OF
THUNDERSTORMS. AFTER A BRIEF BREAK...ANOTHER COLD SYSTEM WILL BRING
SIMILAR WEATHER TO THE AREA LATE MONDAY MORNING THROUGH EARLY
TUESDAY. DRY WEATHER IS EXPECTED LATE TUESDAY THROUGH FRIDAY. THERE
WILL BE A WARMING TREND...WITH DAYTIME TEMPERATURES NEAR OR ABOVE
NORMAL BY THURSDAY.

&&

.SHORT TERM (TODAY-MON)...

MAIN UPDATE THIS MORNING WAS TO DECREASE THE POPS AND CLOUD COVER
FOR THE MORNING HOURS BASED ON CURRENT SATELLITE AND RADAR TRENDS.
NOT EXPECTING MUCH SHOWER ACTIVITY FOR AREAS S OF THE MOUNTAINS THIS
MORNING DUE TO NW FLOW ALOFT. CLOUD COVERAGE AND RAIN CHANCES WILL
INCREASE THIS AFTERNOON AS THE UPPER LOW THAT IS CURRENTLY OVER
NORTHERN CA CONTINUES TO MOVE S. DAYTIME SURFACE HEATING WILL ALSO
HELP SHOWERS TO DEVELOP...AS THIS WILL BE A CONVECTIVE SCENARIO WITH
COLD AIR MOVING IN ALOFT. COULD EVEN BE SOME ISOLATED THUNDERSTORMS
N OF POINT CONCEPTION TODAY...WHERE THERE IS SOME WEAK INSTABILITY.

***FROM PREVIOUS DISCUSSION***

THE UPPER LOW WILL SLOWLY DROP SWD TO NEAR POINT CONCEPTION LATE
TONIGHT...MOVE VERY LITTLE ON SUNDAY...THEN PUSH SLOWLY INTO
LOS ANGELES COUNTY SUNDAY NIGHT. THIS WILL MAINTAIN A MOIST AND
UNSTABLE AIRMASS ACROSS THE REGION...SO EXPECT QUITE A BIT OF SHOWER
ACTIVITY OVERNIGHT THROUGH SUNDAY NIGHT...WITH A SLIGHT CHANCE OF
TSTMS. THE TEMPERATURE PROFILE THROUGH THE ATMOSPHERE WILL BE
FAVORABLE FOR SOME SMALL HAIL...AND INDEED...THIS HAS BEEN REPORTED
ACROSS NRN CA. ANY THUNDERSTORM THIS AFTERNOON THROUGH SUNDAY
EVENING WILL HAVE THE CAPABILITY OF PRODUCING SMALL HAIL AND HEAVY
DOWNPOURS. WHILE SHOWERS MAY OCCUR ANYWHERE AT ANY TIME...IT APPEARS
THAT THE BEST CHANCES OF ORGANIZED SHOWER ACTIVITY WILL BE TONIGHT
ACROSS L.A. COUNTY AND EASTERN VTU COUNTY AS SOME LOW LEVEL SWLY
FLOW DEVELOPS...AND SUNDAY AFTERNOON AND EVENING AS THE UPPER LOW
MOVES OVERHEAD. DUE TO THE SHOWERY NATURE OF THE PRECIPITATION...
RAINFALL TOTALS THROUGH SUNDAY NIGHT WILL BE HIGHLY VARIABLE...BUT
IN GENERAL...EXPECT TOTALS OF ONE QUARTER TO ONE HALF INCH...
EXCEPT ONE HALF INCH TO ONE INCH ACROSS THE MOUNTAINS...THE SAN
GABRIEL VALLEY...AND POSSIBLY PORTIONS OF THE REMAINDER OF THE L.A.
COUNTY VALLEYS AND THE VALLEYS OF ERN VTU COUNTY. LOCAL TOTALS UP TO
2 INCHES ARE POSSIBLE IN THE SAN GABRIEL MOUNTAINS AND FOOTHILLS.

SNOW WILL BE AN ISSUE FOR TRAVELERS THIS WEEKEND. SNOW LEVELS ARE
EXPECTED TO LOWER TO 5000 FEET LATE TODAY...THEN TO BETWEEN 3500 AND
4000 FEET LATE TONIGHT OR EARLY SUNDAY...THEN LINGER AT THOSE LEVELS
INTO SUNDAY NIGHT. SNOW MAY WELL AFFECT TRAVEL ACROSS HIGHER
PORTIONS OF INTERSTATE 5...HIGHWAY 14 AND HIGHWAY 33...ESPECIALLY
LATE TONIGHT THROUGH EARLY MONDAY. HAVE EXPANDED WINTER WEATHER
ADVISORIES TO INCLUDE THE MOUNTAINS OF SANTA BARBARA COUNTY. ON
AVERAGE...EXPECT A TOTAL OF 4 TO 8 INCHES OF SNOW BETWEEN 5000 AND
6500 FEET...WITH TOTALS OF 8 TO 12 INCHES ABOVE 6500 FEET...AND 2 TO
4 INCHES BETWEEN 4000 AND 5000 FEET. THERE COULD BE LOCAL TOTALS AS
HIGH AS 18 INCHES ACROSS PORTIONS OF THE SAN GABRIEL MOUNTAINS...OR
HIGHER ELEVATIONS IN VTU COUNTY. WAS STRONGLY CONSIDERING UPGRADING
TO A WINTER STORM WARNING...BUT HAVE DECIDED AGAINST IT...SINCE THE
SNOW ACCUMULATIONS MAY NOT MEET THE REQUIRED TOTALS IN ANY 12 OR 24
HOUR PERIOD. LATER SHIFTS MAY WELL HAVE TO UPGRADE DEPENDING UPON
SHOWER DEVELOPMENT.

SHOWERS WILL DECREASE ACROSS THE REGION SUNDAY NIGHT...AND MAY END
JUST ABOUT EVERYWHERE. HOWEVER...ANOTHER COLD UPPER LOW DROPPING
RAPIDLY SOUTHWARD WILL CAUSE SHOWERS TO BECOME LIKELY AGAIN MONDAY
AFTERNOON...WITH SHOWERS CONTINUING MONDAY NIGHT. THAT SYSTEM WILL
ALSO HAVE LOW SNOW LEVELS...AND PROBABLY ALSO A SLIGHT CHANCE OF
TSTMS. THAT SYSTEM WILL MOVE A BIT FASTER...BUT MAY ALSO TRACK A BIT
FARTHER OFF THE COAST...SO IT MAY PICK UP MORE MOISTURE. SHOWERS
SHOULD WIND DOWN IN MOST AREAS LATE MON NIGHT. MAX TEMPERATURES WILL
BE WELL BELOW NORMAL THROUGH MONDAY.

.LONG TERM (TUE-FRI)...THERE COULD BE A FEW LINGERING SHOWERS
TUE...BUT THAT IS LOOKING LESS AND LESS LIKELY. HEIGHTS WILL REBOUND
TUE AFTERNOON...AND WITH SOME SUNSHINE...EXPECT AT LEAST A BIT OR
WARMING. THE 06Z GFS NOW SHOWS A WEAK IMPULSE DROPPING SWD INTO THE
REGION ON WED...AND THAT WAS NOT ON THE PREVIOUS RUN. NO SHOWER
EXPECTED...BUT IT COULD KEEP MAX TEMPS ON THE COOL SIDE. AN UPPER
RIDGE AND HIGHER HEIGHTS WILL BRING WARMER WEATHER THU AND
FRI...WITH DAYTIME TEMPS LIKELY ABOVE NORMAL.


&&

.AVIATION...28/1800Z...

MID/UPPER LEVEL TROUGH CENTER OVER CENTRAL/NORTHERN CALIFORNIA WILL
SHIFT SOUTH. UPPER LEVEL STRONG WEST-SOUTHWEST WINDS WILL BECOME
STRONG SOUTHWEST WHILE MID LEVEL MODERATE WEST WINDS BECOME LIGHT TO
MODERATE SOUTHWEST AFTER 01/05Z OVER THE AREA. FREEZING LEVEL WAS
APPROXIMATELY 6KFT THIS MORNING AND WILL DIFFER BY MINUS 1KFT SUNDAY
MORNING. ISOLATED THUNDERSTORMS WITH TOPS APPROXIMATELY 30KFT ARE
EXPECTED TO MOVE EAST-NORTHEAST AFTER 01/05Z.

MARINE LAYER AT LAX AT 1715Z IS NONE.

KLAX...CHANCE CIGS 030 AT TIMES THROUGH 28/20Z THEN CHANCE CIGS 030
AND -SHRA BETWEEN 01/03-01/11Z. CHANCE CIGS 030-035 AND -TSRA
BETWEEN 01/11-01/15Z THEN CHANCE CIGS 035-040 THEREAFTER.

KBUR...CHANCE CIGS 025 THROUGH 28/19Z THEN CHANCE CIGS 035 BETWEEN
29/19-01/11Z. CHANCE -TSRA CIGS 030 BETWEEN 01/11-01/15Z.

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

&&

.MARINE...28/900 AM...

THERE IS A CHANCE SMALL CRAFT ADVISORY CONDITIONS WILL PERSIST
THROUGH THE AFTERNOON IN THE INNER AND OUTER WATERS SOUTH OF THE
NORTHERN CHANNELS. OTHERWISE ISOLATED THUNDERSTORMS ARE EXPECTED
THROUGH MONDAY MORNING. THEN THUNDERSTORMS WILL MOVE WEST-SOUTHWEST
AROUND 28 KT TODAY THROUGH THIS AFTERNOON THEN AS THE TROUGH AXIS
SETTLES OVER THE AREA TONIGHT THROUGH SUNDAY NIGHT THE STORMS SOUTH
OF POINT CONCEPTION WILL MOVE NORTHEAST 25 KT AND SOUTHWEST AROUND
15 KT NORTH OF POINT CONCEPTION. A SWELL GENERATED IN THE SOUTHERN
HEMISPHERE WITHIN 190-210 DEGREES RELATIVE TO VENTURA COUNTY LAST
TUESDAY IS EXPECTED TO ARRIVE NEXT WEEK TUE THROUGH WEDNESDAY.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...SUKUP/DB
AVIATION...30
MARINE...30
SYNOPSIS...SMITH

WWW.WEATHER.GOV/LOSANGELES









000
FXUS66 KLOX 281812
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1011 AM PST SAT FEB 28 2015

.SYNOPSIS...

A COLD LOW PRESSURE SYSTEM WILL BRING SHOWERS AND MOUNTAIN SNOW TO
SOUTHWEST CALIFORNIA THIS WEEKEND...ALONG WITH A SLIGHT CHANCE OF
THUNDERSTORMS. AFTER A BRIEF BREAK...ANOTHER COLD SYSTEM WILL BRING
SIMILAR WEATHER TO THE AREA LATE MONDAY MORNING THROUGH EARLY
TUESDAY. DRY WEATHER IS EXPECTED LATE TUESDAY THROUGH FRIDAY. THERE
WILL BE A WARMING TREND...WITH DAYTIME TEMPERATURES NEAR OR ABOVE
NORMAL BY THURSDAY.

&&

.SHORT TERM (TODAY-MON)...

MAIN UPDATE THIS MORNING WAS TO DECREASE THE POPS AND CLOUD COVER
FOR THE MORNING HOURS BASED ON CURRENT SATELLITE AND RADAR TRENDS.
NOT EXPECTING MUCH SHOWER ACTIVITY FOR AREAS S OF THE MOUNTAINS THIS
MORNING DUE TO NW FLOW ALOFT. CLOUD COVERAGE AND RAIN CHANCES WILL
INCREASE THIS AFTERNOON AS THE UPPER LOW THAT IS CURRENTLY OVER
NORTHERN CA CONTINUES TO MOVE S. DAYTIME SURFACE HEATING WILL ALSO
HELP SHOWERS TO DEVELOP...AS THIS WILL BE A CONVECTIVE SCENARIO WITH
COLD AIR MOVING IN ALOFT. COULD EVEN BE SOME ISOLATED THUNDERSTORMS
N OF POINT CONCEPTION TODAY...WHERE THERE IS SOME WEAK INSTABILITY.

***FROM PREVIOUS DISCUSSION***

THE UPPER LOW WILL SLOWLY DROP SWD TO NEAR POINT CONCEPTION LATE
TONIGHT...MOVE VERY LITTLE ON SUNDAY...THEN PUSH SLOWLY INTO
LOS ANGELES COUNTY SUNDAY NIGHT. THIS WILL MAINTAIN A MOIST AND
UNSTABLE AIRMASS ACROSS THE REGION...SO EXPECT QUITE A BIT OF SHOWER
ACTIVITY OVERNIGHT THROUGH SUNDAY NIGHT...WITH A SLIGHT CHANCE OF
TSTMS. THE TEMPERATURE PROFILE THROUGH THE ATMOSPHERE WILL BE
FAVORABLE FOR SOME SMALL HAIL...AND INDEED...THIS HAS BEEN REPORTED
ACROSS NRN CA. ANY THUNDERSTORM THIS AFTERNOON THROUGH SUNDAY
EVENING WILL HAVE THE CAPABILITY OF PRODUCING SMALL HAIL AND HEAVY
DOWNPOURS. WHILE SHOWERS MAY OCCUR ANYWHERE AT ANY TIME...IT APPEARS
THAT THE BEST CHANCES OF ORGANIZED SHOWER ACTIVITY WILL BE TONIGHT
ACROSS L.A. COUNTY AND EASTERN VTU COUNTY AS SOME LOW LEVEL SWLY
FLOW DEVELOPS...AND SUNDAY AFTERNOON AND EVENING AS THE UPPER LOW
MOVES OVERHEAD. DUE TO THE SHOWERY NATURE OF THE PRECIPITATION...
RAINFALL TOTALS THROUGH SUNDAY NIGHT WILL BE HIGHLY VARIABLE...BUT
IN GENERAL...EXPECT TOTALS OF ONE QUARTER TO ONE HALF INCH...
EXCEPT ONE HALF INCH TO ONE INCH ACROSS THE MOUNTAINS...THE SAN
GABRIEL VALLEY...AND POSSIBLY PORTIONS OF THE REMAINDER OF THE L.A.
COUNTY VALLEYS AND THE VALLEYS OF ERN VTU COUNTY. LOCAL TOTALS UP TO
2 INCHES ARE POSSIBLE IN THE SAN GABRIEL MOUNTAINS AND FOOTHILLS.

SNOW WILL BE AN ISSUE FOR TRAVELERS THIS WEEKEND. SNOW LEVELS ARE
EXPECTED TO LOWER TO 5000 FEET LATE TODAY...THEN TO BETWEEN 3500 AND
4000 FEET LATE TONIGHT OR EARLY SUNDAY...THEN LINGER AT THOSE LEVELS
INTO SUNDAY NIGHT. SNOW MAY WELL AFFECT TRAVEL ACROSS HIGHER
PORTIONS OF INTERSTATE 5...HIGHWAY 14 AND HIGHWAY 33...ESPECIALLY
LATE TONIGHT THROUGH EARLY MONDAY. HAVE EXPANDED WINTER WEATHER
ADVISORIES TO INCLUDE THE MOUNTAINS OF SANTA BARBARA COUNTY. ON
AVERAGE...EXPECT A TOTAL OF 4 TO 8 INCHES OF SNOW BETWEEN 5000 AND
6500 FEET...WITH TOTALS OF 8 TO 12 INCHES ABOVE 6500 FEET...AND 2 TO
4 INCHES BETWEEN 4000 AND 5000 FEET. THERE COULD BE LOCAL TOTALS AS
HIGH AS 18 INCHES ACROSS PORTIONS OF THE SAN GABRIEL MOUNTAINS...OR
HIGHER ELEVATIONS IN VTU COUNTY. WAS STRONGLY CONSIDERING UPGRADING
TO A WINTER STORM WARNING...BUT HAVE DECIDED AGAINST IT...SINCE THE
SNOW ACCUMULATIONS MAY NOT MEET THE REQUIRED TOTALS IN ANY 12 OR 24
HOUR PERIOD. LATER SHIFTS MAY WELL HAVE TO UPGRADE DEPENDING UPON
SHOWER DEVELOPMENT.

SHOWERS WILL DECREASE ACROSS THE REGION SUNDAY NIGHT...AND MAY END
JUST ABOUT EVERYWHERE. HOWEVER...ANOTHER COLD UPPER LOW DROPPING
RAPIDLY SOUTHWARD WILL CAUSE SHOWERS TO BECOME LIKELY AGAIN MONDAY
AFTERNOON...WITH SHOWERS CONTINUING MONDAY NIGHT. THAT SYSTEM WILL
ALSO HAVE LOW SNOW LEVELS...AND PROBABLY ALSO A SLIGHT CHANCE OF
TSTMS. THAT SYSTEM WILL MOVE A BIT FASTER...BUT MAY ALSO TRACK A BIT
FARTHER OFF THE COAST...SO IT MAY PICK UP MORE MOISTURE. SHOWERS
SHOULD WIND DOWN IN MOST AREAS LATE MON NIGHT. MAX TEMPERATURES WILL
BE WELL BELOW NORMAL THROUGH MONDAY.

.LONG TERM (TUE-FRI)...THERE COULD BE A FEW LINGERING SHOWERS
TUE...BUT THAT IS LOOKING LESS AND LESS LIKELY. HEIGHTS WILL REBOUND
TUE AFTERNOON...AND WITH SOME SUNSHINE...EXPECT AT LEAST A BIT OR
WARMING. THE 06Z GFS NOW SHOWS A WEAK IMPULSE DROPPING SWD INTO THE
REGION ON WED...AND THAT WAS NOT ON THE PREVIOUS RUN. NO SHOWER
EXPECTED...BUT IT COULD KEEP MAX TEMPS ON THE COOL SIDE. AN UPPER
RIDGE AND HIGHER HEIGHTS WILL BRING WARMER WEATHER THU AND
FRI...WITH DAYTIME TEMPS LIKELY ABOVE NORMAL.


&&

.AVIATION...28/1800Z...

MID/UPPER LEVEL TROUGH CENTER OVER CENTRAL/NORTHERN CALIFORNIA WILL
SHIFT SOUTH. UPPER LEVEL STRONG WEST-SOUTHWEST WINDS WILL BECOME
STRONG SOUTHWEST WHILE MID LEVEL MODERATE WEST WINDS BECOME LIGHT TO
MODERATE SOUTHWEST AFTER 01/05Z OVER THE AREA. FREEZING LEVEL WAS
APPROXIMATELY 6KFT THIS MORNING AND WILL DIFFER BY MINUS 1KFT SUNDAY
MORNING. ISOLATED THUNDERSTORMS WITH TOPS APPROXIMATELY 30KFT ARE
EXPECTED TO MOVE EAST-NORTHEAST AFTER 01/05Z.

MARINE LAYER AT LAX AT 1715Z IS NONE.

KLAX...CHANCE CIGS 030 AT TIMES THROUGH 28/20Z THEN CHANCE CIGS 030
AND -SHRA BETWEEN 01/03-01/11Z. CHANCE CIGS 030-035 AND -TSRA
BETWEEN 01/11-01/15Z THEN CHANCE CIGS 035-040 THEREAFTER.

KBUR...CHANCE CIGS 025 THROUGH 28/19Z THEN CHANCE CIGS 035 BETWEEN
29/19-01/11Z. CHANCE -TSRA CIGS 030 BETWEEN 01/11-01/15Z.

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

&&

.MARINE...28/900 AM...

THERE IS A CHANCE SMALL CRAFT ADVISORY CONDITIONS WILL PERSIST
THROUGH THE AFTERNOON IN THE INNER AND OUTER WATERS SOUTH OF THE
NORTHERN CHANNELS. OTHERWISE ISOLATED THUNDERSTORMS ARE EXPECTED
THROUGH MONDAY MORNING. THEN THUNDERSTORMS WILL MOVE WEST-SOUTHWEST
AROUND 28 KT TODAY THROUGH THIS AFTERNOON THEN AS THE TROUGH AXIS
SETTLES OVER THE AREA TONIGHT THROUGH SUNDAY NIGHT THE STORMS SOUTH
OF POINT CONCEPTION WILL MOVE NORTHEAST 25 KT AND SOUTHWEST AROUND
15 KT NORTH OF POINT CONCEPTION. A SWELL GENERATED IN THE SOUTHERN
HEMISPHERE WITHIN 190-210 DEGREES RELATIVE TO VENTURA COUNTY LAST
TUESDAY IS EXPECTED TO ARRIVE NEXT WEEK TUE THROUGH WEDNESDAY.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...SUKUP/DB
AVIATION...30
MARINE...30
SYNOPSIS...SMITH

WWW.WEATHER.GOV/LOSANGELES










000
FXUS66 KLOX 281812
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1011 AM PST SAT FEB 28 2015

.SYNOPSIS...

A COLD LOW PRESSURE SYSTEM WILL BRING SHOWERS AND MOUNTAIN SNOW TO
SOUTHWEST CALIFORNIA THIS WEEKEND...ALONG WITH A SLIGHT CHANCE OF
THUNDERSTORMS. AFTER A BRIEF BREAK...ANOTHER COLD SYSTEM WILL BRING
SIMILAR WEATHER TO THE AREA LATE MONDAY MORNING THROUGH EARLY
TUESDAY. DRY WEATHER IS EXPECTED LATE TUESDAY THROUGH FRIDAY. THERE
WILL BE A WARMING TREND...WITH DAYTIME TEMPERATURES NEAR OR ABOVE
NORMAL BY THURSDAY.

&&

.SHORT TERM (TODAY-MON)...

MAIN UPDATE THIS MORNING WAS TO DECREASE THE POPS AND CLOUD COVER
FOR THE MORNING HOURS BASED ON CURRENT SATELLITE AND RADAR TRENDS.
NOT EXPECTING MUCH SHOWER ACTIVITY FOR AREAS S OF THE MOUNTAINS THIS
MORNING DUE TO NW FLOW ALOFT. CLOUD COVERAGE AND RAIN CHANCES WILL
INCREASE THIS AFTERNOON AS THE UPPER LOW THAT IS CURRENTLY OVER
NORTHERN CA CONTINUES TO MOVE S. DAYTIME SURFACE HEATING WILL ALSO
HELP SHOWERS TO DEVELOP...AS THIS WILL BE A CONVECTIVE SCENARIO WITH
COLD AIR MOVING IN ALOFT. COULD EVEN BE SOME ISOLATED THUNDERSTORMS
N OF POINT CONCEPTION TODAY...WHERE THERE IS SOME WEAK INSTABILITY.

***FROM PREVIOUS DISCUSSION***

THE UPPER LOW WILL SLOWLY DROP SWD TO NEAR POINT CONCEPTION LATE
TONIGHT...MOVE VERY LITTLE ON SUNDAY...THEN PUSH SLOWLY INTO
LOS ANGELES COUNTY SUNDAY NIGHT. THIS WILL MAINTAIN A MOIST AND
UNSTABLE AIRMASS ACROSS THE REGION...SO EXPECT QUITE A BIT OF SHOWER
ACTIVITY OVERNIGHT THROUGH SUNDAY NIGHT...WITH A SLIGHT CHANCE OF
TSTMS. THE TEMPERATURE PROFILE THROUGH THE ATMOSPHERE WILL BE
FAVORABLE FOR SOME SMALL HAIL...AND INDEED...THIS HAS BEEN REPORTED
ACROSS NRN CA. ANY THUNDERSTORM THIS AFTERNOON THROUGH SUNDAY
EVENING WILL HAVE THE CAPABILITY OF PRODUCING SMALL HAIL AND HEAVY
DOWNPOURS. WHILE SHOWERS MAY OCCUR ANYWHERE AT ANY TIME...IT APPEARS
THAT THE BEST CHANCES OF ORGANIZED SHOWER ACTIVITY WILL BE TONIGHT
ACROSS L.A. COUNTY AND EASTERN VTU COUNTY AS SOME LOW LEVEL SWLY
FLOW DEVELOPS...AND SUNDAY AFTERNOON AND EVENING AS THE UPPER LOW
MOVES OVERHEAD. DUE TO THE SHOWERY NATURE OF THE PRECIPITATION...
RAINFALL TOTALS THROUGH SUNDAY NIGHT WILL BE HIGHLY VARIABLE...BUT
IN GENERAL...EXPECT TOTALS OF ONE QUARTER TO ONE HALF INCH...
EXCEPT ONE HALF INCH TO ONE INCH ACROSS THE MOUNTAINS...THE SAN
GABRIEL VALLEY...AND POSSIBLY PORTIONS OF THE REMAINDER OF THE L.A.
COUNTY VALLEYS AND THE VALLEYS OF ERN VTU COUNTY. LOCAL TOTALS UP TO
2 INCHES ARE POSSIBLE IN THE SAN GABRIEL MOUNTAINS AND FOOTHILLS.

SNOW WILL BE AN ISSUE FOR TRAVELERS THIS WEEKEND. SNOW LEVELS ARE
EXPECTED TO LOWER TO 5000 FEET LATE TODAY...THEN TO BETWEEN 3500 AND
4000 FEET LATE TONIGHT OR EARLY SUNDAY...THEN LINGER AT THOSE LEVELS
INTO SUNDAY NIGHT. SNOW MAY WELL AFFECT TRAVEL ACROSS HIGHER
PORTIONS OF INTERSTATE 5...HIGHWAY 14 AND HIGHWAY 33...ESPECIALLY
LATE TONIGHT THROUGH EARLY MONDAY. HAVE EXPANDED WINTER WEATHER
ADVISORIES TO INCLUDE THE MOUNTAINS OF SANTA BARBARA COUNTY. ON
AVERAGE...EXPECT A TOTAL OF 4 TO 8 INCHES OF SNOW BETWEEN 5000 AND
6500 FEET...WITH TOTALS OF 8 TO 12 INCHES ABOVE 6500 FEET...AND 2 TO
4 INCHES BETWEEN 4000 AND 5000 FEET. THERE COULD BE LOCAL TOTALS AS
HIGH AS 18 INCHES ACROSS PORTIONS OF THE SAN GABRIEL MOUNTAINS...OR
HIGHER ELEVATIONS IN VTU COUNTY. WAS STRONGLY CONSIDERING UPGRADING
TO A WINTER STORM WARNING...BUT HAVE DECIDED AGAINST IT...SINCE THE
SNOW ACCUMULATIONS MAY NOT MEET THE REQUIRED TOTALS IN ANY 12 OR 24
HOUR PERIOD. LATER SHIFTS MAY WELL HAVE TO UPGRADE DEPENDING UPON
SHOWER DEVELOPMENT.

SHOWERS WILL DECREASE ACROSS THE REGION SUNDAY NIGHT...AND MAY END
JUST ABOUT EVERYWHERE. HOWEVER...ANOTHER COLD UPPER LOW DROPPING
RAPIDLY SOUTHWARD WILL CAUSE SHOWERS TO BECOME LIKELY AGAIN MONDAY
AFTERNOON...WITH SHOWERS CONTINUING MONDAY NIGHT. THAT SYSTEM WILL
ALSO HAVE LOW SNOW LEVELS...AND PROBABLY ALSO A SLIGHT CHANCE OF
TSTMS. THAT SYSTEM WILL MOVE A BIT FASTER...BUT MAY ALSO TRACK A BIT
FARTHER OFF THE COAST...SO IT MAY PICK UP MORE MOISTURE. SHOWERS
SHOULD WIND DOWN IN MOST AREAS LATE MON NIGHT. MAX TEMPERATURES WILL
BE WELL BELOW NORMAL THROUGH MONDAY.

.LONG TERM (TUE-FRI)...THERE COULD BE A FEW LINGERING SHOWERS
TUE...BUT THAT IS LOOKING LESS AND LESS LIKELY. HEIGHTS WILL REBOUND
TUE AFTERNOON...AND WITH SOME SUNSHINE...EXPECT AT LEAST A BIT OR
WARMING. THE 06Z GFS NOW SHOWS A WEAK IMPULSE DROPPING SWD INTO THE
REGION ON WED...AND THAT WAS NOT ON THE PREVIOUS RUN. NO SHOWER
EXPECTED...BUT IT COULD KEEP MAX TEMPS ON THE COOL SIDE. AN UPPER
RIDGE AND HIGHER HEIGHTS WILL BRING WARMER WEATHER THU AND
FRI...WITH DAYTIME TEMPS LIKELY ABOVE NORMAL.


&&

.AVIATION...28/1800Z...

MID/UPPER LEVEL TROUGH CENTER OVER CENTRAL/NORTHERN CALIFORNIA WILL
SHIFT SOUTH. UPPER LEVEL STRONG WEST-SOUTHWEST WINDS WILL BECOME
STRONG SOUTHWEST WHILE MID LEVEL MODERATE WEST WINDS BECOME LIGHT TO
MODERATE SOUTHWEST AFTER 01/05Z OVER THE AREA. FREEZING LEVEL WAS
APPROXIMATELY 6KFT THIS MORNING AND WILL DIFFER BY MINUS 1KFT SUNDAY
MORNING. ISOLATED THUNDERSTORMS WITH TOPS APPROXIMATELY 30KFT ARE
EXPECTED TO MOVE EAST-NORTHEAST AFTER 01/05Z.

MARINE LAYER AT LAX AT 1715Z IS NONE.

KLAX...CHANCE CIGS 030 AT TIMES THROUGH 28/20Z THEN CHANCE CIGS 030
AND -SHRA BETWEEN 01/03-01/11Z. CHANCE CIGS 030-035 AND -TSRA
BETWEEN 01/11-01/15Z THEN CHANCE CIGS 035-040 THEREAFTER.

KBUR...CHANCE CIGS 025 THROUGH 28/19Z THEN CHANCE CIGS 035 BETWEEN
29/19-01/11Z. CHANCE -TSRA CIGS 030 BETWEEN 01/11-01/15Z.

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

&&

.MARINE...28/900 AM...

THERE IS A CHANCE SMALL CRAFT ADVISORY CONDITIONS WILL PERSIST
THROUGH THE AFTERNOON IN THE INNER AND OUTER WATERS SOUTH OF THE
NORTHERN CHANNELS. OTHERWISE ISOLATED THUNDERSTORMS ARE EXPECTED
THROUGH MONDAY MORNING. THEN THUNDERSTORMS WILL MOVE WEST-SOUTHWEST
AROUND 28 KT TODAY THROUGH THIS AFTERNOON THEN AS THE TROUGH AXIS
SETTLES OVER THE AREA TONIGHT THROUGH SUNDAY NIGHT THE STORMS SOUTH
OF POINT CONCEPTION WILL MOVE NORTHEAST 25 KT AND SOUTHWEST AROUND
15 KT NORTH OF POINT CONCEPTION. A SWELL GENERATED IN THE SOUTHERN
HEMISPHERE WITHIN 190-210 DEGREES RELATIVE TO VENTURA COUNTY LAST
TUESDAY IS EXPECTED TO ARRIVE NEXT WEEK TUE THROUGH WEDNESDAY.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...SUKUP/DB
AVIATION...30
MARINE...30
SYNOPSIS...SMITH

WWW.WEATHER.GOV/LOSANGELES









000
FXUS66 KLOX 281812
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1011 AM PST SAT FEB 28 2015

.SYNOPSIS...

A COLD LOW PRESSURE SYSTEM WILL BRING SHOWERS AND MOUNTAIN SNOW TO
SOUTHWEST CALIFORNIA THIS WEEKEND...ALONG WITH A SLIGHT CHANCE OF
THUNDERSTORMS. AFTER A BRIEF BREAK...ANOTHER COLD SYSTEM WILL BRING
SIMILAR WEATHER TO THE AREA LATE MONDAY MORNING THROUGH EARLY
TUESDAY. DRY WEATHER IS EXPECTED LATE TUESDAY THROUGH FRIDAY. THERE
WILL BE A WARMING TREND...WITH DAYTIME TEMPERATURES NEAR OR ABOVE
NORMAL BY THURSDAY.

&&

.SHORT TERM (TODAY-MON)...

MAIN UPDATE THIS MORNING WAS TO DECREASE THE POPS AND CLOUD COVER
FOR THE MORNING HOURS BASED ON CURRENT SATELLITE AND RADAR TRENDS.
NOT EXPECTING MUCH SHOWER ACTIVITY FOR AREAS S OF THE MOUNTAINS THIS
MORNING DUE TO NW FLOW ALOFT. CLOUD COVERAGE AND RAIN CHANCES WILL
INCREASE THIS AFTERNOON AS THE UPPER LOW THAT IS CURRENTLY OVER
NORTHERN CA CONTINUES TO MOVE S. DAYTIME SURFACE HEATING WILL ALSO
HELP SHOWERS TO DEVELOP...AS THIS WILL BE A CONVECTIVE SCENARIO WITH
COLD AIR MOVING IN ALOFT. COULD EVEN BE SOME ISOLATED THUNDERSTORMS
N OF POINT CONCEPTION TODAY...WHERE THERE IS SOME WEAK INSTABILITY.

***FROM PREVIOUS DISCUSSION***

THE UPPER LOW WILL SLOWLY DROP SWD TO NEAR POINT CONCEPTION LATE
TONIGHT...MOVE VERY LITTLE ON SUNDAY...THEN PUSH SLOWLY INTO
LOS ANGELES COUNTY SUNDAY NIGHT. THIS WILL MAINTAIN A MOIST AND
UNSTABLE AIRMASS ACROSS THE REGION...SO EXPECT QUITE A BIT OF SHOWER
ACTIVITY OVERNIGHT THROUGH SUNDAY NIGHT...WITH A SLIGHT CHANCE OF
TSTMS. THE TEMPERATURE PROFILE THROUGH THE ATMOSPHERE WILL BE
FAVORABLE FOR SOME SMALL HAIL...AND INDEED...THIS HAS BEEN REPORTED
ACROSS NRN CA. ANY THUNDERSTORM THIS AFTERNOON THROUGH SUNDAY
EVENING WILL HAVE THE CAPABILITY OF PRODUCING SMALL HAIL AND HEAVY
DOWNPOURS. WHILE SHOWERS MAY OCCUR ANYWHERE AT ANY TIME...IT APPEARS
THAT THE BEST CHANCES OF ORGANIZED SHOWER ACTIVITY WILL BE TONIGHT
ACROSS L.A. COUNTY AND EASTERN VTU COUNTY AS SOME LOW LEVEL SWLY
FLOW DEVELOPS...AND SUNDAY AFTERNOON AND EVENING AS THE UPPER LOW
MOVES OVERHEAD. DUE TO THE SHOWERY NATURE OF THE PRECIPITATION...
RAINFALL TOTALS THROUGH SUNDAY NIGHT WILL BE HIGHLY VARIABLE...BUT
IN GENERAL...EXPECT TOTALS OF ONE QUARTER TO ONE HALF INCH...
EXCEPT ONE HALF INCH TO ONE INCH ACROSS THE MOUNTAINS...THE SAN
GABRIEL VALLEY...AND POSSIBLY PORTIONS OF THE REMAINDER OF THE L.A.
COUNTY VALLEYS AND THE VALLEYS OF ERN VTU COUNTY. LOCAL TOTALS UP TO
2 INCHES ARE POSSIBLE IN THE SAN GABRIEL MOUNTAINS AND FOOTHILLS.

SNOW WILL BE AN ISSUE FOR TRAVELERS THIS WEEKEND. SNOW LEVELS ARE
EXPECTED TO LOWER TO 5000 FEET LATE TODAY...THEN TO BETWEEN 3500 AND
4000 FEET LATE TONIGHT OR EARLY SUNDAY...THEN LINGER AT THOSE LEVELS
INTO SUNDAY NIGHT. SNOW MAY WELL AFFECT TRAVEL ACROSS HIGHER
PORTIONS OF INTERSTATE 5...HIGHWAY 14 AND HIGHWAY 33...ESPECIALLY
LATE TONIGHT THROUGH EARLY MONDAY. HAVE EXPANDED WINTER WEATHER
ADVISORIES TO INCLUDE THE MOUNTAINS OF SANTA BARBARA COUNTY. ON
AVERAGE...EXPECT A TOTAL OF 4 TO 8 INCHES OF SNOW BETWEEN 5000 AND
6500 FEET...WITH TOTALS OF 8 TO 12 INCHES ABOVE 6500 FEET...AND 2 TO
4 INCHES BETWEEN 4000 AND 5000 FEET. THERE COULD BE LOCAL TOTALS AS
HIGH AS 18 INCHES ACROSS PORTIONS OF THE SAN GABRIEL MOUNTAINS...OR
HIGHER ELEVATIONS IN VTU COUNTY. WAS STRONGLY CONSIDERING UPGRADING
TO A WINTER STORM WARNING...BUT HAVE DECIDED AGAINST IT...SINCE THE
SNOW ACCUMULATIONS MAY NOT MEET THE REQUIRED TOTALS IN ANY 12 OR 24
HOUR PERIOD. LATER SHIFTS MAY WELL HAVE TO UPGRADE DEPENDING UPON
SHOWER DEVELOPMENT.

SHOWERS WILL DECREASE ACROSS THE REGION SUNDAY NIGHT...AND MAY END
JUST ABOUT EVERYWHERE. HOWEVER...ANOTHER COLD UPPER LOW DROPPING
RAPIDLY SOUTHWARD WILL CAUSE SHOWERS TO BECOME LIKELY AGAIN MONDAY
AFTERNOON...WITH SHOWERS CONTINUING MONDAY NIGHT. THAT SYSTEM WILL
ALSO HAVE LOW SNOW LEVELS...AND PROBABLY ALSO A SLIGHT CHANCE OF
TSTMS. THAT SYSTEM WILL MOVE A BIT FASTER...BUT MAY ALSO TRACK A BIT
FARTHER OFF THE COAST...SO IT MAY PICK UP MORE MOISTURE. SHOWERS
SHOULD WIND DOWN IN MOST AREAS LATE MON NIGHT. MAX TEMPERATURES WILL
BE WELL BELOW NORMAL THROUGH MONDAY.

.LONG TERM (TUE-FRI)...THERE COULD BE A FEW LINGERING SHOWERS
TUE...BUT THAT IS LOOKING LESS AND LESS LIKELY. HEIGHTS WILL REBOUND
TUE AFTERNOON...AND WITH SOME SUNSHINE...EXPECT AT LEAST A BIT OR
WARMING. THE 06Z GFS NOW SHOWS A WEAK IMPULSE DROPPING SWD INTO THE
REGION ON WED...AND THAT WAS NOT ON THE PREVIOUS RUN. NO SHOWER
EXPECTED...BUT IT COULD KEEP MAX TEMPS ON THE COOL SIDE. AN UPPER
RIDGE AND HIGHER HEIGHTS WILL BRING WARMER WEATHER THU AND
FRI...WITH DAYTIME TEMPS LIKELY ABOVE NORMAL.


&&

.AVIATION...28/1800Z...

MID/UPPER LEVEL TROUGH CENTER OVER CENTRAL/NORTHERN CALIFORNIA WILL
SHIFT SOUTH. UPPER LEVEL STRONG WEST-SOUTHWEST WINDS WILL BECOME
STRONG SOUTHWEST WHILE MID LEVEL MODERATE WEST WINDS BECOME LIGHT TO
MODERATE SOUTHWEST AFTER 01/05Z OVER THE AREA. FREEZING LEVEL WAS
APPROXIMATELY 6KFT THIS MORNING AND WILL DIFFER BY MINUS 1KFT SUNDAY
MORNING. ISOLATED THUNDERSTORMS WITH TOPS APPROXIMATELY 30KFT ARE
EXPECTED TO MOVE EAST-NORTHEAST AFTER 01/05Z.

MARINE LAYER AT LAX AT 1715Z IS NONE.

KLAX...CHANCE CIGS 030 AT TIMES THROUGH 28/20Z THEN CHANCE CIGS 030
AND -SHRA BETWEEN 01/03-01/11Z. CHANCE CIGS 030-035 AND -TSRA
BETWEEN 01/11-01/15Z THEN CHANCE CIGS 035-040 THEREAFTER.

KBUR...CHANCE CIGS 025 THROUGH 28/19Z THEN CHANCE CIGS 035 BETWEEN
29/19-01/11Z. CHANCE -TSRA CIGS 030 BETWEEN 01/11-01/15Z.

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

&&

.MARINE...28/900 AM...

THERE IS A CHANCE SMALL CRAFT ADVISORY CONDITIONS WILL PERSIST
THROUGH THE AFTERNOON IN THE INNER AND OUTER WATERS SOUTH OF THE
NORTHERN CHANNELS. OTHERWISE ISOLATED THUNDERSTORMS ARE EXPECTED
THROUGH MONDAY MORNING. THEN THUNDERSTORMS WILL MOVE WEST-SOUTHWEST
AROUND 28 KT TODAY THROUGH THIS AFTERNOON THEN AS THE TROUGH AXIS
SETTLES OVER THE AREA TONIGHT THROUGH SUNDAY NIGHT THE STORMS SOUTH
OF POINT CONCEPTION WILL MOVE NORTHEAST 25 KT AND SOUTHWEST AROUND
15 KT NORTH OF POINT CONCEPTION. A SWELL GENERATED IN THE SOUTHERN
HEMISPHERE WITHIN 190-210 DEGREES RELATIVE TO VENTURA COUNTY LAST
TUESDAY IS EXPECTED TO ARRIVE NEXT WEEK TUE THROUGH WEDNESDAY.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...SUKUP/DB
AVIATION...30
MARINE...30
SYNOPSIS...SMITH

WWW.WEATHER.GOV/LOSANGELES










000
FXUS66 KLOX 281744
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
940 AM PST SAT FEB 28 2015

.SYNOPSIS...

A COLD LOW PRESSURE SYSTEM WILL BRING SHOWERS AND MOUNTAIN SNOW TO
SOUTHWEST CALIFORNIA THIS WEEKEND...ALONG WITH A SLIGHT CHANCE OF
THUNDERSTORMS. AFTER A BRIEF BREAK...ANOTHER COLD SYSTEM WILL BRING
SIMILAR WEATHER TO THE AREA LATE MONDAY MORNING THROUGH EARLY
TUESDAY. DRY WEATHER IS EXPECTED LATE TUESDAY THROUGH FRIDAY. THERE
WILL BE A WARMING TREND...WITH DAYTIME TEMPERATURES NEAR OR ABOVE
NORMAL BY THURSDAY.

&&

.SHORT TERM (TODAY-MON)...

MAIN UPDATE THIS MORNING WAS TO DECREASE THE POPS AND CLOUD COVER
FOR THE MORNING HOURS BASED ON CURRENT SATELLITE AND RADAR TRENDS.
NOT EXPECTING MUCH SHOWER ACTIVITY FOR AREAS S OF THE MOUNTAINS THIS
MORNING DUE TO NW FLOW ALOFT. CLOUD COVERAGE AND RAIN CHANCES WILL
INCREASE THIS AFTERNOON AS THE UPPER LOW THAT IS CURRENTLY OVER
NORTHERN CA CONTINUES TO MOVE S. DAYTIME SURFACE HEATING WILL ALSO
HELP SHOWERS TO DEVELOP...AS THIS WILL BE A CONVECTIVE SCENARIO WITH
COLD AIR MOVING IN ALOFT. COULD EVEN BE SOME ISOLATED THUNDERSTORMS
N OF POINT CONCEPTION TODAY...WHERE THERE IS SOME WEAK INSTABILITY.

***FROM PREVIOUS DISCUSSION***

THE UPPER LOW WILL SLOWLY DROP SWD TO NEAR POINT CONCEPTION LATE
TONIGHT...MOVE VERY LITTLE ON SUNDAY...THEN PUSH SLOWLY INTO
LOS ANGELES COUNTY SUNDAY NIGHT. THIS WILL MAINTAIN A MOIST AND
UNSTABLE AIRMASS ACROSS THE REGION...SO EXPECT QUITE A BIT OF SHOWER
ACTIVITY OVERNIGHT THROUGH SUNDAY NIGHT...WITH A SLIGHT CHANCE OF
TSTMS. THE TEMPERATURE PROFILE THROUGH THE ATMOSPHERE WILL BE
FAVORABLE FOR SOME SMALL HAIL...AND INDEED...THIS HAS BEEN REPORTED
ACROSS NRN CA. ANY THUNDERSTORM THIS AFTERNOON THROUGH SUNDAY
EVENING WILL HAVE THE CAPABILITY OF PRODUCING SMALL HAIL AND HEAVY
DOWNPOURS. WHILE SHOWERS MAY OCCUR ANYWHERE AT ANY TIME...IT APPEARS
THAT THE BEST CHANCES OF ORGANIZED SHOWER ACTIVITY WILL BE TONIGHT
ACROSS L.A. COUNTY AND EASTERN VTU COUNTY AS SOME LOW LEVEL SWLY
FLOW DEVELOPS...AND SUNDAY AFTERNOON AND EVENING AS THE UPPER LOW
MOVES OVERHEAD. DUE TO THE SHOWERY NATURE OF THE PRECIPITATION...
RAINFALL TOTALS THROUGH SUNDAY NIGHT WILL BE HIGHLY VARIABLE...BUT
IN GENERAL...EXPECT TOTALS OF ONE QUARTER TO ONE HALF INCH...
EXCEPT ONE HALF INCH TO ONE INCH ACROSS THE MOUNTAINS...THE SAN
GABRIEL VALLEY...AND POSSIBLY PORTIONS OF THE REMAINDER OF THE L.A.
COUNTY VALLEYS AND THE VALLEYS OF ERN VTU COUNTY. LOCAL TOTALS UP TO
2 INCHES ARE POSSIBLE IN THE SAN GABRIEL MOUNTAINS AND FOOTHILLS.

SNOW WILL BE AN ISSUE FOR TRAVELERS THIS WEEKEND. SNOW LEVELS ARE
EXPECTED TO LOWER TO 5000 FEET LATE TODAY...THEN TO BETWEEN 3500 AND
4000 FEET LATE TONIGHT OR EARLY SUNDAY...THEN LINGER AT THOSE LEVELS
INTO SUNDAY NIGHT. SNOW MAY WELL AFFECT TRAVEL ACROSS HIGHER
PORTIONS OF INTERSTATE 5...HIGHWAY 14 AND HIGHWAY 33...ESPECIALLY
LATE TONIGHT THROUGH EARLY MONDAY. HAVE EXPANDED WINTER WEATHER
ADVISORIES TO INCLUDE THE MOUNTAINS OF SANTA BARBARA COUNTY. ON
AVERAGE...EXPECT A TOTAL OF 4 TO 8 INCHES OF SNOW BETWEEN 5000 AND
6500 FEET...WITH TOTALS OF 8 TO 12 INCHES ABOVE 6500 FEET...AND 2 TO
4 INCHES BETWEEN 4000 AND 5000 FEET. THERE COULD BE LOCAL TOTALS AS
HIGH AS 18 INCHES ACROSS PORTIONS OF THE SAN GABRIEL MOUNTAINS...OR
HIGHER ELEVATIONS IN VTU COUNTY. WAS STRONGLY CONSIDERING UPGRADING
TO A WINTER STORM WARNING...BUT HAVE DECIDED AGAINST IT...SINCE THE
SNOW ACCUMULATIONS MAY NOT MEET THE REQUIRED TOTALS IN ANY 12 OR 24
HOUR PERIOD. LATER SHIFTS MAY WELL HAVE TO UPGRADE DEPENDING UPON
SHOWER DEVELOPMENT.

SHOWERS WILL DECREASE ACROSS THE REGION SUNDAY NIGHT...AND MAY END
JUST ABOUT EVERYWHERE. HOWEVER...ANOTHER COLD UPPER LOW DROPPING
RAPIDLY SOUTHWARD WILL CAUSE SHOWERS TO BECOME LIKELY AGAIN MONDAY
AFTERNOON...WITH SHOWERS CONTINUING MONDAY NIGHT. THAT SYSTEM WILL
ALSO HAVE LOW SNOW LEVELS...AND PROBABLY ALSO A SLIGHT CHANCE OF
TSTMS. THAT SYSTEM WILL MOVE A BIT FASTER...BUT MAY ALSO TRACK A BIT
FARTHER OFF THE COAST...SO IT MAY PICK UP MORE MOISTURE. SHOWERS
SHOULD WIND DOWN IN MOST AREAS LATE MON NIGHT. MAX TEMPERATURES WILL
BE WELL BELOW NORMAL THROUGH MONDAY.

.LONG TERM (TUE-FRI)...THERE COULD BE A FEW LINGERING SHOWERS
TUE...BUT THAT IS LOOKING LESS AND LESS LIKELY. HEIGHTS WILL REBOUND
TUE AFTERNOON...AND WITH SOME SUNSHINE...EXPECT AT LEAST A BIT OR
WARMING. THE 06Z GFS NOW SHOWS A WEAK IMPULSE DROPPING SWD INTO THE
REGION ON WED...AND THAT WAS NOT ON THE PREVIOUS RUN. NO SHOWER
EXPECTED...BUT IT COULD KEEP MAX TEMPS ON THE COOL SIDE. AN UPPER
RIDGE AND HIGHER HEIGHTS WILL BRING WARMER WEATHER THU AND
FRI...WITH DAYTIME TEMPS LIKELY ABOVE NORMAL.


&&

.AVIATION...28/1135Z...

AT 0940Z...THE INVERSION AT KLAX WAS BASED AT 4300 FEET. THE TOP OF
THE INVERSION WAS AT 6300 FEET WITH A TEMPERATURE OF 5 DEGREES
CELSIUS.

OVERALL...LOW CONFIDENCE IN 12Z TAF PACKAGE. INCREASING COLD AND
UNSTABLE AIR MASS WILL GENERATE SHOWERS THROUGHOUT THE TAF PERIOD.
ADDITIONALLY...THERE WILL BE THE POSSIBILITY OF TSTMS FROM THIS
AFTERNOON THROUGH TONIGHT. CIGS WILL VARY RANDOMLY...GENERALLY
BETWEEN MVFR AND VFR LEVELS.

KLAX...LOW CONFIDENCE IN 12Z TAF. CIGS WILL BOUNCE BETWEEN MVFR AND
VFR LEVELS THROUGH THIS AFTERNOON. SHOWERS WILL LIKELY BEGIN LATE
THIS AFTERNOON/EARLY THIS EVENING (ALTHOUGH CONFIDENCE IN EXACT
START TIME IS VERY LOW). CHANCES OF TSTMS AT THE AIRFIELD TONIGHT
WILL BE 10-15%.

KBUR...LOW CONFIDENCE IN 12Z TAF. CIGS WILL BOUNCE BETWEEN MVFR AND
VFR LEVELS THROUGH THIS AFTERNOON. SHOWERS WILL LIKELY BEGIN LATE
THIS AFTERNOON/EARLY THIS EVENING (ALTHOUGH CONFIDENCE IN EXACT
START TIME IS VERY LOW). CHANCES OF TSTMS AT THE AIRFIELD TONIGHT
WILL BE 10-15%.

&&

.MARINE...28/900 AM...

THERE IS A CHANCE SMALL CRAFT ADVISORY CONDITIONS WILL PERSIST
THROUGH THE AFTERNOON IN THE INNER AND OUTER WATERS SOUTH OF THE
NORTHERN CHANNELS. OTHERWISE ISOLATED THUNDERSTORMS ARE EXPECTED
THROUGH MONDAY MORNING. THEN THUNDERSTORMS WILL MOVE WEST-SOUTHWEST
AROUND 28 KT TODAY THROUGH THIS AFTERNOON THEN AS THE TROUGH AXIS
SETTLES OVER THE AREA TONIGHT THROUGH SUNDAY NIGHT THE STORMS SOUTH
OF POINT CONCEPTION WILL MOVE NORTHEAST 25 KT AND SOUTHWEST AROUND
15 KT NORTH OF POINT CONCEPTION. A SWELL GENERATED IN THE SOUTHERN
HEMISPHERE WITHIN 190-210 DEGREES RELATIVE TO VENTURA COUNTY LAST
TUESDAY IS EXPECTED TO ARRIVE NEXT WEEK TUE THROUGH WEDNESDAY.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...SUKUP/DB
AVIATION...RAT
MARINE...30
SYNOPSIS...SMITH

WWW.WEATHER.GOV/LOSANGELES






000
FXUS66 KLOX 281744
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
940 AM PST SAT FEB 28 2015

.SYNOPSIS...

A COLD LOW PRESSURE SYSTEM WILL BRING SHOWERS AND MOUNTAIN SNOW TO
SOUTHWEST CALIFORNIA THIS WEEKEND...ALONG WITH A SLIGHT CHANCE OF
THUNDERSTORMS. AFTER A BRIEF BREAK...ANOTHER COLD SYSTEM WILL BRING
SIMILAR WEATHER TO THE AREA LATE MONDAY MORNING THROUGH EARLY
TUESDAY. DRY WEATHER IS EXPECTED LATE TUESDAY THROUGH FRIDAY. THERE
WILL BE A WARMING TREND...WITH DAYTIME TEMPERATURES NEAR OR ABOVE
NORMAL BY THURSDAY.

&&

.SHORT TERM (TODAY-MON)...

MAIN UPDATE THIS MORNING WAS TO DECREASE THE POPS AND CLOUD COVER
FOR THE MORNING HOURS BASED ON CURRENT SATELLITE AND RADAR TRENDS.
NOT EXPECTING MUCH SHOWER ACTIVITY FOR AREAS S OF THE MOUNTAINS THIS
MORNING DUE TO NW FLOW ALOFT. CLOUD COVERAGE AND RAIN CHANCES WILL
INCREASE THIS AFTERNOON AS THE UPPER LOW THAT IS CURRENTLY OVER
NORTHERN CA CONTINUES TO MOVE S. DAYTIME SURFACE HEATING WILL ALSO
HELP SHOWERS TO DEVELOP...AS THIS WILL BE A CONVECTIVE SCENARIO WITH
COLD AIR MOVING IN ALOFT. COULD EVEN BE SOME ISOLATED THUNDERSTORMS
N OF POINT CONCEPTION TODAY...WHERE THERE IS SOME WEAK INSTABILITY.

***FROM PREVIOUS DISCUSSION***

THE UPPER LOW WILL SLOWLY DROP SWD TO NEAR POINT CONCEPTION LATE
TONIGHT...MOVE VERY LITTLE ON SUNDAY...THEN PUSH SLOWLY INTO
LOS ANGELES COUNTY SUNDAY NIGHT. THIS WILL MAINTAIN A MOIST AND
UNSTABLE AIRMASS ACROSS THE REGION...SO EXPECT QUITE A BIT OF SHOWER
ACTIVITY OVERNIGHT THROUGH SUNDAY NIGHT...WITH A SLIGHT CHANCE OF
TSTMS. THE TEMPERATURE PROFILE THROUGH THE ATMOSPHERE WILL BE
FAVORABLE FOR SOME SMALL HAIL...AND INDEED...THIS HAS BEEN REPORTED
ACROSS NRN CA. ANY THUNDERSTORM THIS AFTERNOON THROUGH SUNDAY
EVENING WILL HAVE THE CAPABILITY OF PRODUCING SMALL HAIL AND HEAVY
DOWNPOURS. WHILE SHOWERS MAY OCCUR ANYWHERE AT ANY TIME...IT APPEARS
THAT THE BEST CHANCES OF ORGANIZED SHOWER ACTIVITY WILL BE TONIGHT
ACROSS L.A. COUNTY AND EASTERN VTU COUNTY AS SOME LOW LEVEL SWLY
FLOW DEVELOPS...AND SUNDAY AFTERNOON AND EVENING AS THE UPPER LOW
MOVES OVERHEAD. DUE TO THE SHOWERY NATURE OF THE PRECIPITATION...
RAINFALL TOTALS THROUGH SUNDAY NIGHT WILL BE HIGHLY VARIABLE...BUT
IN GENERAL...EXPECT TOTALS OF ONE QUARTER TO ONE HALF INCH...
EXCEPT ONE HALF INCH TO ONE INCH ACROSS THE MOUNTAINS...THE SAN
GABRIEL VALLEY...AND POSSIBLY PORTIONS OF THE REMAINDER OF THE L.A.
COUNTY VALLEYS AND THE VALLEYS OF ERN VTU COUNTY. LOCAL TOTALS UP TO
2 INCHES ARE POSSIBLE IN THE SAN GABRIEL MOUNTAINS AND FOOTHILLS.

SNOW WILL BE AN ISSUE FOR TRAVELERS THIS WEEKEND. SNOW LEVELS ARE
EXPECTED TO LOWER TO 5000 FEET LATE TODAY...THEN TO BETWEEN 3500 AND
4000 FEET LATE TONIGHT OR EARLY SUNDAY...THEN LINGER AT THOSE LEVELS
INTO SUNDAY NIGHT. SNOW MAY WELL AFFECT TRAVEL ACROSS HIGHER
PORTIONS OF INTERSTATE 5...HIGHWAY 14 AND HIGHWAY 33...ESPECIALLY
LATE TONIGHT THROUGH EARLY MONDAY. HAVE EXPANDED WINTER WEATHER
ADVISORIES TO INCLUDE THE MOUNTAINS OF SANTA BARBARA COUNTY. ON
AVERAGE...EXPECT A TOTAL OF 4 TO 8 INCHES OF SNOW BETWEEN 5000 AND
6500 FEET...WITH TOTALS OF 8 TO 12 INCHES ABOVE 6500 FEET...AND 2 TO
4 INCHES BETWEEN 4000 AND 5000 FEET. THERE COULD BE LOCAL TOTALS AS
HIGH AS 18 INCHES ACROSS PORTIONS OF THE SAN GABRIEL MOUNTAINS...OR
HIGHER ELEVATIONS IN VTU COUNTY. WAS STRONGLY CONSIDERING UPGRADING
TO A WINTER STORM WARNING...BUT HAVE DECIDED AGAINST IT...SINCE THE
SNOW ACCUMULATIONS MAY NOT MEET THE REQUIRED TOTALS IN ANY 12 OR 24
HOUR PERIOD. LATER SHIFTS MAY WELL HAVE TO UPGRADE DEPENDING UPON
SHOWER DEVELOPMENT.

SHOWERS WILL DECREASE ACROSS THE REGION SUNDAY NIGHT...AND MAY END
JUST ABOUT EVERYWHERE. HOWEVER...ANOTHER COLD UPPER LOW DROPPING
RAPIDLY SOUTHWARD WILL CAUSE SHOWERS TO BECOME LIKELY AGAIN MONDAY
AFTERNOON...WITH SHOWERS CONTINUING MONDAY NIGHT. THAT SYSTEM WILL
ALSO HAVE LOW SNOW LEVELS...AND PROBABLY ALSO A SLIGHT CHANCE OF
TSTMS. THAT SYSTEM WILL MOVE A BIT FASTER...BUT MAY ALSO TRACK A BIT
FARTHER OFF THE COAST...SO IT MAY PICK UP MORE MOISTURE. SHOWERS
SHOULD WIND DOWN IN MOST AREAS LATE MON NIGHT. MAX TEMPERATURES WILL
BE WELL BELOW NORMAL THROUGH MONDAY.

.LONG TERM (TUE-FRI)...THERE COULD BE A FEW LINGERING SHOWERS
TUE...BUT THAT IS LOOKING LESS AND LESS LIKELY. HEIGHTS WILL REBOUND
TUE AFTERNOON...AND WITH SOME SUNSHINE...EXPECT AT LEAST A BIT OR
WARMING. THE 06Z GFS NOW SHOWS A WEAK IMPULSE DROPPING SWD INTO THE
REGION ON WED...AND THAT WAS NOT ON THE PREVIOUS RUN. NO SHOWER
EXPECTED...BUT IT COULD KEEP MAX TEMPS ON THE COOL SIDE. AN UPPER
RIDGE AND HIGHER HEIGHTS WILL BRING WARMER WEATHER THU AND
FRI...WITH DAYTIME TEMPS LIKELY ABOVE NORMAL.


&&

.AVIATION...28/1135Z...

AT 0940Z...THE INVERSION AT KLAX WAS BASED AT 4300 FEET. THE TOP OF
THE INVERSION WAS AT 6300 FEET WITH A TEMPERATURE OF 5 DEGREES
CELSIUS.

OVERALL...LOW CONFIDENCE IN 12Z TAF PACKAGE. INCREASING COLD AND
UNSTABLE AIR MASS WILL GENERATE SHOWERS THROUGHOUT THE TAF PERIOD.
ADDITIONALLY...THERE WILL BE THE POSSIBILITY OF TSTMS FROM THIS
AFTERNOON THROUGH TONIGHT. CIGS WILL VARY RANDOMLY...GENERALLY
BETWEEN MVFR AND VFR LEVELS.

KLAX...LOW CONFIDENCE IN 12Z TAF. CIGS WILL BOUNCE BETWEEN MVFR AND
VFR LEVELS THROUGH THIS AFTERNOON. SHOWERS WILL LIKELY BEGIN LATE
THIS AFTERNOON/EARLY THIS EVENING (ALTHOUGH CONFIDENCE IN EXACT
START TIME IS VERY LOW). CHANCES OF TSTMS AT THE AIRFIELD TONIGHT
WILL BE 10-15%.

KBUR...LOW CONFIDENCE IN 12Z TAF. CIGS WILL BOUNCE BETWEEN MVFR AND
VFR LEVELS THROUGH THIS AFTERNOON. SHOWERS WILL LIKELY BEGIN LATE
THIS AFTERNOON/EARLY THIS EVENING (ALTHOUGH CONFIDENCE IN EXACT
START TIME IS VERY LOW). CHANCES OF TSTMS AT THE AIRFIELD TONIGHT
WILL BE 10-15%.

&&

.MARINE...28/900 AM...

THERE IS A CHANCE SMALL CRAFT ADVISORY CONDITIONS WILL PERSIST
THROUGH THE AFTERNOON IN THE INNER AND OUTER WATERS SOUTH OF THE
NORTHERN CHANNELS. OTHERWISE ISOLATED THUNDERSTORMS ARE EXPECTED
THROUGH MONDAY MORNING. THEN THUNDERSTORMS WILL MOVE WEST-SOUTHWEST
AROUND 28 KT TODAY THROUGH THIS AFTERNOON THEN AS THE TROUGH AXIS
SETTLES OVER THE AREA TONIGHT THROUGH SUNDAY NIGHT THE STORMS SOUTH
OF POINT CONCEPTION WILL MOVE NORTHEAST 25 KT AND SOUTHWEST AROUND
15 KT NORTH OF POINT CONCEPTION. A SWELL GENERATED IN THE SOUTHERN
HEMISPHERE WITHIN 190-210 DEGREES RELATIVE TO VENTURA COUNTY LAST
TUESDAY IS EXPECTED TO ARRIVE NEXT WEEK TUE THROUGH WEDNESDAY.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...SUKUP/DB
AVIATION...RAT
MARINE...30
SYNOPSIS...SMITH

WWW.WEATHER.GOV/LOSANGELES







000
FXUS66 KLOX 281744
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
940 AM PST SAT FEB 28 2015

.SYNOPSIS...

A COLD LOW PRESSURE SYSTEM WILL BRING SHOWERS AND MOUNTAIN SNOW TO
SOUTHWEST CALIFORNIA THIS WEEKEND...ALONG WITH A SLIGHT CHANCE OF
THUNDERSTORMS. AFTER A BRIEF BREAK...ANOTHER COLD SYSTEM WILL BRING
SIMILAR WEATHER TO THE AREA LATE MONDAY MORNING THROUGH EARLY
TUESDAY. DRY WEATHER IS EXPECTED LATE TUESDAY THROUGH FRIDAY. THERE
WILL BE A WARMING TREND...WITH DAYTIME TEMPERATURES NEAR OR ABOVE
NORMAL BY THURSDAY.

&&

.SHORT TERM (TODAY-MON)...

MAIN UPDATE THIS MORNING WAS TO DECREASE THE POPS AND CLOUD COVER
FOR THE MORNING HOURS BASED ON CURRENT SATELLITE AND RADAR TRENDS.
NOT EXPECTING MUCH SHOWER ACTIVITY FOR AREAS S OF THE MOUNTAINS THIS
MORNING DUE TO NW FLOW ALOFT. CLOUD COVERAGE AND RAIN CHANCES WILL
INCREASE THIS AFTERNOON AS THE UPPER LOW THAT IS CURRENTLY OVER
NORTHERN CA CONTINUES TO MOVE S. DAYTIME SURFACE HEATING WILL ALSO
HELP SHOWERS TO DEVELOP...AS THIS WILL BE A CONVECTIVE SCENARIO WITH
COLD AIR MOVING IN ALOFT. COULD EVEN BE SOME ISOLATED THUNDERSTORMS
N OF POINT CONCEPTION TODAY...WHERE THERE IS SOME WEAK INSTABILITY.

***FROM PREVIOUS DISCUSSION***

THE UPPER LOW WILL SLOWLY DROP SWD TO NEAR POINT CONCEPTION LATE
TONIGHT...MOVE VERY LITTLE ON SUNDAY...THEN PUSH SLOWLY INTO
LOS ANGELES COUNTY SUNDAY NIGHT. THIS WILL MAINTAIN A MOIST AND
UNSTABLE AIRMASS ACROSS THE REGION...SO EXPECT QUITE A BIT OF SHOWER
ACTIVITY OVERNIGHT THROUGH SUNDAY NIGHT...WITH A SLIGHT CHANCE OF
TSTMS. THE TEMPERATURE PROFILE THROUGH THE ATMOSPHERE WILL BE
FAVORABLE FOR SOME SMALL HAIL...AND INDEED...THIS HAS BEEN REPORTED
ACROSS NRN CA. ANY THUNDERSTORM THIS AFTERNOON THROUGH SUNDAY
EVENING WILL HAVE THE CAPABILITY OF PRODUCING SMALL HAIL AND HEAVY
DOWNPOURS. WHILE SHOWERS MAY OCCUR ANYWHERE AT ANY TIME...IT APPEARS
THAT THE BEST CHANCES OF ORGANIZED SHOWER ACTIVITY WILL BE TONIGHT
ACROSS L.A. COUNTY AND EASTERN VTU COUNTY AS SOME LOW LEVEL SWLY
FLOW DEVELOPS...AND SUNDAY AFTERNOON AND EVENING AS THE UPPER LOW
MOVES OVERHEAD. DUE TO THE SHOWERY NATURE OF THE PRECIPITATION...
RAINFALL TOTALS THROUGH SUNDAY NIGHT WILL BE HIGHLY VARIABLE...BUT
IN GENERAL...EXPECT TOTALS OF ONE QUARTER TO ONE HALF INCH...
EXCEPT ONE HALF INCH TO ONE INCH ACROSS THE MOUNTAINS...THE SAN
GABRIEL VALLEY...AND POSSIBLY PORTIONS OF THE REMAINDER OF THE L.A.
COUNTY VALLEYS AND THE VALLEYS OF ERN VTU COUNTY. LOCAL TOTALS UP TO
2 INCHES ARE POSSIBLE IN THE SAN GABRIEL MOUNTAINS AND FOOTHILLS.

SNOW WILL BE AN ISSUE FOR TRAVELERS THIS WEEKEND. SNOW LEVELS ARE
EXPECTED TO LOWER TO 5000 FEET LATE TODAY...THEN TO BETWEEN 3500 AND
4000 FEET LATE TONIGHT OR EARLY SUNDAY...THEN LINGER AT THOSE LEVELS
INTO SUNDAY NIGHT. SNOW MAY WELL AFFECT TRAVEL ACROSS HIGHER
PORTIONS OF INTERSTATE 5...HIGHWAY 14 AND HIGHWAY 33...ESPECIALLY
LATE TONIGHT THROUGH EARLY MONDAY. HAVE EXPANDED WINTER WEATHER
ADVISORIES TO INCLUDE THE MOUNTAINS OF SANTA BARBARA COUNTY. ON
AVERAGE...EXPECT A TOTAL OF 4 TO 8 INCHES OF SNOW BETWEEN 5000 AND
6500 FEET...WITH TOTALS OF 8 TO 12 INCHES ABOVE 6500 FEET...AND 2 TO
4 INCHES BETWEEN 4000 AND 5000 FEET. THERE COULD BE LOCAL TOTALS AS
HIGH AS 18 INCHES ACROSS PORTIONS OF THE SAN GABRIEL MOUNTAINS...OR
HIGHER ELEVATIONS IN VTU COUNTY. WAS STRONGLY CONSIDERING UPGRADING
TO A WINTER STORM WARNING...BUT HAVE DECIDED AGAINST IT...SINCE THE
SNOW ACCUMULATIONS MAY NOT MEET THE REQUIRED TOTALS IN ANY 12 OR 24
HOUR PERIOD. LATER SHIFTS MAY WELL HAVE TO UPGRADE DEPENDING UPON
SHOWER DEVELOPMENT.

SHOWERS WILL DECREASE ACROSS THE REGION SUNDAY NIGHT...AND MAY END
JUST ABOUT EVERYWHERE. HOWEVER...ANOTHER COLD UPPER LOW DROPPING
RAPIDLY SOUTHWARD WILL CAUSE SHOWERS TO BECOME LIKELY AGAIN MONDAY
AFTERNOON...WITH SHOWERS CONTINUING MONDAY NIGHT. THAT SYSTEM WILL
ALSO HAVE LOW SNOW LEVELS...AND PROBABLY ALSO A SLIGHT CHANCE OF
TSTMS. THAT SYSTEM WILL MOVE A BIT FASTER...BUT MAY ALSO TRACK A BIT
FARTHER OFF THE COAST...SO IT MAY PICK UP MORE MOISTURE. SHOWERS
SHOULD WIND DOWN IN MOST AREAS LATE MON NIGHT. MAX TEMPERATURES WILL
BE WELL BELOW NORMAL THROUGH MONDAY.

.LONG TERM (TUE-FRI)...THERE COULD BE A FEW LINGERING SHOWERS
TUE...BUT THAT IS LOOKING LESS AND LESS LIKELY. HEIGHTS WILL REBOUND
TUE AFTERNOON...AND WITH SOME SUNSHINE...EXPECT AT LEAST A BIT OR
WARMING. THE 06Z GFS NOW SHOWS A WEAK IMPULSE DROPPING SWD INTO THE
REGION ON WED...AND THAT WAS NOT ON THE PREVIOUS RUN. NO SHOWER
EXPECTED...BUT IT COULD KEEP MAX TEMPS ON THE COOL SIDE. AN UPPER
RIDGE AND HIGHER HEIGHTS WILL BRING WARMER WEATHER THU AND
FRI...WITH DAYTIME TEMPS LIKELY ABOVE NORMAL.


&&

.AVIATION...28/1135Z...

AT 0940Z...THE INVERSION AT KLAX WAS BASED AT 4300 FEET. THE TOP OF
THE INVERSION WAS AT 6300 FEET WITH A TEMPERATURE OF 5 DEGREES
CELSIUS.

OVERALL...LOW CONFIDENCE IN 12Z TAF PACKAGE. INCREASING COLD AND
UNSTABLE AIR MASS WILL GENERATE SHOWERS THROUGHOUT THE TAF PERIOD.
ADDITIONALLY...THERE WILL BE THE POSSIBILITY OF TSTMS FROM THIS
AFTERNOON THROUGH TONIGHT. CIGS WILL VARY RANDOMLY...GENERALLY
BETWEEN MVFR AND VFR LEVELS.

KLAX...LOW CONFIDENCE IN 12Z TAF. CIGS WILL BOUNCE BETWEEN MVFR AND
VFR LEVELS THROUGH THIS AFTERNOON. SHOWERS WILL LIKELY BEGIN LATE
THIS AFTERNOON/EARLY THIS EVENING (ALTHOUGH CONFIDENCE IN EXACT
START TIME IS VERY LOW). CHANCES OF TSTMS AT THE AIRFIELD TONIGHT
WILL BE 10-15%.

KBUR...LOW CONFIDENCE IN 12Z TAF. CIGS WILL BOUNCE BETWEEN MVFR AND
VFR LEVELS THROUGH THIS AFTERNOON. SHOWERS WILL LIKELY BEGIN LATE
THIS AFTERNOON/EARLY THIS EVENING (ALTHOUGH CONFIDENCE IN EXACT
START TIME IS VERY LOW). CHANCES OF TSTMS AT THE AIRFIELD TONIGHT
WILL BE 10-15%.

&&

.MARINE...28/900 AM...

THERE IS A CHANCE SMALL CRAFT ADVISORY CONDITIONS WILL PERSIST
THROUGH THE AFTERNOON IN THE INNER AND OUTER WATERS SOUTH OF THE
NORTHERN CHANNELS. OTHERWISE ISOLATED THUNDERSTORMS ARE EXPECTED
THROUGH MONDAY MORNING. THEN THUNDERSTORMS WILL MOVE WEST-SOUTHWEST
AROUND 28 KT TODAY THROUGH THIS AFTERNOON THEN AS THE TROUGH AXIS
SETTLES OVER THE AREA TONIGHT THROUGH SUNDAY NIGHT THE STORMS SOUTH
OF POINT CONCEPTION WILL MOVE NORTHEAST 25 KT AND SOUTHWEST AROUND
15 KT NORTH OF POINT CONCEPTION. A SWELL GENERATED IN THE SOUTHERN
HEMISPHERE WITHIN 190-210 DEGREES RELATIVE TO VENTURA COUNTY LAST
TUESDAY IS EXPECTED TO ARRIVE NEXT WEEK TUE THROUGH WEDNESDAY.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...SUKUP/DB
AVIATION...RAT
MARINE...30
SYNOPSIS...SMITH

WWW.WEATHER.GOV/LOSANGELES






000
FXUS66 KLOX 281744
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
940 AM PST SAT FEB 28 2015

.SYNOPSIS...

A COLD LOW PRESSURE SYSTEM WILL BRING SHOWERS AND MOUNTAIN SNOW TO
SOUTHWEST CALIFORNIA THIS WEEKEND...ALONG WITH A SLIGHT CHANCE OF
THUNDERSTORMS. AFTER A BRIEF BREAK...ANOTHER COLD SYSTEM WILL BRING
SIMILAR WEATHER TO THE AREA LATE MONDAY MORNING THROUGH EARLY
TUESDAY. DRY WEATHER IS EXPECTED LATE TUESDAY THROUGH FRIDAY. THERE
WILL BE A WARMING TREND...WITH DAYTIME TEMPERATURES NEAR OR ABOVE
NORMAL BY THURSDAY.

&&

.SHORT TERM (TODAY-MON)...

MAIN UPDATE THIS MORNING WAS TO DECREASE THE POPS AND CLOUD COVER
FOR THE MORNING HOURS BASED ON CURRENT SATELLITE AND RADAR TRENDS.
NOT EXPECTING MUCH SHOWER ACTIVITY FOR AREAS S OF THE MOUNTAINS THIS
MORNING DUE TO NW FLOW ALOFT. CLOUD COVERAGE AND RAIN CHANCES WILL
INCREASE THIS AFTERNOON AS THE UPPER LOW THAT IS CURRENTLY OVER
NORTHERN CA CONTINUES TO MOVE S. DAYTIME SURFACE HEATING WILL ALSO
HELP SHOWERS TO DEVELOP...AS THIS WILL BE A CONVECTIVE SCENARIO WITH
COLD AIR MOVING IN ALOFT. COULD EVEN BE SOME ISOLATED THUNDERSTORMS
N OF POINT CONCEPTION TODAY...WHERE THERE IS SOME WEAK INSTABILITY.

***FROM PREVIOUS DISCUSSION***

THE UPPER LOW WILL SLOWLY DROP SWD TO NEAR POINT CONCEPTION LATE
TONIGHT...MOVE VERY LITTLE ON SUNDAY...THEN PUSH SLOWLY INTO
LOS ANGELES COUNTY SUNDAY NIGHT. THIS WILL MAINTAIN A MOIST AND
UNSTABLE AIRMASS ACROSS THE REGION...SO EXPECT QUITE A BIT OF SHOWER
ACTIVITY OVERNIGHT THROUGH SUNDAY NIGHT...WITH A SLIGHT CHANCE OF
TSTMS. THE TEMPERATURE PROFILE THROUGH THE ATMOSPHERE WILL BE
FAVORABLE FOR SOME SMALL HAIL...AND INDEED...THIS HAS BEEN REPORTED
ACROSS NRN CA. ANY THUNDERSTORM THIS AFTERNOON THROUGH SUNDAY
EVENING WILL HAVE THE CAPABILITY OF PRODUCING SMALL HAIL AND HEAVY
DOWNPOURS. WHILE SHOWERS MAY OCCUR ANYWHERE AT ANY TIME...IT APPEARS
THAT THE BEST CHANCES OF ORGANIZED SHOWER ACTIVITY WILL BE TONIGHT
ACROSS L.A. COUNTY AND EASTERN VTU COUNTY AS SOME LOW LEVEL SWLY
FLOW DEVELOPS...AND SUNDAY AFTERNOON AND EVENING AS THE UPPER LOW
MOVES OVERHEAD. DUE TO THE SHOWERY NATURE OF THE PRECIPITATION...
RAINFALL TOTALS THROUGH SUNDAY NIGHT WILL BE HIGHLY VARIABLE...BUT
IN GENERAL...EXPECT TOTALS OF ONE QUARTER TO ONE HALF INCH...
EXCEPT ONE HALF INCH TO ONE INCH ACROSS THE MOUNTAINS...THE SAN
GABRIEL VALLEY...AND POSSIBLY PORTIONS OF THE REMAINDER OF THE L.A.
COUNTY VALLEYS AND THE VALLEYS OF ERN VTU COUNTY. LOCAL TOTALS UP TO
2 INCHES ARE POSSIBLE IN THE SAN GABRIEL MOUNTAINS AND FOOTHILLS.

SNOW WILL BE AN ISSUE FOR TRAVELERS THIS WEEKEND. SNOW LEVELS ARE
EXPECTED TO LOWER TO 5000 FEET LATE TODAY...THEN TO BETWEEN 3500 AND
4000 FEET LATE TONIGHT OR EARLY SUNDAY...THEN LINGER AT THOSE LEVELS
INTO SUNDAY NIGHT. SNOW MAY WELL AFFECT TRAVEL ACROSS HIGHER
PORTIONS OF INTERSTATE 5...HIGHWAY 14 AND HIGHWAY 33...ESPECIALLY
LATE TONIGHT THROUGH EARLY MONDAY. HAVE EXPANDED WINTER WEATHER
ADVISORIES TO INCLUDE THE MOUNTAINS OF SANTA BARBARA COUNTY. ON
AVERAGE...EXPECT A TOTAL OF 4 TO 8 INCHES OF SNOW BETWEEN 5000 AND
6500 FEET...WITH TOTALS OF 8 TO 12 INCHES ABOVE 6500 FEET...AND 2 TO
4 INCHES BETWEEN 4000 AND 5000 FEET. THERE COULD BE LOCAL TOTALS AS
HIGH AS 18 INCHES ACROSS PORTIONS OF THE SAN GABRIEL MOUNTAINS...OR
HIGHER ELEVATIONS IN VTU COUNTY. WAS STRONGLY CONSIDERING UPGRADING
TO A WINTER STORM WARNING...BUT HAVE DECIDED AGAINST IT...SINCE THE
SNOW ACCUMULATIONS MAY NOT MEET THE REQUIRED TOTALS IN ANY 12 OR 24
HOUR PERIOD. LATER SHIFTS MAY WELL HAVE TO UPGRADE DEPENDING UPON
SHOWER DEVELOPMENT.

SHOWERS WILL DECREASE ACROSS THE REGION SUNDAY NIGHT...AND MAY END
JUST ABOUT EVERYWHERE. HOWEVER...ANOTHER COLD UPPER LOW DROPPING
RAPIDLY SOUTHWARD WILL CAUSE SHOWERS TO BECOME LIKELY AGAIN MONDAY
AFTERNOON...WITH SHOWERS CONTINUING MONDAY NIGHT. THAT SYSTEM WILL
ALSO HAVE LOW SNOW LEVELS...AND PROBABLY ALSO A SLIGHT CHANCE OF
TSTMS. THAT SYSTEM WILL MOVE A BIT FASTER...BUT MAY ALSO TRACK A BIT
FARTHER OFF THE COAST...SO IT MAY PICK UP MORE MOISTURE. SHOWERS
SHOULD WIND DOWN IN MOST AREAS LATE MON NIGHT. MAX TEMPERATURES WILL
BE WELL BELOW NORMAL THROUGH MONDAY.

.LONG TERM (TUE-FRI)...THERE COULD BE A FEW LINGERING SHOWERS
TUE...BUT THAT IS LOOKING LESS AND LESS LIKELY. HEIGHTS WILL REBOUND
TUE AFTERNOON...AND WITH SOME SUNSHINE...EXPECT AT LEAST A BIT OR
WARMING. THE 06Z GFS NOW SHOWS A WEAK IMPULSE DROPPING SWD INTO THE
REGION ON WED...AND THAT WAS NOT ON THE PREVIOUS RUN. NO SHOWER
EXPECTED...BUT IT COULD KEEP MAX TEMPS ON THE COOL SIDE. AN UPPER
RIDGE AND HIGHER HEIGHTS WILL BRING WARMER WEATHER THU AND
FRI...WITH DAYTIME TEMPS LIKELY ABOVE NORMAL.


&&

.AVIATION...28/1135Z...

AT 0940Z...THE INVERSION AT KLAX WAS BASED AT 4300 FEET. THE TOP OF
THE INVERSION WAS AT 6300 FEET WITH A TEMPERATURE OF 5 DEGREES
CELSIUS.

OVERALL...LOW CONFIDENCE IN 12Z TAF PACKAGE. INCREASING COLD AND
UNSTABLE AIR MASS WILL GENERATE SHOWERS THROUGHOUT THE TAF PERIOD.
ADDITIONALLY...THERE WILL BE THE POSSIBILITY OF TSTMS FROM THIS
AFTERNOON THROUGH TONIGHT. CIGS WILL VARY RANDOMLY...GENERALLY
BETWEEN MVFR AND VFR LEVELS.

KLAX...LOW CONFIDENCE IN 12Z TAF. CIGS WILL BOUNCE BETWEEN MVFR AND
VFR LEVELS THROUGH THIS AFTERNOON. SHOWERS WILL LIKELY BEGIN LATE
THIS AFTERNOON/EARLY THIS EVENING (ALTHOUGH CONFIDENCE IN EXACT
START TIME IS VERY LOW). CHANCES OF TSTMS AT THE AIRFIELD TONIGHT
WILL BE 10-15%.

KBUR...LOW CONFIDENCE IN 12Z TAF. CIGS WILL BOUNCE BETWEEN MVFR AND
VFR LEVELS THROUGH THIS AFTERNOON. SHOWERS WILL LIKELY BEGIN LATE
THIS AFTERNOON/EARLY THIS EVENING (ALTHOUGH CONFIDENCE IN EXACT
START TIME IS VERY LOW). CHANCES OF TSTMS AT THE AIRFIELD TONIGHT
WILL BE 10-15%.

&&

.MARINE...28/900 AM...

THERE IS A CHANCE SMALL CRAFT ADVISORY CONDITIONS WILL PERSIST
THROUGH THE AFTERNOON IN THE INNER AND OUTER WATERS SOUTH OF THE
NORTHERN CHANNELS. OTHERWISE ISOLATED THUNDERSTORMS ARE EXPECTED
THROUGH MONDAY MORNING. THEN THUNDERSTORMS WILL MOVE WEST-SOUTHWEST
AROUND 28 KT TODAY THROUGH THIS AFTERNOON THEN AS THE TROUGH AXIS
SETTLES OVER THE AREA TONIGHT THROUGH SUNDAY NIGHT THE STORMS SOUTH
OF POINT CONCEPTION WILL MOVE NORTHEAST 25 KT AND SOUTHWEST AROUND
15 KT NORTH OF POINT CONCEPTION. A SWELL GENERATED IN THE SOUTHERN
HEMISPHERE WITHIN 190-210 DEGREES RELATIVE TO VENTURA COUNTY LAST
TUESDAY IS EXPECTED TO ARRIVE NEXT WEEK TUE THROUGH WEDNESDAY.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...SUKUP/DB
AVIATION...RAT
MARINE...30
SYNOPSIS...SMITH

WWW.WEATHER.GOV/LOSANGELES







000
FXUS66 KLOX 281300
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
344 AM PST SAT FEB 28 2015

.SYNOPSIS...
A COLD LOW PRESSURE SYSTEM WILL BRING SHOWERS...POSSIBLE
THUNDERSTORMS AND MOUNTAIN SNOW TO THE AREA THIS WEEKEND. AFTER
A BRIEF BREAK...ANOTHER COLD SYSTEM WILL BRING SIMILAR WEATHER
LATE MONDAY MORNING THROUGH EARLY TUESDAY. DRY WEATHER IS EXPECTED
LATE TUESDAY THROUGH FRIDAY. THERE WILL BE A WARMING TREND...WITH
DAYTIME TEMPERATURES LIKELY ABOVE NORMAL BY THURSDAY.


&&

.SHORT TERM (TODAY-MON)...SKIES WERE GENERALLY MOSTLY CLOUDY ACROSS
THE REGION EARLY THIS MORNING...EXCEPT STILL MOSTLY CLEAR TO
PARTLY CLOUDY ACROSS COASTAL SECTIONS SOUTH OF POINT CONCEPTION.
SOME LIGHT SHOWERS HAVE DEVELOPED IN THE SAN GABRIEL MOUNTAINS AND
IN THE SAN GABRIEL VALLEY...PARTICULARLY IN THE FOOTHILLS. SCATTERED
SHOWERS CONTINUED TO MOVE SOUTHEASTWARD ACROSS THE COASTAL WATERS
THIS MORNING. WATER VAPOR IMAGERY SHOWED THE CENTER OF A FAIRLY
STRONG AND VERY COLD UPPER LEVEL LOW OVER EXTREME NORTHERN CA...WITH
A POTENT VORT ON ITS BACKSIDE DROPPING SOUTHWARD OFF THE COAST.

THIS UPPER LOW IS FORECAST TO DROP SOUTHWARD TODAY...WITH THE VORT
HELPING TO PULL THE UPPER CENTER SLIGHTLY OFF THE COAST TO A
POSITION JUST WEST OF MONTEREY BY LATE THIS AFTERNOON. AS THIS
HAPPENS...FLOW THROUGHOUT THE ATMOSPHERE ACROSS SOUTHWESTERN CA
SHOULD BACK FROM NWLY TO WSWLY. SHOWER ACTIVITY THAT WAS MOVING
PARALLEL TO THE COAST IN THE NWLY FLOW EARLY THIS MORNING SHOULD
BEGIN TO MOVE ONSHORE THIS AFTERNOON...ESPECIALLY IN AREAS N OF PT
CONCEPTION. INCREASINGLY MOIST CYCLONIC FLOW AND SOME EXTRA LIFT
SHOULD CAUSE SHOWER ACTIVITY TO BECOME MORE WIDESPREAD S OF PT
CONCEPTION THIS AFTERNOON...ESPECIALLY ACROSS EASTERN L.A. COUNTY.
VERY COLD AIR ALOFT WILL CAUSE INCREASING INSTABILITY...WHICH
SHOULD BRING AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS TO SLO AND
SBA COUNTIES THIS AFTERNOON.

THE UPPER LOW WILL SLOWLY DROP SWD TO NEAR POINT CONCEPTION LATE
TONIGHT...MOVE VERY LITTLE ON SUNDAY...THEN PUSH SLOWLY INTO
LOS ANGELES COUNTY SUNDAY NIGHT. THIS WILL MAINTAIN A MOIST AND
UNSTABLE AIRMASS ACROSS THE REGION...SO EXPECT QUITE A BIT OF SHOWER
ACTIVITY OVERNIGHT THROUGH SUNDAY NIGHT...WITH A SLIGHT CHANCE OF
TSTMS. THE TEMPERATURE PROFILE THROUGH THE ATMOSPHERE WILL BE
FAVORABLE FOR SOME SMALL HAIL...AND INDEED...THIS HAS BEEN REPORTED
ACROSS NRN CA. ANY THUNDERSTORM THIS AFTERNOON THROUGH SUNDAY
EVENING WILL HAVE THE CAPABILITY OF PRODUCING SMALL HAIL AND HEAVY
DOWNPOURS. WHILE SHOWERS MAY OCCUR ANYWHERE AT ANY TIME...IT APPEARS
THAT THE BEST CHANCES OF ORGANIZED SHOWER ACTIVITY WILL BE TONIGHT
ACROSS L.A. COUNTY AND EASTERN VTU COUNTY AS SOME LOW LEVEL SWLY
FLOW DEVELOPS...AND SUNDAY AFTERNOON AND EVENING AS THE UPPER LOW
MOVES OVERHEAD. DUE TO THE SHOWERY NATURE OF THE PRECIPITATION...
RAINFALL TOTALS THROUGH SUNDAY NIGHT WILL BE HIGHLY VARIABLE...BUT
IN GENERAL...EXPECT TOTALS OF ONE QUARTER TO ONE HALF INCH...
EXCEPT ONE HALF INCH TO ONE INCH ACROSS THE MOUNTAINS...THE SAN
GABRIEL VALLEY...AND POSSIBLY PORTIONS OF THE REMAINDER OF THE L.A.
COUNTY VALLEYS AND THE VALLEYS OF ERN VTU COUNTY. LOCAL TOTALS UP TO
2 INCHES ARE POSSIBLE IN THE SAN GABRIEL MOUNTAINS AND FOOTHILLS.

SNOW WILL BE AN ISSUE FOR TRAVELERS THIS WEEKEND. SNOW LEVELS ARE
EXPECTED TO LOWER TO 5000 FEET LATE TODAY...THEN TO BETWEEN 3500 AND
4000 FEET LATE TONIGHT OR EARLY SUNDAY...THEN LINGER AT THOSE LEVELS
INTO SUNDAY NIGHT. SNOW MAY WELL AFFECT TRAVEL ACROSS HIGHER
PORTIONS OF INTERSTATE 5...HIGHWAY 14 AND HIGHWAY 33...ESPECIALLY
LATE TONIGHT THROUGH EARLY MONDAY. HAVE EXPANDED WINTER WEATHER
ADVISORIES TO INCLUDE THE MOUNTAINS OF SANTA BARBARA COUNTY. ON
AVERAGE...EXPECT A TOTAL OF 4 TO 8 INCHES OF SNOW BETWEEN 5000 AND
6500 FEET...WITH TOTALS OF 8 TO 12 INCHES ABOVE 6500 FEET...AND 2 TO
4 INCHES BETWEEN 4000 AND 5000 FEET. THERE COULD BE LOCAL TOTALS AS
HIGH AS 18 INCHES ACROSS PORTIONS OF THE SAN GABRIEL MOUNTAINS...OR
HIGHER ELEVATIONS IN VTU COUNTY. WAS STRONGLY CONSIDERING UPGRADING
TO A WINTER STORM WARNING...BUT HAVE DECIDED AGAINST IT...SINCE THE
SNOW ACCUMULATIONS MAY NOT MEET THE REQUIRED TOTALS IN ANY 12 OR 24
HOUR PERIOD. LATER SHIFTS MAY WELL HAVE TO UPGRADE DEPENDING UPON
SHOWER DEVELOPMENT.

SHOWERS WILL DECREASE ACROSS THE REGION SUNDAY NIGHT...AND MAY END
JUST ABOUT EVERYWHERE. HOWEVER...ANOTHER COLD UPPER LOW DROPPING
RAPIDLY SOUTHWARD WILL CAUSE SHOWERS TO BECOME LIKELY AGAIN MONDAY
AFTERNOON...WITH SHOWERS CONTINUING MONDAY NIGHT. THAT SYSTEM WILL
ALSO HAVE LOW SNOW LEVELS...AND PROBABLY ALSO A SLIGHT CHANCE OF
TSTMS. THAT SYSTEM WILL MOVE A BIT FASTER...BUT MAY ALSO TRACK A BIT
FARTHER OFF THE COAST...SO IT MAY PICK UP MORE MOISTURE. SHOWERS
SHOULD WIND DOWN IN MOST AREAS LATE MON NIGHT. MAX TEMPERATURES WILL
BE WELL BELOW NORMAL THROUGH MONDAY.

.LONG TERM (TUE-FRI)...THERE COULD BE A FEW LINGERING SHOWERS
TUE...BUT THAT IS LOOKING LESS AND LESS LIKELY. HEIGHTS WILL REBOUND
TUE AFTERNOON...AND WITH SOME SUNSHINE...EXPECT AT LEAST A BIT OR
WARMING. THE 06Z GFS NOW SHOWS A WEAK IMPULSE DROPPING SWD INTO THE
REGION ON WED...AND THAT WAS NOT ON THE PREVIOUS RUN. NO SHOWER
EXPECTED...BUT IT COULD KEEP MAX TEMPS ON THE COOL SIDE. AN UPPER
RIDGE AND HIGHER HEIGHTS WILL BRING WARMER WEATHER THU AND
FRI...WITH DAYTIME TEMPS LIKELY ABOVE NORMAL.


&&

.AVIATION...28/1135Z...

AT 0940Z...THE INVERSION AT KLAX WAS BASED AT 4300 FEET. THE TOP OF
THE INVERSION WAS AT 6300 FEET WITH A TEMPERATURE OF 5 DEGREES
CELSIUS.

OVERALL...LOW CONFIDENCE IN 12Z TAF PACKAGE. INCREASING COLD AND
UNSTABLE AIR MASS WILL GENERATE SHOWERS THROUGHOUT THE TAF PERIOD.
ADDITIONALLY...THERE WILL BE THE POSSIBILITY OF TSTMS FROM THIS
AFTERNOON THROUGH TONIGHT. CIGS WILL VARY RANDOMLY...GENERALLY
BETWEEN MVFR AND VFR LEVELS.

KLAX...LOW CONFIDENCE IN 12Z TAF. CIGS WILL BOUNCE BETWEEN MVFR AND
VFR LEVELS THROUGH THIS AFTERNOON. SHOWERS WILL LIKELY BEGIN LATE
THIS AFTERNOON/EARLY THIS EVENING (ALTHOUGH CONFIDENCE IN EXACT
START TIME IS VERY LOW). CHANCES OF TSTMS AT THE AIRFIELD TONIGHT
WILL BE 10-15%.

KBUR...LOW CONFIDENCE IN 12Z TAF. CIGS WILL BOUNCE BETWEEN MVFR AND
VFR LEVELS THROUGH THIS AFTERNOON. SHOWERS WILL LIKELY BEGIN LATE
THIS AFTERNOON/EARLY THIS EVENING (ALTHOUGH CONFIDENCE IN EXACT
START TIME IS VERY LOW). CHANCES OF TSTMS AT THE AIRFIELD TONIGHT
WILL BE 10-15%.

&&

.MARINE...28/330 AM...

FOR THE OUTER WATERS...HIGH CONFIDENCE IN SMALL CRAFT ADVISORY LEVEL
NORTHWEST WINDS CONTINUING THROUGH THIS MORNING...BEFORE DIMINISHING
BELOW ADVISORY LEVELS THIS AFTERNOON. HIGH CONFIDENCE IN WINDS
REMAINING BELOW SMALL CRAFT ADVISORY LEVELS SUNDAY THROUGH
MONDAY...WITH A CHANCE OF WINDS INCREASING ON TUESDAY.

FOR THE INNER WATERS...HIGH CONFIDENCE IN SMALL CRAFT ADVISORY LEVEL
WEST TO NORTHWEST WINDS CONTINUING THROUGH THIS MORNING...BEFORE
DIMINISHING BELOW ADVISORY LEVELS THIS AFTERNOON. HIGH CONFIDENCE IN
WINDS REMAINING BELOW SMALL CRAFT ADVISORY LEVEL SUNDAY THROUGH
EARLY NEXT WEEK.

A COLD AND UNSTABLE AIR MASS WILL MOVE OVER THE COASTAL WATERS TODAY
AND CONTINUE THROUGH MONDAY. THIS WILL RESULT IN SHOWERS ALONG WITH
THE SLIGHT CHANCE OF THUNDERSTORMS THROUGH THE PERIOD. ANY
THUNDERSTORMS THAT DEVELOP WILL LIKELY PRODUCE GUSTY WINDS...ROUGH
AND CHOPPY SEAS AS WELL AS SMALL HAIL. ADDITIONALLY...THERE WILL BE
THE POSSIBILITY OF AN ISOLATED WATERSPOUT.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...DB
AVIATION/MARINE...RAT
SYNOPSIS...DB

WWW.WEATHER.GOV/LOSANGELES










000
FXUS66 KLOX 281300
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
344 AM PST SAT FEB 28 2015

.SYNOPSIS...
A COLD LOW PRESSURE SYSTEM WILL BRING SHOWERS...POSSIBLE
THUNDERSTORMS AND MOUNTAIN SNOW TO THE AREA THIS WEEKEND. AFTER
A BRIEF BREAK...ANOTHER COLD SYSTEM WILL BRING SIMILAR WEATHER
LATE MONDAY MORNING THROUGH EARLY TUESDAY. DRY WEATHER IS EXPECTED
LATE TUESDAY THROUGH FRIDAY. THERE WILL BE A WARMING TREND...WITH
DAYTIME TEMPERATURES LIKELY ABOVE NORMAL BY THURSDAY.


&&

.SHORT TERM (TODAY-MON)...SKIES WERE GENERALLY MOSTLY CLOUDY ACROSS
THE REGION EARLY THIS MORNING...EXCEPT STILL MOSTLY CLEAR TO
PARTLY CLOUDY ACROSS COASTAL SECTIONS SOUTH OF POINT CONCEPTION.
SOME LIGHT SHOWERS HAVE DEVELOPED IN THE SAN GABRIEL MOUNTAINS AND
IN THE SAN GABRIEL VALLEY...PARTICULARLY IN THE FOOTHILLS. SCATTERED
SHOWERS CONTINUED TO MOVE SOUTHEASTWARD ACROSS THE COASTAL WATERS
THIS MORNING. WATER VAPOR IMAGERY SHOWED THE CENTER OF A FAIRLY
STRONG AND VERY COLD UPPER LEVEL LOW OVER EXTREME NORTHERN CA...WITH
A POTENT VORT ON ITS BACKSIDE DROPPING SOUTHWARD OFF THE COAST.

THIS UPPER LOW IS FORECAST TO DROP SOUTHWARD TODAY...WITH THE VORT
HELPING TO PULL THE UPPER CENTER SLIGHTLY OFF THE COAST TO A
POSITION JUST WEST OF MONTEREY BY LATE THIS AFTERNOON. AS THIS
HAPPENS...FLOW THROUGHOUT THE ATMOSPHERE ACROSS SOUTHWESTERN CA
SHOULD BACK FROM NWLY TO WSWLY. SHOWER ACTIVITY THAT WAS MOVING
PARALLEL TO THE COAST IN THE NWLY FLOW EARLY THIS MORNING SHOULD
BEGIN TO MOVE ONSHORE THIS AFTERNOON...ESPECIALLY IN AREAS N OF PT
CONCEPTION. INCREASINGLY MOIST CYCLONIC FLOW AND SOME EXTRA LIFT
SHOULD CAUSE SHOWER ACTIVITY TO BECOME MORE WIDESPREAD S OF PT
CONCEPTION THIS AFTERNOON...ESPECIALLY ACROSS EASTERN L.A. COUNTY.
VERY COLD AIR ALOFT WILL CAUSE INCREASING INSTABILITY...WHICH
SHOULD BRING AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS TO SLO AND
SBA COUNTIES THIS AFTERNOON.

THE UPPER LOW WILL SLOWLY DROP SWD TO NEAR POINT CONCEPTION LATE
TONIGHT...MOVE VERY LITTLE ON SUNDAY...THEN PUSH SLOWLY INTO
LOS ANGELES COUNTY SUNDAY NIGHT. THIS WILL MAINTAIN A MOIST AND
UNSTABLE AIRMASS ACROSS THE REGION...SO EXPECT QUITE A BIT OF SHOWER
ACTIVITY OVERNIGHT THROUGH SUNDAY NIGHT...WITH A SLIGHT CHANCE OF
TSTMS. THE TEMPERATURE PROFILE THROUGH THE ATMOSPHERE WILL BE
FAVORABLE FOR SOME SMALL HAIL...AND INDEED...THIS HAS BEEN REPORTED
ACROSS NRN CA. ANY THUNDERSTORM THIS AFTERNOON THROUGH SUNDAY
EVENING WILL HAVE THE CAPABILITY OF PRODUCING SMALL HAIL AND HEAVY
DOWNPOURS. WHILE SHOWERS MAY OCCUR ANYWHERE AT ANY TIME...IT APPEARS
THAT THE BEST CHANCES OF ORGANIZED SHOWER ACTIVITY WILL BE TONIGHT
ACROSS L.A. COUNTY AND EASTERN VTU COUNTY AS SOME LOW LEVEL SWLY
FLOW DEVELOPS...AND SUNDAY AFTERNOON AND EVENING AS THE UPPER LOW
MOVES OVERHEAD. DUE TO THE SHOWERY NATURE OF THE PRECIPITATION...
RAINFALL TOTALS THROUGH SUNDAY NIGHT WILL BE HIGHLY VARIABLE...BUT
IN GENERAL...EXPECT TOTALS OF ONE QUARTER TO ONE HALF INCH...
EXCEPT ONE HALF INCH TO ONE INCH ACROSS THE MOUNTAINS...THE SAN
GABRIEL VALLEY...AND POSSIBLY PORTIONS OF THE REMAINDER OF THE L.A.
COUNTY VALLEYS AND THE VALLEYS OF ERN VTU COUNTY. LOCAL TOTALS UP TO
2 INCHES ARE POSSIBLE IN THE SAN GABRIEL MOUNTAINS AND FOOTHILLS.

SNOW WILL BE AN ISSUE FOR TRAVELERS THIS WEEKEND. SNOW LEVELS ARE
EXPECTED TO LOWER TO 5000 FEET LATE TODAY...THEN TO BETWEEN 3500 AND
4000 FEET LATE TONIGHT OR EARLY SUNDAY...THEN LINGER AT THOSE LEVELS
INTO SUNDAY NIGHT. SNOW MAY WELL AFFECT TRAVEL ACROSS HIGHER
PORTIONS OF INTERSTATE 5...HIGHWAY 14 AND HIGHWAY 33...ESPECIALLY
LATE TONIGHT THROUGH EARLY MONDAY. HAVE EXPANDED WINTER WEATHER
ADVISORIES TO INCLUDE THE MOUNTAINS OF SANTA BARBARA COUNTY. ON
AVERAGE...EXPECT A TOTAL OF 4 TO 8 INCHES OF SNOW BETWEEN 5000 AND
6500 FEET...WITH TOTALS OF 8 TO 12 INCHES ABOVE 6500 FEET...AND 2 TO
4 INCHES BETWEEN 4000 AND 5000 FEET. THERE COULD BE LOCAL TOTALS AS
HIGH AS 18 INCHES ACROSS PORTIONS OF THE SAN GABRIEL MOUNTAINS...OR
HIGHER ELEVATIONS IN VTU COUNTY. WAS STRONGLY CONSIDERING UPGRADING
TO A WINTER STORM WARNING...BUT HAVE DECIDED AGAINST IT...SINCE THE
SNOW ACCUMULATIONS MAY NOT MEET THE REQUIRED TOTALS IN ANY 12 OR 24
HOUR PERIOD. LATER SHIFTS MAY WELL HAVE TO UPGRADE DEPENDING UPON
SHOWER DEVELOPMENT.

SHOWERS WILL DECREASE ACROSS THE REGION SUNDAY NIGHT...AND MAY END
JUST ABOUT EVERYWHERE. HOWEVER...ANOTHER COLD UPPER LOW DROPPING
RAPIDLY SOUTHWARD WILL CAUSE SHOWERS TO BECOME LIKELY AGAIN MONDAY
AFTERNOON...WITH SHOWERS CONTINUING MONDAY NIGHT. THAT SYSTEM WILL
ALSO HAVE LOW SNOW LEVELS...AND PROBABLY ALSO A SLIGHT CHANCE OF
TSTMS. THAT SYSTEM WILL MOVE A BIT FASTER...BUT MAY ALSO TRACK A BIT
FARTHER OFF THE COAST...SO IT MAY PICK UP MORE MOISTURE. SHOWERS
SHOULD WIND DOWN IN MOST AREAS LATE MON NIGHT. MAX TEMPERATURES WILL
BE WELL BELOW NORMAL THROUGH MONDAY.

.LONG TERM (TUE-FRI)...THERE COULD BE A FEW LINGERING SHOWERS
TUE...BUT THAT IS LOOKING LESS AND LESS LIKELY. HEIGHTS WILL REBOUND
TUE AFTERNOON...AND WITH SOME SUNSHINE...EXPECT AT LEAST A BIT OR
WARMING. THE 06Z GFS NOW SHOWS A WEAK IMPULSE DROPPING SWD INTO THE
REGION ON WED...AND THAT WAS NOT ON THE PREVIOUS RUN. NO SHOWER
EXPECTED...BUT IT COULD KEEP MAX TEMPS ON THE COOL SIDE. AN UPPER
RIDGE AND HIGHER HEIGHTS WILL BRING WARMER WEATHER THU AND
FRI...WITH DAYTIME TEMPS LIKELY ABOVE NORMAL.


&&

.AVIATION...28/1135Z...

AT 0940Z...THE INVERSION AT KLAX WAS BASED AT 4300 FEET. THE TOP OF
THE INVERSION WAS AT 6300 FEET WITH A TEMPERATURE OF 5 DEGREES
CELSIUS.

OVERALL...LOW CONFIDENCE IN 12Z TAF PACKAGE. INCREASING COLD AND
UNSTABLE AIR MASS WILL GENERATE SHOWERS THROUGHOUT THE TAF PERIOD.
ADDITIONALLY...THERE WILL BE THE POSSIBILITY OF TSTMS FROM THIS
AFTERNOON THROUGH TONIGHT. CIGS WILL VARY RANDOMLY...GENERALLY
BETWEEN MVFR AND VFR LEVELS.

KLAX...LOW CONFIDENCE IN 12Z TAF. CIGS WILL BOUNCE BETWEEN MVFR AND
VFR LEVELS THROUGH THIS AFTERNOON. SHOWERS WILL LIKELY BEGIN LATE
THIS AFTERNOON/EARLY THIS EVENING (ALTHOUGH CONFIDENCE IN EXACT
START TIME IS VERY LOW). CHANCES OF TSTMS AT THE AIRFIELD TONIGHT
WILL BE 10-15%.

KBUR...LOW CONFIDENCE IN 12Z TAF. CIGS WILL BOUNCE BETWEEN MVFR AND
VFR LEVELS THROUGH THIS AFTERNOON. SHOWERS WILL LIKELY BEGIN LATE
THIS AFTERNOON/EARLY THIS EVENING (ALTHOUGH CONFIDENCE IN EXACT
START TIME IS VERY LOW). CHANCES OF TSTMS AT THE AIRFIELD TONIGHT
WILL BE 10-15%.

&&

.MARINE...28/330 AM...

FOR THE OUTER WATERS...HIGH CONFIDENCE IN SMALL CRAFT ADVISORY LEVEL
NORTHWEST WINDS CONTINUING THROUGH THIS MORNING...BEFORE DIMINISHING
BELOW ADVISORY LEVELS THIS AFTERNOON. HIGH CONFIDENCE IN WINDS
REMAINING BELOW SMALL CRAFT ADVISORY LEVELS SUNDAY THROUGH
MONDAY...WITH A CHANCE OF WINDS INCREASING ON TUESDAY.

FOR THE INNER WATERS...HIGH CONFIDENCE IN SMALL CRAFT ADVISORY LEVEL
WEST TO NORTHWEST WINDS CONTINUING THROUGH THIS MORNING...BEFORE
DIMINISHING BELOW ADVISORY LEVELS THIS AFTERNOON. HIGH CONFIDENCE IN
WINDS REMAINING BELOW SMALL CRAFT ADVISORY LEVEL SUNDAY THROUGH
EARLY NEXT WEEK.

A COLD AND UNSTABLE AIR MASS WILL MOVE OVER THE COASTAL WATERS TODAY
AND CONTINUE THROUGH MONDAY. THIS WILL RESULT IN SHOWERS ALONG WITH
THE SLIGHT CHANCE OF THUNDERSTORMS THROUGH THE PERIOD. ANY
THUNDERSTORMS THAT DEVELOP WILL LIKELY PRODUCE GUSTY WINDS...ROUGH
AND CHOPPY SEAS AS WELL AS SMALL HAIL. ADDITIONALLY...THERE WILL BE
THE POSSIBILITY OF AN ISOLATED WATERSPOUT.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...DB
AVIATION/MARINE...RAT
SYNOPSIS...DB

WWW.WEATHER.GOV/LOSANGELES









000
FXUS66 KLOX 281300
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
344 AM PST SAT FEB 28 2015

.SYNOPSIS...
A COLD LOW PRESSURE SYSTEM WILL BRING SHOWERS...POSSIBLE
THUNDERSTORMS AND MOUNTAIN SNOW TO THE AREA THIS WEEKEND. AFTER
A BRIEF BREAK...ANOTHER COLD SYSTEM WILL BRING SIMILAR WEATHER
LATE MONDAY MORNING THROUGH EARLY TUESDAY. DRY WEATHER IS EXPECTED
LATE TUESDAY THROUGH FRIDAY. THERE WILL BE A WARMING TREND...WITH
DAYTIME TEMPERATURES LIKELY ABOVE NORMAL BY THURSDAY.


&&

.SHORT TERM (TODAY-MON)...SKIES WERE GENERALLY MOSTLY CLOUDY ACROSS
THE REGION EARLY THIS MORNING...EXCEPT STILL MOSTLY CLEAR TO
PARTLY CLOUDY ACROSS COASTAL SECTIONS SOUTH OF POINT CONCEPTION.
SOME LIGHT SHOWERS HAVE DEVELOPED IN THE SAN GABRIEL MOUNTAINS AND
IN THE SAN GABRIEL VALLEY...PARTICULARLY IN THE FOOTHILLS. SCATTERED
SHOWERS CONTINUED TO MOVE SOUTHEASTWARD ACROSS THE COASTAL WATERS
THIS MORNING. WATER VAPOR IMAGERY SHOWED THE CENTER OF A FAIRLY
STRONG AND VERY COLD UPPER LEVEL LOW OVER EXTREME NORTHERN CA...WITH
A POTENT VORT ON ITS BACKSIDE DROPPING SOUTHWARD OFF THE COAST.

THIS UPPER LOW IS FORECAST TO DROP SOUTHWARD TODAY...WITH THE VORT
HELPING TO PULL THE UPPER CENTER SLIGHTLY OFF THE COAST TO A
POSITION JUST WEST OF MONTEREY BY LATE THIS AFTERNOON. AS THIS
HAPPENS...FLOW THROUGHOUT THE ATMOSPHERE ACROSS SOUTHWESTERN CA
SHOULD BACK FROM NWLY TO WSWLY. SHOWER ACTIVITY THAT WAS MOVING
PARALLEL TO THE COAST IN THE NWLY FLOW EARLY THIS MORNING SHOULD
BEGIN TO MOVE ONSHORE THIS AFTERNOON...ESPECIALLY IN AREAS N OF PT
CONCEPTION. INCREASINGLY MOIST CYCLONIC FLOW AND SOME EXTRA LIFT
SHOULD CAUSE SHOWER ACTIVITY TO BECOME MORE WIDESPREAD S OF PT
CONCEPTION THIS AFTERNOON...ESPECIALLY ACROSS EASTERN L.A. COUNTY.
VERY COLD AIR ALOFT WILL CAUSE INCREASING INSTABILITY...WHICH
SHOULD BRING AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS TO SLO AND
SBA COUNTIES THIS AFTERNOON.

THE UPPER LOW WILL SLOWLY DROP SWD TO NEAR POINT CONCEPTION LATE
TONIGHT...MOVE VERY LITTLE ON SUNDAY...THEN PUSH SLOWLY INTO
LOS ANGELES COUNTY SUNDAY NIGHT. THIS WILL MAINTAIN A MOIST AND
UNSTABLE AIRMASS ACROSS THE REGION...SO EXPECT QUITE A BIT OF SHOWER
ACTIVITY OVERNIGHT THROUGH SUNDAY NIGHT...WITH A SLIGHT CHANCE OF
TSTMS. THE TEMPERATURE PROFILE THROUGH THE ATMOSPHERE WILL BE
FAVORABLE FOR SOME SMALL HAIL...AND INDEED...THIS HAS BEEN REPORTED
ACROSS NRN CA. ANY THUNDERSTORM THIS AFTERNOON THROUGH SUNDAY
EVENING WILL HAVE THE CAPABILITY OF PRODUCING SMALL HAIL AND HEAVY
DOWNPOURS. WHILE SHOWERS MAY OCCUR ANYWHERE AT ANY TIME...IT APPEARS
THAT THE BEST CHANCES OF ORGANIZED SHOWER ACTIVITY WILL BE TONIGHT
ACROSS L.A. COUNTY AND EASTERN VTU COUNTY AS SOME LOW LEVEL SWLY
FLOW DEVELOPS...AND SUNDAY AFTERNOON AND EVENING AS THE UPPER LOW
MOVES OVERHEAD. DUE TO THE SHOWERY NATURE OF THE PRECIPITATION...
RAINFALL TOTALS THROUGH SUNDAY NIGHT WILL BE HIGHLY VARIABLE...BUT
IN GENERAL...EXPECT TOTALS OF ONE QUARTER TO ONE HALF INCH...
EXCEPT ONE HALF INCH TO ONE INCH ACROSS THE MOUNTAINS...THE SAN
GABRIEL VALLEY...AND POSSIBLY PORTIONS OF THE REMAINDER OF THE L.A.
COUNTY VALLEYS AND THE VALLEYS OF ERN VTU COUNTY. LOCAL TOTALS UP TO
2 INCHES ARE POSSIBLE IN THE SAN GABRIEL MOUNTAINS AND FOOTHILLS.

SNOW WILL BE AN ISSUE FOR TRAVELERS THIS WEEKEND. SNOW LEVELS ARE
EXPECTED TO LOWER TO 5000 FEET LATE TODAY...THEN TO BETWEEN 3500 AND
4000 FEET LATE TONIGHT OR EARLY SUNDAY...THEN LINGER AT THOSE LEVELS
INTO SUNDAY NIGHT. SNOW MAY WELL AFFECT TRAVEL ACROSS HIGHER
PORTIONS OF INTERSTATE 5...HIGHWAY 14 AND HIGHWAY 33...ESPECIALLY
LATE TONIGHT THROUGH EARLY MONDAY. HAVE EXPANDED WINTER WEATHER
ADVISORIES TO INCLUDE THE MOUNTAINS OF SANTA BARBARA COUNTY. ON
AVERAGE...EXPECT A TOTAL OF 4 TO 8 INCHES OF SNOW BETWEEN 5000 AND
6500 FEET...WITH TOTALS OF 8 TO 12 INCHES ABOVE 6500 FEET...AND 2 TO
4 INCHES BETWEEN 4000 AND 5000 FEET. THERE COULD BE LOCAL TOTALS AS
HIGH AS 18 INCHES ACROSS PORTIONS OF THE SAN GABRIEL MOUNTAINS...OR
HIGHER ELEVATIONS IN VTU COUNTY. WAS STRONGLY CONSIDERING UPGRADING
TO A WINTER STORM WARNING...BUT HAVE DECIDED AGAINST IT...SINCE THE
SNOW ACCUMULATIONS MAY NOT MEET THE REQUIRED TOTALS IN ANY 12 OR 24
HOUR PERIOD. LATER SHIFTS MAY WELL HAVE TO UPGRADE DEPENDING UPON
SHOWER DEVELOPMENT.

SHOWERS WILL DECREASE ACROSS THE REGION SUNDAY NIGHT...AND MAY END
JUST ABOUT EVERYWHERE. HOWEVER...ANOTHER COLD UPPER LOW DROPPING
RAPIDLY SOUTHWARD WILL CAUSE SHOWERS TO BECOME LIKELY AGAIN MONDAY
AFTERNOON...WITH SHOWERS CONTINUING MONDAY NIGHT. THAT SYSTEM WILL
ALSO HAVE LOW SNOW LEVELS...AND PROBABLY ALSO A SLIGHT CHANCE OF
TSTMS. THAT SYSTEM WILL MOVE A BIT FASTER...BUT MAY ALSO TRACK A BIT
FARTHER OFF THE COAST...SO IT MAY PICK UP MORE MOISTURE. SHOWERS
SHOULD WIND DOWN IN MOST AREAS LATE MON NIGHT. MAX TEMPERATURES WILL
BE WELL BELOW NORMAL THROUGH MONDAY.

.LONG TERM (TUE-FRI)...THERE COULD BE A FEW LINGERING SHOWERS
TUE...BUT THAT IS LOOKING LESS AND LESS LIKELY. HEIGHTS WILL REBOUND
TUE AFTERNOON...AND WITH SOME SUNSHINE...EXPECT AT LEAST A BIT OR
WARMING. THE 06Z GFS NOW SHOWS A WEAK IMPULSE DROPPING SWD INTO THE
REGION ON WED...AND THAT WAS NOT ON THE PREVIOUS RUN. NO SHOWER
EXPECTED...BUT IT COULD KEEP MAX TEMPS ON THE COOL SIDE. AN UPPER
RIDGE AND HIGHER HEIGHTS WILL BRING WARMER WEATHER THU AND
FRI...WITH DAYTIME TEMPS LIKELY ABOVE NORMAL.


&&

.AVIATION...28/1135Z...

AT 0940Z...THE INVERSION AT KLAX WAS BASED AT 4300 FEET. THE TOP OF
THE INVERSION WAS AT 6300 FEET WITH A TEMPERATURE OF 5 DEGREES
CELSIUS.

OVERALL...LOW CONFIDENCE IN 12Z TAF PACKAGE. INCREASING COLD AND
UNSTABLE AIR MASS WILL GENERATE SHOWERS THROUGHOUT THE TAF PERIOD.
ADDITIONALLY...THERE WILL BE THE POSSIBILITY OF TSTMS FROM THIS
AFTERNOON THROUGH TONIGHT. CIGS WILL VARY RANDOMLY...GENERALLY
BETWEEN MVFR AND VFR LEVELS.

KLAX...LOW CONFIDENCE IN 12Z TAF. CIGS WILL BOUNCE BETWEEN MVFR AND
VFR LEVELS THROUGH THIS AFTERNOON. SHOWERS WILL LIKELY BEGIN LATE
THIS AFTERNOON/EARLY THIS EVENING (ALTHOUGH CONFIDENCE IN EXACT
START TIME IS VERY LOW). CHANCES OF TSTMS AT THE AIRFIELD TONIGHT
WILL BE 10-15%.

KBUR...LOW CONFIDENCE IN 12Z TAF. CIGS WILL BOUNCE BETWEEN MVFR AND
VFR LEVELS THROUGH THIS AFTERNOON. SHOWERS WILL LIKELY BEGIN LATE
THIS AFTERNOON/EARLY THIS EVENING (ALTHOUGH CONFIDENCE IN EXACT
START TIME IS VERY LOW). CHANCES OF TSTMS AT THE AIRFIELD TONIGHT
WILL BE 10-15%.

&&

.MARINE...28/330 AM...

FOR THE OUTER WATERS...HIGH CONFIDENCE IN SMALL CRAFT ADVISORY LEVEL
NORTHWEST WINDS CONTINUING THROUGH THIS MORNING...BEFORE DIMINISHING
BELOW ADVISORY LEVELS THIS AFTERNOON. HIGH CONFIDENCE IN WINDS
REMAINING BELOW SMALL CRAFT ADVISORY LEVELS SUNDAY THROUGH
MONDAY...WITH A CHANCE OF WINDS INCREASING ON TUESDAY.

FOR THE INNER WATERS...HIGH CONFIDENCE IN SMALL CRAFT ADVISORY LEVEL
WEST TO NORTHWEST WINDS CONTINUING THROUGH THIS MORNING...BEFORE
DIMINISHING BELOW ADVISORY LEVELS THIS AFTERNOON. HIGH CONFIDENCE IN
WINDS REMAINING BELOW SMALL CRAFT ADVISORY LEVEL SUNDAY THROUGH
EARLY NEXT WEEK.

A COLD AND UNSTABLE AIR MASS WILL MOVE OVER THE COASTAL WATERS TODAY
AND CONTINUE THROUGH MONDAY. THIS WILL RESULT IN SHOWERS ALONG WITH
THE SLIGHT CHANCE OF THUNDERSTORMS THROUGH THE PERIOD. ANY
THUNDERSTORMS THAT DEVELOP WILL LIKELY PRODUCE GUSTY WINDS...ROUGH
AND CHOPPY SEAS AS WELL AS SMALL HAIL. ADDITIONALLY...THERE WILL BE
THE POSSIBILITY OF AN ISOLATED WATERSPOUT.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...DB
AVIATION/MARINE...RAT
SYNOPSIS...DB

WWW.WEATHER.GOV/LOSANGELES










000
FXUS66 KLOX 281300
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
344 AM PST SAT FEB 28 2015

.SYNOPSIS...
A COLD LOW PRESSURE SYSTEM WILL BRING SHOWERS...POSSIBLE
THUNDERSTORMS AND MOUNTAIN SNOW TO THE AREA THIS WEEKEND. AFTER
A BRIEF BREAK...ANOTHER COLD SYSTEM WILL BRING SIMILAR WEATHER
LATE MONDAY MORNING THROUGH EARLY TUESDAY. DRY WEATHER IS EXPECTED
LATE TUESDAY THROUGH FRIDAY. THERE WILL BE A WARMING TREND...WITH
DAYTIME TEMPERATURES LIKELY ABOVE NORMAL BY THURSDAY.


&&

.SHORT TERM (TODAY-MON)...SKIES WERE GENERALLY MOSTLY CLOUDY ACROSS
THE REGION EARLY THIS MORNING...EXCEPT STILL MOSTLY CLEAR TO
PARTLY CLOUDY ACROSS COASTAL SECTIONS SOUTH OF POINT CONCEPTION.
SOME LIGHT SHOWERS HAVE DEVELOPED IN THE SAN GABRIEL MOUNTAINS AND
IN THE SAN GABRIEL VALLEY...PARTICULARLY IN THE FOOTHILLS. SCATTERED
SHOWERS CONTINUED TO MOVE SOUTHEASTWARD ACROSS THE COASTAL WATERS
THIS MORNING. WATER VAPOR IMAGERY SHOWED THE CENTER OF A FAIRLY
STRONG AND VERY COLD UPPER LEVEL LOW OVER EXTREME NORTHERN CA...WITH
A POTENT VORT ON ITS BACKSIDE DROPPING SOUTHWARD OFF THE COAST.

THIS UPPER LOW IS FORECAST TO DROP SOUTHWARD TODAY...WITH THE VORT
HELPING TO PULL THE UPPER CENTER SLIGHTLY OFF THE COAST TO A
POSITION JUST WEST OF MONTEREY BY LATE THIS AFTERNOON. AS THIS
HAPPENS...FLOW THROUGHOUT THE ATMOSPHERE ACROSS SOUTHWESTERN CA
SHOULD BACK FROM NWLY TO WSWLY. SHOWER ACTIVITY THAT WAS MOVING
PARALLEL TO THE COAST IN THE NWLY FLOW EARLY THIS MORNING SHOULD
BEGIN TO MOVE ONSHORE THIS AFTERNOON...ESPECIALLY IN AREAS N OF PT
CONCEPTION. INCREASINGLY MOIST CYCLONIC FLOW AND SOME EXTRA LIFT
SHOULD CAUSE SHOWER ACTIVITY TO BECOME MORE WIDESPREAD S OF PT
CONCEPTION THIS AFTERNOON...ESPECIALLY ACROSS EASTERN L.A. COUNTY.
VERY COLD AIR ALOFT WILL CAUSE INCREASING INSTABILITY...WHICH
SHOULD BRING AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS TO SLO AND
SBA COUNTIES THIS AFTERNOON.

THE UPPER LOW WILL SLOWLY DROP SWD TO NEAR POINT CONCEPTION LATE
TONIGHT...MOVE VERY LITTLE ON SUNDAY...THEN PUSH SLOWLY INTO
LOS ANGELES COUNTY SUNDAY NIGHT. THIS WILL MAINTAIN A MOIST AND
UNSTABLE AIRMASS ACROSS THE REGION...SO EXPECT QUITE A BIT OF SHOWER
ACTIVITY OVERNIGHT THROUGH SUNDAY NIGHT...WITH A SLIGHT CHANCE OF
TSTMS. THE TEMPERATURE PROFILE THROUGH THE ATMOSPHERE WILL BE
FAVORABLE FOR SOME SMALL HAIL...AND INDEED...THIS HAS BEEN REPORTED
ACROSS NRN CA. ANY THUNDERSTORM THIS AFTERNOON THROUGH SUNDAY
EVENING WILL HAVE THE CAPABILITY OF PRODUCING SMALL HAIL AND HEAVY
DOWNPOURS. WHILE SHOWERS MAY OCCUR ANYWHERE AT ANY TIME...IT APPEARS
THAT THE BEST CHANCES OF ORGANIZED SHOWER ACTIVITY WILL BE TONIGHT
ACROSS L.A. COUNTY AND EASTERN VTU COUNTY AS SOME LOW LEVEL SWLY
FLOW DEVELOPS...AND SUNDAY AFTERNOON AND EVENING AS THE UPPER LOW
MOVES OVERHEAD. DUE TO THE SHOWERY NATURE OF THE PRECIPITATION...
RAINFALL TOTALS THROUGH SUNDAY NIGHT WILL BE HIGHLY VARIABLE...BUT
IN GENERAL...EXPECT TOTALS OF ONE QUARTER TO ONE HALF INCH...
EXCEPT ONE HALF INCH TO ONE INCH ACROSS THE MOUNTAINS...THE SAN
GABRIEL VALLEY...AND POSSIBLY PORTIONS OF THE REMAINDER OF THE L.A.
COUNTY VALLEYS AND THE VALLEYS OF ERN VTU COUNTY. LOCAL TOTALS UP TO
2 INCHES ARE POSSIBLE IN THE SAN GABRIEL MOUNTAINS AND FOOTHILLS.

SNOW WILL BE AN ISSUE FOR TRAVELERS THIS WEEKEND. SNOW LEVELS ARE
EXPECTED TO LOWER TO 5000 FEET LATE TODAY...THEN TO BETWEEN 3500 AND
4000 FEET LATE TONIGHT OR EARLY SUNDAY...THEN LINGER AT THOSE LEVELS
INTO SUNDAY NIGHT. SNOW MAY WELL AFFECT TRAVEL ACROSS HIGHER
PORTIONS OF INTERSTATE 5...HIGHWAY 14 AND HIGHWAY 33...ESPECIALLY
LATE TONIGHT THROUGH EARLY MONDAY. HAVE EXPANDED WINTER WEATHER
ADVISORIES TO INCLUDE THE MOUNTAINS OF SANTA BARBARA COUNTY. ON
AVERAGE...EXPECT A TOTAL OF 4 TO 8 INCHES OF SNOW BETWEEN 5000 AND
6500 FEET...WITH TOTALS OF 8 TO 12 INCHES ABOVE 6500 FEET...AND 2 TO
4 INCHES BETWEEN 4000 AND 5000 FEET. THERE COULD BE LOCAL TOTALS AS
HIGH AS 18 INCHES ACROSS PORTIONS OF THE SAN GABRIEL MOUNTAINS...OR
HIGHER ELEVATIONS IN VTU COUNTY. WAS STRONGLY CONSIDERING UPGRADING
TO A WINTER STORM WARNING...BUT HAVE DECIDED AGAINST IT...SINCE THE
SNOW ACCUMULATIONS MAY NOT MEET THE REQUIRED TOTALS IN ANY 12 OR 24
HOUR PERIOD. LATER SHIFTS MAY WELL HAVE TO UPGRADE DEPENDING UPON
SHOWER DEVELOPMENT.

SHOWERS WILL DECREASE ACROSS THE REGION SUNDAY NIGHT...AND MAY END
JUST ABOUT EVERYWHERE. HOWEVER...ANOTHER COLD UPPER LOW DROPPING
RAPIDLY SOUTHWARD WILL CAUSE SHOWERS TO BECOME LIKELY AGAIN MONDAY
AFTERNOON...WITH SHOWERS CONTINUING MONDAY NIGHT. THAT SYSTEM WILL
ALSO HAVE LOW SNOW LEVELS...AND PROBABLY ALSO A SLIGHT CHANCE OF
TSTMS. THAT SYSTEM WILL MOVE A BIT FASTER...BUT MAY ALSO TRACK A BIT
FARTHER OFF THE COAST...SO IT MAY PICK UP MORE MOISTURE. SHOWERS
SHOULD WIND DOWN IN MOST AREAS LATE MON NIGHT. MAX TEMPERATURES WILL
BE WELL BELOW NORMAL THROUGH MONDAY.

.LONG TERM (TUE-FRI)...THERE COULD BE A FEW LINGERING SHOWERS
TUE...BUT THAT IS LOOKING LESS AND LESS LIKELY. HEIGHTS WILL REBOUND
TUE AFTERNOON...AND WITH SOME SUNSHINE...EXPECT AT LEAST A BIT OR
WARMING. THE 06Z GFS NOW SHOWS A WEAK IMPULSE DROPPING SWD INTO THE
REGION ON WED...AND THAT WAS NOT ON THE PREVIOUS RUN. NO SHOWER
EXPECTED...BUT IT COULD KEEP MAX TEMPS ON THE COOL SIDE. AN UPPER
RIDGE AND HIGHER HEIGHTS WILL BRING WARMER WEATHER THU AND
FRI...WITH DAYTIME TEMPS LIKELY ABOVE NORMAL.


&&

.AVIATION...28/1135Z...

AT 0940Z...THE INVERSION AT KLAX WAS BASED AT 4300 FEET. THE TOP OF
THE INVERSION WAS AT 6300 FEET WITH A TEMPERATURE OF 5 DEGREES
CELSIUS.

OVERALL...LOW CONFIDENCE IN 12Z TAF PACKAGE. INCREASING COLD AND
UNSTABLE AIR MASS WILL GENERATE SHOWERS THROUGHOUT THE TAF PERIOD.
ADDITIONALLY...THERE WILL BE THE POSSIBILITY OF TSTMS FROM THIS
AFTERNOON THROUGH TONIGHT. CIGS WILL VARY RANDOMLY...GENERALLY
BETWEEN MVFR AND VFR LEVELS.

KLAX...LOW CONFIDENCE IN 12Z TAF. CIGS WILL BOUNCE BETWEEN MVFR AND
VFR LEVELS THROUGH THIS AFTERNOON. SHOWERS WILL LIKELY BEGIN LATE
THIS AFTERNOON/EARLY THIS EVENING (ALTHOUGH CONFIDENCE IN EXACT
START TIME IS VERY LOW). CHANCES OF TSTMS AT THE AIRFIELD TONIGHT
WILL BE 10-15%.

KBUR...LOW CONFIDENCE IN 12Z TAF. CIGS WILL BOUNCE BETWEEN MVFR AND
VFR LEVELS THROUGH THIS AFTERNOON. SHOWERS WILL LIKELY BEGIN LATE
THIS AFTERNOON/EARLY THIS EVENING (ALTHOUGH CONFIDENCE IN EXACT
START TIME IS VERY LOW). CHANCES OF TSTMS AT THE AIRFIELD TONIGHT
WILL BE 10-15%.

&&

.MARINE...28/330 AM...

FOR THE OUTER WATERS...HIGH CONFIDENCE IN SMALL CRAFT ADVISORY LEVEL
NORTHWEST WINDS CONTINUING THROUGH THIS MORNING...BEFORE DIMINISHING
BELOW ADVISORY LEVELS THIS AFTERNOON. HIGH CONFIDENCE IN WINDS
REMAINING BELOW SMALL CRAFT ADVISORY LEVELS SUNDAY THROUGH
MONDAY...WITH A CHANCE OF WINDS INCREASING ON TUESDAY.

FOR THE INNER WATERS...HIGH CONFIDENCE IN SMALL CRAFT ADVISORY LEVEL
WEST TO NORTHWEST WINDS CONTINUING THROUGH THIS MORNING...BEFORE
DIMINISHING BELOW ADVISORY LEVELS THIS AFTERNOON. HIGH CONFIDENCE IN
WINDS REMAINING BELOW SMALL CRAFT ADVISORY LEVEL SUNDAY THROUGH
EARLY NEXT WEEK.

A COLD AND UNSTABLE AIR MASS WILL MOVE OVER THE COASTAL WATERS TODAY
AND CONTINUE THROUGH MONDAY. THIS WILL RESULT IN SHOWERS ALONG WITH
THE SLIGHT CHANCE OF THUNDERSTORMS THROUGH THE PERIOD. ANY
THUNDERSTORMS THAT DEVELOP WILL LIKELY PRODUCE GUSTY WINDS...ROUGH
AND CHOPPY SEAS AS WELL AS SMALL HAIL. ADDITIONALLY...THERE WILL BE
THE POSSIBILITY OF AN ISOLATED WATERSPOUT.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...DB
AVIATION/MARINE...RAT
SYNOPSIS...DB

WWW.WEATHER.GOV/LOSANGELES









000
FXUS66 KLOX 281222
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
344 AM PST SAT FEB 28 2015

.SYNOPSIS...
A COLD LOW PRESSURE SYSTEM WILL BRING SHOWERS...POSSIBLE
THUNDERSTORMS AND MOUNTAIN SNOW TO THE AREA THIS WEEKEND. AFTER
A BRIEF BREAK...ANOTHER COLD SYSTEM WILL BRING SIMILAR WEATHER LATE
MONDAY MORNING THROUGH EARLY TUESDAY. DRY WEATHER IS EXPECTED
LATE TUESDAY THROUGH FRIDAY. THERE WILL BE A WARMING TREND...
WITH DAYTIME TEMPERATURES LIKELY ABOVE NORMAL BY THURSDAY.


&&

.SHORT TERM (TODAY-MON)...SKIES WERE GENERALLY MOSTLY CLOUDY ACROSS
THE REGION EARLY THIS MORNING...EXCEPT STILL MOSTLY CLEAR TO
PARTLY CLOUDY ACROSS COASTAL SECTIONS SOUTH OF POINT CONCEPTION.
SOME LIGHT SHOWERS HAVE DEVELOPED IN THE SAN GABRIEL MOUNTAINS AND
IN THE SAN GABRIEL VALLEY...PARTICULARLY IN THE FOOTHILLS. SCATTERED
SHOWERS CONTINUED TO MOVE SOUTHEASTWARD ACROSS THE COASTAL WATERS IN
THIS MORNING. WATER VAPOR IMAGERY SHOWED THE CENTER OF A FAIRLY
STRONG AND VERY COLD UPPER LEVEL LOW OVER EXTREME NORTHERN CA...WITH
A POTENT VORT ON ITS BACKSIDE DROPPING SOUTHWARD OFF THE COAST.

THIS UPPER LOW IS FORECAST TO DROP SOUTHWARD TODAY...WITH THE VORT
HELPING TO PULL THE UPPER CENTER SLIGHTLY OFF THE COAST TO A
POSITION JUST WEST OF MONTEREY BY LATE THIS AFTERNOON. AS THIS
HAPPENS...FLOW THROUGHOUT THE ATMOSPHERE ACROSS SOUTHWESTERN CA
SHOULD BACK FROM NWLY TO WSWLY. SHOWER ACTIVITY THAT WAS MOVING
PARALLEL TO THE COAST IN THE NWLY FLOW EARLY THIS MORNING SHOULD
BEGIN TO MOVE ONSHORE THIS AFTERNOON...ESPECIALLY IN AREAS N OF PT
CONCEPTION. INCREASINGLY MOIST CYCLONIC FLOW AND SOME EXTRA LIFT
SHOULD CAUSE SHOWER ACTIVITY TO BECOME MORE WIDESPREAD S OF PT
CONCEPTION THIS AFTERNOON...ESPECIALLY ACROSS EASTERN L.A. COUNTY.
VERY COLD AIR ALOFT WILL CAUSE INCREASING INSTABILITY...WHICH
SHOULD BRING AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS TO SLO AND
SBA COUNTIES THIS AFTERNOON.

THE UPPER LOW WILL SLOWLY DROP SWD TO NEAR POINT CONCEPTION LATE
TONIGHT...THEN MOVE VERY LITTLE ON SUNDAY...THEN PUSH SLOWLY INTO
LOS ANGELES COUNTY SUNDAY NIGHT. THIS WILL MAINTAIN A MOIST AND
UNSTABLE AIRMASS ACROSS THE REGION...SO EXPECT QUITE A BIT OF SHOWER
ACTIVITY OVERNIGHT THROUGH SUNDAY NIGHT...WITH A SLIGHT CHANCE OF
TSTMS. THE ATMOSPHERIC TEMPERATURE PROFILE WILL BE FAVORABLE FOR
SMALL HAIL...AND INDEED...THIS HAS BEEN REPORTED ACROSS NRN CA.
ANY THUNDERSTORM THIS AFTERNOON THROUGH SUNDAY EVENING WILL HAVE THE
CAPABILITY OF PRODUCING SMALL HAIL AND HEAVY DOWNPOURS. WHILE
SHOWERS MAY OCCUR ANYWHERE AT ANY TIME...IT APPEARS THAT THE BEST
CHANCE OF ORGANIZED SHOWER ACTIVITY WILL BE TONIGHT ACROSS L.A.
COUNTY AND EASTERN VTU COUNTY AS SOME LOW LEVEL SWLY FLOW
DEVELOPS...AND SUNDAY AFTERNOON AND EVENING AS THE UPPER LOW MOVES
OVERHEAD. DUE TO THE SHOWERY NATURE OF THE PRECIPITATION...RAINFALL
TOTALS THROUGH SUNDAY NIGHT WILL BE HIGHLY VARIABLE...BUT GENERAL
TOTALS OF ONE QUARTER TO ONE HALF INCH LOOK REASONABLE...WITH
AMOUNTS OF ONE HALF INCH TO ONE INCH ACROSS THE MOUNTAINS...THE SAN
GABRIEL VALLEY...AND POSSIBLY PORTIONS OF THE REMAINDER OF THE L.A.
COUNTY VALLEYS AND THE VALLEYS OF ERN VTU COUNTIES. LOCAL TOTALS TO
2 INCHES ARE POSSIBLE IN THE SAN GABRIEL MOUNTAINS AND FOOTHILLS.

SNOW WILL BE AN ISSUE FOR TRAVELERS THIS WEEKEND. SNOW LEVELS ARE
EXPECTED TO LOWER TO 4500 FEET LATE TODAY...THEN TO BETWEEN 3500 AND
4000 FEET LATE TONIGHT AND SUNDAY...AND LINGER AT THOSE LEVELS
SUNDAY NIGHT. SNOW MAY WELL AFFECT TRAVEL ACROSS HIGHER PORTIONS OF
INTERSTATE 5...HIGHWAY 14 AND HIGHWAY 33...ESPECIALLY LATE TONIGHT
THROUGH EARLY MONDAY. HAVE EXPANDED WINTER WEATHER ADVISORIES TO
INCLUDE THE MOUNTAINS OF SANTA BARBARA COUNTY. ON AVERAGE...EXPECT A
TOTAL OF 4 TO 8 INCHES OF SNOW BETWEEN 5000 AND 6500 FEET...WITH
TOTALS OF 8 TO 12 INCHES ABOVE 6500 FEET...AND 2 TO 4 INCHES BETWEEN
4000 AND 5000 FEET. THERE COULD BE LOCAL TOTALS AS HIGH AS 18 INCHES
ACROSS PORTIONS OF THE SAN GABRIEL MOUNTAINS...OR HIGHER ELEVATIONS
IN VTU COUNTY. WAS STRONGLY CONSIDERING UPGRADING TO A WINTER STORM
WARNING...BUT HAVE DECIDED AGAINST IT...SINCE THE SNOW ACCUMULATIONS
MAY NOT MEET THE REQUIRED TOTALS IN ANY 12 OR 24 HOUR PERIOD. LATER
SHIFTS MAY WELL HAVE TO UPGRADE DEPENDING UPON SHOWER DEVELOPMENT.

SHOWERS WILL DECREASE ACROSS THE REGION SUNDAY NIGHT...AND MAY END
JUST ABOUT EVERYWHERE. HOWEVER...ANOTHER COLD UPPER LOW DROPPING
RAPIDLY SOUTHWARD WILL LIKELY CAUSE SHOWERS TO BECOME LIKELY AGAIN
MONDAY AFTERNOON...WITH SHOWERS CONTINUING MONDAY NIGHT. THAT SYSTEM
WILL ALSO HAVE LOW SNOW LEVELS...AND PROBABLY ALSO A SLIGHT CHANCE
OF TSTMS. THAT SYSTEM WILL MOVE A BIT FASTER...BUT MAY ALSO TRACK A
BIT FARTHER OFF THE COAST...SO IT MAY PICK UP MORE MOISTURE. SHOWERS
SHOULD WIND DOWN IN MOST AREAS LATE MON NIGHT.

.LONG TERM (TUE-FRI)...THERE COULD BE A FEW LINGERING SHOWERS
TUE...BUT THAT IS LOOKING LESS AND LESS LIKELY. HEIGHTS WILL REBOUND
TUE AFTERNOON...AND WITH SOME SUNSHINE...EXPECT AT LEAST A BIT OR
WARMING. THE 06Z GFS NOW SHOWS A WEAK IMPULSE DROPPING SWD INTO THE
REGION ON WED...AND THAT WAS NOT ON THE PREVIOUS RUN. NO SHOWER
EXPECTED...BUT IT COULD KEEP MAX TEMPS ON THE COOL SIDE. AN UPPER
RIDGE AND HIGHER HEIGHTS WILL BRING WARMER WEATHER THU AND
FRI...WITH DAYTIME TEMPS LIKELY ABOVE NORMAL.


&&

.AVIATION...28/1135Z...

AT 0940Z...THE INVERSION AT KLAX WAS BASED AT 4300 FEET. THE TOP OF
THE INVERSION WAS AT 6300 FEET WITH A TEMPERATURE OF 5 DEGREES
CELSIUS.

OVERALL...LOW CONFIDENCE IN 12Z TAF PACKAGE. INCREASING COLD AND
UNSTABLE AIR MASS WILL GENERATE SHOWERS THROUGHOUT THE TAF PERIOD.
ADDITIONALLY...THERE WILL BE THE POSSIBILITY OF TSTMS FROM THIS
AFTERNOON THROUGH TONIGHT. CIGS WILL VARY RANDOMLY...GENERALLY
BETWEEN MVFR AND VFR LEVELS.

KLAX...LOW CONFIDENCE IN 12Z TAF. CIGS WILL BOUNCE BETWEEN MVFR AND
VFR LEVELS THROUGH THIS AFTERNOON. SHOWERS WILL LIKELY BEGIN LATE
THIS AFTERNOON/EARLY THIS EVENING (ALTHOUGH CONFIDENCE IN EXACT
START TIME IS VERY LOW). CHANCES OF TSTMS AT THE AIRFIELD TONIGHT
WILL BE 10-15%.

KBUR...LOW CONFIDENCE IN 12Z TAF. CIGS WILL BOUNCE BETWEEN MVFR AND
VFR LEVELS THROUGH THIS AFTERNOON. SHOWERS WILL LIKELY BEGIN LATE
THIS AFTERNOON/EARLY THIS EVENING (ALTHOUGH CONFIDENCE IN EXACT
START TIME IS VERY LOW). CHANCES OF TSTMS AT THE AIRFIELD TONIGHT
WILL BE 10-15%.

&&

.MARINE...28/330 AM...

FOR THE OUTER WATERS...HIGH CONFIDENCE IN SMALL CRAFT ADVISORY LEVEL
NORTHWEST WINDS CONTINUING THROUGH THIS MORNING...BEFORE DIMINISHING
BELOW ADVISORY LEVELS THIS AFTERNOON. HIGH CONFIDENCE IN WINDS
REMAINING BELOW SMALL CRAFT ADVISORY LEVELS SUNDAY THROUGH
MONDAY...WITH A CHANCE OF WINDS INCREASING ON TUESDAY.

FOR THE INNER WATERS...HIGH CONFIDENCE IN SMALL CRAFT ADVISORY LEVEL
WEST TO NORTHWEST WINDS CONTINUING THROUGH THIS MORNING...BEFORE
DIMINISHING BELOW ADVISORY LEVELS THIS AFTERNOON. HIGH CONFIDENCE IN
WINDS REMAINING BELOW SMALL CRAFT ADVISORY LEVEL SUNDAY THROUGH
EARLY NEXT WEEK.

A COLD AND UNSTABLE AIR MASS WILL MOVE OVER THE COASTAL WATERS TODAY
AND CONTINUE THROUGH MONDAY. THIS WILL RESULT IN SHOWERS ALONG WITH
THE SLIGHT CHANCE OF THUNDERSTORMS THROUGH THE PERIOD. ANY
THUNDERSTORMS THAT DEVELOP WILL LIKELY PRODUCE GUSTY WINDS...ROUGH
AND CHOPPY SEAS AS WELL AS SMALL HAIL. ADDITIONALLY...THERE WILL BE
THE POSSIBILITY OF AN ISOLATED WATERSPOUT.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).

&&

$$

PUBLIC...DB
AVIATION/MARINE...RAT
SYNOPSIS...DB

WWW.WEATHER.GOV/LOSANGELES







000
FXUS66 KLOX 281222
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
344 AM PST SAT FEB 28 2015

.SYNOPSIS...
A COLD LOW PRESSURE SYSTEM WILL BRING SHOWERS...POSSIBLE
THUNDERSTORMS AND MOUNTAIN SNOW TO THE AREA THIS WEEKEND. AFTER
A BRIEF BREAK...ANOTHER COLD SYSTEM WILL BRING SIMILAR WEATHER LATE
MONDAY MORNING THROUGH EARLY TUESDAY. DRY WEATHER IS EXPECTED
LATE TUESDAY THROUGH FRIDAY. THERE WILL BE A WARMING TREND...
WITH DAYTIME TEMPERATURES LIKELY ABOVE NORMAL BY THURSDAY.


&&

.SHORT TERM (TODAY-MON)...SKIES WERE GENERALLY MOSTLY CLOUDY ACROSS
THE REGION EARLY THIS MORNING...EXCEPT STILL MOSTLY CLEAR TO
PARTLY CLOUDY ACROSS COASTAL SECTIONS SOUTH OF POINT CONCEPTION.
SOME LIGHT SHOWERS HAVE DEVELOPED IN THE SAN GABRIEL MOUNTAINS AND
IN THE SAN GABRIEL VALLEY...PARTICULARLY IN THE FOOTHILLS. SCATTERED
SHOWERS CONTINUED TO MOVE SOUTHEASTWARD ACROSS THE COASTAL WATERS IN
THIS MORNING. WATER VAPOR IMAGERY SHOWED THE CENTER OF A FAIRLY
STRONG AND VERY COLD UPPER LEVEL LOW OVER EXTREME NORTHERN CA...WITH
A POTENT VORT ON ITS BACKSIDE DROPPING SOUTHWARD OFF THE COAST.

THIS UPPER LOW IS FORECAST TO DROP SOUTHWARD TODAY...WITH THE VORT
HELPING TO PULL THE UPPER CENTER SLIGHTLY OFF THE COAST TO A
POSITION JUST WEST OF MONTEREY BY LATE THIS AFTERNOON. AS THIS
HAPPENS...FLOW THROUGHOUT THE ATMOSPHERE ACROSS SOUTHWESTERN CA
SHOULD BACK FROM NWLY TO WSWLY. SHOWER ACTIVITY THAT WAS MOVING
PARALLEL TO THE COAST IN THE NWLY FLOW EARLY THIS MORNING SHOULD
BEGIN TO MOVE ONSHORE THIS AFTERNOON...ESPECIALLY IN AREAS N OF PT
CONCEPTION. INCREASINGLY MOIST CYCLONIC FLOW AND SOME EXTRA LIFT
SHOULD CAUSE SHOWER ACTIVITY TO BECOME MORE WIDESPREAD S OF PT
CONCEPTION THIS AFTERNOON...ESPECIALLY ACROSS EASTERN L.A. COUNTY.
VERY COLD AIR ALOFT WILL CAUSE INCREASING INSTABILITY...WHICH
SHOULD BRING AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS TO SLO AND
SBA COUNTIES THIS AFTERNOON.

THE UPPER LOW WILL SLOWLY DROP SWD TO NEAR POINT CONCEPTION LATE
TONIGHT...THEN MOVE VERY LITTLE ON SUNDAY...THEN PUSH SLOWLY INTO
LOS ANGELES COUNTY SUNDAY NIGHT. THIS WILL MAINTAIN A MOIST AND
UNSTABLE AIRMASS ACROSS THE REGION...SO EXPECT QUITE A BIT OF SHOWER
ACTIVITY OVERNIGHT THROUGH SUNDAY NIGHT...WITH A SLIGHT CHANCE OF
TSTMS. THE ATMOSPHERIC TEMPERATURE PROFILE WILL BE FAVORABLE FOR
SMALL HAIL...AND INDEED...THIS HAS BEEN REPORTED ACROSS NRN CA.
ANY THUNDERSTORM THIS AFTERNOON THROUGH SUNDAY EVENING WILL HAVE THE
CAPABILITY OF PRODUCING SMALL HAIL AND HEAVY DOWNPOURS. WHILE
SHOWERS MAY OCCUR ANYWHERE AT ANY TIME...IT APPEARS THAT THE BEST
CHANCE OF ORGANIZED SHOWER ACTIVITY WILL BE TONIGHT ACROSS L.A.
COUNTY AND EASTERN VTU COUNTY AS SOME LOW LEVEL SWLY FLOW
DEVELOPS...AND SUNDAY AFTERNOON AND EVENING AS THE UPPER LOW MOVES
OVERHEAD. DUE TO THE SHOWERY NATURE OF THE PRECIPITATION...RAINFALL
TOTALS THROUGH SUNDAY NIGHT WILL BE HIGHLY VARIABLE...BUT GENERAL
TOTALS OF ONE QUARTER TO ONE HALF INCH LOOK REASONABLE...WITH
AMOUNTS OF ONE HALF INCH TO ONE INCH ACROSS THE MOUNTAINS...THE SAN
GABRIEL VALLEY...AND POSSIBLY PORTIONS OF THE REMAINDER OF THE L.A.
COUNTY VALLEYS AND THE VALLEYS OF ERN VTU COUNTIES. LOCAL TOTALS TO
2 INCHES ARE POSSIBLE IN THE SAN GABRIEL MOUNTAINS AND FOOTHILLS.

SNOW WILL BE AN ISSUE FOR TRAVELERS THIS WEEKEND. SNOW LEVELS ARE
EXPECTED TO LOWER TO 4500 FEET LATE TODAY...THEN TO BETWEEN 3500 AND
4000 FEET LATE TONIGHT AND SUNDAY...AND LINGER AT THOSE LEVELS
SUNDAY NIGHT. SNOW MAY WELL AFFECT TRAVEL ACROSS HIGHER PORTIONS OF
INTERSTATE 5...HIGHWAY 14 AND HIGHWAY 33...ESPECIALLY LATE TONIGHT
THROUGH EARLY MONDAY. HAVE EXPANDED WINTER WEATHER ADVISORIES TO
INCLUDE THE MOUNTAINS OF SANTA BARBARA COUNTY. ON AVERAGE...EXPECT A
TOTAL OF 4 TO 8 INCHES OF SNOW BETWEEN 5000 AND 6500 FEET...WITH
TOTALS OF 8 TO 12 INCHES ABOVE 6500 FEET...AND 2 TO 4 INCHES BETWEEN
4000 AND 5000 FEET. THERE COULD BE LOCAL TOTALS AS HIGH AS 18 INCHES
ACROSS PORTIONS OF THE SAN GABRIEL MOUNTAINS...OR HIGHER ELEVATIONS
IN VTU COUNTY. WAS STRONGLY CONSIDERING UPGRADING TO A WINTER STORM
WARNING...BUT HAVE DECIDED AGAINST IT...SINCE THE SNOW ACCUMULATIONS
MAY NOT MEET THE REQUIRED TOTALS IN ANY 12 OR 24 HOUR PERIOD. LATER
SHIFTS MAY WELL HAVE TO UPGRADE DEPENDING UPON SHOWER DEVELOPMENT.

SHOWERS WILL DECREASE ACROSS THE REGION SUNDAY NIGHT...AND MAY END
JUST ABOUT EVERYWHERE. HOWEVER...ANOTHER COLD UPPER LOW DROPPING
RAPIDLY SOUTHWARD WILL LIKELY CAUSE SHOWERS TO BECOME LIKELY AGAIN
MONDAY AFTERNOON...WITH SHOWERS CONTINUING MONDAY NIGHT. THAT SYSTEM
WILL ALSO HAVE LOW SNOW LEVELS...AND PROBABLY ALSO A SLIGHT CHANCE
OF TSTMS. THAT SYSTEM WILL MOVE A BIT FASTER...BUT MAY ALSO TRACK A
BIT FARTHER OFF THE COAST...SO IT MAY PICK UP MORE MOISTURE. SHOWERS
SHOULD WIND DOWN IN MOST AREAS LATE MON NIGHT.

.LONG TERM (TUE-FRI)...THERE COULD BE A FEW LINGERING SHOWERS
TUE...BUT THAT IS LOOKING LESS AND LESS LIKELY. HEIGHTS WILL REBOUND
TUE AFTERNOON...AND WITH SOME SUNSHINE...EXPECT AT LEAST A BIT OR
WARMING. THE 06Z GFS NOW SHOWS A WEAK IMPULSE DROPPING SWD INTO THE
REGION ON WED...AND THAT WAS NOT ON THE PREVIOUS RUN. NO SHOWER
EXPECTED...BUT IT COULD KEEP MAX TEMPS ON THE COOL SIDE. AN UPPER
RIDGE AND HIGHER HEIGHTS WILL BRING WARMER WEATHER THU AND
FRI...WITH DAYTIME TEMPS LIKELY ABOVE NORMAL.


&&

.AVIATION...28/1135Z...

AT 0940Z...THE INVERSION AT KLAX WAS BASED AT 4300 FEET. THE TOP OF
THE INVERSION WAS AT 6300 FEET WITH A TEMPERATURE OF 5 DEGREES
CELSIUS.

OVERALL...LOW CONFIDENCE IN 12Z TAF PACKAGE. INCREASING COLD AND
UNSTABLE AIR MASS WILL GENERATE SHOWERS THROUGHOUT THE TAF PERIOD.
ADDITIONALLY...THERE WILL BE THE POSSIBILITY OF TSTMS FROM THIS
AFTERNOON THROUGH TONIGHT. CIGS WILL VARY RANDOMLY...GENERALLY
BETWEEN MVFR AND VFR LEVELS.

KLAX...LOW CONFIDENCE IN 12Z TAF. CIGS WILL BOUNCE BETWEEN MVFR AND
VFR LEVELS THROUGH THIS AFTERNOON. SHOWERS WILL LIKELY BEGIN LATE
THIS AFTERNOON/EARLY THIS EVENING (ALTHOUGH CONFIDENCE IN EXACT
START TIME IS VERY LOW). CHANCES OF TSTMS AT THE AIRFIELD TONIGHT
WILL BE 10-15%.

KBUR...LOW CONFIDENCE IN 12Z TAF. CIGS WILL BOUNCE BETWEEN MVFR AND
VFR LEVELS THROUGH THIS AFTERNOON. SHOWERS WILL LIKELY BEGIN LATE
THIS AFTERNOON/EARLY THIS EVENING (ALTHOUGH CONFIDENCE IN EXACT
START TIME IS VERY LOW). CHANCES OF TSTMS AT THE AIRFIELD TONIGHT
WILL BE 10-15%.

&&

.MARINE...28/330 AM...

FOR THE OUTER WATERS...HIGH CONFIDENCE IN SMALL CRAFT ADVISORY LEVEL
NORTHWEST WINDS CONTINUING THROUGH THIS MORNING...BEFORE DIMINISHING
BELOW ADVISORY LEVELS THIS AFTERNOON. HIGH CONFIDENCE IN WINDS
REMAINING BELOW SMALL CRAFT ADVISORY LEVELS SUNDAY THROUGH
MONDAY...WITH A CHANCE OF WINDS INCREASING ON TUESDAY.

FOR THE INNER WATERS...HIGH CONFIDENCE IN SMALL CRAFT ADVISORY LEVEL
WEST TO NORTHWEST WINDS CONTINUING THROUGH THIS MORNING...BEFORE
DIMINISHING BELOW ADVISORY LEVELS THIS AFTERNOON. HIGH CONFIDENCE IN
WINDS REMAINING BELOW SMALL CRAFT ADVISORY LEVEL SUNDAY THROUGH
EARLY NEXT WEEK.

A COLD AND UNSTABLE AIR MASS WILL MOVE OVER THE COASTAL WATERS TODAY
AND CONTINUE THROUGH MONDAY. THIS WILL RESULT IN SHOWERS ALONG WITH
THE SLIGHT CHANCE OF THUNDERSTORMS THROUGH THE PERIOD. ANY
THUNDERSTORMS THAT DEVELOP WILL LIKELY PRODUCE GUSTY WINDS...ROUGH
AND CHOPPY SEAS AS WELL AS SMALL HAIL. ADDITIONALLY...THERE WILL BE
THE POSSIBILITY OF AN ISOLATED WATERSPOUT.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).

&&

$$

PUBLIC...DB
AVIATION/MARINE...RAT
SYNOPSIS...DB

WWW.WEATHER.GOV/LOSANGELES






000
FXUS66 KLOX 281222
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
344 AM PST SAT FEB 28 2015

.SYNOPSIS...
A COLD LOW PRESSURE SYSTEM WILL BRING SHOWERS...POSSIBLE
THUNDERSTORMS AND MOUNTAIN SNOW TO THE AREA THIS WEEKEND. AFTER
A BRIEF BREAK...ANOTHER COLD SYSTEM WILL BRING SIMILAR WEATHER LATE
MONDAY MORNING THROUGH EARLY TUESDAY. DRY WEATHER IS EXPECTED
LATE TUESDAY THROUGH FRIDAY. THERE WILL BE A WARMING TREND...
WITH DAYTIME TEMPERATURES LIKELY ABOVE NORMAL BY THURSDAY.


&&

.SHORT TERM (TODAY-MON)...SKIES WERE GENERALLY MOSTLY CLOUDY ACROSS
THE REGION EARLY THIS MORNING...EXCEPT STILL MOSTLY CLEAR TO
PARTLY CLOUDY ACROSS COASTAL SECTIONS SOUTH OF POINT CONCEPTION.
SOME LIGHT SHOWERS HAVE DEVELOPED IN THE SAN GABRIEL MOUNTAINS AND
IN THE SAN GABRIEL VALLEY...PARTICULARLY IN THE FOOTHILLS. SCATTERED
SHOWERS CONTINUED TO MOVE SOUTHEASTWARD ACROSS THE COASTAL WATERS IN
THIS MORNING. WATER VAPOR IMAGERY SHOWED THE CENTER OF A FAIRLY
STRONG AND VERY COLD UPPER LEVEL LOW OVER EXTREME NORTHERN CA...WITH
A POTENT VORT ON ITS BACKSIDE DROPPING SOUTHWARD OFF THE COAST.

THIS UPPER LOW IS FORECAST TO DROP SOUTHWARD TODAY...WITH THE VORT
HELPING TO PULL THE UPPER CENTER SLIGHTLY OFF THE COAST TO A
POSITION JUST WEST OF MONTEREY BY LATE THIS AFTERNOON. AS THIS
HAPPENS...FLOW THROUGHOUT THE ATMOSPHERE ACROSS SOUTHWESTERN CA
SHOULD BACK FROM NWLY TO WSWLY. SHOWER ACTIVITY THAT WAS MOVING
PARALLEL TO THE COAST IN THE NWLY FLOW EARLY THIS MORNING SHOULD
BEGIN TO MOVE ONSHORE THIS AFTERNOON...ESPECIALLY IN AREAS N OF PT
CONCEPTION. INCREASINGLY MOIST CYCLONIC FLOW AND SOME EXTRA LIFT
SHOULD CAUSE SHOWER ACTIVITY TO BECOME MORE WIDESPREAD S OF PT
CONCEPTION THIS AFTERNOON...ESPECIALLY ACROSS EASTERN L.A. COUNTY.
VERY COLD AIR ALOFT WILL CAUSE INCREASING INSTABILITY...WHICH
SHOULD BRING AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS TO SLO AND
SBA COUNTIES THIS AFTERNOON.

THE UPPER LOW WILL SLOWLY DROP SWD TO NEAR POINT CONCEPTION LATE
TONIGHT...THEN MOVE VERY LITTLE ON SUNDAY...THEN PUSH SLOWLY INTO
LOS ANGELES COUNTY SUNDAY NIGHT. THIS WILL MAINTAIN A MOIST AND
UNSTABLE AIRMASS ACROSS THE REGION...SO EXPECT QUITE A BIT OF SHOWER
ACTIVITY OVERNIGHT THROUGH SUNDAY NIGHT...WITH A SLIGHT CHANCE OF
TSTMS. THE ATMOSPHERIC TEMPERATURE PROFILE WILL BE FAVORABLE FOR
SMALL HAIL...AND INDEED...THIS HAS BEEN REPORTED ACROSS NRN CA.
ANY THUNDERSTORM THIS AFTERNOON THROUGH SUNDAY EVENING WILL HAVE THE
CAPABILITY OF PRODUCING SMALL HAIL AND HEAVY DOWNPOURS. WHILE
SHOWERS MAY OCCUR ANYWHERE AT ANY TIME...IT APPEARS THAT THE BEST
CHANCE OF ORGANIZED SHOWER ACTIVITY WILL BE TONIGHT ACROSS L.A.
COUNTY AND EASTERN VTU COUNTY AS SOME LOW LEVEL SWLY FLOW
DEVELOPS...AND SUNDAY AFTERNOON AND EVENING AS THE UPPER LOW MOVES
OVERHEAD. DUE TO THE SHOWERY NATURE OF THE PRECIPITATION...RAINFALL
TOTALS THROUGH SUNDAY NIGHT WILL BE HIGHLY VARIABLE...BUT GENERAL
TOTALS OF ONE QUARTER TO ONE HALF INCH LOOK REASONABLE...WITH
AMOUNTS OF ONE HALF INCH TO ONE INCH ACROSS THE MOUNTAINS...THE SAN
GABRIEL VALLEY...AND POSSIBLY PORTIONS OF THE REMAINDER OF THE L.A.
COUNTY VALLEYS AND THE VALLEYS OF ERN VTU COUNTIES. LOCAL TOTALS TO
2 INCHES ARE POSSIBLE IN THE SAN GABRIEL MOUNTAINS AND FOOTHILLS.

SNOW WILL BE AN ISSUE FOR TRAVELERS THIS WEEKEND. SNOW LEVELS ARE
EXPECTED TO LOWER TO 4500 FEET LATE TODAY...THEN TO BETWEEN 3500 AND
4000 FEET LATE TONIGHT AND SUNDAY...AND LINGER AT THOSE LEVELS
SUNDAY NIGHT. SNOW MAY WELL AFFECT TRAVEL ACROSS HIGHER PORTIONS OF
INTERSTATE 5...HIGHWAY 14 AND HIGHWAY 33...ESPECIALLY LATE TONIGHT
THROUGH EARLY MONDAY. HAVE EXPANDED WINTER WEATHER ADVISORIES TO
INCLUDE THE MOUNTAINS OF SANTA BARBARA COUNTY. ON AVERAGE...EXPECT A
TOTAL OF 4 TO 8 INCHES OF SNOW BETWEEN 5000 AND 6500 FEET...WITH
TOTALS OF 8 TO 12 INCHES ABOVE 6500 FEET...AND 2 TO 4 INCHES BETWEEN
4000 AND 5000 FEET. THERE COULD BE LOCAL TOTALS AS HIGH AS 18 INCHES
ACROSS PORTIONS OF THE SAN GABRIEL MOUNTAINS...OR HIGHER ELEVATIONS
IN VTU COUNTY. WAS STRONGLY CONSIDERING UPGRADING TO A WINTER STORM
WARNING...BUT HAVE DECIDED AGAINST IT...SINCE THE SNOW ACCUMULATIONS
MAY NOT MEET THE REQUIRED TOTALS IN ANY 12 OR 24 HOUR PERIOD. LATER
SHIFTS MAY WELL HAVE TO UPGRADE DEPENDING UPON SHOWER DEVELOPMENT.

SHOWERS WILL DECREASE ACROSS THE REGION SUNDAY NIGHT...AND MAY END
JUST ABOUT EVERYWHERE. HOWEVER...ANOTHER COLD UPPER LOW DROPPING
RAPIDLY SOUTHWARD WILL LIKELY CAUSE SHOWERS TO BECOME LIKELY AGAIN
MONDAY AFTERNOON...WITH SHOWERS CONTINUING MONDAY NIGHT. THAT SYSTEM
WILL ALSO HAVE LOW SNOW LEVELS...AND PROBABLY ALSO A SLIGHT CHANCE
OF TSTMS. THAT SYSTEM WILL MOVE A BIT FASTER...BUT MAY ALSO TRACK A
BIT FARTHER OFF THE COAST...SO IT MAY PICK UP MORE MOISTURE. SHOWERS
SHOULD WIND DOWN IN MOST AREAS LATE MON NIGHT.

.LONG TERM (TUE-FRI)...THERE COULD BE A FEW LINGERING SHOWERS
TUE...BUT THAT IS LOOKING LESS AND LESS LIKELY. HEIGHTS WILL REBOUND
TUE AFTERNOON...AND WITH SOME SUNSHINE...EXPECT AT LEAST A BIT OR
WARMING. THE 06Z GFS NOW SHOWS A WEAK IMPULSE DROPPING SWD INTO THE
REGION ON WED...AND THAT WAS NOT ON THE PREVIOUS RUN. NO SHOWER
EXPECTED...BUT IT COULD KEEP MAX TEMPS ON THE COOL SIDE. AN UPPER
RIDGE AND HIGHER HEIGHTS WILL BRING WARMER WEATHER THU AND
FRI...WITH DAYTIME TEMPS LIKELY ABOVE NORMAL.


&&

.AVIATION...28/1135Z...

AT 0940Z...THE INVERSION AT KLAX WAS BASED AT 4300 FEET. THE TOP OF
THE INVERSION WAS AT 6300 FEET WITH A TEMPERATURE OF 5 DEGREES
CELSIUS.

OVERALL...LOW CONFIDENCE IN 12Z TAF PACKAGE. INCREASING COLD AND
UNSTABLE AIR MASS WILL GENERATE SHOWERS THROUGHOUT THE TAF PERIOD.
ADDITIONALLY...THERE WILL BE THE POSSIBILITY OF TSTMS FROM THIS
AFTERNOON THROUGH TONIGHT. CIGS WILL VARY RANDOMLY...GENERALLY
BETWEEN MVFR AND VFR LEVELS.

KLAX...LOW CONFIDENCE IN 12Z TAF. CIGS WILL BOUNCE BETWEEN MVFR AND
VFR LEVELS THROUGH THIS AFTERNOON. SHOWERS WILL LIKELY BEGIN LATE
THIS AFTERNOON/EARLY THIS EVENING (ALTHOUGH CONFIDENCE IN EXACT
START TIME IS VERY LOW). CHANCES OF TSTMS AT THE AIRFIELD TONIGHT
WILL BE 10-15%.

KBUR...LOW CONFIDENCE IN 12Z TAF. CIGS WILL BOUNCE BETWEEN MVFR AND
VFR LEVELS THROUGH THIS AFTERNOON. SHOWERS WILL LIKELY BEGIN LATE
THIS AFTERNOON/EARLY THIS EVENING (ALTHOUGH CONFIDENCE IN EXACT
START TIME IS VERY LOW). CHANCES OF TSTMS AT THE AIRFIELD TONIGHT
WILL BE 10-15%.

&&

.MARINE...28/330 AM...

FOR THE OUTER WATERS...HIGH CONFIDENCE IN SMALL CRAFT ADVISORY LEVEL
NORTHWEST WINDS CONTINUING THROUGH THIS MORNING...BEFORE DIMINISHING
BELOW ADVISORY LEVELS THIS AFTERNOON. HIGH CONFIDENCE IN WINDS
REMAINING BELOW SMALL CRAFT ADVISORY LEVELS SUNDAY THROUGH
MONDAY...WITH A CHANCE OF WINDS INCREASING ON TUESDAY.

FOR THE INNER WATERS...HIGH CONFIDENCE IN SMALL CRAFT ADVISORY LEVEL
WEST TO NORTHWEST WINDS CONTINUING THROUGH THIS MORNING...BEFORE
DIMINISHING BELOW ADVISORY LEVELS THIS AFTERNOON. HIGH CONFIDENCE IN
WINDS REMAINING BELOW SMALL CRAFT ADVISORY LEVEL SUNDAY THROUGH
EARLY NEXT WEEK.

A COLD AND UNSTABLE AIR MASS WILL MOVE OVER THE COASTAL WATERS TODAY
AND CONTINUE THROUGH MONDAY. THIS WILL RESULT IN SHOWERS ALONG WITH
THE SLIGHT CHANCE OF THUNDERSTORMS THROUGH THE PERIOD. ANY
THUNDERSTORMS THAT DEVELOP WILL LIKELY PRODUCE GUSTY WINDS...ROUGH
AND CHOPPY SEAS AS WELL AS SMALL HAIL. ADDITIONALLY...THERE WILL BE
THE POSSIBILITY OF AN ISOLATED WATERSPOUT.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).

&&

$$

PUBLIC...DB
AVIATION/MARINE...RAT
SYNOPSIS...DB

WWW.WEATHER.GOV/LOSANGELES






000
FXUS66 KLOX 281222
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
344 AM PST SAT FEB 28 2015

.SYNOPSIS...
A COLD LOW PRESSURE SYSTEM WILL BRING SHOWERS...POSSIBLE
THUNDERSTORMS AND MOUNTAIN SNOW TO THE AREA THIS WEEKEND. AFTER
A BRIEF BREAK...ANOTHER COLD SYSTEM WILL BRING SIMILAR WEATHER LATE
MONDAY MORNING THROUGH EARLY TUESDAY. DRY WEATHER IS EXPECTED
LATE TUESDAY THROUGH FRIDAY. THERE WILL BE A WARMING TREND...
WITH DAYTIME TEMPERATURES LIKELY ABOVE NORMAL BY THURSDAY.


&&

.SHORT TERM (TODAY-MON)...SKIES WERE GENERALLY MOSTLY CLOUDY ACROSS
THE REGION EARLY THIS MORNING...EXCEPT STILL MOSTLY CLEAR TO
PARTLY CLOUDY ACROSS COASTAL SECTIONS SOUTH OF POINT CONCEPTION.
SOME LIGHT SHOWERS HAVE DEVELOPED IN THE SAN GABRIEL MOUNTAINS AND
IN THE SAN GABRIEL VALLEY...PARTICULARLY IN THE FOOTHILLS. SCATTERED
SHOWERS CONTINUED TO MOVE SOUTHEASTWARD ACROSS THE COASTAL WATERS IN
THIS MORNING. WATER VAPOR IMAGERY SHOWED THE CENTER OF A FAIRLY
STRONG AND VERY COLD UPPER LEVEL LOW OVER EXTREME NORTHERN CA...WITH
A POTENT VORT ON ITS BACKSIDE DROPPING SOUTHWARD OFF THE COAST.

THIS UPPER LOW IS FORECAST TO DROP SOUTHWARD TODAY...WITH THE VORT
HELPING TO PULL THE UPPER CENTER SLIGHTLY OFF THE COAST TO A
POSITION JUST WEST OF MONTEREY BY LATE THIS AFTERNOON. AS THIS
HAPPENS...FLOW THROUGHOUT THE ATMOSPHERE ACROSS SOUTHWESTERN CA
SHOULD BACK FROM NWLY TO WSWLY. SHOWER ACTIVITY THAT WAS MOVING
PARALLEL TO THE COAST IN THE NWLY FLOW EARLY THIS MORNING SHOULD
BEGIN TO MOVE ONSHORE THIS AFTERNOON...ESPECIALLY IN AREAS N OF PT
CONCEPTION. INCREASINGLY MOIST CYCLONIC FLOW AND SOME EXTRA LIFT
SHOULD CAUSE SHOWER ACTIVITY TO BECOME MORE WIDESPREAD S OF PT
CONCEPTION THIS AFTERNOON...ESPECIALLY ACROSS EASTERN L.A. COUNTY.
VERY COLD AIR ALOFT WILL CAUSE INCREASING INSTABILITY...WHICH
SHOULD BRING AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS TO SLO AND
SBA COUNTIES THIS AFTERNOON.

THE UPPER LOW WILL SLOWLY DROP SWD TO NEAR POINT CONCEPTION LATE
TONIGHT...THEN MOVE VERY LITTLE ON SUNDAY...THEN PUSH SLOWLY INTO
LOS ANGELES COUNTY SUNDAY NIGHT. THIS WILL MAINTAIN A MOIST AND
UNSTABLE AIRMASS ACROSS THE REGION...SO EXPECT QUITE A BIT OF SHOWER
ACTIVITY OVERNIGHT THROUGH SUNDAY NIGHT...WITH A SLIGHT CHANCE OF
TSTMS. THE ATMOSPHERIC TEMPERATURE PROFILE WILL BE FAVORABLE FOR
SMALL HAIL...AND INDEED...THIS HAS BEEN REPORTED ACROSS NRN CA.
ANY THUNDERSTORM THIS AFTERNOON THROUGH SUNDAY EVENING WILL HAVE THE
CAPABILITY OF PRODUCING SMALL HAIL AND HEAVY DOWNPOURS. WHILE
SHOWERS MAY OCCUR ANYWHERE AT ANY TIME...IT APPEARS THAT THE BEST
CHANCE OF ORGANIZED SHOWER ACTIVITY WILL BE TONIGHT ACROSS L.A.
COUNTY AND EASTERN VTU COUNTY AS SOME LOW LEVEL SWLY FLOW
DEVELOPS...AND SUNDAY AFTERNOON AND EVENING AS THE UPPER LOW MOVES
OVERHEAD. DUE TO THE SHOWERY NATURE OF THE PRECIPITATION...RAINFALL
TOTALS THROUGH SUNDAY NIGHT WILL BE HIGHLY VARIABLE...BUT GENERAL
TOTALS OF ONE QUARTER TO ONE HALF INCH LOOK REASONABLE...WITH
AMOUNTS OF ONE HALF INCH TO ONE INCH ACROSS THE MOUNTAINS...THE SAN
GABRIEL VALLEY...AND POSSIBLY PORTIONS OF THE REMAINDER OF THE L.A.
COUNTY VALLEYS AND THE VALLEYS OF ERN VTU COUNTIES. LOCAL TOTALS TO
2 INCHES ARE POSSIBLE IN THE SAN GABRIEL MOUNTAINS AND FOOTHILLS.

SNOW WILL BE AN ISSUE FOR TRAVELERS THIS WEEKEND. SNOW LEVELS ARE
EXPECTED TO LOWER TO 4500 FEET LATE TODAY...THEN TO BETWEEN 3500 AND
4000 FEET LATE TONIGHT AND SUNDAY...AND LINGER AT THOSE LEVELS
SUNDAY NIGHT. SNOW MAY WELL AFFECT TRAVEL ACROSS HIGHER PORTIONS OF
INTERSTATE 5...HIGHWAY 14 AND HIGHWAY 33...ESPECIALLY LATE TONIGHT
THROUGH EARLY MONDAY. HAVE EXPANDED WINTER WEATHER ADVISORIES TO
INCLUDE THE MOUNTAINS OF SANTA BARBARA COUNTY. ON AVERAGE...EXPECT A
TOTAL OF 4 TO 8 INCHES OF SNOW BETWEEN 5000 AND 6500 FEET...WITH
TOTALS OF 8 TO 12 INCHES ABOVE 6500 FEET...AND 2 TO 4 INCHES BETWEEN
4000 AND 5000 FEET. THERE COULD BE LOCAL TOTALS AS HIGH AS 18 INCHES
ACROSS PORTIONS OF THE SAN GABRIEL MOUNTAINS...OR HIGHER ELEVATIONS
IN VTU COUNTY. WAS STRONGLY CONSIDERING UPGRADING TO A WINTER STORM
WARNING...BUT HAVE DECIDED AGAINST IT...SINCE THE SNOW ACCUMULATIONS
MAY NOT MEET THE REQUIRED TOTALS IN ANY 12 OR 24 HOUR PERIOD. LATER
SHIFTS MAY WELL HAVE TO UPGRADE DEPENDING UPON SHOWER DEVELOPMENT.

SHOWERS WILL DECREASE ACROSS THE REGION SUNDAY NIGHT...AND MAY END
JUST ABOUT EVERYWHERE. HOWEVER...ANOTHER COLD UPPER LOW DROPPING
RAPIDLY SOUTHWARD WILL LIKELY CAUSE SHOWERS TO BECOME LIKELY AGAIN
MONDAY AFTERNOON...WITH SHOWERS CONTINUING MONDAY NIGHT. THAT SYSTEM
WILL ALSO HAVE LOW SNOW LEVELS...AND PROBABLY ALSO A SLIGHT CHANCE
OF TSTMS. THAT SYSTEM WILL MOVE A BIT FASTER...BUT MAY ALSO TRACK A
BIT FARTHER OFF THE COAST...SO IT MAY PICK UP MORE MOISTURE. SHOWERS
SHOULD WIND DOWN IN MOST AREAS LATE MON NIGHT.

.LONG TERM (TUE-FRI)...THERE COULD BE A FEW LINGERING SHOWERS
TUE...BUT THAT IS LOOKING LESS AND LESS LIKELY. HEIGHTS WILL REBOUND
TUE AFTERNOON...AND WITH SOME SUNSHINE...EXPECT AT LEAST A BIT OR
WARMING. THE 06Z GFS NOW SHOWS A WEAK IMPULSE DROPPING SWD INTO THE
REGION ON WED...AND THAT WAS NOT ON THE PREVIOUS RUN. NO SHOWER
EXPECTED...BUT IT COULD KEEP MAX TEMPS ON THE COOL SIDE. AN UPPER
RIDGE AND HIGHER HEIGHTS WILL BRING WARMER WEATHER THU AND
FRI...WITH DAYTIME TEMPS LIKELY ABOVE NORMAL.


&&

.AVIATION...28/1135Z...

AT 0940Z...THE INVERSION AT KLAX WAS BASED AT 4300 FEET. THE TOP OF
THE INVERSION WAS AT 6300 FEET WITH A TEMPERATURE OF 5 DEGREES
CELSIUS.

OVERALL...LOW CONFIDENCE IN 12Z TAF PACKAGE. INCREASING COLD AND
UNSTABLE AIR MASS WILL GENERATE SHOWERS THROUGHOUT THE TAF PERIOD.
ADDITIONALLY...THERE WILL BE THE POSSIBILITY OF TSTMS FROM THIS
AFTERNOON THROUGH TONIGHT. CIGS WILL VARY RANDOMLY...GENERALLY
BETWEEN MVFR AND VFR LEVELS.

KLAX...LOW CONFIDENCE IN 12Z TAF. CIGS WILL BOUNCE BETWEEN MVFR AND
VFR LEVELS THROUGH THIS AFTERNOON. SHOWERS WILL LIKELY BEGIN LATE
THIS AFTERNOON/EARLY THIS EVENING (ALTHOUGH CONFIDENCE IN EXACT
START TIME IS VERY LOW). CHANCES OF TSTMS AT THE AIRFIELD TONIGHT
WILL BE 10-15%.

KBUR...LOW CONFIDENCE IN 12Z TAF. CIGS WILL BOUNCE BETWEEN MVFR AND
VFR LEVELS THROUGH THIS AFTERNOON. SHOWERS WILL LIKELY BEGIN LATE
THIS AFTERNOON/EARLY THIS EVENING (ALTHOUGH CONFIDENCE IN EXACT
START TIME IS VERY LOW). CHANCES OF TSTMS AT THE AIRFIELD TONIGHT
WILL BE 10-15%.

&&

.MARINE...28/330 AM...

FOR THE OUTER WATERS...HIGH CONFIDENCE IN SMALL CRAFT ADVISORY LEVEL
NORTHWEST WINDS CONTINUING THROUGH THIS MORNING...BEFORE DIMINISHING
BELOW ADVISORY LEVELS THIS AFTERNOON. HIGH CONFIDENCE IN WINDS
REMAINING BELOW SMALL CRAFT ADVISORY LEVELS SUNDAY THROUGH
MONDAY...WITH A CHANCE OF WINDS INCREASING ON TUESDAY.

FOR THE INNER WATERS...HIGH CONFIDENCE IN SMALL CRAFT ADVISORY LEVEL
WEST TO NORTHWEST WINDS CONTINUING THROUGH THIS MORNING...BEFORE
DIMINISHING BELOW ADVISORY LEVELS THIS AFTERNOON. HIGH CONFIDENCE IN
WINDS REMAINING BELOW SMALL CRAFT ADVISORY LEVEL SUNDAY THROUGH
EARLY NEXT WEEK.

A COLD AND UNSTABLE AIR MASS WILL MOVE OVER THE COASTAL WATERS TODAY
AND CONTINUE THROUGH MONDAY. THIS WILL RESULT IN SHOWERS ALONG WITH
THE SLIGHT CHANCE OF THUNDERSTORMS THROUGH THE PERIOD. ANY
THUNDERSTORMS THAT DEVELOP WILL LIKELY PRODUCE GUSTY WINDS...ROUGH
AND CHOPPY SEAS AS WELL AS SMALL HAIL. ADDITIONALLY...THERE WILL BE
THE POSSIBILITY OF AN ISOLATED WATERSPOUT.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).

&&

$$

PUBLIC...DB
AVIATION/MARINE...RAT
SYNOPSIS...DB

WWW.WEATHER.GOV/LOSANGELES







000
FXUS66 KLOX 280519
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
920 PM PST FRI FEB 27 2015

.SYNOPSIS...

A COLD LOW PRESSURE SYSTEM WILL BRING SCATTERED SHOWERS...POSSIBLE
THUNDERSTORMS AND MOUNTAIN SNOW TO THE AREA THIS WEEKEND. A WEAKER
SYSTEM WILL BE ON THE HEELS OF THE FIRST ARRIVING MONDAY INTO
TUESDAY MORNING. DRIER CONDITIONS AND OFFSHORE BREEZES ARE EXPECTED
TO BRING ABOVE NORMAL TEMPERATURES TO THE AREA BY LATE NEXT WEEK.

&&

.SHORT TERM (TONIGHT-MON)...PLENTY OF STRATOCU COVERED THE FORECAST
AREA THIS EVENING AS A COOL AND MOIST AIRMASS CONTINUED TO FILTER
INTO THE AREA FROM THE NORTH. THERE WERE ISOLATED SHOWERS NOTED OVER
THE EASTERN SAN GABRIEL VLY WHICH PRODUCED A FEW HUNDREDTHS OF AN
INCH OF PRECIP. A SLIGHT CHANCE TO CHANCE OF SHOWERS WILL PERSIST
ACROSS SWRN CA THRU THE NIGHT AS AN UPPER LOW CONTINUES TO APPROACH
THE AREA FROM NRN CA. GOOD ONSHORE FLOW PRODUCED GUSTY W TO NW WINDS
FOR MOST COASTAL AREAS THIS EVENING...AND THESE WINDS MAY PERSIST
FOR A WHILE OVERNIGHT...ESPECIALLY FOR VTU/L.A. COUNTIES. THERE WERE
ALSO GUSTY NW TO N CANYON WINDS AFFECTING THE SBA S COAST AND MTNS
THIS EVENING...WITH A WIND ADVISORY IN EFFECT THERE UNTIL 10 PM.

THE UPPER LOW WILL CONTINUE TO SLIDE S ON SAT TO A POSITION AROUND
MONTEREY COUNTY IN THE AFTERNOON...THEN TO A POSITION OVER SBA
COUNTY SAT NIGHT AND SUN. THIS UPPER LOW WILL MOVE SLOWLY E SUN
NIGHT...THEN ANOTHER UPPER LEVEL LOW WILL APPROACH FROM THE N ON
MON. THESE UPPER LEVEL LOW PRESSURE SYSTEMS WILL BRING PLENTY OF
SHOWERS AND MOUNTAIN SNOW SHOWERS TO THE FORECAST AREA SAT THRU SUN
EVENING...WITH MORE SHOWERS INTO MON. COLD...UNSTABLE AIR ALOFT (500
MB TEMPS DROPPING TO -26 TO -28 DEG C) WILL ALSO BRING A THREAT OF
THUNDERSTORMS TO THE REGION SAT THRU SUN EVENING. AN ISOLATED
THUNDERSTORM CANNOT BE RULED OUT MON AFTERNOON AND EVENING AS WELL.
ANY THUNDERSTORMS THAT DEVELOP WOULD BE CAPABLE OF PRODUCING BRIEF
HEAVY RAIN...GUSTY WINDS AND SMALL HAIL.

THIS WILL BE A SHOWERY WEATHER SYSTEM AND PRECIP AMOUNTS WILL BE
QUITE VARIABLE. OVERALL...0.10 TO 0.50 INCH LOOKS REASONABLE FOR THE
COAST AND VLYS...WITH 0.50 TO 1.50 INCHES IN THE MOUNTAINS. ISOLATED
PRECIPITATION TOTALS COULD BE UP TO AN INCH FOR THE COAST AND VLYS
AND UP TO 2.00 INCHES OR MORE FOR THE MTNS.

SNOW LEVELS WILL FALL TO 5000 FEET BY SAT AFTERNOON...TO 4000 FEET
SAT NIGHT...AND TO 3500 TO 4000 FEET ON SUN. SIGNIFICANT
ACCUMULATING SNOW OVER THE WEEKEND IS EXPECTED FOR THE MTNS...WITH
6-12 INCHES POSSIBLE IN THE MOUNTAINS ABOVE 7000 FEET...4-8 INCHES
FROM 5000 TO 7000 FEET...AND 2 TO 5 INCHES DOWN TO 5000 FEET.
ACCUMULATIONS LESS THAN AN INCH WILL BE POSSIBLE DOWN TO 4000 FEET
MAINLY SUNDAY AND SUNDAY NIGHT. EVEN SO...THERE MAY BE TRAVEL
PROBLEMS OVER ON THE I-5 OVER THE GRAPEVINE LATE IN THE WEEKEND. A
WINTER WEATHER ADVISORY IS IN EFFECT FOR THE MTNS OF VTU/L.A.
COUNTIES FROM LATE SAT AFTERNOON TO LATE SUN NIGHT.

ADDITIONAL PRECIP AMOUNTS LATER SUN NIGHT AND MON COULD TOTAL 0.10
TO 0.25 INCH FOR MOST AREAS...WITH AN INCH OR TWO OF SNOW
ACCUMULATION POSSIBLE IN THE MTNS DOWN TO 4500 FEET.

NEEDLESS TO SAY...WITH THE COLD UPPER LEVEL SYSTEMS OVER SWRN
CA...TEMPERATURES ACROSS THE REGION WILL BE SEVERAL DEGREES BELOW
NORMAL SAT THRU MON.

***FROM PREVIOUS DISCUSSION***

.LONG TERM (TUE-FRI)...THE UPPER LOW THAT ZIPS IN BEHIND THE WEEKEND
LOW AND MOVES THROUGH MONDAY NIGHT AND EARLY TUESDAY IS NOT AS
STRONG OR DEEP SO EXPECT PRECIPITATION AMOUNTS TO BE LESS. HEIGHT
RISES MOVE IN ON TUESDAY TO START A WARMING AND DRYING TREND FOR THE
REMAINDER OF THE WEEK...AND PEAKING THURSDAY...WITH SOME WEAK
OFFSHORE FLOW TO KEEP SKIES CLEAR.

&&

.AVIATION...28/0015Z.

AT 2305Z...THE MARINE INVERSION AT KLAX WAS AT 4700 FEET DEEP...THE
TOP OF THE INVERSION WAS AT 6300 FT WITH A TEMP OF 7 DEG C.

MODERATE CONFIDENCE AT BEST IN THE 00Z TAFS. MOSTLY VFR CIGS ARE
EXPECTED AT THE AIRFIELDS THRU SAT...HOWEVER THERE IS A 40-50
PERCENT CHANCE OF MVFR CIGS PREVAILING FOR MOST OF THE TIME DURING
THE DAY ON SAT FOR MANY AIRFIELDS. OTHERWISE...MVFR CIGS MAY BE
INTERMITTENT AT TIMES DURING THE TAF PERIOD. THERE WILL ALSO BE A
CHANCE OF SHOWERS MAINLY ON SAT WITH SOME REDUCED VSBYS AT TIMES. A
SLIGHT CHANCE OF THUNDERSTORMS CAN BE EXPECTED AS WELL ON SAT
AFTERNOON. GUSTY WINDS WILL AFFECT KSMX...KSBP AND KSBA THIS
EVENING...WITH LOW LEVEL WIND SHEAR POSSIBLE AT KSBA FROM 02Z-09Z.
GUSTY SW TO W WINDS WILL AFFECT KPRB AND KWJF THRU SAT.

KLAX...MODERATE CONFIDENCE AT BEST IN THE 00Z TAF. MOSTLY VFR CIGS
ARE EXPECTED AT THE AIRFIELD THRU SAT EVENING...WITH SOME PERIODS OF
MVFR CIGS. HOWEVER THERE IS A 40-50 PERCENT CHANCE OF MVFR CIGS
PREVAILING FOR MOST OF THE TIME DURING THE DAY ON SAT INTO SAT
EVENING. THERE WILL ALSO BE A CHANCE OF SHOWERS ON SAT AND SAT
EVENING WITH A 30-40 PERCENT CHANCE OF MVFR VSBYS AT TIMES. A SLIGHT
CHANCE OF THUNDERSTORMS CAN BE EXPECTED AS WELL SAT EVENING.

KBUR...MODERATE CONFIDENCE AT BEST IN THE 00Z TAF. MOSTLY VFR CIGS
ARE EXPECTED AT THE AIRFIELD THRU SAT...WITH SOME PERIODS OF MVFR
CIGS. HOWEVER THERE IS A 40-50 PERCENT CHANCE OF MVFR CIGS
PREVAILING FOR MOST OF THE TIME DURING THE DAY ON SAT. THERE WILL
ALSO BE A CHANCE OF SHOWERS ON SAT WITH A 30-40 PERCENT CHANCE OF
MVFR VSBYS AT TIMES.

&&

.MARINE...27/800 PM...

FOR THE OUTER WATERS...SCA CONDITIONS WILL CONTINUE THROUGH LATE
TONIGHT FOR PZZ670/673...AND TO 9 AM SAT FOR PZZ676. WINDS WILL
DIMINISH THROUGH THE WEEKEND THEN INCREASE TO GALE OR NEAR-GALE
MONDAY NIGHT INTO TUESDAY...BUT THIS IS LOWER CONFIDENCE AS MODEL
AGREEMENT IS NOT VERY GOOD AT THIS TIME.

FOR THE INNER WATERS...GOOD CONFIDENCE IN SCA LEVEL WINDS ACROSS
PZZ650/655 THROUGH MID MORNING SAT. THE STRONGEST WINDS WILL BE
ACROSS THE WESTERN SECTIONS FROM THE CHANNEL ISLANDS TO CATALINA
ISLAND...WHERE GUSTS TO 30 KNOTS WILL BE POSSIBLE. SHORT PERIOD
ROUGH SEAS ARE EXPECTED.

SHOWERS ARE EXPECTED ACROSS THE WATERS THIS WEEKEND AS A COUPLE OF
FRONTAL SYSTEMS CROSS THE AREA. FROM SATURDAY AFTERNOON THROUGH
SUNDAY EVENING...THERE WILL BE A SLIGHT CHANCE OF THUNDERSTORMS WITH
LOCALLY GUSTY WINDS...ROUGH CHOPPY SEAS...AND POSSIBLE WATERSPOUTS.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH (SEE LAXWSWLOX).
WIND ADVISORY (SEE LAXNPWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).

&&

$$

PUBLIC...SIRARD/JACKSON
AVIATION...SIRARD
MARINE...SMITH/SIRARD
SYNOPSIS...B

WWW.WEATHER.GOV/LOSANGELES






000
FXUS66 KLOX 280519
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
920 PM PST FRI FEB 27 2015

.SYNOPSIS...

A COLD LOW PRESSURE SYSTEM WILL BRING SCATTERED SHOWERS...POSSIBLE
THUNDERSTORMS AND MOUNTAIN SNOW TO THE AREA THIS WEEKEND. A WEAKER
SYSTEM WILL BE ON THE HEELS OF THE FIRST ARRIVING MONDAY INTO
TUESDAY MORNING. DRIER CONDITIONS AND OFFSHORE BREEZES ARE EXPECTED
TO BRING ABOVE NORMAL TEMPERATURES TO THE AREA BY LATE NEXT WEEK.

&&

.SHORT TERM (TONIGHT-MON)...PLENTY OF STRATOCU COVERED THE FORECAST
AREA THIS EVENING AS A COOL AND MOIST AIRMASS CONTINUED TO FILTER
INTO THE AREA FROM THE NORTH. THERE WERE ISOLATED SHOWERS NOTED OVER
THE EASTERN SAN GABRIEL VLY WHICH PRODUCED A FEW HUNDREDTHS OF AN
INCH OF PRECIP. A SLIGHT CHANCE TO CHANCE OF SHOWERS WILL PERSIST
ACROSS SWRN CA THRU THE NIGHT AS AN UPPER LOW CONTINUES TO APPROACH
THE AREA FROM NRN CA. GOOD ONSHORE FLOW PRODUCED GUSTY W TO NW WINDS
FOR MOST COASTAL AREAS THIS EVENING...AND THESE WINDS MAY PERSIST
FOR A WHILE OVERNIGHT...ESPECIALLY FOR VTU/L.A. COUNTIES. THERE WERE
ALSO GUSTY NW TO N CANYON WINDS AFFECTING THE SBA S COAST AND MTNS
THIS EVENING...WITH A WIND ADVISORY IN EFFECT THERE UNTIL 10 PM.

THE UPPER LOW WILL CONTINUE TO SLIDE S ON SAT TO A POSITION AROUND
MONTEREY COUNTY IN THE AFTERNOON...THEN TO A POSITION OVER SBA
COUNTY SAT NIGHT AND SUN. THIS UPPER LOW WILL MOVE SLOWLY E SUN
NIGHT...THEN ANOTHER UPPER LEVEL LOW WILL APPROACH FROM THE N ON
MON. THESE UPPER LEVEL LOW PRESSURE SYSTEMS WILL BRING PLENTY OF
SHOWERS AND MOUNTAIN SNOW SHOWERS TO THE FORECAST AREA SAT THRU SUN
EVENING...WITH MORE SHOWERS INTO MON. COLD...UNSTABLE AIR ALOFT (500
MB TEMPS DROPPING TO -26 TO -28 DEG C) WILL ALSO BRING A THREAT OF
THUNDERSTORMS TO THE REGION SAT THRU SUN EVENING. AN ISOLATED
THUNDERSTORM CANNOT BE RULED OUT MON AFTERNOON AND EVENING AS WELL.
ANY THUNDERSTORMS THAT DEVELOP WOULD BE CAPABLE OF PRODUCING BRIEF
HEAVY RAIN...GUSTY WINDS AND SMALL HAIL.

THIS WILL BE A SHOWERY WEATHER SYSTEM AND PRECIP AMOUNTS WILL BE
QUITE VARIABLE. OVERALL...0.10 TO 0.50 INCH LOOKS REASONABLE FOR THE
COAST AND VLYS...WITH 0.50 TO 1.50 INCHES IN THE MOUNTAINS. ISOLATED
PRECIPITATION TOTALS COULD BE UP TO AN INCH FOR THE COAST AND VLYS
AND UP TO 2.00 INCHES OR MORE FOR THE MTNS.

SNOW LEVELS WILL FALL TO 5000 FEET BY SAT AFTERNOON...TO 4000 FEET
SAT NIGHT...AND TO 3500 TO 4000 FEET ON SUN. SIGNIFICANT
ACCUMULATING SNOW OVER THE WEEKEND IS EXPECTED FOR THE MTNS...WITH
6-12 INCHES POSSIBLE IN THE MOUNTAINS ABOVE 7000 FEET...4-8 INCHES
FROM 5000 TO 7000 FEET...AND 2 TO 5 INCHES DOWN TO 5000 FEET.
ACCUMULATIONS LESS THAN AN INCH WILL BE POSSIBLE DOWN TO 4000 FEET
MAINLY SUNDAY AND SUNDAY NIGHT. EVEN SO...THERE MAY BE TRAVEL
PROBLEMS OVER ON THE I-5 OVER THE GRAPEVINE LATE IN THE WEEKEND. A
WINTER WEATHER ADVISORY IS IN EFFECT FOR THE MTNS OF VTU/L.A.
COUNTIES FROM LATE SAT AFTERNOON TO LATE SUN NIGHT.

ADDITIONAL PRECIP AMOUNTS LATER SUN NIGHT AND MON COULD TOTAL 0.10
TO 0.25 INCH FOR MOST AREAS...WITH AN INCH OR TWO OF SNOW
ACCUMULATION POSSIBLE IN THE MTNS DOWN TO 4500 FEET.

NEEDLESS TO SAY...WITH THE COLD UPPER LEVEL SYSTEMS OVER SWRN
CA...TEMPERATURES ACROSS THE REGION WILL BE SEVERAL DEGREES BELOW
NORMAL SAT THRU MON.

***FROM PREVIOUS DISCUSSION***

.LONG TERM (TUE-FRI)...THE UPPER LOW THAT ZIPS IN BEHIND THE WEEKEND
LOW AND MOVES THROUGH MONDAY NIGHT AND EARLY TUESDAY IS NOT AS
STRONG OR DEEP SO EXPECT PRECIPITATION AMOUNTS TO BE LESS. HEIGHT
RISES MOVE IN ON TUESDAY TO START A WARMING AND DRYING TREND FOR THE
REMAINDER OF THE WEEK...AND PEAKING THURSDAY...WITH SOME WEAK
OFFSHORE FLOW TO KEEP SKIES CLEAR.

&&

.AVIATION...28/0015Z.

AT 2305Z...THE MARINE INVERSION AT KLAX WAS AT 4700 FEET DEEP...THE
TOP OF THE INVERSION WAS AT 6300 FT WITH A TEMP OF 7 DEG C.

MODERATE CONFIDENCE AT BEST IN THE 00Z TAFS. MOSTLY VFR CIGS ARE
EXPECTED AT THE AIRFIELDS THRU SAT...HOWEVER THERE IS A 40-50
PERCENT CHANCE OF MVFR CIGS PREVAILING FOR MOST OF THE TIME DURING
THE DAY ON SAT FOR MANY AIRFIELDS. OTHERWISE...MVFR CIGS MAY BE
INTERMITTENT AT TIMES DURING THE TAF PERIOD. THERE WILL ALSO BE A
CHANCE OF SHOWERS MAINLY ON SAT WITH SOME REDUCED VSBYS AT TIMES. A
SLIGHT CHANCE OF THUNDERSTORMS CAN BE EXPECTED AS WELL ON SAT
AFTERNOON. GUSTY WINDS WILL AFFECT KSMX...KSBP AND KSBA THIS
EVENING...WITH LOW LEVEL WIND SHEAR POSSIBLE AT KSBA FROM 02Z-09Z.
GUSTY SW TO W WINDS WILL AFFECT KPRB AND KWJF THRU SAT.

KLAX...MODERATE CONFIDENCE AT BEST IN THE 00Z TAF. MOSTLY VFR CIGS
ARE EXPECTED AT THE AIRFIELD THRU SAT EVENING...WITH SOME PERIODS OF
MVFR CIGS. HOWEVER THERE IS A 40-50 PERCENT CHANCE OF MVFR CIGS
PREVAILING FOR MOST OF THE TIME DURING THE DAY ON SAT INTO SAT
EVENING. THERE WILL ALSO BE A CHANCE OF SHOWERS ON SAT AND SAT
EVENING WITH A 30-40 PERCENT CHANCE OF MVFR VSBYS AT TIMES. A SLIGHT
CHANCE OF THUNDERSTORMS CAN BE EXPECTED AS WELL SAT EVENING.

KBUR...MODERATE CONFIDENCE AT BEST IN THE 00Z TAF. MOSTLY VFR CIGS
ARE EXPECTED AT THE AIRFIELD THRU SAT...WITH SOME PERIODS OF MVFR
CIGS. HOWEVER THERE IS A 40-50 PERCENT CHANCE OF MVFR CIGS
PREVAILING FOR MOST OF THE TIME DURING THE DAY ON SAT. THERE WILL
ALSO BE A CHANCE OF SHOWERS ON SAT WITH A 30-40 PERCENT CHANCE OF
MVFR VSBYS AT TIMES.

&&

.MARINE...27/800 PM...

FOR THE OUTER WATERS...SCA CONDITIONS WILL CONTINUE THROUGH LATE
TONIGHT FOR PZZ670/673...AND TO 9 AM SAT FOR PZZ676. WINDS WILL
DIMINISH THROUGH THE WEEKEND THEN INCREASE TO GALE OR NEAR-GALE
MONDAY NIGHT INTO TUESDAY...BUT THIS IS LOWER CONFIDENCE AS MODEL
AGREEMENT IS NOT VERY GOOD AT THIS TIME.

FOR THE INNER WATERS...GOOD CONFIDENCE IN SCA LEVEL WINDS ACROSS
PZZ650/655 THROUGH MID MORNING SAT. THE STRONGEST WINDS WILL BE
ACROSS THE WESTERN SECTIONS FROM THE CHANNEL ISLANDS TO CATALINA
ISLAND...WHERE GUSTS TO 30 KNOTS WILL BE POSSIBLE. SHORT PERIOD
ROUGH SEAS ARE EXPECTED.

SHOWERS ARE EXPECTED ACROSS THE WATERS THIS WEEKEND AS A COUPLE OF
FRONTAL SYSTEMS CROSS THE AREA. FROM SATURDAY AFTERNOON THROUGH
SUNDAY EVENING...THERE WILL BE A SLIGHT CHANCE OF THUNDERSTORMS WITH
LOCALLY GUSTY WINDS...ROUGH CHOPPY SEAS...AND POSSIBLE WATERSPOUTS.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH (SEE LAXWSWLOX).
WIND ADVISORY (SEE LAXNPWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).

&&

$$

PUBLIC...SIRARD/JACKSON
AVIATION...SIRARD
MARINE...SMITH/SIRARD
SYNOPSIS...B

WWW.WEATHER.GOV/LOSANGELES






000
FXUS66 KLOX 280519
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
920 PM PST FRI FEB 27 2015

.SYNOPSIS...

A COLD LOW PRESSURE SYSTEM WILL BRING SCATTERED SHOWERS...POSSIBLE
THUNDERSTORMS AND MOUNTAIN SNOW TO THE AREA THIS WEEKEND. A WEAKER
SYSTEM WILL BE ON THE HEELS OF THE FIRST ARRIVING MONDAY INTO
TUESDAY MORNING. DRIER CONDITIONS AND OFFSHORE BREEZES ARE EXPECTED
TO BRING ABOVE NORMAL TEMPERATURES TO THE AREA BY LATE NEXT WEEK.

&&

.SHORT TERM (TONIGHT-MON)...PLENTY OF STRATOCU COVERED THE FORECAST
AREA THIS EVENING AS A COOL AND MOIST AIRMASS CONTINUED TO FILTER
INTO THE AREA FROM THE NORTH. THERE WERE ISOLATED SHOWERS NOTED OVER
THE EASTERN SAN GABRIEL VLY WHICH PRODUCED A FEW HUNDREDTHS OF AN
INCH OF PRECIP. A SLIGHT CHANCE TO CHANCE OF SHOWERS WILL PERSIST
ACROSS SWRN CA THRU THE NIGHT AS AN UPPER LOW CONTINUES TO APPROACH
THE AREA FROM NRN CA. GOOD ONSHORE FLOW PRODUCED GUSTY W TO NW WINDS
FOR MOST COASTAL AREAS THIS EVENING...AND THESE WINDS MAY PERSIST
FOR A WHILE OVERNIGHT...ESPECIALLY FOR VTU/L.A. COUNTIES. THERE WERE
ALSO GUSTY NW TO N CANYON WINDS AFFECTING THE SBA S COAST AND MTNS
THIS EVENING...WITH A WIND ADVISORY IN EFFECT THERE UNTIL 10 PM.

THE UPPER LOW WILL CONTINUE TO SLIDE S ON SAT TO A POSITION AROUND
MONTEREY COUNTY IN THE AFTERNOON...THEN TO A POSITION OVER SBA
COUNTY SAT NIGHT AND SUN. THIS UPPER LOW WILL MOVE SLOWLY E SUN
NIGHT...THEN ANOTHER UPPER LEVEL LOW WILL APPROACH FROM THE N ON
MON. THESE UPPER LEVEL LOW PRESSURE SYSTEMS WILL BRING PLENTY OF
SHOWERS AND MOUNTAIN SNOW SHOWERS TO THE FORECAST AREA SAT THRU SUN
EVENING...WITH MORE SHOWERS INTO MON. COLD...UNSTABLE AIR ALOFT (500
MB TEMPS DROPPING TO -26 TO -28 DEG C) WILL ALSO BRING A THREAT OF
THUNDERSTORMS TO THE REGION SAT THRU SUN EVENING. AN ISOLATED
THUNDERSTORM CANNOT BE RULED OUT MON AFTERNOON AND EVENING AS WELL.
ANY THUNDERSTORMS THAT DEVELOP WOULD BE CAPABLE OF PRODUCING BRIEF
HEAVY RAIN...GUSTY WINDS AND SMALL HAIL.

THIS WILL BE A SHOWERY WEATHER SYSTEM AND PRECIP AMOUNTS WILL BE
QUITE VARIABLE. OVERALL...0.10 TO 0.50 INCH LOOKS REASONABLE FOR THE
COAST AND VLYS...WITH 0.50 TO 1.50 INCHES IN THE MOUNTAINS. ISOLATED
PRECIPITATION TOTALS COULD BE UP TO AN INCH FOR THE COAST AND VLYS
AND UP TO 2.00 INCHES OR MORE FOR THE MTNS.

SNOW LEVELS WILL FALL TO 5000 FEET BY SAT AFTERNOON...TO 4000 FEET
SAT NIGHT...AND TO 3500 TO 4000 FEET ON SUN. SIGNIFICANT
ACCUMULATING SNOW OVER THE WEEKEND IS EXPECTED FOR THE MTNS...WITH
6-12 INCHES POSSIBLE IN THE MOUNTAINS ABOVE 7000 FEET...4-8 INCHES
FROM 5000 TO 7000 FEET...AND 2 TO 5 INCHES DOWN TO 5000 FEET.
ACCUMULATIONS LESS THAN AN INCH WILL BE POSSIBLE DOWN TO 4000 FEET
MAINLY SUNDAY AND SUNDAY NIGHT. EVEN SO...THERE MAY BE TRAVEL
PROBLEMS OVER ON THE I-5 OVER THE GRAPEVINE LATE IN THE WEEKEND. A
WINTER WEATHER ADVISORY IS IN EFFECT FOR THE MTNS OF VTU/L.A.
COUNTIES FROM LATE SAT AFTERNOON TO LATE SUN NIGHT.

ADDITIONAL PRECIP AMOUNTS LATER SUN NIGHT AND MON COULD TOTAL 0.10
TO 0.25 INCH FOR MOST AREAS...WITH AN INCH OR TWO OF SNOW
ACCUMULATION POSSIBLE IN THE MTNS DOWN TO 4500 FEET.

NEEDLESS TO SAY...WITH THE COLD UPPER LEVEL SYSTEMS OVER SWRN
CA...TEMPERATURES ACROSS THE REGION WILL BE SEVERAL DEGREES BELOW
NORMAL SAT THRU MON.

***FROM PREVIOUS DISCUSSION***

.LONG TERM (TUE-FRI)...THE UPPER LOW THAT ZIPS IN BEHIND THE WEEKEND
LOW AND MOVES THROUGH MONDAY NIGHT AND EARLY TUESDAY IS NOT AS
STRONG OR DEEP SO EXPECT PRECIPITATION AMOUNTS TO BE LESS. HEIGHT
RISES MOVE IN ON TUESDAY TO START A WARMING AND DRYING TREND FOR THE
REMAINDER OF THE WEEK...AND PEAKING THURSDAY...WITH SOME WEAK
OFFSHORE FLOW TO KEEP SKIES CLEAR.

&&

.AVIATION...28/0015Z.

AT 2305Z...THE MARINE INVERSION AT KLAX WAS AT 4700 FEET DEEP...THE
TOP OF THE INVERSION WAS AT 6300 FT WITH A TEMP OF 7 DEG C.

MODERATE CONFIDENCE AT BEST IN THE 00Z TAFS. MOSTLY VFR CIGS ARE
EXPECTED AT THE AIRFIELDS THRU SAT...HOWEVER THERE IS A 40-50
PERCENT CHANCE OF MVFR CIGS PREVAILING FOR MOST OF THE TIME DURING
THE DAY ON SAT FOR MANY AIRFIELDS. OTHERWISE...MVFR CIGS MAY BE
INTERMITTENT AT TIMES DURING THE TAF PERIOD. THERE WILL ALSO BE A
CHANCE OF SHOWERS MAINLY ON SAT WITH SOME REDUCED VSBYS AT TIMES. A
SLIGHT CHANCE OF THUNDERSTORMS CAN BE EXPECTED AS WELL ON SAT
AFTERNOON. GUSTY WINDS WILL AFFECT KSMX...KSBP AND KSBA THIS
EVENING...WITH LOW LEVEL WIND SHEAR POSSIBLE AT KSBA FROM 02Z-09Z.
GUSTY SW TO W WINDS WILL AFFECT KPRB AND KWJF THRU SAT.

KLAX...MODERATE CONFIDENCE AT BEST IN THE 00Z TAF. MOSTLY VFR CIGS
ARE EXPECTED AT THE AIRFIELD THRU SAT EVENING...WITH SOME PERIODS OF
MVFR CIGS. HOWEVER THERE IS A 40-50 PERCENT CHANCE OF MVFR CIGS
PREVAILING FOR MOST OF THE TIME DURING THE DAY ON SAT INTO SAT
EVENING. THERE WILL ALSO BE A CHANCE OF SHOWERS ON SAT AND SAT
EVENING WITH A 30-40 PERCENT CHANCE OF MVFR VSBYS AT TIMES. A SLIGHT
CHANCE OF THUNDERSTORMS CAN BE EXPECTED AS WELL SAT EVENING.

KBUR...MODERATE CONFIDENCE AT BEST IN THE 00Z TAF. MOSTLY VFR CIGS
ARE EXPECTED AT THE AIRFIELD THRU SAT...WITH SOME PERIODS OF MVFR
CIGS. HOWEVER THERE IS A 40-50 PERCENT CHANCE OF MVFR CIGS
PREVAILING FOR MOST OF THE TIME DURING THE DAY ON SAT. THERE WILL
ALSO BE A CHANCE OF SHOWERS ON SAT WITH A 30-40 PERCENT CHANCE OF
MVFR VSBYS AT TIMES.

&&

.MARINE...27/800 PM...

FOR THE OUTER WATERS...SCA CONDITIONS WILL CONTINUE THROUGH LATE
TONIGHT FOR PZZ670/673...AND TO 9 AM SAT FOR PZZ676. WINDS WILL
DIMINISH THROUGH THE WEEKEND THEN INCREASE TO GALE OR NEAR-GALE
MONDAY NIGHT INTO TUESDAY...BUT THIS IS LOWER CONFIDENCE AS MODEL
AGREEMENT IS NOT VERY GOOD AT THIS TIME.

FOR THE INNER WATERS...GOOD CONFIDENCE IN SCA LEVEL WINDS ACROSS
PZZ650/655 THROUGH MID MORNING SAT. THE STRONGEST WINDS WILL BE
ACROSS THE WESTERN SECTIONS FROM THE CHANNEL ISLANDS TO CATALINA
ISLAND...WHERE GUSTS TO 30 KNOTS WILL BE POSSIBLE. SHORT PERIOD
ROUGH SEAS ARE EXPECTED.

SHOWERS ARE EXPECTED ACROSS THE WATERS THIS WEEKEND AS A COUPLE OF
FRONTAL SYSTEMS CROSS THE AREA. FROM SATURDAY AFTERNOON THROUGH
SUNDAY EVENING...THERE WILL BE A SLIGHT CHANCE OF THUNDERSTORMS WITH
LOCALLY GUSTY WINDS...ROUGH CHOPPY SEAS...AND POSSIBLE WATERSPOUTS.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH (SEE LAXWSWLOX).
WIND ADVISORY (SEE LAXNPWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).

&&

$$

PUBLIC...SIRARD/JACKSON
AVIATION...SIRARD
MARINE...SMITH/SIRARD
SYNOPSIS...B

WWW.WEATHER.GOV/LOSANGELES







000
FXUS66 KLOX 280519
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
920 PM PST FRI FEB 27 2015

.SYNOPSIS...

A COLD LOW PRESSURE SYSTEM WILL BRING SCATTERED SHOWERS...POSSIBLE
THUNDERSTORMS AND MOUNTAIN SNOW TO THE AREA THIS WEEKEND. A WEAKER
SYSTEM WILL BE ON THE HEELS OF THE FIRST ARRIVING MONDAY INTO
TUESDAY MORNING. DRIER CONDITIONS AND OFFSHORE BREEZES ARE EXPECTED
TO BRING ABOVE NORMAL TEMPERATURES TO THE AREA BY LATE NEXT WEEK.

&&

.SHORT TERM (TONIGHT-MON)...PLENTY OF STRATOCU COVERED THE FORECAST
AREA THIS EVENING AS A COOL AND MOIST AIRMASS CONTINUED TO FILTER
INTO THE AREA FROM THE NORTH. THERE WERE ISOLATED SHOWERS NOTED OVER
THE EASTERN SAN GABRIEL VLY WHICH PRODUCED A FEW HUNDREDTHS OF AN
INCH OF PRECIP. A SLIGHT CHANCE TO CHANCE OF SHOWERS WILL PERSIST
ACROSS SWRN CA THRU THE NIGHT AS AN UPPER LOW CONTINUES TO APPROACH
THE AREA FROM NRN CA. GOOD ONSHORE FLOW PRODUCED GUSTY W TO NW WINDS
FOR MOST COASTAL AREAS THIS EVENING...AND THESE WINDS MAY PERSIST
FOR A WHILE OVERNIGHT...ESPECIALLY FOR VTU/L.A. COUNTIES. THERE WERE
ALSO GUSTY NW TO N CANYON WINDS AFFECTING THE SBA S COAST AND MTNS
THIS EVENING...WITH A WIND ADVISORY IN EFFECT THERE UNTIL 10 PM.

THE UPPER LOW WILL CONTINUE TO SLIDE S ON SAT TO A POSITION AROUND
MONTEREY COUNTY IN THE AFTERNOON...THEN TO A POSITION OVER SBA
COUNTY SAT NIGHT AND SUN. THIS UPPER LOW WILL MOVE SLOWLY E SUN
NIGHT...THEN ANOTHER UPPER LEVEL LOW WILL APPROACH FROM THE N ON
MON. THESE UPPER LEVEL LOW PRESSURE SYSTEMS WILL BRING PLENTY OF
SHOWERS AND MOUNTAIN SNOW SHOWERS TO THE FORECAST AREA SAT THRU SUN
EVENING...WITH MORE SHOWERS INTO MON. COLD...UNSTABLE AIR ALOFT (500
MB TEMPS DROPPING TO -26 TO -28 DEG C) WILL ALSO BRING A THREAT OF
THUNDERSTORMS TO THE REGION SAT THRU SUN EVENING. AN ISOLATED
THUNDERSTORM CANNOT BE RULED OUT MON AFTERNOON AND EVENING AS WELL.
ANY THUNDERSTORMS THAT DEVELOP WOULD BE CAPABLE OF PRODUCING BRIEF
HEAVY RAIN...GUSTY WINDS AND SMALL HAIL.

THIS WILL BE A SHOWERY WEATHER SYSTEM AND PRECIP AMOUNTS WILL BE
QUITE VARIABLE. OVERALL...0.10 TO 0.50 INCH LOOKS REASONABLE FOR THE
COAST AND VLYS...WITH 0.50 TO 1.50 INCHES IN THE MOUNTAINS. ISOLATED
PRECIPITATION TOTALS COULD BE UP TO AN INCH FOR THE COAST AND VLYS
AND UP TO 2.00 INCHES OR MORE FOR THE MTNS.

SNOW LEVELS WILL FALL TO 5000 FEET BY SAT AFTERNOON...TO 4000 FEET
SAT NIGHT...AND TO 3500 TO 4000 FEET ON SUN. SIGNIFICANT
ACCUMULATING SNOW OVER THE WEEKEND IS EXPECTED FOR THE MTNS...WITH
6-12 INCHES POSSIBLE IN THE MOUNTAINS ABOVE 7000 FEET...4-8 INCHES
FROM 5000 TO 7000 FEET...AND 2 TO 5 INCHES DOWN TO 5000 FEET.
ACCUMULATIONS LESS THAN AN INCH WILL BE POSSIBLE DOWN TO 4000 FEET
MAINLY SUNDAY AND SUNDAY NIGHT. EVEN SO...THERE MAY BE TRAVEL
PROBLEMS OVER ON THE I-5 OVER THE GRAPEVINE LATE IN THE WEEKEND. A
WINTER WEATHER ADVISORY IS IN EFFECT FOR THE MTNS OF VTU/L.A.
COUNTIES FROM LATE SAT AFTERNOON TO LATE SUN NIGHT.

ADDITIONAL PRECIP AMOUNTS LATER SUN NIGHT AND MON COULD TOTAL 0.10
TO 0.25 INCH FOR MOST AREAS...WITH AN INCH OR TWO OF SNOW
ACCUMULATION POSSIBLE IN THE MTNS DOWN TO 4500 FEET.

NEEDLESS TO SAY...WITH THE COLD UPPER LEVEL SYSTEMS OVER SWRN
CA...TEMPERATURES ACROSS THE REGION WILL BE SEVERAL DEGREES BELOW
NORMAL SAT THRU MON.

***FROM PREVIOUS DISCUSSION***

.LONG TERM (TUE-FRI)...THE UPPER LOW THAT ZIPS IN BEHIND THE WEEKEND
LOW AND MOVES THROUGH MONDAY NIGHT AND EARLY TUESDAY IS NOT AS
STRONG OR DEEP SO EXPECT PRECIPITATION AMOUNTS TO BE LESS. HEIGHT
RISES MOVE IN ON TUESDAY TO START A WARMING AND DRYING TREND FOR THE
REMAINDER OF THE WEEK...AND PEAKING THURSDAY...WITH SOME WEAK
OFFSHORE FLOW TO KEEP SKIES CLEAR.

&&

.AVIATION...28/0015Z.

AT 2305Z...THE MARINE INVERSION AT KLAX WAS AT 4700 FEET DEEP...THE
TOP OF THE INVERSION WAS AT 6300 FT WITH A TEMP OF 7 DEG C.

MODERATE CONFIDENCE AT BEST IN THE 00Z TAFS. MOSTLY VFR CIGS ARE
EXPECTED AT THE AIRFIELDS THRU SAT...HOWEVER THERE IS A 40-50
PERCENT CHANCE OF MVFR CIGS PREVAILING FOR MOST OF THE TIME DURING
THE DAY ON SAT FOR MANY AIRFIELDS. OTHERWISE...MVFR CIGS MAY BE
INTERMITTENT AT TIMES DURING THE TAF PERIOD. THERE WILL ALSO BE A
CHANCE OF SHOWERS MAINLY ON SAT WITH SOME REDUCED VSBYS AT TIMES. A
SLIGHT CHANCE OF THUNDERSTORMS CAN BE EXPECTED AS WELL ON SAT
AFTERNOON. GUSTY WINDS WILL AFFECT KSMX...KSBP AND KSBA THIS
EVENING...WITH LOW LEVEL WIND SHEAR POSSIBLE AT KSBA FROM 02Z-09Z.
GUSTY SW TO W WINDS WILL AFFECT KPRB AND KWJF THRU SAT.

KLAX...MODERATE CONFIDENCE AT BEST IN THE 00Z TAF. MOSTLY VFR CIGS
ARE EXPECTED AT THE AIRFIELD THRU SAT EVENING...WITH SOME PERIODS OF
MVFR CIGS. HOWEVER THERE IS A 40-50 PERCENT CHANCE OF MVFR CIGS
PREVAILING FOR MOST OF THE TIME DURING THE DAY ON SAT INTO SAT
EVENING. THERE WILL ALSO BE A CHANCE OF SHOWERS ON SAT AND SAT
EVENING WITH A 30-40 PERCENT CHANCE OF MVFR VSBYS AT TIMES. A SLIGHT
CHANCE OF THUNDERSTORMS CAN BE EXPECTED AS WELL SAT EVENING.

KBUR...MODERATE CONFIDENCE AT BEST IN THE 00Z TAF. MOSTLY VFR CIGS
ARE EXPECTED AT THE AIRFIELD THRU SAT...WITH SOME PERIODS OF MVFR
CIGS. HOWEVER THERE IS A 40-50 PERCENT CHANCE OF MVFR CIGS
PREVAILING FOR MOST OF THE TIME DURING THE DAY ON SAT. THERE WILL
ALSO BE A CHANCE OF SHOWERS ON SAT WITH A 30-40 PERCENT CHANCE OF
MVFR VSBYS AT TIMES.

&&

.MARINE...27/800 PM...

FOR THE OUTER WATERS...SCA CONDITIONS WILL CONTINUE THROUGH LATE
TONIGHT FOR PZZ670/673...AND TO 9 AM SAT FOR PZZ676. WINDS WILL
DIMINISH THROUGH THE WEEKEND THEN INCREASE TO GALE OR NEAR-GALE
MONDAY NIGHT INTO TUESDAY...BUT THIS IS LOWER CONFIDENCE AS MODEL
AGREEMENT IS NOT VERY GOOD AT THIS TIME.

FOR THE INNER WATERS...GOOD CONFIDENCE IN SCA LEVEL WINDS ACROSS
PZZ650/655 THROUGH MID MORNING SAT. THE STRONGEST WINDS WILL BE
ACROSS THE WESTERN SECTIONS FROM THE CHANNEL ISLANDS TO CATALINA
ISLAND...WHERE GUSTS TO 30 KNOTS WILL BE POSSIBLE. SHORT PERIOD
ROUGH SEAS ARE EXPECTED.

SHOWERS ARE EXPECTED ACROSS THE WATERS THIS WEEKEND AS A COUPLE OF
FRONTAL SYSTEMS CROSS THE AREA. FROM SATURDAY AFTERNOON THROUGH
SUNDAY EVENING...THERE WILL BE A SLIGHT CHANCE OF THUNDERSTORMS WITH
LOCALLY GUSTY WINDS...ROUGH CHOPPY SEAS...AND POSSIBLE WATERSPOUTS.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH (SEE LAXWSWLOX).
WIND ADVISORY (SEE LAXNPWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).

&&

$$

PUBLIC...SIRARD/JACKSON
AVIATION...SIRARD
MARINE...SMITH/SIRARD
SYNOPSIS...B

WWW.WEATHER.GOV/LOSANGELES







000
FXUS66 KLOX 280022 AAA
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
425 PM PST FRI FEB 27 2015

...UPDATED AVIATION DISCUSSION...

.SYNOPSIS...

A WEATHER PATTERN CHANGE WILL BEGIN TONIGHT AS THERE WILL BE PERIODS
OF RAIN SHOWERS THROUGH EARLY NEXT WEEK...WITH LOWER SNOW LEVELS
EXPECTED ACROSS MOUNTAIN LOCATIONS...POSSIBLY AFFECTING THE
INTERSTATE 5 CORRIDOR SATURDAY THROUGH MONDAY. THUNDERSTORMS ARE
POSSIBLE FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT.

&&

.SHORT TERM (SAT-MON)...A COLD UPPER LEVEL LOW WILL SLIDE DOWN THE
WEST COAST AND BRING VALLEY RAIN AND MOUNTAIN SNOW THROUGH MONDAY
MORNING. MODELS ARE ALL IN GOOD SYNOPTIC AGREEMENT...BUT THERE ARE
SOME DIFFERENCES IN THE OUTCOMES OF THIS LOW PRESSURE SYSTEM STORM
TOTAL PRECIP-WISE. SKIES WILL GRADUALLY CLOUD UP TONIGHT AHEAD OF
THE LOW WITH INCREASING LOW LEVEL MOISTURE. PRECIP CHANCES WILL BE
PRIMARILY CONFINED TO NORTH OF POINT CONCEPTION AND MOUNTAIN
AREAS...WITH THE EXCEPTION OF VERY SLIGHT CHANCES OF SHOWERS IN THE
LA COUNTY COAST AND VALLEYS. BUT SLIGHT CHANCE MAY BE STRETCHING IT
A BIT FOR AREAS SOUTH OF POINT CONCEPTION SO DEFINITELY BETTER
CHANCES OF THOSE AREAS STAYING DRY TONIGHT. MODERATE TO STRONG NW
WINDS JUST OFF THE SURFACE COMING DOWN THE CENTRAL COAST...ALONG
WITH A MODERATE NORTH-SOUTH PRESSURE GRADIENT COULD BRING SOME
LOW-END ADVISORY WINDS TO THE SBA COAST SO HAVE LEFT THE WIND
ADVISORY UP FOR THAT AREA.

BY MIDDAY TOMORROW THE UPPER HAS MOVED SOUTH TO THE BAY AREA AND
SHOWERS BECOME MORE LIKELY OVER THE FORECAST AREA OUT AHEAD OF
IT...ESPECIALLY OVER THE HIGHER ELEVATIONS. FOR TIMING OF THE
PRECIPITATION CHANCES...THEY WILL BE GREATEST OVER THE CENTRAL COAST
DURING THE DAY ON SATURDAY...THEN SHIFT SOUTHWARD TO AREAS SOUTH OF
POINT CONCEPTION OVERNIGHT SATURDAY WHEN THE COLDEST CORE OF THE LOW
SHOULD BE JUST OFF POINT CONCEPTION LATE SATURDAY NIGHT. MODELS SHOW
SOME DYNAMICAL INFLUENCE INTO SUNDAY MORNING AS WELL WHICH WILL HELP
PRECIP CHANCES SOUTH OF THE POINT. PRECIP CHANCES REMAIN LIKELY OVER
MUCH OF LA AND VTU COUNTIES ON SUNDAY...ALONG WITH THE BEST CHANCES
OF THUNDER...WHEN THE LOW STALLS OUT A BIT AND A VORT LOBE ROTATES
AROUND ITS BACK END TO HELP SWING IT OUT. MONDAY WILL STILL BE COOL
BUT THERE WILL ONLY BE A BRIEF BREAK IN PRECIP BEFORE A WEAKER
SECOND LOW MOVES INTO THE AREA FROM OUR NORTH TO BRING PRECIP
CHANCES BACK FOR MONDAY AFTERNOON AND NIGHT.

OVERALL THE PRECIP WILL BE VERY SHOWERY SINCE THERE WILL BE NO WELL
DEFINED COLD FRONT WITH THIS LOW AND HENCE NO WELL DEFINED
PRECIPITATION BAND. STORM TOTALS EXPECTED FOR SATURDAY THROUGH EARLY
MONDAY MORNING AT THIS TIME ARE EXPECTED TO AROUND .1 TO .50 INCHES
LOWER ELEVATIONS AND .5 TO 1.5 INCHES HIGHER ELEVATIONS. THE COLD
MID LEVEL TEMPS WITH THIS LOW WILL HELP DESTABILIZE THE ATMOSPHERE
TO BRING A SLIGHT CHANCE OF THUNDERSTORMS. ALTHOUGH THIS SYSTEM WILL
NOT HAVE MUCH IN THE WAY OF MOISTURE TO WORK WITH...INSTABILITY
FACTORS COULD PRODUCE HEAVIER SHOWERS IN SOME LOCATIONS...ESPECIALLY
SOUTH OF POINT CONCEPTION FROM EARLY SUNDAY INTO SUNDAY EVENING. SO
SOME LOCAL AMOUNTS COULD GO OVER 1.5 INCHES. PLUS WITH LOW LEVEL
SOUTHWEST WINDS AHEAD OF THE LOW ON SATURDAY NIGHT INTO SUNDAY
MORNING THERE COULD ALSO BE SOME OROGRAPHIC INFLUENCE IN THE
FOOTHILLS AND MOUNTAINS OF LA COUNTY. BOTTOM LINE...WITH SUCH A
SHOWERY SYSTEM...STILL EXPECT STORM TOTAL AMOUNTS TO VARY QUITE A
BIT.

THE OTHER STORY WITH THIS STORM WILL BE THE LOW SNOW LEVELS. THEY`LL
START OUT ALL MOSTLY ABOVE 6000 FEET TONIGHT...LOWER TO AROUND 5000
FEET ON SATURDAY THEN DROP DOWN TO AROUND 4000 FEET OR JUST BELOW
SATURDAY NIGHT. CONVECTIVE SHOWERS OFTEN DROP THE SNOW LEVEL EVEN
FURTHER SO THERE COULD BE SOME LOCALLY LOWER LEVELS IN THE HEAVIER
SNOW SHOWERS. SNOW LEVELS WILL COME UP SOME GOING INTO MONDAY WHEN
THEY`LL BE BETWEEN 4500 AND 5000 FEET. WITH THESE SNOW LEVELS THERE
COULD BE IMPACTS OVER THE GRAPEVINE AND HWY 14...MAINLY SUNDAY
MORNING. AT THIS TIME EXPECTING ACCUMULATIONS OF 4-8 INCHES BELOW
7000 FEET AND 8-12 INCHES ABOVE 7000 FEET. THE HEAVIER AMOUNTS WILL
BE IN THE EASTERN SAN GABRIELS AND ALSO THE NORTHERN SLOPES OF
VENTURA COUNTY...THE LATER OF WHICH WILL BENEFIT FROM SOME
OROGRAPHICS AS THE LOW MOVES OUT AND WINDS TURN NORTHERLY. WILL BE
CONVERTING THE WINTER STORM WATCH TO A WINTER WEATHER ADVISORY FOR
SATURDAY LATE  SINCE THE AMOUNTS ARE JUST BELOW WARNING LEVELS. THE
HIGHER ELEVATIONS SOUTH OF LA COUNTY WILL BENEFIT FROM BETTER
MOISTURE AND DYNAMICS AND HENCE GREATER SNOW AMOUNTS...THUS THE
WINTER STORM WARNING ISSUED BY THE SAN DIEGO OFFICE.

.LONG TERM (TUE-FRI)...THE UPPER LOW THAT ZIPS IN BEHIND THE WEEKEND
LOW AND MOVES THROUGH MONDAY NIGHT AND EARLY TUESDAY IS NOT AS
STRONG OR DEEP SO EXPECT PRECIPITATION AMOUNTS TO BE LESS. HEIGHT
RISES MOVE IN ON TUESDAY TO START A WARMING AND DRYING TREND FOR THE
REMAINDER OF THE WEEK...AND PEAKING THURSDAY...WITH SOME WEAK
OFFSHORE FLOW TO KEEP SKIES CLEAR.

&&

.AVIATION...28/0015Z.

AT 2305Z...THE MARINE INVERSION AT KLAX WAS AT 4700 FEET DEEP...THE
TOP OF THE INVERSION WAS AT 6300 FT WITH A TEMP OF 7 DEG C.

MODERATE CONFIDENCE AT BEST IN THE 00Z TAFS. MOSTLY VFR CIGS ARE
EXPECTED AT THE AIRFIELDS THRU SAT...HOWEVER THERE IS A 40-50
PERCENT CHANCE OF MVFR CIGS PREVAILING FOR MOST OF THE TIME DURING
THE DAY ON SAT FOR MANY AIRFIELDS. OTHERWISE...MVFR CIGS MAY BE
INTERMITTENT AT TIMES DURING THE TAF PERIOD. THERE WILL ALSO BE A
CHANCE OF SHOWERS MAINLY ON SAT WITH SOME REDUCED VSBYS AT TIMES. A
SLIGHT CHANCE OF THUNDERSTORMS CAN BE EXPECTED AS WELL ON SAT
AFTERNOON. GUSTY WINDS WILL AFFECT KSMX...KSBP AND KSBA THIS
EVENING...WITH LOW LEVEL WIND SHEAR POSSIBLE AT KSBA FROM 02Z-09Z.
GUSTY SW TO W WINDS WILL AFFECT KPRB AND KWJF THRU SAT.

KLAX...MODERATE CONFIDENCE AT BEST IN THE 00Z TAF. MOSTLY VFR CIGS
ARE EXPECTED AT THE AIRFIELD THRU SAT EVENING...WITH SOME PERIODS OF
MVFR CIGS. HOWEVER THERE IS A 40-50 PERCENT CHANCE OF MVFR CIGS
PREVAILING FOR MOST OF THE TIME DURING THE DAY ON SAT INTO SAT
EVENING. THERE WILL ALSO BE A CHANCE OF SHOWERS ON SAT AND SAT
EVENING WITH A 30-40 PERCENT CHANCE OF MVFR VSBYS AT TIMES. A SLIGHT
CHANCE OF THUNDERSTORMS CAN BE EXPECTED AS WELL SAT EVENING.

KBUR...MODERATE CONFIDENCE AT BEST IN THE 00Z TAF. MOSTLY VFR CIGS
ARE EXPECTED AT THE AIRFIELD THRU SAT...WITH SOME PERIODS OF MVFR
CIGS. HOWEVER THERE IS A 40-50 PERCENT CHANCE OF MVFR CIGS
PREVAILING FOR MOST OF THE TIME DURING THE DAY ON SAT. THERE WILL
ALSO BE A CHANCE OF SHOWERS ON SAT WITH A 30-40 PERCENT CHANCE OF
MVFR VSBYS AT TIMES.

&&

.MARINE...27/200 PM...

FOR THE OUTER WATERS...NORTHWEST GALES THROUGH TONIGHT...EXCEPT
DIMINISHING TO SCA LEVELS ACROSS PZZ670 THIS EVENING. THE STRONGER
WINDS WILL BE OVER PZZ673-676. SCA CONDS ARE EXPECTED ACROSS PZZ676
NORTHWEST OF SAN NICOLAS ISLAND THROUGH SATURDAY AFTERNOON. WINDS
WILL DIMINISH THROUGH THE WEEKEND THEN INCREASE TO GALE OR NEAR-GALE
MONDAY NIGHT INTO TUESDAY...BUT THIS IS LOWER CONFIDENCE AS MODEL
AGREEMENT IS NOT VERY GOOD AT THIS TIME.

FOR THE INNER WATERS...GOOD CONFIDENCE IN SCA LEVEL WINDS ACROSS
PZZ645 THIS AFTERNOON THROUGH THIS EVENING...AND ACROSS THE SANTA
BARBARA CHANNEL AND SOUTHERN INNER WATERS FROM LATE THIS AFTERNOON
THROUGH MID MORNING SAT. THE STRONGEST WINDS WILL BE ACROSS THE
WESTERN SECTIONS FROM THE CHANNEL ISLANDS TO CATALINA ISLAND...WHERE
GUSTS TO 30 KNOTS AND LOCALLY UP TO 35 KNOTS WILL BE POSSIBLE. 30
PERCENT CHANCE THAT A GALE WARNING WILL NEED TO BE ISSUED FOR THE
GALE FORCE GUSTS LATE THIS EVENING THROUGH EARLY SATURDAY MORNING.
SHORT PERIOD ROUGH SEAS ARE EXPECTED.

SHOWERS ARE EXPECTED ACROSS THE WATERS THIS WEEKEND AS A COUPLE OF
FRONTAL SYSTEMS CROSS THE AREA. FROM SATURDAY AFTERNOON THROUGH
SUNDAY EVENING...THERE WILL BE A SLIGHT CHANCE OF THUNDERSTORMS WITH
LOCALLY GUSTY WINDS...ROUGH CHOPPY SEAS...AND POSSIBLE A WATERSPOUTS.

&&

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

&&

$$

PUBLIC...JACKSON
AVIATION...SIRARD
MARINE...SMITH

WWW.WEATHER.GOV/LOSANGELES






000
FXUS66 KLOX 272238
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
236 PM PST FRI FEB 27 2015

.SYNOPSIS...

A WEATHER PATTERN CHANGE WILL BEGIN TONIGHT AS THERE WILL BE PERIODS
OF RAIN SHOWERS THROUGH EARLY NEXT WEEK...WITH LOWER SNOW LEVELS
EXPECTED ACROSS MOUNTAIN LOCATIONS...POSSIBLY AFFECTING THE
INTERSTATE 5 CORRIDOR SATURDAY THROUGH MONDAY. THUNDERSTORMS ARE
POSSIBLE FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT.

&&

.SHORT TERM (SAT-MON)...A COLD UPPER LEVEL LOW WILL SLIDE DOWN THE
WEST COAST AND BRING VALLEY RAIN AND MOUNTAIN SNOW THROUGH MONDAY
MORNING. MODELS ARE ALL IN GOOD SYNOPTIC AGREEMENT...BUT THERE ARE
SOME DIFFERENCES IN THE OUTCOMES OF THIS LOW PRESSURE SYSTEM STORM
TOTAL PRECIP-WISE. SKIES WILL GRADUALLY CLOUD UP TONIGHT AHEAD OF
THE LOW WITH INCREASING LOW LEVEL MOISTURE. PRECIP CHANCES WILL BE
PRIMARILY CONFINED TO NORTH OF POINT CONCEPTION AND MOUNTAIN
AREAS...WITH THE EXCEPTION OF VERY SLIGHT CHANCES OF SHOWERS IN THE
LA COUNTY COAST AND VALLEYS. BUT SLIGHT CHANCE MAY BE STRETCHING IT
A BIT FOR AREAS SOUTH OF POINT CONCEPTION SO DEFINITELY BETTER
CHANCES OF THOSE AREAS STAYING DRY TONIGHT. MODERATE TO STRONG NW
WINDS JUST OFF THE SURFACE COMING DOWN THE CENTRAL COAST...ALONG
WITH A MODERATE NORTH-SOUTH PRESSURE GRADIENT COULD BRING SOME
LOW-END ADVISORY WINDS TO THE SBA COAST SO HAVE LEFT THE WIND
ADVISORY UP FOR THAT AREA.

BY MIDDAY TOMORROW THE UPPER HAS MOVED SOUTH TO THE BAY AREA AND
SHOWERS BECOME MORE LIKELY OVER THE FORECAST AREA OUT AHEAD OF
IT...ESPECIALLY OVER THE HIGHER ELEVATIONS. FOR TIMING OF THE
PRECIPITATION CHANCES...THEY WILL BE GREATEST OVER THE CENTRAL COAST
DURING THE DAY ON SATURDAY...THEN SHIFT SOUTHWARD TO AREAS SOUTH OF
POINT CONCEPTION OVERNIGHT SATURDAY WHEN THE COLDEST CORE OF THE LOW
SHOULD BE JUST OFF POINT CONCEPTION LATE SATURDAY NIGHT. MODELS SHOW
SOME DYNAMICAL INFLUENCE INTO SUNDAY MORNING AS WELL WHICH WILL HELP
PRECIP CHANCES SOUTH OF THE POINT. PRECIP CHANCES REMAIN LIKELY OVER
MUCH OF LA AND VTU COUNTIES ON SUNDAY...ALONG WITH THE BEST CHANCES
OF THUNDER...WHEN THE LOW STALLS OUT A BIT AND A VORT LOBE ROTATES
AROUND ITS BACK END TO HELP SWING IT OUT. MONDAY WILL STILL BE COOL
BUT THERE WILL ONLY BE A BRIEF BREAK IN PRECIP BEFORE A WEAKER
SECOND LOW MOVES INTO THE AREA FROM OUR NORTH TO BRING PRECIP
CHANCES BACK FOR MONDAY AFTERNOON AND NIGHT.

OVERALL THE PRECIP WILL BE VERY SHOWERY SINCE THERE WILL BE NO WELL
DEFINED COLD FRONT WITH THIS LOW AND HENCE NO WELL DEFINED
PRECIPITATION BAND. STORM TOTALS EXPECTED FOR SATURDAY THROUGH EARLY
MONDAY MORNING AT THIS TIME ARE EXPECTED TO AROUND .1 TO .50 INCHES
LOWER ELEVATIONS AND .5 TO 1.5 INCHES HIGHER ELEVATIONS. THE COLD
MID LEVEL TEMPS WITH THIS LOW WILL HELP DESTABILIZE THE ATMOSPHERE
TO BRING A SLIGHT CHANCE OF THUNDERSTORMS. ALTHOUGH THIS SYSTEM WILL
NOT HAVE MUCH IN THE WAY OF MOISTURE TO WORK WITH...INSTABILITY
FACTORS COULD PRODUCE HEAVIER SHOWERS IN SOME LOCATIONS...ESPECIALLY
SOUTH OF POINT CONCEPTION FROM EARLY SUNDAY INTO SUNDAY EVENING. SO
SOME LOCAL AMOUNTS COULD GO OVER 1.5 INCHES. PLUS WITH LOW LEVEL
SOUTHWEST WINDS AHEAD OF THE LOW ON SATURDAY NIGHT INTO SUNDAY
MORNING THERE COULD ALSO BE SOME OROGRAPHIC INFLUENCE IN THE
FOOTHILLS AND MOUNTAINS OF LA COUNTY. BOTTOM LINE...WITH SUCH A
SHOWERY SYSTEM...STILL EXPECT STORM TOTAL AMOUNTS TO VARY QUITE A
BIT.

THE OTHER STORY WITH THIS STORM WILL BE THE LOW SNOW LEVELS. THEY`LL
START OUT ALL MOSTLY ABOVE 6000 FEET TONIGHT...LOWER TO AROUND 5000
FEET ON SATURDAY THEN DROP DOWN TO AROUND 4000 FEET OR JUST BELOW
SATURDAY NIGHT. CONVECTIVE SHOWERS OFTEN DROP THE SNOW LEVEL EVEN
FURTHER SO THERE COULD BE SOME LOCALLY LOWER LEVELS IN THE HEAVIER
SNOW SHOWERS. SNOW LEVELS WILL COME UP SOME GOING INTO MONDAY WHEN
THEY`LL BE BETWEEN 4500 AND 5000 FEET. WITH THESE SNOW LEVELS THERE
COULD BE IMPACTS OVER THE GRAPEVINE AND HWY 14...MAINLY SUNDAY
MORNING. AT THIS TIME EXPECTING ACCUMULATIONS OF 4-8 INCHES BELOW
7000 FEET AND 8-12 INCHES ABOVE 7000 FEET. THE HEAVIER AMOUNTS WILL
BE IN THE EASTERN SAN GABRIELS AND ALSO THE NORTHERN SLOPES OF
VENTURA COUNTY...THE LATER OF WHICH WILL BENEFIT FROM SOME
OROGRAPHICS AS THE LOW MOVES OUT AND WINDS TURN NORTHERLY. WILL BE
CONVERTING THE WINTER STORM WATCH TO A WINTER WEATHER ADVISORY FOR
SATURDAY LATE  SINCE THE AMOUNTS ARE JUST BELOW WARNING LEVELS. THE
HIGHER ELEVATIONS SOUTH OF LA COUNTY WILL BENEFIT FROM BETTER
MOISTURE AND DYNAMICS AND HENCE GREATER SNOW AMOUNTS...THUS THE
WINTER STORM WARNING ISSUED BY THE SAN DIEGO OFFICE.

.LONG TERM (TUE-FRI)...THE UPPER LOW THAT ZIPS IN BEHIND THE WEEKEND
LOW AND MOVES THROUGH MONDAY NIGHT AND EARLY TUESDAY IS NOT AS
STRONG OR DEEP SO EXPECT PRECIPITATION AMOUNTS TO BE LESS. HEIGHT
RISES MOVE IN ON TUESDAY TO START A WARMING AND DRYING TREND FOR THE
REMAINDER OF THE WEEK...AND PEAKING THURSDAY...WITH SOME WEAK
OFFSHORE FLOW TO KEEP SKIES CLEAR.

&&

.AVIATION...27/1800Z.

AT 1730Z...THE MARINE LAYER AT KLAX WAS 2000 FEET DEEP...THE TOP OF
THE INVERSION WAS LOCATED AT 2800 FT WITH A TEMP OF 12C.

LOW TO MODERATE CONFIDENCE IN 18Z TAFS TODAY. STRATUS CLOUDS
EXPECTED TO LIFT OVER COAST/VALLEY SECTIONS THIS AFTERNOON...AND MAY
SCATTER OUT ACROSS THE VALLEYS BUT LIKELY REMAIN MVFR/VFR BKN
COVERAGE FOR MANY COASTAL AREAS.

EXPECT WIDESPREAD MVFR CIGS TO RETURN TO ALL AREAS WEST OF THE MTNS
THIS EVENING...POSSIBLY EVEN INTO THE ANTELOPE VLY BY LATER TONIGHT.
CHANCE OF RAIN N OF PT CONCEPTION AFTER MIDNIGHT...WITH SOME
DRIZZLE/LIGHT -SHRA POSSIBLE S OF PT CONCEPTION BY 14-15Z. GUSTY
WINDS THRU AND BELOW PASSES AND CANYONS OF SRN SBA COUNTY THIS
EVENING WITH LLWS AND MDT UDDF.

KLAX...MODERATE CONFIDENCE IN THE 18Z TAF. THERE IS A 30 PERCENT
CHANCE THAT MVFR CIGS WILL PERSIST THROUGH THE DAY. GUSTY WEST WINDS
EXPECTED FROM 06Z THROUGH AT LEAST 18Z SAT. -DZ OR -SHRA BY 15Z WITH
-RA AFTER 18Z BUT TIMING IS LOW CERTAINTY.


KBUR...MODERATE CONFIDENCE IN THE 18Z TAF. THERE IS A 20 PERCENT
CHANCE MVFR CIGS WILL LINGER BEYOND 19Z OR EVEN THROUGH THE
AFTERNOON. MVFR CIGS WILL RETURN FOR THE OVERNIGHT PERIOD. TIMING OF
CIGS RETURN AND ONSET OF -DZ/VCSH IS LOWER CERTAINTY.

&&

.MARINE...27/200 PM...

FOR THE OUTER WATERS...NORTHWEST GALES THROUGH TONIGHT...EXCEPT
DIMINISHING TO SCA LEVELS ACROSS PZZ670 THIS EVENING. THE STRONGER
WINDS WILL BE OVER PZZ673-676. SCA CONDS ARE EXPECTED ACROSS PZZ676
NORTHWEST OF SAN NICOLAS ISLAND THROUGH SATURDAY AFTERNOON. WINDS
WILL DIMINISH THROUGH THE WEEKEND THEN INCREASE TO GALE OR NEAR-GALE
MONDAY NIGHT INTO TUESDAY...BUT THIS IS LOWER CONFIDENCE AS MODEL
AGREEMENT IS NOT VERY GOOD AT THIS TIME.

FOR THE INNER WATERS...GOOD CONFIDENCE IN SCA LEVEL WINDS ACROSS
PZZ645 THIS AFTERNOON THROUGH THIS EVENING...AND ACROSS THE SANTA
BARBARA CHANNEL AND SOUTHERN INNER WATERS FROM LATE THIS AFTERNOON
THROUGH MID MORNING SAT. THE STRONGEST WINDS WILL BE ACROSS THE
WESTERN SECTIONS FROM THE CHANNEL ISLANDS TO CATALINA ISLAND...WHERE
GUSTS TO 30 KNOTS AND LOCALLY UP TO 35 KNOTS WILL BE POSSIBLE. 30
PERCENT CHANCE THAT A GALE WARNING WILL NEED TO BE ISSUED FOR THE
GALE FORCE GUSTS LATE THIS EVENING THROUGH EARLY SATURDAY MORNING.
SHORT PERIOD ROUGH SEAS ARE EXPECTED.

SHOWERS ARE EXPECTED ACROSS THE WATERS THIS WEEKEND AS A COUPLE OF
FRONTAL SYSTEMS CROSS THE AREA. FROM SATURDAY AFTERNOON THROUGH
SUNDAY EVENING...THERE WILL BE A SLIGHT CHANCE OF THUNDERSTORMS WITH
LOCALLY GUSTY WINDS...ROUGH CHOPPY SEAS...AND POSSIBLE A WATERSPOUTS.

&&

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

&&

$$

PUBLIC...JACKSON
AVIATION/MARINE...SMITH

WWW.WEATHER.GOV/LOSANGELES




















000
FXUS66 KLOX 272238
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
236 PM PST FRI FEB 27 2015

.SYNOPSIS...

A WEATHER PATTERN CHANGE WILL BEGIN TONIGHT AS THERE WILL BE PERIODS
OF RAIN SHOWERS THROUGH EARLY NEXT WEEK...WITH LOWER SNOW LEVELS
EXPECTED ACROSS MOUNTAIN LOCATIONS...POSSIBLY AFFECTING THE
INTERSTATE 5 CORRIDOR SATURDAY THROUGH MONDAY. THUNDERSTORMS ARE
POSSIBLE FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT.

&&

.SHORT TERM (SAT-MON)...A COLD UPPER LEVEL LOW WILL SLIDE DOWN THE
WEST COAST AND BRING VALLEY RAIN AND MOUNTAIN SNOW THROUGH MONDAY
MORNING. MODELS ARE ALL IN GOOD SYNOPTIC AGREEMENT...BUT THERE ARE
SOME DIFFERENCES IN THE OUTCOMES OF THIS LOW PRESSURE SYSTEM STORM
TOTAL PRECIP-WISE. SKIES WILL GRADUALLY CLOUD UP TONIGHT AHEAD OF
THE LOW WITH INCREASING LOW LEVEL MOISTURE. PRECIP CHANCES WILL BE
PRIMARILY CONFINED TO NORTH OF POINT CONCEPTION AND MOUNTAIN
AREAS...WITH THE EXCEPTION OF VERY SLIGHT CHANCES OF SHOWERS IN THE
LA COUNTY COAST AND VALLEYS. BUT SLIGHT CHANCE MAY BE STRETCHING IT
A BIT FOR AREAS SOUTH OF POINT CONCEPTION SO DEFINITELY BETTER
CHANCES OF THOSE AREAS STAYING DRY TONIGHT. MODERATE TO STRONG NW
WINDS JUST OFF THE SURFACE COMING DOWN THE CENTRAL COAST...ALONG
WITH A MODERATE NORTH-SOUTH PRESSURE GRADIENT COULD BRING SOME
LOW-END ADVISORY WINDS TO THE SBA COAST SO HAVE LEFT THE WIND
ADVISORY UP FOR THAT AREA.

BY MIDDAY TOMORROW THE UPPER HAS MOVED SOUTH TO THE BAY AREA AND
SHOWERS BECOME MORE LIKELY OVER THE FORECAST AREA OUT AHEAD OF
IT...ESPECIALLY OVER THE HIGHER ELEVATIONS. FOR TIMING OF THE
PRECIPITATION CHANCES...THEY WILL BE GREATEST OVER THE CENTRAL COAST
DURING THE DAY ON SATURDAY...THEN SHIFT SOUTHWARD TO AREAS SOUTH OF
POINT CONCEPTION OVERNIGHT SATURDAY WHEN THE COLDEST CORE OF THE LOW
SHOULD BE JUST OFF POINT CONCEPTION LATE SATURDAY NIGHT. MODELS SHOW
SOME DYNAMICAL INFLUENCE INTO SUNDAY MORNING AS WELL WHICH WILL HELP
PRECIP CHANCES SOUTH OF THE POINT. PRECIP CHANCES REMAIN LIKELY OVER
MUCH OF LA AND VTU COUNTIES ON SUNDAY...ALONG WITH THE BEST CHANCES
OF THUNDER...WHEN THE LOW STALLS OUT A BIT AND A VORT LOBE ROTATES
AROUND ITS BACK END TO HELP SWING IT OUT. MONDAY WILL STILL BE COOL
BUT THERE WILL ONLY BE A BRIEF BREAK IN PRECIP BEFORE A WEAKER
SECOND LOW MOVES INTO THE AREA FROM OUR NORTH TO BRING PRECIP
CHANCES BACK FOR MONDAY AFTERNOON AND NIGHT.

OVERALL THE PRECIP WILL BE VERY SHOWERY SINCE THERE WILL BE NO WELL
DEFINED COLD FRONT WITH THIS LOW AND HENCE NO WELL DEFINED
PRECIPITATION BAND. STORM TOTALS EXPECTED FOR SATURDAY THROUGH EARLY
MONDAY MORNING AT THIS TIME ARE EXPECTED TO AROUND .1 TO .50 INCHES
LOWER ELEVATIONS AND .5 TO 1.5 INCHES HIGHER ELEVATIONS. THE COLD
MID LEVEL TEMPS WITH THIS LOW WILL HELP DESTABILIZE THE ATMOSPHERE
TO BRING A SLIGHT CHANCE OF THUNDERSTORMS. ALTHOUGH THIS SYSTEM WILL
NOT HAVE MUCH IN THE WAY OF MOISTURE TO WORK WITH...INSTABILITY
FACTORS COULD PRODUCE HEAVIER SHOWERS IN SOME LOCATIONS...ESPECIALLY
SOUTH OF POINT CONCEPTION FROM EARLY SUNDAY INTO SUNDAY EVENING. SO
SOME LOCAL AMOUNTS COULD GO OVER 1.5 INCHES. PLUS WITH LOW LEVEL
SOUTHWEST WINDS AHEAD OF THE LOW ON SATURDAY NIGHT INTO SUNDAY
MORNING THERE COULD ALSO BE SOME OROGRAPHIC INFLUENCE IN THE
FOOTHILLS AND MOUNTAINS OF LA COUNTY. BOTTOM LINE...WITH SUCH A
SHOWERY SYSTEM...STILL EXPECT STORM TOTAL AMOUNTS TO VARY QUITE A
BIT.

THE OTHER STORY WITH THIS STORM WILL BE THE LOW SNOW LEVELS. THEY`LL
START OUT ALL MOSTLY ABOVE 6000 FEET TONIGHT...LOWER TO AROUND 5000
FEET ON SATURDAY THEN DROP DOWN TO AROUND 4000 FEET OR JUST BELOW
SATURDAY NIGHT. CONVECTIVE SHOWERS OFTEN DROP THE SNOW LEVEL EVEN
FURTHER SO THERE COULD BE SOME LOCALLY LOWER LEVELS IN THE HEAVIER
SNOW SHOWERS. SNOW LEVELS WILL COME UP SOME GOING INTO MONDAY WHEN
THEY`LL BE BETWEEN 4500 AND 5000 FEET. WITH THESE SNOW LEVELS THERE
COULD BE IMPACTS OVER THE GRAPEVINE AND HWY 14...MAINLY SUNDAY
MORNING. AT THIS TIME EXPECTING ACCUMULATIONS OF 4-8 INCHES BELOW
7000 FEET AND 8-12 INCHES ABOVE 7000 FEET. THE HEAVIER AMOUNTS WILL
BE IN THE EASTERN SAN GABRIELS AND ALSO THE NORTHERN SLOPES OF
VENTURA COUNTY...THE LATER OF WHICH WILL BENEFIT FROM SOME
OROGRAPHICS AS THE LOW MOVES OUT AND WINDS TURN NORTHERLY. WILL BE
CONVERTING THE WINTER STORM WATCH TO A WINTER WEATHER ADVISORY FOR
SATURDAY LATE  SINCE THE AMOUNTS ARE JUST BELOW WARNING LEVELS. THE
HIGHER ELEVATIONS SOUTH OF LA COUNTY WILL BENEFIT FROM BETTER
MOISTURE AND DYNAMICS AND HENCE GREATER SNOW AMOUNTS...THUS THE
WINTER STORM WARNING ISSUED BY THE SAN DIEGO OFFICE.

.LONG TERM (TUE-FRI)...THE UPPER LOW THAT ZIPS IN BEHIND THE WEEKEND
LOW AND MOVES THROUGH MONDAY NIGHT AND EARLY TUESDAY IS NOT AS
STRONG OR DEEP SO EXPECT PRECIPITATION AMOUNTS TO BE LESS. HEIGHT
RISES MOVE IN ON TUESDAY TO START A WARMING AND DRYING TREND FOR THE
REMAINDER OF THE WEEK...AND PEAKING THURSDAY...WITH SOME WEAK
OFFSHORE FLOW TO KEEP SKIES CLEAR.

&&

.AVIATION...27/1800Z.

AT 1730Z...THE MARINE LAYER AT KLAX WAS 2000 FEET DEEP...THE TOP OF
THE INVERSION WAS LOCATED AT 2800 FT WITH A TEMP OF 12C.

LOW TO MODERATE CONFIDENCE IN 18Z TAFS TODAY. STRATUS CLOUDS
EXPECTED TO LIFT OVER COAST/VALLEY SECTIONS THIS AFTERNOON...AND MAY
SCATTER OUT ACROSS THE VALLEYS BUT LIKELY REMAIN MVFR/VFR BKN
COVERAGE FOR MANY COASTAL AREAS.

EXPECT WIDESPREAD MVFR CIGS TO RETURN TO ALL AREAS WEST OF THE MTNS
THIS EVENING...POSSIBLY EVEN INTO THE ANTELOPE VLY BY LATER TONIGHT.
CHANCE OF RAIN N OF PT CONCEPTION AFTER MIDNIGHT...WITH SOME
DRIZZLE/LIGHT -SHRA POSSIBLE S OF PT CONCEPTION BY 14-15Z. GUSTY
WINDS THRU AND BELOW PASSES AND CANYONS OF SRN SBA COUNTY THIS
EVENING WITH LLWS AND MDT UDDF.

KLAX...MODERATE CONFIDENCE IN THE 18Z TAF. THERE IS A 30 PERCENT
CHANCE THAT MVFR CIGS WILL PERSIST THROUGH THE DAY. GUSTY WEST WINDS
EXPECTED FROM 06Z THROUGH AT LEAST 18Z SAT. -DZ OR -SHRA BY 15Z WITH
-RA AFTER 18Z BUT TIMING IS LOW CERTAINTY.


KBUR...MODERATE CONFIDENCE IN THE 18Z TAF. THERE IS A 20 PERCENT
CHANCE MVFR CIGS WILL LINGER BEYOND 19Z OR EVEN THROUGH THE
AFTERNOON. MVFR CIGS WILL RETURN FOR THE OVERNIGHT PERIOD. TIMING OF
CIGS RETURN AND ONSET OF -DZ/VCSH IS LOWER CERTAINTY.

&&

.MARINE...27/200 PM...

FOR THE OUTER WATERS...NORTHWEST GALES THROUGH TONIGHT...EXCEPT
DIMINISHING TO SCA LEVELS ACROSS PZZ670 THIS EVENING. THE STRONGER
WINDS WILL BE OVER PZZ673-676. SCA CONDS ARE EXPECTED ACROSS PZZ676
NORTHWEST OF SAN NICOLAS ISLAND THROUGH SATURDAY AFTERNOON. WINDS
WILL DIMINISH THROUGH THE WEEKEND THEN INCREASE TO GALE OR NEAR-GALE
MONDAY NIGHT INTO TUESDAY...BUT THIS IS LOWER CONFIDENCE AS MODEL
AGREEMENT IS NOT VERY GOOD AT THIS TIME.

FOR THE INNER WATERS...GOOD CONFIDENCE IN SCA LEVEL WINDS ACROSS
PZZ645 THIS AFTERNOON THROUGH THIS EVENING...AND ACROSS THE SANTA
BARBARA CHANNEL AND SOUTHERN INNER WATERS FROM LATE THIS AFTERNOON
THROUGH MID MORNING SAT. THE STRONGEST WINDS WILL BE ACROSS THE
WESTERN SECTIONS FROM THE CHANNEL ISLANDS TO CATALINA ISLAND...WHERE
GUSTS TO 30 KNOTS AND LOCALLY UP TO 35 KNOTS WILL BE POSSIBLE. 30
PERCENT CHANCE THAT A GALE WARNING WILL NEED TO BE ISSUED FOR THE
GALE FORCE GUSTS LATE THIS EVENING THROUGH EARLY SATURDAY MORNING.
SHORT PERIOD ROUGH SEAS ARE EXPECTED.

SHOWERS ARE EXPECTED ACROSS THE WATERS THIS WEEKEND AS A COUPLE OF
FRONTAL SYSTEMS CROSS THE AREA. FROM SATURDAY AFTERNOON THROUGH
SUNDAY EVENING...THERE WILL BE A SLIGHT CHANCE OF THUNDERSTORMS WITH
LOCALLY GUSTY WINDS...ROUGH CHOPPY SEAS...AND POSSIBLE A WATERSPOUTS.

&&

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

&&

$$

PUBLIC...JACKSON
AVIATION/MARINE...SMITH

WWW.WEATHER.GOV/LOSANGELES





















000
FXUS66 KLOX 272238
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
236 PM PST FRI FEB 27 2015

.SYNOPSIS...

A WEATHER PATTERN CHANGE WILL BEGIN TONIGHT AS THERE WILL BE PERIODS
OF RAIN SHOWERS THROUGH EARLY NEXT WEEK...WITH LOWER SNOW LEVELS
EXPECTED ACROSS MOUNTAIN LOCATIONS...POSSIBLY AFFECTING THE
INTERSTATE 5 CORRIDOR SATURDAY THROUGH MONDAY. THUNDERSTORMS ARE
POSSIBLE FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT.

&&

.SHORT TERM (SAT-MON)...A COLD UPPER LEVEL LOW WILL SLIDE DOWN THE
WEST COAST AND BRING VALLEY RAIN AND MOUNTAIN SNOW THROUGH MONDAY
MORNING. MODELS ARE ALL IN GOOD SYNOPTIC AGREEMENT...BUT THERE ARE
SOME DIFFERENCES IN THE OUTCOMES OF THIS LOW PRESSURE SYSTEM STORM
TOTAL PRECIP-WISE. SKIES WILL GRADUALLY CLOUD UP TONIGHT AHEAD OF
THE LOW WITH INCREASING LOW LEVEL MOISTURE. PRECIP CHANCES WILL BE
PRIMARILY CONFINED TO NORTH OF POINT CONCEPTION AND MOUNTAIN
AREAS...WITH THE EXCEPTION OF VERY SLIGHT CHANCES OF SHOWERS IN THE
LA COUNTY COAST AND VALLEYS. BUT SLIGHT CHANCE MAY BE STRETCHING IT
A BIT FOR AREAS SOUTH OF POINT CONCEPTION SO DEFINITELY BETTER
CHANCES OF THOSE AREAS STAYING DRY TONIGHT. MODERATE TO STRONG NW
WINDS JUST OFF THE SURFACE COMING DOWN THE CENTRAL COAST...ALONG
WITH A MODERATE NORTH-SOUTH PRESSURE GRADIENT COULD BRING SOME
LOW-END ADVISORY WINDS TO THE SBA COAST SO HAVE LEFT THE WIND
ADVISORY UP FOR THAT AREA.

BY MIDDAY TOMORROW THE UPPER HAS MOVED SOUTH TO THE BAY AREA AND
SHOWERS BECOME MORE LIKELY OVER THE FORECAST AREA OUT AHEAD OF
IT...ESPECIALLY OVER THE HIGHER ELEVATIONS. FOR TIMING OF THE
PRECIPITATION CHANCES...THEY WILL BE GREATEST OVER THE CENTRAL COAST
DURING THE DAY ON SATURDAY...THEN SHIFT SOUTHWARD TO AREAS SOUTH OF
POINT CONCEPTION OVERNIGHT SATURDAY WHEN THE COLDEST CORE OF THE LOW
SHOULD BE JUST OFF POINT CONCEPTION LATE SATURDAY NIGHT. MODELS SHOW
SOME DYNAMICAL INFLUENCE INTO SUNDAY MORNING AS WELL WHICH WILL HELP
PRECIP CHANCES SOUTH OF THE POINT. PRECIP CHANCES REMAIN LIKELY OVER
MUCH OF LA AND VTU COUNTIES ON SUNDAY...ALONG WITH THE BEST CHANCES
OF THUNDER...WHEN THE LOW STALLS OUT A BIT AND A VORT LOBE ROTATES
AROUND ITS BACK END TO HELP SWING IT OUT. MONDAY WILL STILL BE COOL
BUT THERE WILL ONLY BE A BRIEF BREAK IN PRECIP BEFORE A WEAKER
SECOND LOW MOVES INTO THE AREA FROM OUR NORTH TO BRING PRECIP
CHANCES BACK FOR MONDAY AFTERNOON AND NIGHT.

OVERALL THE PRECIP WILL BE VERY SHOWERY SINCE THERE WILL BE NO WELL
DEFINED COLD FRONT WITH THIS LOW AND HENCE NO WELL DEFINED
PRECIPITATION BAND. STORM TOTALS EXPECTED FOR SATURDAY THROUGH EARLY
MONDAY MORNING AT THIS TIME ARE EXPECTED TO AROUND .1 TO .50 INCHES
LOWER ELEVATIONS AND .5 TO 1.5 INCHES HIGHER ELEVATIONS. THE COLD
MID LEVEL TEMPS WITH THIS LOW WILL HELP DESTABILIZE THE ATMOSPHERE
TO BRING A SLIGHT CHANCE OF THUNDERSTORMS. ALTHOUGH THIS SYSTEM WILL
NOT HAVE MUCH IN THE WAY OF MOISTURE TO WORK WITH...INSTABILITY
FACTORS COULD PRODUCE HEAVIER SHOWERS IN SOME LOCATIONS...ESPECIALLY
SOUTH OF POINT CONCEPTION FROM EARLY SUNDAY INTO SUNDAY EVENING. SO
SOME LOCAL AMOUNTS COULD GO OVER 1.5 INCHES. PLUS WITH LOW LEVEL
SOUTHWEST WINDS AHEAD OF THE LOW ON SATURDAY NIGHT INTO SUNDAY
MORNING THERE COULD ALSO BE SOME OROGRAPHIC INFLUENCE IN THE
FOOTHILLS AND MOUNTAINS OF LA COUNTY. BOTTOM LINE...WITH SUCH A
SHOWERY SYSTEM...STILL EXPECT STORM TOTAL AMOUNTS TO VARY QUITE A
BIT.

THE OTHER STORY WITH THIS STORM WILL BE THE LOW SNOW LEVELS. THEY`LL
START OUT ALL MOSTLY ABOVE 6000 FEET TONIGHT...LOWER TO AROUND 5000
FEET ON SATURDAY THEN DROP DOWN TO AROUND 4000 FEET OR JUST BELOW
SATURDAY NIGHT. CONVECTIVE SHOWERS OFTEN DROP THE SNOW LEVEL EVEN
FURTHER SO THERE COULD BE SOME LOCALLY LOWER LEVELS IN THE HEAVIER
SNOW SHOWERS. SNOW LEVELS WILL COME UP SOME GOING INTO MONDAY WHEN
THEY`LL BE BETWEEN 4500 AND 5000 FEET. WITH THESE SNOW LEVELS THERE
COULD BE IMPACTS OVER THE GRAPEVINE AND HWY 14...MAINLY SUNDAY
MORNING. AT THIS TIME EXPECTING ACCUMULATIONS OF 4-8 INCHES BELOW
7000 FEET AND 8-12 INCHES ABOVE 7000 FEET. THE HEAVIER AMOUNTS WILL
BE IN THE EASTERN SAN GABRIELS AND ALSO THE NORTHERN SLOPES OF
VENTURA COUNTY...THE LATER OF WHICH WILL BENEFIT FROM SOME
OROGRAPHICS AS THE LOW MOVES OUT AND WINDS TURN NORTHERLY. WILL BE
CONVERTING THE WINTER STORM WATCH TO A WINTER WEATHER ADVISORY FOR
SATURDAY LATE  SINCE THE AMOUNTS ARE JUST BELOW WARNING LEVELS. THE
HIGHER ELEVATIONS SOUTH OF LA COUNTY WILL BENEFIT FROM BETTER
MOISTURE AND DYNAMICS AND HENCE GREATER SNOW AMOUNTS...THUS THE
WINTER STORM WARNING ISSUED BY THE SAN DIEGO OFFICE.

.LONG TERM (TUE-FRI)...THE UPPER LOW THAT ZIPS IN BEHIND THE WEEKEND
LOW AND MOVES THROUGH MONDAY NIGHT AND EARLY TUESDAY IS NOT AS
STRONG OR DEEP SO EXPECT PRECIPITATION AMOUNTS TO BE LESS. HEIGHT
RISES MOVE IN ON TUESDAY TO START A WARMING AND DRYING TREND FOR THE
REMAINDER OF THE WEEK...AND PEAKING THURSDAY...WITH SOME WEAK
OFFSHORE FLOW TO KEEP SKIES CLEAR.

&&

.AVIATION...27/1800Z.

AT 1730Z...THE MARINE LAYER AT KLAX WAS 2000 FEET DEEP...THE TOP OF
THE INVERSION WAS LOCATED AT 2800 FT WITH A TEMP OF 12C.

LOW TO MODERATE CONFIDENCE IN 18Z TAFS TODAY. STRATUS CLOUDS
EXPECTED TO LIFT OVER COAST/VALLEY SECTIONS THIS AFTERNOON...AND MAY
SCATTER OUT ACROSS THE VALLEYS BUT LIKELY REMAIN MVFR/VFR BKN
COVERAGE FOR MANY COASTAL AREAS.

EXPECT WIDESPREAD MVFR CIGS TO RETURN TO ALL AREAS WEST OF THE MTNS
THIS EVENING...POSSIBLY EVEN INTO THE ANTELOPE VLY BY LATER TONIGHT.
CHANCE OF RAIN N OF PT CONCEPTION AFTER MIDNIGHT...WITH SOME
DRIZZLE/LIGHT -SHRA POSSIBLE S OF PT CONCEPTION BY 14-15Z. GUSTY
WINDS THRU AND BELOW PASSES AND CANYONS OF SRN SBA COUNTY THIS
EVENING WITH LLWS AND MDT UDDF.

KLAX...MODERATE CONFIDENCE IN THE 18Z TAF. THERE IS A 30 PERCENT
CHANCE THAT MVFR CIGS WILL PERSIST THROUGH THE DAY. GUSTY WEST WINDS
EXPECTED FROM 06Z THROUGH AT LEAST 18Z SAT. -DZ OR -SHRA BY 15Z WITH
-RA AFTER 18Z BUT TIMING IS LOW CERTAINTY.


KBUR...MODERATE CONFIDENCE IN THE 18Z TAF. THERE IS A 20 PERCENT
CHANCE MVFR CIGS WILL LINGER BEYOND 19Z OR EVEN THROUGH THE
AFTERNOON. MVFR CIGS WILL RETURN FOR THE OVERNIGHT PERIOD. TIMING OF
CIGS RETURN AND ONSET OF -DZ/VCSH IS LOWER CERTAINTY.

&&

.MARINE...27/200 PM...

FOR THE OUTER WATERS...NORTHWEST GALES THROUGH TONIGHT...EXCEPT
DIMINISHING TO SCA LEVELS ACROSS PZZ670 THIS EVENING. THE STRONGER
WINDS WILL BE OVER PZZ673-676. SCA CONDS ARE EXPECTED ACROSS PZZ676
NORTHWEST OF SAN NICOLAS ISLAND THROUGH SATURDAY AFTERNOON. WINDS
WILL DIMINISH THROUGH THE WEEKEND THEN INCREASE TO GALE OR NEAR-GALE
MONDAY NIGHT INTO TUESDAY...BUT THIS IS LOWER CONFIDENCE AS MODEL
AGREEMENT IS NOT VERY GOOD AT THIS TIME.

FOR THE INNER WATERS...GOOD CONFIDENCE IN SCA LEVEL WINDS ACROSS
PZZ645 THIS AFTERNOON THROUGH THIS EVENING...AND ACROSS THE SANTA
BARBARA CHANNEL AND SOUTHERN INNER WATERS FROM LATE THIS AFTERNOON
THROUGH MID MORNING SAT. THE STRONGEST WINDS WILL BE ACROSS THE
WESTERN SECTIONS FROM THE CHANNEL ISLANDS TO CATALINA ISLAND...WHERE
GUSTS TO 30 KNOTS AND LOCALLY UP TO 35 KNOTS WILL BE POSSIBLE. 30
PERCENT CHANCE THAT A GALE WARNING WILL NEED TO BE ISSUED FOR THE
GALE FORCE GUSTS LATE THIS EVENING THROUGH EARLY SATURDAY MORNING.
SHORT PERIOD ROUGH SEAS ARE EXPECTED.

SHOWERS ARE EXPECTED ACROSS THE WATERS THIS WEEKEND AS A COUPLE OF
FRONTAL SYSTEMS CROSS THE AREA. FROM SATURDAY AFTERNOON THROUGH
SUNDAY EVENING...THERE WILL BE A SLIGHT CHANCE OF THUNDERSTORMS WITH
LOCALLY GUSTY WINDS...ROUGH CHOPPY SEAS...AND POSSIBLE A WATERSPOUTS.

&&

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

&&

$$

PUBLIC...JACKSON
AVIATION/MARINE...SMITH

WWW.WEATHER.GOV/LOSANGELES




















000
FXUS66 KLOX 272238
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
236 PM PST FRI FEB 27 2015

.SYNOPSIS...

A WEATHER PATTERN CHANGE WILL BEGIN TONIGHT AS THERE WILL BE PERIODS
OF RAIN SHOWERS THROUGH EARLY NEXT WEEK...WITH LOWER SNOW LEVELS
EXPECTED ACROSS MOUNTAIN LOCATIONS...POSSIBLY AFFECTING THE
INTERSTATE 5 CORRIDOR SATURDAY THROUGH MONDAY. THUNDERSTORMS ARE
POSSIBLE FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT.

&&

.SHORT TERM (SAT-MON)...A COLD UPPER LEVEL LOW WILL SLIDE DOWN THE
WEST COAST AND BRING VALLEY RAIN AND MOUNTAIN SNOW THROUGH MONDAY
MORNING. MODELS ARE ALL IN GOOD SYNOPTIC AGREEMENT...BUT THERE ARE
SOME DIFFERENCES IN THE OUTCOMES OF THIS LOW PRESSURE SYSTEM STORM
TOTAL PRECIP-WISE. SKIES WILL GRADUALLY CLOUD UP TONIGHT AHEAD OF
THE LOW WITH INCREASING LOW LEVEL MOISTURE. PRECIP CHANCES WILL BE
PRIMARILY CONFINED TO NORTH OF POINT CONCEPTION AND MOUNTAIN
AREAS...WITH THE EXCEPTION OF VERY SLIGHT CHANCES OF SHOWERS IN THE
LA COUNTY COAST AND VALLEYS. BUT SLIGHT CHANCE MAY BE STRETCHING IT
A BIT FOR AREAS SOUTH OF POINT CONCEPTION SO DEFINITELY BETTER
CHANCES OF THOSE AREAS STAYING DRY TONIGHT. MODERATE TO STRONG NW
WINDS JUST OFF THE SURFACE COMING DOWN THE CENTRAL COAST...ALONG
WITH A MODERATE NORTH-SOUTH PRESSURE GRADIENT COULD BRING SOME
LOW-END ADVISORY WINDS TO THE SBA COAST SO HAVE LEFT THE WIND
ADVISORY UP FOR THAT AREA.

BY MIDDAY TOMORROW THE UPPER HAS MOVED SOUTH TO THE BAY AREA AND
SHOWERS BECOME MORE LIKELY OVER THE FORECAST AREA OUT AHEAD OF
IT...ESPECIALLY OVER THE HIGHER ELEVATIONS. FOR TIMING OF THE
PRECIPITATION CHANCES...THEY WILL BE GREATEST OVER THE CENTRAL COAST
DURING THE DAY ON SATURDAY...THEN SHIFT SOUTHWARD TO AREAS SOUTH OF
POINT CONCEPTION OVERNIGHT SATURDAY WHEN THE COLDEST CORE OF THE LOW
SHOULD BE JUST OFF POINT CONCEPTION LATE SATURDAY NIGHT. MODELS SHOW
SOME DYNAMICAL INFLUENCE INTO SUNDAY MORNING AS WELL WHICH WILL HELP
PRECIP CHANCES SOUTH OF THE POINT. PRECIP CHANCES REMAIN LIKELY OVER
MUCH OF LA AND VTU COUNTIES ON SUNDAY...ALONG WITH THE BEST CHANCES
OF THUNDER...WHEN THE LOW STALLS OUT A BIT AND A VORT LOBE ROTATES
AROUND ITS BACK END TO HELP SWING IT OUT. MONDAY WILL STILL BE COOL
BUT THERE WILL ONLY BE A BRIEF BREAK IN PRECIP BEFORE A WEAKER
SECOND LOW MOVES INTO THE AREA FROM OUR NORTH TO BRING PRECIP
CHANCES BACK FOR MONDAY AFTERNOON AND NIGHT.

OVERALL THE PRECIP WILL BE VERY SHOWERY SINCE THERE WILL BE NO WELL
DEFINED COLD FRONT WITH THIS LOW AND HENCE NO WELL DEFINED
PRECIPITATION BAND. STORM TOTALS EXPECTED FOR SATURDAY THROUGH EARLY
MONDAY MORNING AT THIS TIME ARE EXPECTED TO AROUND .1 TO .50 INCHES
LOWER ELEVATIONS AND .5 TO 1.5 INCHES HIGHER ELEVATIONS. THE COLD
MID LEVEL TEMPS WITH THIS LOW WILL HELP DESTABILIZE THE ATMOSPHERE
TO BRING A SLIGHT CHANCE OF THUNDERSTORMS. ALTHOUGH THIS SYSTEM WILL
NOT HAVE MUCH IN THE WAY OF MOISTURE TO WORK WITH...INSTABILITY
FACTORS COULD PRODUCE HEAVIER SHOWERS IN SOME LOCATIONS...ESPECIALLY
SOUTH OF POINT CONCEPTION FROM EARLY SUNDAY INTO SUNDAY EVENING. SO
SOME LOCAL AMOUNTS COULD GO OVER 1.5 INCHES. PLUS WITH LOW LEVEL
SOUTHWEST WINDS AHEAD OF THE LOW ON SATURDAY NIGHT INTO SUNDAY
MORNING THERE COULD ALSO BE SOME OROGRAPHIC INFLUENCE IN THE
FOOTHILLS AND MOUNTAINS OF LA COUNTY. BOTTOM LINE...WITH SUCH A
SHOWERY SYSTEM...STILL EXPECT STORM TOTAL AMOUNTS TO VARY QUITE A
BIT.

THE OTHER STORY WITH THIS STORM WILL BE THE LOW SNOW LEVELS. THEY`LL
START OUT ALL MOSTLY ABOVE 6000 FEET TONIGHT...LOWER TO AROUND 5000
FEET ON SATURDAY THEN DROP DOWN TO AROUND 4000 FEET OR JUST BELOW
SATURDAY NIGHT. CONVECTIVE SHOWERS OFTEN DROP THE SNOW LEVEL EVEN
FURTHER SO THERE COULD BE SOME LOCALLY LOWER LEVELS IN THE HEAVIER
SNOW SHOWERS. SNOW LEVELS WILL COME UP SOME GOING INTO MONDAY WHEN
THEY`LL BE BETWEEN 4500 AND 5000 FEET. WITH THESE SNOW LEVELS THERE
COULD BE IMPACTS OVER THE GRAPEVINE AND HWY 14...MAINLY SUNDAY
MORNING. AT THIS TIME EXPECTING ACCUMULATIONS OF 4-8 INCHES BELOW
7000 FEET AND 8-12 INCHES ABOVE 7000 FEET. THE HEAVIER AMOUNTS WILL
BE IN THE EASTERN SAN GABRIELS AND ALSO THE NORTHERN SLOPES OF
VENTURA COUNTY...THE LATER OF WHICH WILL BENEFIT FROM SOME
OROGRAPHICS AS THE LOW MOVES OUT AND WINDS TURN NORTHERLY. WILL BE
CONVERTING THE WINTER STORM WATCH TO A WINTER WEATHER ADVISORY FOR
SATURDAY LATE  SINCE THE AMOUNTS ARE JUST BELOW WARNING LEVELS. THE
HIGHER ELEVATIONS SOUTH OF LA COUNTY WILL BENEFIT FROM BETTER
MOISTURE AND DYNAMICS AND HENCE GREATER SNOW AMOUNTS...THUS THE
WINTER STORM WARNING ISSUED BY THE SAN DIEGO OFFICE.

.LONG TERM (TUE-FRI)...THE UPPER LOW THAT ZIPS IN BEHIND THE WEEKEND
LOW AND MOVES THROUGH MONDAY NIGHT AND EARLY TUESDAY IS NOT AS
STRONG OR DEEP SO EXPECT PRECIPITATION AMOUNTS TO BE LESS. HEIGHT
RISES MOVE IN ON TUESDAY TO START A WARMING AND DRYING TREND FOR THE
REMAINDER OF THE WEEK...AND PEAKING THURSDAY...WITH SOME WEAK
OFFSHORE FLOW TO KEEP SKIES CLEAR.

&&

.AVIATION...27/1800Z.

AT 1730Z...THE MARINE LAYER AT KLAX WAS 2000 FEET DEEP...THE TOP OF
THE INVERSION WAS LOCATED AT 2800 FT WITH A TEMP OF 12C.

LOW TO MODERATE CONFIDENCE IN 18Z TAFS TODAY. STRATUS CLOUDS
EXPECTED TO LIFT OVER COAST/VALLEY SECTIONS THIS AFTERNOON...AND MAY
SCATTER OUT ACROSS THE VALLEYS BUT LIKELY REMAIN MVFR/VFR BKN
COVERAGE FOR MANY COASTAL AREAS.

EXPECT WIDESPREAD MVFR CIGS TO RETURN TO ALL AREAS WEST OF THE MTNS
THIS EVENING...POSSIBLY EVEN INTO THE ANTELOPE VLY BY LATER TONIGHT.
CHANCE OF RAIN N OF PT CONCEPTION AFTER MIDNIGHT...WITH SOME
DRIZZLE/LIGHT -SHRA POSSIBLE S OF PT CONCEPTION BY 14-15Z. GUSTY
WINDS THRU AND BELOW PASSES AND CANYONS OF SRN SBA COUNTY THIS
EVENING WITH LLWS AND MDT UDDF.

KLAX...MODERATE CONFIDENCE IN THE 18Z TAF. THERE IS A 30 PERCENT
CHANCE THAT MVFR CIGS WILL PERSIST THROUGH THE DAY. GUSTY WEST WINDS
EXPECTED FROM 06Z THROUGH AT LEAST 18Z SAT. -DZ OR -SHRA BY 15Z WITH
-RA AFTER 18Z BUT TIMING IS LOW CERTAINTY.


KBUR...MODERATE CONFIDENCE IN THE 18Z TAF. THERE IS A 20 PERCENT
CHANCE MVFR CIGS WILL LINGER BEYOND 19Z OR EVEN THROUGH THE
AFTERNOON. MVFR CIGS WILL RETURN FOR THE OVERNIGHT PERIOD. TIMING OF
CIGS RETURN AND ONSET OF -DZ/VCSH IS LOWER CERTAINTY.

&&

.MARINE...27/200 PM...

FOR THE OUTER WATERS...NORTHWEST GALES THROUGH TONIGHT...EXCEPT
DIMINISHING TO SCA LEVELS ACROSS PZZ670 THIS EVENING. THE STRONGER
WINDS WILL BE OVER PZZ673-676. SCA CONDS ARE EXPECTED ACROSS PZZ676
NORTHWEST OF SAN NICOLAS ISLAND THROUGH SATURDAY AFTERNOON. WINDS
WILL DIMINISH THROUGH THE WEEKEND THEN INCREASE TO GALE OR NEAR-GALE
MONDAY NIGHT INTO TUESDAY...BUT THIS IS LOWER CONFIDENCE AS MODEL
AGREEMENT IS NOT VERY GOOD AT THIS TIME.

FOR THE INNER WATERS...GOOD CONFIDENCE IN SCA LEVEL WINDS ACROSS
PZZ645 THIS AFTERNOON THROUGH THIS EVENING...AND ACROSS THE SANTA
BARBARA CHANNEL AND SOUTHERN INNER WATERS FROM LATE THIS AFTERNOON
THROUGH MID MORNING SAT. THE STRONGEST WINDS WILL BE ACROSS THE
WESTERN SECTIONS FROM THE CHANNEL ISLANDS TO CATALINA ISLAND...WHERE
GUSTS TO 30 KNOTS AND LOCALLY UP TO 35 KNOTS WILL BE POSSIBLE. 30
PERCENT CHANCE THAT A GALE WARNING WILL NEED TO BE ISSUED FOR THE
GALE FORCE GUSTS LATE THIS EVENING THROUGH EARLY SATURDAY MORNING.
SHORT PERIOD ROUGH SEAS ARE EXPECTED.

SHOWERS ARE EXPECTED ACROSS THE WATERS THIS WEEKEND AS A COUPLE OF
FRONTAL SYSTEMS CROSS THE AREA. FROM SATURDAY AFTERNOON THROUGH
SUNDAY EVENING...THERE WILL BE A SLIGHT CHANCE OF THUNDERSTORMS WITH
LOCALLY GUSTY WINDS...ROUGH CHOPPY SEAS...AND POSSIBLE A WATERSPOUTS.

&&

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

&&

$$

PUBLIC...JACKSON
AVIATION/MARINE...SMITH

WWW.WEATHER.GOV/LOSANGELES





















000
FXUS66 KLOX 271754
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
954 AM PST FRI FEB 27 2015

.SYNOPSIS...

A WEATHER PATTERN CHANGE WILL BEGIN TONIGHT AS THERE WILL BE PERIODS
OF RAIN THROUGH EARLY NEXT WEEK WITH LOWER SNOW LEVELS EXPECTED
ACROSS MOUNTAIN LOCATIONS...POSSIBLY AFFECTING THE INTERSTATE 5
CORRIDOR SATURDAY THROUGH MONDAY. TEMPERATURES WILL BE BELOW NORMAL
AS WELL THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM (REST OF TODAY-SUN)...NOT MUCH CHANGE OVER THE FORECAST
THINKING OF THE PREVIOUS SHIFT. THE UPPER LOW TO BRING SHOWERS TO
THE AREA THE NEXT SEVERAL DAYS IS CURRENTLY OVER SW WASHINGTON/NW
OREGON AND MAKING ITS WAY SOUTHWARD. AHEAD OF THIS LOW IS MODERATE
NW FLOW THAT`S BRINGING SCATTERED AREAS OF CLOUDINESS TO THE AREAS.
NO REPORTS OF FOG ATTM OVER COASTAL VENTURA AND LA COUNTIES...BUT
PLENTY OF LOW CLOUD COVERAGE AS LOW LEVEL MOISTURE IS PUSHING UP AND
INTO THE FOOTHILLS THANKS TO AN OBVIOUS EDDY AND SOME LOW LEVEL
MOISTURE POOLING IN AHEAD OF THE SYSTEM.  MOST MOUNTAIN AND DESERT
AREAS ARE CLEAR. LA AND VTU COUNTY COASTS AND VALLEYS MAY SEE THE
SUN PEAK THROUGH AT TIMES BUT OVERALL MOSTLY CLOUDY THE REST OF THE
DAYLIGHT HOURS. HAVE BRUSHED UP THE SKY COVER FORECAST FOR THIS
AFTERNOON WHICH HAD PREVIOUSLY BEEN MORE PESSIMISTIC. WIND WISE THE
WIND ADVISORY FOR THIS AFTERNOON AND EVE SBA COUNTY SOUTH COAST
LOOKS GOOD...MAINLY FOR THE WESTERN SECTIONS. THE NORTH-SOUTH
PRESSURE GRADIENTS ARE NOT TOO STRONG BUT SHOULD AT LEAST GET SOME
LOW-END ADVISORY WINDS LATER THIS AFTERNOON AND EVENING.

LATEST LOOK AT 12Z MODELS SHOW FAIRLY GOOD CONSISTENCY WITH PREVIOUS
RUNS...THE ONLY MINOR TREND IS THE DIG MORE ENERGY FURTHER SOUTHWEST
BUT THE TRACK OF THE LOW`S CORE IS PRETTY MUCH UNCHANGED.  THE UPPER
LOW WILL CONTINUE TO DIVE DOWN THE WEST COAST AND WITH THE CORE OF
THE LOW SOMEWHERE OVER POINT CONCEPTION BY MIDDAY SUNDAY. SHOWERS
TONIGHT THROUGH TOMORROW WITH A BEST CHANCE OF PRECIP SATURDAY NIGHT
AND SUNDAY MORNING AS THE BEST DYNAMICAL FORCING SWINGS
THROUGH...THEN CONTINUED SHOWER CHANCES THROUGH SUNDAY NIGHT. STORM
TOTAL PRECIP FORECASTS STILL FAVOR THE EASTERN SAN GABRIEL MOUNTAINS
AND VENTURA COUNTY MOUNTAINS. LATEST GUIDANCE INDICATING AN INCH OR
MORE LIQUID THESE AREAS WITH A TENTH TO A HALF ELSEWHERE. GIVEN THE
SHOWERY NATURE OF THIS SYSTEM AND THE LACK OF ANY WELL-DEFINED
PRECIP BAND DUE TO THE LACK OF A DEFINABLE COLD FRONT...TOTALS WILL
BE WIDELY VARIED. WOULD NOT BE SURPRISED TO SEE SOME AREAS GET VERY
LITTLE PRECIPITATION WITH THIS SYSTEM WHILE THE THREAT OF
THUNDERSTORMS COULD BRING SOME LOCALLY HEAVIER AMOUNTS. SNOW LEVELS
EXPECTED TO LOWER TO BETWEEN 4500 AND 5000 FEET ON SUNDAY NIGHT
WHICH WILL IMPACT THE GRAPEVINE AND HWY 14. WILL MAKE A DECISION ON
THE WINTER STORM WATCH THIS AFTERNOON...AT THIS TIME AMOUNTS APPEAR
TO BE RIGHT ON THE EDGE OF ADVISORY AND WINTER STORM WARNING.

***FROM PREVIOUS DISCUSSION***

.LONG TERM (MON-THU)...THE UPPER TROUGH AXIS WILL BE JUST SOUTH OF
THE AREA MONDAY...BUT THERE WILL BE LINGERING SHOWERS ACROSS THE
FORECAST AREA...ESPECIALLY FOR AREAS S OF POINT CONCEPTION.
HOWEVER...ANOTHER SHORT WAVE DISTURBANCE IS POISED TO MOVE IN OVER
THE FORECAST AREA BY MONDAY NIGHT INTO TUE MORNING. THIS WILL ALLOW
FOR SOME ADDITIONAL SHOWERS TO OCCUR WITH CONTINUED COLDER THAN
NORMAL TEMPS ON TUESDAY. EXCEPT FOR A FEW LINGERING CLOUDS AROUND
THE MOUNTAINS...SKIES SHOULD BE MOSTLY CLEAR...WITH WEAK OFFSHORE
FLOW FOR INTERIOR AREAS BOTH WED/THU. WARMEST DAY WILL BE THURDAY
FOR COAST AND VALLEYS WITH HIGHS IN THE LOWER 70S.


&&

.AVIATION...27/1800Z.

AT 1730Z...THE MARINE LAYER AT KLAX WAS 2000 FEET DEEP...THE TOP OF
THE INVERSION WAS LOCATED AT 2800 FT WITH A TEMP OF 12C.

LOW TO MODERATE CONFIDENCE IN 18Z TAFS TODAY. STRATUS CLOUDS
EXPECTED TO LIFT OVER COAST/VALLEY SECTIONS THIS AFTERNOON...AND MAY
SCATTER OUT ACROSS THE VALLEYS BUT LIKELY REMAIN MVFR/VFR BKN
COVERAGE FOR MANY COASTAL AREAS.

EXPECT WIDESPREAD MVFR CIGS TO RETURN TO ALL AREAS WEST OF THE MTNS
THIS EVENING...POSSIBLY EVEN INTO THE ANTELOPE VLY BY LATER TONIGHT.
CHANCE OF RAIN N OF PT CONCEPTION AFTER MIDNIGHT...WITH SOME
DRIZZLE/LIGHT -SHRA POSSIBLE S OF PT CONCEPTION BY 14-15Z. GUSTY
WINDS THRU AND BELOW PASSES AND CANYONS OF SRN SBA COUNTY THIS
EVENING WITH LLWS AND MDT UDDF.

KLAX...MODERATE CONFIDENCE IN THE 18Z TAF. THERE IS A 30 PERCENT
CHANCE THAT MVFR CIGS WILL PERSIST THROUGH THE DAY. GUSTY WEST WINDS
EXPECTED FROM 06Z THROUGH AT LEAST 18Z SAT. -DZ OR -SHRA BY 15Z WITH
-RA AFTER 18Z BUT TIMING IS LOW CERTAINTY.


KBUR...MODERATE CONFIDENCE IN THE 18Z TAF. THERE IS A 20 PERCENT
CHANCE MVFR CIGS WILL LINGER BEYOND 19Z OR EVEN THROUGH THE
AFTERNOON. MVFR CIGS WILL RETURN FOR THE OVERNIGHT PERIOD. TIMING OF
CIGS RETURN AND ONSET OF -DZ/VCSH IS LOWER CERTAINTY.

&&

.MARINE...27/900 AM...

FOR THE OUTER WATERS...HIGH CONFIDENCE IN NORTHWEST GALES THROUGH
TONIGHT...EXCEPT DIMINISHING BELOW GALE FORCE TO SCA LEVELS ACROSS
NORTHERN SECTIONS THIS EVENING. THE STRONGEST WINDS WILL BE OVER
PZZ673-676. SCA CONDS ARE EXPECTED ACROSS THE SOUTHERN TWO OUTER
WATERS ZONES SAT.

FOR THE INNER WATERS...GOOD CONFIDENCE IN SCA LEVEL WINDS ACROSS THE
NORTHERN INNER WATERS THIS AFTERNOON THROUGH THIS EVENING...AND
ACROSS THE SANTA BARBARA CHANNEL AND SOUTHERN INNER WATERS FROM LATE
THIS AFTERNOON THROUGH MID MORNING SAT. WE CONTINUE TO SEE A 20
PERCENT CHANCE OF GALE FORCE WINDS ACROSS WESTERN PORTIONS OF THESE
ZONES TONIGHT...BUT MORE LIKELY WILL BE LOCALIZED GUSTS TO 35 KNOTS
AROUND THE ISLANDS.

SHOWERS ARE EXPECTED ACROSS THE WATERS THIS WEEKEND. FROM SATURDAY
AFTERNOON THROUGH SUNDAY EVENING...THERE WILL BE A SLIGHT CHANCE OF
THUNDERSTORMS WHICH COULD PRODUCE GUSTY WINDS...LOCALLY HIGHER
SEAS...AND POSSIBLY AN ISOLATED WATERSPOUT.

&&

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

&&

$$

PUBLIC...JACKSON/KAPLAN
AVIATION/MARINE...DB/SMITH

WWW.WEATHER.GOV/LOSANGELES

















000
FXUS66 KLOX 271754
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
954 AM PST FRI FEB 27 2015

.SYNOPSIS...

A WEATHER PATTERN CHANGE WILL BEGIN TONIGHT AS THERE WILL BE PERIODS
OF RAIN THROUGH EARLY NEXT WEEK WITH LOWER SNOW LEVELS EXPECTED
ACROSS MOUNTAIN LOCATIONS...POSSIBLY AFFECTING THE INTERSTATE 5
CORRIDOR SATURDAY THROUGH MONDAY. TEMPERATURES WILL BE BELOW NORMAL
AS WELL THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM (REST OF TODAY-SUN)...NOT MUCH CHANGE OVER THE FORECAST
THINKING OF THE PREVIOUS SHIFT. THE UPPER LOW TO BRING SHOWERS TO
THE AREA THE NEXT SEVERAL DAYS IS CURRENTLY OVER SW WASHINGTON/NW
OREGON AND MAKING ITS WAY SOUTHWARD. AHEAD OF THIS LOW IS MODERATE
NW FLOW THAT`S BRINGING SCATTERED AREAS OF CLOUDINESS TO THE AREAS.
NO REPORTS OF FOG ATTM OVER COASTAL VENTURA AND LA COUNTIES...BUT
PLENTY OF LOW CLOUD COVERAGE AS LOW LEVEL MOISTURE IS PUSHING UP AND
INTO THE FOOTHILLS THANKS TO AN OBVIOUS EDDY AND SOME LOW LEVEL
MOISTURE POOLING IN AHEAD OF THE SYSTEM.  MOST MOUNTAIN AND DESERT
AREAS ARE CLEAR. LA AND VTU COUNTY COASTS AND VALLEYS MAY SEE THE
SUN PEAK THROUGH AT TIMES BUT OVERALL MOSTLY CLOUDY THE REST OF THE
DAYLIGHT HOURS. HAVE BRUSHED UP THE SKY COVER FORECAST FOR THIS
AFTERNOON WHICH HAD PREVIOUSLY BEEN MORE PESSIMISTIC. WIND WISE THE
WIND ADVISORY FOR THIS AFTERNOON AND EVE SBA COUNTY SOUTH COAST
LOOKS GOOD...MAINLY FOR THE WESTERN SECTIONS. THE NORTH-SOUTH
PRESSURE GRADIENTS ARE NOT TOO STRONG BUT SHOULD AT LEAST GET SOME
LOW-END ADVISORY WINDS LATER THIS AFTERNOON AND EVENING.

LATEST LOOK AT 12Z MODELS SHOW FAIRLY GOOD CONSISTENCY WITH PREVIOUS
RUNS...THE ONLY MINOR TREND IS THE DIG MORE ENERGY FURTHER SOUTHWEST
BUT THE TRACK OF THE LOW`S CORE IS PRETTY MUCH UNCHANGED.  THE UPPER
LOW WILL CONTINUE TO DIVE DOWN THE WEST COAST AND WITH THE CORE OF
THE LOW SOMEWHERE OVER POINT CONCEPTION BY MIDDAY SUNDAY. SHOWERS
TONIGHT THROUGH TOMORROW WITH A BEST CHANCE OF PRECIP SATURDAY NIGHT
AND SUNDAY MORNING AS THE BEST DYNAMICAL FORCING SWINGS
THROUGH...THEN CONTINUED SHOWER CHANCES THROUGH SUNDAY NIGHT. STORM
TOTAL PRECIP FORECASTS STILL FAVOR THE EASTERN SAN GABRIEL MOUNTAINS
AND VENTURA COUNTY MOUNTAINS. LATEST GUIDANCE INDICATING AN INCH OR
MORE LIQUID THESE AREAS WITH A TENTH TO A HALF ELSEWHERE. GIVEN THE
SHOWERY NATURE OF THIS SYSTEM AND THE LACK OF ANY WELL-DEFINED
PRECIP BAND DUE TO THE LACK OF A DEFINABLE COLD FRONT...TOTALS WILL
BE WIDELY VARIED. WOULD NOT BE SURPRISED TO SEE SOME AREAS GET VERY
LITTLE PRECIPITATION WITH THIS SYSTEM WHILE THE THREAT OF
THUNDERSTORMS COULD BRING SOME LOCALLY HEAVIER AMOUNTS. SNOW LEVELS
EXPECTED TO LOWER TO BETWEEN 4500 AND 5000 FEET ON SUNDAY NIGHT
WHICH WILL IMPACT THE GRAPEVINE AND HWY 14. WILL MAKE A DECISION ON
THE WINTER STORM WATCH THIS AFTERNOON...AT THIS TIME AMOUNTS APPEAR
TO BE RIGHT ON THE EDGE OF ADVISORY AND WINTER STORM WARNING.

***FROM PREVIOUS DISCUSSION***

.LONG TERM (MON-THU)...THE UPPER TROUGH AXIS WILL BE JUST SOUTH OF
THE AREA MONDAY...BUT THERE WILL BE LINGERING SHOWERS ACROSS THE
FORECAST AREA...ESPECIALLY FOR AREAS S OF POINT CONCEPTION.
HOWEVER...ANOTHER SHORT WAVE DISTURBANCE IS POISED TO MOVE IN OVER
THE FORECAST AREA BY MONDAY NIGHT INTO TUE MORNING. THIS WILL ALLOW
FOR SOME ADDITIONAL SHOWERS TO OCCUR WITH CONTINUED COLDER THAN
NORMAL TEMPS ON TUESDAY. EXCEPT FOR A FEW LINGERING CLOUDS AROUND
THE MOUNTAINS...SKIES SHOULD BE MOSTLY CLEAR...WITH WEAK OFFSHORE
FLOW FOR INTERIOR AREAS BOTH WED/THU. WARMEST DAY WILL BE THURDAY
FOR COAST AND VALLEYS WITH HIGHS IN THE LOWER 70S.


&&

.AVIATION...27/1800Z.

AT 1730Z...THE MARINE LAYER AT KLAX WAS 2000 FEET DEEP...THE TOP OF
THE INVERSION WAS LOCATED AT 2800 FT WITH A TEMP OF 12C.

LOW TO MODERATE CONFIDENCE IN 18Z TAFS TODAY. STRATUS CLOUDS
EXPECTED TO LIFT OVER COAST/VALLEY SECTIONS THIS AFTERNOON...AND MAY
SCATTER OUT ACROSS THE VALLEYS BUT LIKELY REMAIN MVFR/VFR BKN
COVERAGE FOR MANY COASTAL AREAS.

EXPECT WIDESPREAD MVFR CIGS TO RETURN TO ALL AREAS WEST OF THE MTNS
THIS EVENING...POSSIBLY EVEN INTO THE ANTELOPE VLY BY LATER TONIGHT.
CHANCE OF RAIN N OF PT CONCEPTION AFTER MIDNIGHT...WITH SOME
DRIZZLE/LIGHT -SHRA POSSIBLE S OF PT CONCEPTION BY 14-15Z. GUSTY
WINDS THRU AND BELOW PASSES AND CANYONS OF SRN SBA COUNTY THIS
EVENING WITH LLWS AND MDT UDDF.

KLAX...MODERATE CONFIDENCE IN THE 18Z TAF. THERE IS A 30 PERCENT
CHANCE THAT MVFR CIGS WILL PERSIST THROUGH THE DAY. GUSTY WEST WINDS
EXPECTED FROM 06Z THROUGH AT LEAST 18Z SAT. -DZ OR -SHRA BY 15Z WITH
-RA AFTER 18Z BUT TIMING IS LOW CERTAINTY.


KBUR...MODERATE CONFIDENCE IN THE 18Z TAF. THERE IS A 20 PERCENT
CHANCE MVFR CIGS WILL LINGER BEYOND 19Z OR EVEN THROUGH THE
AFTERNOON. MVFR CIGS WILL RETURN FOR THE OVERNIGHT PERIOD. TIMING OF
CIGS RETURN AND ONSET OF -DZ/VCSH IS LOWER CERTAINTY.

&&

.MARINE...27/900 AM...

FOR THE OUTER WATERS...HIGH CONFIDENCE IN NORTHWEST GALES THROUGH
TONIGHT...EXCEPT DIMINISHING BELOW GALE FORCE TO SCA LEVELS ACROSS
NORTHERN SECTIONS THIS EVENING. THE STRONGEST WINDS WILL BE OVER
PZZ673-676. SCA CONDS ARE EXPECTED ACROSS THE SOUTHERN TWO OUTER
WATERS ZONES SAT.

FOR THE INNER WATERS...GOOD CONFIDENCE IN SCA LEVEL WINDS ACROSS THE
NORTHERN INNER WATERS THIS AFTERNOON THROUGH THIS EVENING...AND
ACROSS THE SANTA BARBARA CHANNEL AND SOUTHERN INNER WATERS FROM LATE
THIS AFTERNOON THROUGH MID MORNING SAT. WE CONTINUE TO SEE A 20
PERCENT CHANCE OF GALE FORCE WINDS ACROSS WESTERN PORTIONS OF THESE
ZONES TONIGHT...BUT MORE LIKELY WILL BE LOCALIZED GUSTS TO 35 KNOTS
AROUND THE ISLANDS.

SHOWERS ARE EXPECTED ACROSS THE WATERS THIS WEEKEND. FROM SATURDAY
AFTERNOON THROUGH SUNDAY EVENING...THERE WILL BE A SLIGHT CHANCE OF
THUNDERSTORMS WHICH COULD PRODUCE GUSTY WINDS...LOCALLY HIGHER
SEAS...AND POSSIBLY AN ISOLATED WATERSPOUT.

&&

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

&&

$$

PUBLIC...JACKSON/KAPLAN
AVIATION/MARINE...DB/SMITH

WWW.WEATHER.GOV/LOSANGELES


















000
FXUS66 KLOX 271754
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
954 AM PST FRI FEB 27 2015

.SYNOPSIS...

A WEATHER PATTERN CHANGE WILL BEGIN TONIGHT AS THERE WILL BE PERIODS
OF RAIN THROUGH EARLY NEXT WEEK WITH LOWER SNOW LEVELS EXPECTED
ACROSS MOUNTAIN LOCATIONS...POSSIBLY AFFECTING THE INTERSTATE 5
CORRIDOR SATURDAY THROUGH MONDAY. TEMPERATURES WILL BE BELOW NORMAL
AS WELL THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM (REST OF TODAY-SUN)...NOT MUCH CHANGE OVER THE FORECAST
THINKING OF THE PREVIOUS SHIFT. THE UPPER LOW TO BRING SHOWERS TO
THE AREA THE NEXT SEVERAL DAYS IS CURRENTLY OVER SW WASHINGTON/NW
OREGON AND MAKING ITS WAY SOUTHWARD. AHEAD OF THIS LOW IS MODERATE
NW FLOW THAT`S BRINGING SCATTERED AREAS OF CLOUDINESS TO THE AREAS.
NO REPORTS OF FOG ATTM OVER COASTAL VENTURA AND LA COUNTIES...BUT
PLENTY OF LOW CLOUD COVERAGE AS LOW LEVEL MOISTURE IS PUSHING UP AND
INTO THE FOOTHILLS THANKS TO AN OBVIOUS EDDY AND SOME LOW LEVEL
MOISTURE POOLING IN AHEAD OF THE SYSTEM.  MOST MOUNTAIN AND DESERT
AREAS ARE CLEAR. LA AND VTU COUNTY COASTS AND VALLEYS MAY SEE THE
SUN PEAK THROUGH AT TIMES BUT OVERALL MOSTLY CLOUDY THE REST OF THE
DAYLIGHT HOURS. HAVE BRUSHED UP THE SKY COVER FORECAST FOR THIS
AFTERNOON WHICH HAD PREVIOUSLY BEEN MORE PESSIMISTIC. WIND WISE THE
WIND ADVISORY FOR THIS AFTERNOON AND EVE SBA COUNTY SOUTH COAST
LOOKS GOOD...MAINLY FOR THE WESTERN SECTIONS. THE NORTH-SOUTH
PRESSURE GRADIENTS ARE NOT TOO STRONG BUT SHOULD AT LEAST GET SOME
LOW-END ADVISORY WINDS LATER THIS AFTERNOON AND EVENING.

LATEST LOOK AT 12Z MODELS SHOW FAIRLY GOOD CONSISTENCY WITH PREVIOUS
RUNS...THE ONLY MINOR TREND IS THE DIG MORE ENERGY FURTHER SOUTHWEST
BUT THE TRACK OF THE LOW`S CORE IS PRETTY MUCH UNCHANGED.  THE UPPER
LOW WILL CONTINUE TO DIVE DOWN THE WEST COAST AND WITH THE CORE OF
THE LOW SOMEWHERE OVER POINT CONCEPTION BY MIDDAY SUNDAY. SHOWERS
TONIGHT THROUGH TOMORROW WITH A BEST CHANCE OF PRECIP SATURDAY NIGHT
AND SUNDAY MORNING AS THE BEST DYNAMICAL FORCING SWINGS
THROUGH...THEN CONTINUED SHOWER CHANCES THROUGH SUNDAY NIGHT. STORM
TOTAL PRECIP FORECASTS STILL FAVOR THE EASTERN SAN GABRIEL MOUNTAINS
AND VENTURA COUNTY MOUNTAINS. LATEST GUIDANCE INDICATING AN INCH OR
MORE LIQUID THESE AREAS WITH A TENTH TO A HALF ELSEWHERE. GIVEN THE
SHOWERY NATURE OF THIS SYSTEM AND THE LACK OF ANY WELL-DEFINED
PRECIP BAND DUE TO THE LACK OF A DEFINABLE COLD FRONT...TOTALS WILL
BE WIDELY VARIED. WOULD NOT BE SURPRISED TO SEE SOME AREAS GET VERY
LITTLE PRECIPITATION WITH THIS SYSTEM WHILE THE THREAT OF
THUNDERSTORMS COULD BRING SOME LOCALLY HEAVIER AMOUNTS. SNOW LEVELS
EXPECTED TO LOWER TO BETWEEN 4500 AND 5000 FEET ON SUNDAY NIGHT
WHICH WILL IMPACT THE GRAPEVINE AND HWY 14. WILL MAKE A DECISION ON
THE WINTER STORM WATCH THIS AFTERNOON...AT THIS TIME AMOUNTS APPEAR
TO BE RIGHT ON THE EDGE OF ADVISORY AND WINTER STORM WARNING.

***FROM PREVIOUS DISCUSSION***

.LONG TERM (MON-THU)...THE UPPER TROUGH AXIS WILL BE JUST SOUTH OF
THE AREA MONDAY...BUT THERE WILL BE LINGERING SHOWERS ACROSS THE
FORECAST AREA...ESPECIALLY FOR AREAS S OF POINT CONCEPTION.
HOWEVER...ANOTHER SHORT WAVE DISTURBANCE IS POISED TO MOVE IN OVER
THE FORECAST AREA BY MONDAY NIGHT INTO TUE MORNING. THIS WILL ALLOW
FOR SOME ADDITIONAL SHOWERS TO OCCUR WITH CONTINUED COLDER THAN
NORMAL TEMPS ON TUESDAY. EXCEPT FOR A FEW LINGERING CLOUDS AROUND
THE MOUNTAINS...SKIES SHOULD BE MOSTLY CLEAR...WITH WEAK OFFSHORE
FLOW FOR INTERIOR AREAS BOTH WED/THU. WARMEST DAY WILL BE THURDAY
FOR COAST AND VALLEYS WITH HIGHS IN THE LOWER 70S.


&&

.AVIATION...27/1800Z.

AT 1730Z...THE MARINE LAYER AT KLAX WAS 2000 FEET DEEP...THE TOP OF
THE INVERSION WAS LOCATED AT 2800 FT WITH A TEMP OF 12C.

LOW TO MODERATE CONFIDENCE IN 18Z TAFS TODAY. STRATUS CLOUDS
EXPECTED TO LIFT OVER COAST/VALLEY SECTIONS THIS AFTERNOON...AND MAY
SCATTER OUT ACROSS THE VALLEYS BUT LIKELY REMAIN MVFR/VFR BKN
COVERAGE FOR MANY COASTAL AREAS.

EXPECT WIDESPREAD MVFR CIGS TO RETURN TO ALL AREAS WEST OF THE MTNS
THIS EVENING...POSSIBLY EVEN INTO THE ANTELOPE VLY BY LATER TONIGHT.
CHANCE OF RAIN N OF PT CONCEPTION AFTER MIDNIGHT...WITH SOME
DRIZZLE/LIGHT -SHRA POSSIBLE S OF PT CONCEPTION BY 14-15Z. GUSTY
WINDS THRU AND BELOW PASSES AND CANYONS OF SRN SBA COUNTY THIS
EVENING WITH LLWS AND MDT UDDF.

KLAX...MODERATE CONFIDENCE IN THE 18Z TAF. THERE IS A 30 PERCENT
CHANCE THAT MVFR CIGS WILL PERSIST THROUGH THE DAY. GUSTY WEST WINDS
EXPECTED FROM 06Z THROUGH AT LEAST 18Z SAT. -DZ OR -SHRA BY 15Z WITH
-RA AFTER 18Z BUT TIMING IS LOW CERTAINTY.


KBUR...MODERATE CONFIDENCE IN THE 18Z TAF. THERE IS A 20 PERCENT
CHANCE MVFR CIGS WILL LINGER BEYOND 19Z OR EVEN THROUGH THE
AFTERNOON. MVFR CIGS WILL RETURN FOR THE OVERNIGHT PERIOD. TIMING OF
CIGS RETURN AND ONSET OF -DZ/VCSH IS LOWER CERTAINTY.

&&

.MARINE...27/900 AM...

FOR THE OUTER WATERS...HIGH CONFIDENCE IN NORTHWEST GALES THROUGH
TONIGHT...EXCEPT DIMINISHING BELOW GALE FORCE TO SCA LEVELS ACROSS
NORTHERN SECTIONS THIS EVENING. THE STRONGEST WINDS WILL BE OVER
PZZ673-676. SCA CONDS ARE EXPECTED ACROSS THE SOUTHERN TWO OUTER
WATERS ZONES SAT.

FOR THE INNER WATERS...GOOD CONFIDENCE IN SCA LEVEL WINDS ACROSS THE
NORTHERN INNER WATERS THIS AFTERNOON THROUGH THIS EVENING...AND
ACROSS THE SANTA BARBARA CHANNEL AND SOUTHERN INNER WATERS FROM LATE
THIS AFTERNOON THROUGH MID MORNING SAT. WE CONTINUE TO SEE A 20
PERCENT CHANCE OF GALE FORCE WINDS ACROSS WESTERN PORTIONS OF THESE
ZONES TONIGHT...BUT MORE LIKELY WILL BE LOCALIZED GUSTS TO 35 KNOTS
AROUND THE ISLANDS.

SHOWERS ARE EXPECTED ACROSS THE WATERS THIS WEEKEND. FROM SATURDAY
AFTERNOON THROUGH SUNDAY EVENING...THERE WILL BE A SLIGHT CHANCE OF
THUNDERSTORMS WHICH COULD PRODUCE GUSTY WINDS...LOCALLY HIGHER
SEAS...AND POSSIBLY AN ISOLATED WATERSPOUT.

&&

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

&&

$$

PUBLIC...JACKSON/KAPLAN
AVIATION/MARINE...DB/SMITH

WWW.WEATHER.GOV/LOSANGELES


















000
FXUS66 KLOX 271754
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
954 AM PST FRI FEB 27 2015

.SYNOPSIS...

A WEATHER PATTERN CHANGE WILL BEGIN TONIGHT AS THERE WILL BE PERIODS
OF RAIN THROUGH EARLY NEXT WEEK WITH LOWER SNOW LEVELS EXPECTED
ACROSS MOUNTAIN LOCATIONS...POSSIBLY AFFECTING THE INTERSTATE 5
CORRIDOR SATURDAY THROUGH MONDAY. TEMPERATURES WILL BE BELOW NORMAL
AS WELL THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM (REST OF TODAY-SUN)...NOT MUCH CHANGE OVER THE FORECAST
THINKING OF THE PREVIOUS SHIFT. THE UPPER LOW TO BRING SHOWERS TO
THE AREA THE NEXT SEVERAL DAYS IS CURRENTLY OVER SW WASHINGTON/NW
OREGON AND MAKING ITS WAY SOUTHWARD. AHEAD OF THIS LOW IS MODERATE
NW FLOW THAT`S BRINGING SCATTERED AREAS OF CLOUDINESS TO THE AREAS.
NO REPORTS OF FOG ATTM OVER COASTAL VENTURA AND LA COUNTIES...BUT
PLENTY OF LOW CLOUD COVERAGE AS LOW LEVEL MOISTURE IS PUSHING UP AND
INTO THE FOOTHILLS THANKS TO AN OBVIOUS EDDY AND SOME LOW LEVEL
MOISTURE POOLING IN AHEAD OF THE SYSTEM.  MOST MOUNTAIN AND DESERT
AREAS ARE CLEAR. LA AND VTU COUNTY COASTS AND VALLEYS MAY SEE THE
SUN PEAK THROUGH AT TIMES BUT OVERALL MOSTLY CLOUDY THE REST OF THE
DAYLIGHT HOURS. HAVE BRUSHED UP THE SKY COVER FORECAST FOR THIS
AFTERNOON WHICH HAD PREVIOUSLY BEEN MORE PESSIMISTIC. WIND WISE THE
WIND ADVISORY FOR THIS AFTERNOON AND EVE SBA COUNTY SOUTH COAST
LOOKS GOOD...MAINLY FOR THE WESTERN SECTIONS. THE NORTH-SOUTH
PRESSURE GRADIENTS ARE NOT TOO STRONG BUT SHOULD AT LEAST GET SOME
LOW-END ADVISORY WINDS LATER THIS AFTERNOON AND EVENING.

LATEST LOOK AT 12Z MODELS SHOW FAIRLY GOOD CONSISTENCY WITH PREVIOUS
RUNS...THE ONLY MINOR TREND IS THE DIG MORE ENERGY FURTHER SOUTHWEST
BUT THE TRACK OF THE LOW`S CORE IS PRETTY MUCH UNCHANGED.  THE UPPER
LOW WILL CONTINUE TO DIVE DOWN THE WEST COAST AND WITH THE CORE OF
THE LOW SOMEWHERE OVER POINT CONCEPTION BY MIDDAY SUNDAY. SHOWERS
TONIGHT THROUGH TOMORROW WITH A BEST CHANCE OF PRECIP SATURDAY NIGHT
AND SUNDAY MORNING AS THE BEST DYNAMICAL FORCING SWINGS
THROUGH...THEN CONTINUED SHOWER CHANCES THROUGH SUNDAY NIGHT. STORM
TOTAL PRECIP FORECASTS STILL FAVOR THE EASTERN SAN GABRIEL MOUNTAINS
AND VENTURA COUNTY MOUNTAINS. LATEST GUIDANCE INDICATING AN INCH OR
MORE LIQUID THESE AREAS WITH A TENTH TO A HALF ELSEWHERE. GIVEN THE
SHOWERY NATURE OF THIS SYSTEM AND THE LACK OF ANY WELL-DEFINED
PRECIP BAND DUE TO THE LACK OF A DEFINABLE COLD FRONT...TOTALS WILL
BE WIDELY VARIED. WOULD NOT BE SURPRISED TO SEE SOME AREAS GET VERY
LITTLE PRECIPITATION WITH THIS SYSTEM WHILE THE THREAT OF
THUNDERSTORMS COULD BRING SOME LOCALLY HEAVIER AMOUNTS. SNOW LEVELS
EXPECTED TO LOWER TO BETWEEN 4500 AND 5000 FEET ON SUNDAY NIGHT
WHICH WILL IMPACT THE GRAPEVINE AND HWY 14. WILL MAKE A DECISION ON
THE WINTER STORM WATCH THIS AFTERNOON...AT THIS TIME AMOUNTS APPEAR
TO BE RIGHT ON THE EDGE OF ADVISORY AND WINTER STORM WARNING.

***FROM PREVIOUS DISCUSSION***

.LONG TERM (MON-THU)...THE UPPER TROUGH AXIS WILL BE JUST SOUTH OF
THE AREA MONDAY...BUT THERE WILL BE LINGERING SHOWERS ACROSS THE
FORECAST AREA...ESPECIALLY FOR AREAS S OF POINT CONCEPTION.
HOWEVER...ANOTHER SHORT WAVE DISTURBANCE IS POISED TO MOVE IN OVER
THE FORECAST AREA BY MONDAY NIGHT INTO TUE MORNING. THIS WILL ALLOW
FOR SOME ADDITIONAL SHOWERS TO OCCUR WITH CONTINUED COLDER THAN
NORMAL TEMPS ON TUESDAY. EXCEPT FOR A FEW LINGERING CLOUDS AROUND
THE MOUNTAINS...SKIES SHOULD BE MOSTLY CLEAR...WITH WEAK OFFSHORE
FLOW FOR INTERIOR AREAS BOTH WED/THU. WARMEST DAY WILL BE THURDAY
FOR COAST AND VALLEYS WITH HIGHS IN THE LOWER 70S.


&&

.AVIATION...27/1800Z.

AT 1730Z...THE MARINE LAYER AT KLAX WAS 2000 FEET DEEP...THE TOP OF
THE INVERSION WAS LOCATED AT 2800 FT WITH A TEMP OF 12C.

LOW TO MODERATE CONFIDENCE IN 18Z TAFS TODAY. STRATUS CLOUDS
EXPECTED TO LIFT OVER COAST/VALLEY SECTIONS THIS AFTERNOON...AND MAY
SCATTER OUT ACROSS THE VALLEYS BUT LIKELY REMAIN MVFR/VFR BKN
COVERAGE FOR MANY COASTAL AREAS.

EXPECT WIDESPREAD MVFR CIGS TO RETURN TO ALL AREAS WEST OF THE MTNS
THIS EVENING...POSSIBLY EVEN INTO THE ANTELOPE VLY BY LATER TONIGHT.
CHANCE OF RAIN N OF PT CONCEPTION AFTER MIDNIGHT...WITH SOME
DRIZZLE/LIGHT -SHRA POSSIBLE S OF PT CONCEPTION BY 14-15Z. GUSTY
WINDS THRU AND BELOW PASSES AND CANYONS OF SRN SBA COUNTY THIS
EVENING WITH LLWS AND MDT UDDF.

KLAX...MODERATE CONFIDENCE IN THE 18Z TAF. THERE IS A 30 PERCENT
CHANCE THAT MVFR CIGS WILL PERSIST THROUGH THE DAY. GUSTY WEST WINDS
EXPECTED FROM 06Z THROUGH AT LEAST 18Z SAT. -DZ OR -SHRA BY 15Z WITH
-RA AFTER 18Z BUT TIMING IS LOW CERTAINTY.


KBUR...MODERATE CONFIDENCE IN THE 18Z TAF. THERE IS A 20 PERCENT
CHANCE MVFR CIGS WILL LINGER BEYOND 19Z OR EVEN THROUGH THE
AFTERNOON. MVFR CIGS WILL RETURN FOR THE OVERNIGHT PERIOD. TIMING OF
CIGS RETURN AND ONSET OF -DZ/VCSH IS LOWER CERTAINTY.

&&

.MARINE...27/900 AM...

FOR THE OUTER WATERS...HIGH CONFIDENCE IN NORTHWEST GALES THROUGH
TONIGHT...EXCEPT DIMINISHING BELOW GALE FORCE TO SCA LEVELS ACROSS
NORTHERN SECTIONS THIS EVENING. THE STRONGEST WINDS WILL BE OVER
PZZ673-676. SCA CONDS ARE EXPECTED ACROSS THE SOUTHERN TWO OUTER
WATERS ZONES SAT.

FOR THE INNER WATERS...GOOD CONFIDENCE IN SCA LEVEL WINDS ACROSS THE
NORTHERN INNER WATERS THIS AFTERNOON THROUGH THIS EVENING...AND
ACROSS THE SANTA BARBARA CHANNEL AND SOUTHERN INNER WATERS FROM LATE
THIS AFTERNOON THROUGH MID MORNING SAT. WE CONTINUE TO SEE A 20
PERCENT CHANCE OF GALE FORCE WINDS ACROSS WESTERN PORTIONS OF THESE
ZONES TONIGHT...BUT MORE LIKELY WILL BE LOCALIZED GUSTS TO 35 KNOTS
AROUND THE ISLANDS.

SHOWERS ARE EXPECTED ACROSS THE WATERS THIS WEEKEND. FROM SATURDAY
AFTERNOON THROUGH SUNDAY EVENING...THERE WILL BE A SLIGHT CHANCE OF
THUNDERSTORMS WHICH COULD PRODUCE GUSTY WINDS...LOCALLY HIGHER
SEAS...AND POSSIBLY AN ISOLATED WATERSPOUT.

&&

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

&&

$$

PUBLIC...JACKSON/KAPLAN
AVIATION/MARINE...DB/SMITH

WWW.WEATHER.GOV/LOSANGELES

















000
FXUS66 KLOX 271247
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
345 AM PST FRI FEB 27 2015

UPDATED AVIATION SECTION

.SYNOPSIS...

A WEATHER PATTERN CHANGE WILL BEGIN TONIGHT AS THERE WILL BE PERIODS
OF RAIN THROUGH EARLY NEXT WEEK WITH LOWER SNOW LEVELS EXPECTED
ACROSS MOUNTAIN LOCATIONS...POSSIBLY AFFECTING THE INTERSTATE 5
CORRIDOR SATURDAY THROUGH MONDAY. TEMPERATURES WILL BE BELOW NORMAL
AS WELL THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM (TODAY-SUN)...LATEST FOG PRODUCT IMAGERY INDICATED LOW
CLOUDS ACROSS THE CENTRAL COAST AND DEVELOPING ACROSS THE L.A.
COUNTY BASIN AND INTO THE SAN GABRIEL VALLEY AND ADJACENT COASTAL
SLOPES. LOW CLOUDS SHOULD SPREAD INTO THE SAN FERNANDO VALLEY BY
DAWN AND PORTIONS OF THE VENTURA COUNTY COAST AND VALLEYS...BUT
MIGHT HAVE A TOUGH TIME MAKING IT INTO THE SANTA CLARITA VALLEY AS
NORTHERLY WINDS HAVE PERSISTED ACROSS THE I-5 CORRIDOR THIS MORNING.
LATEST ACARS SOUNDING NEAR LAX INDICATED A WEAK INVERSION FROM 1300
FT UP TO 2500 FT. WITH THE INVERSION BEING SO WEAK AND INCREASING
ONSHORE FLOW TODAY...EXPECT LOW CLOUDS TO CONTINUE TO INCREASE
ACROSS MUCH OF LA/VTU COUNTIES LATER THIS MORNING WITH SKIES
BECOMING PARTLY TO MOSTLY CLOUDY TODAY.

A WIND ADVISORY HAS BEEN ISSUED FOR THE SANTA BARBARA COUNTY
MOUNTAINS AND ADJACENT WIND PRONE AREAS ACROSS THE SOUTH COAST OF
SANTA BARBARA FOR GUSTY NW WINDS LATE THIS AFTERNOON THROUGH THIS
EVENING. STRONGEST WIND GUSTS WILL BE BETWEEN 35 AND 45 MPH. THERE
WILL BE GUSTY SW TO W WINDS ACROSS THE ANTELOPE VALLEY AS WELL THIS
AFTERNOON...BUT SHOULD REMAIN JUST BELOW WIND ADVISORY THRESHOLDS.
EXPECT LOCAL GUSTS TO 45 MPH IN SOME LOCATIONS.

SYNOPTICALLY...AN UPPER LEVEL LOW THAT WAS OVER WASHINGTON STATE
THIS MORNING WILL CONTINUE TO TREK SOUTH TOWARDS NORTHERN CALIFORNIA
THIS AFTERNOON. THIS UPPER LEVEL FEATURE WILL THEN MOVE SLOWLY TO
THE SOUTH AND BECOME CUTOFF LATE SATURDAY INTO SUNDAY OVER SOUTHERN
CALIFORNIA...THEN PUSH OUT OF THE AREA BY MONDAY MORNING...AS
ANOTHER UPPER LEVEL DISTURBANCE QUICKLY MOVES IN BEHIND THE EXITING
LOW. THIS WEATHER PATTERN WILL BRING AN EXTENDED PERIOD OF SHOWERS
ACROSS MUCH OF SOUTHWESTERN CALIFORNIA...WITH SNOW SHOWERS IN THE
MOUNTAINS. AS HAS BEEN THE CASE OVER THE PAST SEVERAL STORM
EVENTS...THE UPPER LOWS HAVE BEEN MAINLY OVER LAND AS THEY
RETROGRADED TOWARDS SOUTHERN CALIFORNIA. MOST OF THE SYSTEMS HAVE
HAD A TOUGH TIME TAPPING INTO SOME MOISTURE DUE TO THEIR TRAJECTORY.
HOWEVER...MOST MODELS ARE NOW BRINGING THIS UPPER LOW A TAD FARTHER
WEST OVER THE COASTAL WATERS AS IT REACHES SOUTHERN CALIFORNIA WHICH
SHOULD HELP TO TAP INTO SOME ADDITIONAL MOISTURE. OVERALL...AREAS TO
OUR SOUTH WILL LIKELY SEE THE BETTER PRECIP AMOUNTS DUE TO BEST
CYCLONIC FLOW AROUND THE LOW. THAT BEING SAID...MODELS ARE IN PRETTY
GOOD AGREEMENT WITH THE STORM TRACK...BUT ARE STILL QUITE VARIED
WITH PRECIP AMOUNTS.

AT THIS POINT...WILL STAY WITH WINTER STORM WATCH HOPING THAT NEXT
SET OF MODELS WILL BE A BIT CLEARER AND THE DAY SHIFT CAN MAKE A
BETTER EDUCATED DECISION TO EITHER UPGRADE THE WATCH TO A WINTER
STORM WARNING OR WINTER WEATHER ADVISORY. THE FACT THAT THERE IS NOT
AN ORGANIZED COLD FRONT BRINGING A STEADY PERIOD OF RAIN OVER THE
REGION MAKES THE FORECAST A BIT DIFFICULT. RAINFALL TOTALS WILL VARY
WITH THIS NEXT SYSTEM. THERE WILL BE PLENTY OF COLD AIR ASSOCIATED
WITH THE UPPER LOW TO HELP CAUSE THE ATMOSPHERE TO BECOME UNSTABLE
ON SATURDAY AND BRING A SLIGHT CHANCE OF THUNDERSTORMS TO AREAS N OF
VENTURA COUNTY. AS THE UPPER LOW MOVES FARTHER SOUTH...THE ENTIRE
FORECAST AREA FROM SLO TO LA COUNTIES WILL HAVE A SLIGHT CHANCE OF
THUNDERSTORMS INCLUDING THE ADJACENT COASTAL WATERS. EXPECT MOSTLY
SHOWERY CONDITIONS FROM LATE TONIGHT THROUGH SUNDAY. PRELIMINARY
RAINFALL TOTALS CURRENTLY ARE FORECAST BETWEEN 0.10 AND 0.50
INCHES...WITH UP TO 1.25 INCH IN THE SAN GABRIEL MOUNTAINS. THERE
COULD BE HIGHER AMOUNTS NEAR THUNDERSTORMS.

ONE OF THE MAIN IMPACTS WITH THIS NEXT SYSTEM WILL BE THE LOWER SNOW
LEVELS POSSIBLY AFFECTING THE I-5 CORRIDOR AND HIGHWAY 14.SNOW
LEVELS WITH THIS SYSTEM WILL BE MUCH LOWER THAN THE LAST.
INITIALLY...SNOW LEVELS WILL BE AROUND 6500 FT TONIGHT...THEN LOWER
TO BETWEEN 4500 AND 5000 FEET BY SATURDAY AFTERNOON. SNOW LEVELS
WILL DROP FURTHER BY SATURDAY NIGHT INTO SUNDAY DOWN TO BETWEEN 3500
AND 4000 FT. AT THIS TIME IT LOOKS LIKE SNOW AMOUNTS WILL BE BETWEEN
6 AND 12 INCHES FOR THE LA/VTU/SBA MOUNTAINS ABOVE 5500 FT...WITH
LESSER AMOUNTS BELOW. THE I-5 CORRIDOR COULD BE AFFECTED WITH SNOW
AND ICY CONDS BY LATE SATURDAY AFTERNOON THROUGH MONDAY.

AS FAR AS TEMPS GO OVER THE NEXT FEW DAYS...IT WILL BE MUCH COOLER
WITH MOST AREAS WEST OF THE MOUNTAINS IN THE UPPER 50S TO MID 60S.
OF COURSE IT WILL BE MUCH COLDER ACROSS THE MOUNTAINS AND INTERIOR
LOCATIONS. THE COLDEST DAY LOOKS TO BE SUNDAY.

.LONG TERM (MON-THU)...THE UPPER TROUGH AXIS WILL BE JUST SOUTH OF
THE AREA MONDAY...BUT THERE WILL BE LINGERING SHOWERS ACROSS THE
FORECAST AREA...ESPECIALLY FOR AREAS S OF POINT CONCEPTION.
HOWEVER...ANOTHER SHORT WAVE DISTURBANCE IS POISED TO MOVE IN OVER
THE FORECAST AREA BY MONDAY NIGHT INTO TUE MORNING. THIS WILL ALLOW
FOR SOME ADDITIONAL SHOWERS TO OCCUR WITH CONTINUED COLDER THAN
NORMAL TEMPS ON TUESDAY. EXCEPT FOR A FEW LINGERING CLOUDS AROUND
THE MOUNTAINS...SKIES SHOULD BE MOSTLY CLEAR...WITH WEAK OFFSHORE
FLOW FOR INTERIOR AREAS BOTH WED/THU. WARMEST DAY WILL BE THURDAY
FOR COAST AND VALLEYS WITH HIGHS IN THE LOWER 70S.


&&

.AVIATION...27/1145Z.

AT 0910Z...THE MARINE LAYER AT KLAX WAS 1500 FEET DEEP...THE TOP
OF THE INVERSION WAS LOCATED AT 2400 FT WITH A TEMP OF 13C.

LOW CLOUDS REALLY EXPANDING IN COVERAGE ACROSS THE FCST AREA EARLY
THIS MORNING. CONDITIONS MOSTLY MVFR ACROSS COASTAL SXNS OF L.A. AND
VTU COUNTIES...HIGH IFR IN THE VLYS...AND LIFR/VLIFR ON THE CENTRAL
COAST AND IN THE SANTA YNEZ VALLEY. CIGS SHOULD CONT TO RISE...
ESPECIALLY S OF PT CONCEPTION THIS MORNING. EXPECT SLOW CLEARING
NEAR THE COAST...WITH CLOUDS POSSIBLY LINGERING INTO THE AFTERNOON.
EXPECT WIDESPREAD MVFR CIGS TO RETURN TO ALL AREAS WEST OF THE MTNS
THIS EVENING...POSSIBLY EVEN INTO THE ANTELOPE VLY. THERE IS A
CHANCE OF RAIN N OF PT CONCEPTION AFTER MIDNIGHT...WITH SOME DRIZZLE
POSSIBLE S OF PT CONCEPTION. GUSTY WINDS THRU AND BELOW PASSES AND
CANYONS OF SRN SBA COUNTY THIS EVENING WITH LLWS AND MDT UDDF.


KLAX...MODERATE CONFIDENCE IN THE 12Z TAF. THERE IS A 20 TO 30
PERCENT CHANCE THAT MVFR CIGS WILL LINGER THROUGH THE DAY.


KBUR...MODERATE CONFIDENCE IN THE 12Z TAF. THERE IS A 20 TO 30
PERCENT CHANCE THAT CIGS WILL BE IN THE IFR CATEGORY BETWEEN 12Z AND
17Z.

&&

.MARINE...27/330 AM...

FOR THE OUTER WATERS...HIGH CONFIDENCE IN THE FORCE NORTHWEST WINDS
THROUGH TONIGHT...EXCEPT DIMINISHING BELOW GALE FORCE TO SCA LEVELS
ACROSS NORTHERN SECTIONS THIS EVENING. SCA CONDS ARE EXPECTED ACROSS
THE SOUTHERN TWO OUTER WATERS ZONES SAT.

FOR THE INNER WATERS...GOOD CONFIDENCE IN SCA LEVEL WINDS ACROSS THE
NORTHERN INNER WATERS THIS AFTERNOON THROUGH THIS EVENING...AND
ACROSS THE SANTA BARBARA CHANNEL AND SOUTHERN INNER WATERS FROM LATE
THIS AFTERNOON THROUGH MID MORNING SAT. THERE IS A 20 PERCENT CHANCE
OF GALE FORCE WINDS ACROSS WESTERN PORTIONS OF THESE ZONES
TONIGHT.

SHOWERS ARE EXPECTED ACROSS THE WATERS THIS WEEKEND. FROM SATURDAY
AFTERNOON THROUGH SUNDAY EVENING...THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS WHICH COULD PRODUCE GUSTY WINDS...CHOPPY SEAS...AND
POSSIBLY AN ISOLATED WATERSPOUT.

&&

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

&&

$$

PUBLIC...KAPLAN
AVIATION/MARINE...DB

WWW.WEATHER.GOV/LOSANGELES














000
FXUS66 KLOX 271247
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
345 AM PST FRI FEB 27 2015

UPDATED AVIATION SECTION

.SYNOPSIS...

A WEATHER PATTERN CHANGE WILL BEGIN TONIGHT AS THERE WILL BE PERIODS
OF RAIN THROUGH EARLY NEXT WEEK WITH LOWER SNOW LEVELS EXPECTED
ACROSS MOUNTAIN LOCATIONS...POSSIBLY AFFECTING THE INTERSTATE 5
CORRIDOR SATURDAY THROUGH MONDAY. TEMPERATURES WILL BE BELOW NORMAL
AS WELL THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM (TODAY-SUN)...LATEST FOG PRODUCT IMAGERY INDICATED LOW
CLOUDS ACROSS THE CENTRAL COAST AND DEVELOPING ACROSS THE L.A.
COUNTY BASIN AND INTO THE SAN GABRIEL VALLEY AND ADJACENT COASTAL
SLOPES. LOW CLOUDS SHOULD SPREAD INTO THE SAN FERNANDO VALLEY BY
DAWN AND PORTIONS OF THE VENTURA COUNTY COAST AND VALLEYS...BUT
MIGHT HAVE A TOUGH TIME MAKING IT INTO THE SANTA CLARITA VALLEY AS
NORTHERLY WINDS HAVE PERSISTED ACROSS THE I-5 CORRIDOR THIS MORNING.
LATEST ACARS SOUNDING NEAR LAX INDICATED A WEAK INVERSION FROM 1300
FT UP TO 2500 FT. WITH THE INVERSION BEING SO WEAK AND INCREASING
ONSHORE FLOW TODAY...EXPECT LOW CLOUDS TO CONTINUE TO INCREASE
ACROSS MUCH OF LA/VTU COUNTIES LATER THIS MORNING WITH SKIES
BECOMING PARTLY TO MOSTLY CLOUDY TODAY.

A WIND ADVISORY HAS BEEN ISSUED FOR THE SANTA BARBARA COUNTY
MOUNTAINS AND ADJACENT WIND PRONE AREAS ACROSS THE SOUTH COAST OF
SANTA BARBARA FOR GUSTY NW WINDS LATE THIS AFTERNOON THROUGH THIS
EVENING. STRONGEST WIND GUSTS WILL BE BETWEEN 35 AND 45 MPH. THERE
WILL BE GUSTY SW TO W WINDS ACROSS THE ANTELOPE VALLEY AS WELL THIS
AFTERNOON...BUT SHOULD REMAIN JUST BELOW WIND ADVISORY THRESHOLDS.
EXPECT LOCAL GUSTS TO 45 MPH IN SOME LOCATIONS.

SYNOPTICALLY...AN UPPER LEVEL LOW THAT WAS OVER WASHINGTON STATE
THIS MORNING WILL CONTINUE TO TREK SOUTH TOWARDS NORTHERN CALIFORNIA
THIS AFTERNOON. THIS UPPER LEVEL FEATURE WILL THEN MOVE SLOWLY TO
THE SOUTH AND BECOME CUTOFF LATE SATURDAY INTO SUNDAY OVER SOUTHERN
CALIFORNIA...THEN PUSH OUT OF THE AREA BY MONDAY MORNING...AS
ANOTHER UPPER LEVEL DISTURBANCE QUICKLY MOVES IN BEHIND THE EXITING
LOW. THIS WEATHER PATTERN WILL BRING AN EXTENDED PERIOD OF SHOWERS
ACROSS MUCH OF SOUTHWESTERN CALIFORNIA...WITH SNOW SHOWERS IN THE
MOUNTAINS. AS HAS BEEN THE CASE OVER THE PAST SEVERAL STORM
EVENTS...THE UPPER LOWS HAVE BEEN MAINLY OVER LAND AS THEY
RETROGRADED TOWARDS SOUTHERN CALIFORNIA. MOST OF THE SYSTEMS HAVE
HAD A TOUGH TIME TAPPING INTO SOME MOISTURE DUE TO THEIR TRAJECTORY.
HOWEVER...MOST MODELS ARE NOW BRINGING THIS UPPER LOW A TAD FARTHER
WEST OVER THE COASTAL WATERS AS IT REACHES SOUTHERN CALIFORNIA WHICH
SHOULD HELP TO TAP INTO SOME ADDITIONAL MOISTURE. OVERALL...AREAS TO
OUR SOUTH WILL LIKELY SEE THE BETTER PRECIP AMOUNTS DUE TO BEST
CYCLONIC FLOW AROUND THE LOW. THAT BEING SAID...MODELS ARE IN PRETTY
GOOD AGREEMENT WITH THE STORM TRACK...BUT ARE STILL QUITE VARIED
WITH PRECIP AMOUNTS.

AT THIS POINT...WILL STAY WITH WINTER STORM WATCH HOPING THAT NEXT
SET OF MODELS WILL BE A BIT CLEARER AND THE DAY SHIFT CAN MAKE A
BETTER EDUCATED DECISION TO EITHER UPGRADE THE WATCH TO A WINTER
STORM WARNING OR WINTER WEATHER ADVISORY. THE FACT THAT THERE IS NOT
AN ORGANIZED COLD FRONT BRINGING A STEADY PERIOD OF RAIN OVER THE
REGION MAKES THE FORECAST A BIT DIFFICULT. RAINFALL TOTALS WILL VARY
WITH THIS NEXT SYSTEM. THERE WILL BE PLENTY OF COLD AIR ASSOCIATED
WITH THE UPPER LOW TO HELP CAUSE THE ATMOSPHERE TO BECOME UNSTABLE
ON SATURDAY AND BRING A SLIGHT CHANCE OF THUNDERSTORMS TO AREAS N OF
VENTURA COUNTY. AS THE UPPER LOW MOVES FARTHER SOUTH...THE ENTIRE
FORECAST AREA FROM SLO TO LA COUNTIES WILL HAVE A SLIGHT CHANCE OF
THUNDERSTORMS INCLUDING THE ADJACENT COASTAL WATERS. EXPECT MOSTLY
SHOWERY CONDITIONS FROM LATE TONIGHT THROUGH SUNDAY. PRELIMINARY
RAINFALL TOTALS CURRENTLY ARE FORECAST BETWEEN 0.10 AND 0.50
INCHES...WITH UP TO 1.25 INCH IN THE SAN GABRIEL MOUNTAINS. THERE
COULD BE HIGHER AMOUNTS NEAR THUNDERSTORMS.

ONE OF THE MAIN IMPACTS WITH THIS NEXT SYSTEM WILL BE THE LOWER SNOW
LEVELS POSSIBLY AFFECTING THE I-5 CORRIDOR AND HIGHWAY 14.SNOW
LEVELS WITH THIS SYSTEM WILL BE MUCH LOWER THAN THE LAST.
INITIALLY...SNOW LEVELS WILL BE AROUND 6500 FT TONIGHT...THEN LOWER
TO BETWEEN 4500 AND 5000 FEET BY SATURDAY AFTERNOON. SNOW LEVELS
WILL DROP FURTHER BY SATURDAY NIGHT INTO SUNDAY DOWN TO BETWEEN 3500
AND 4000 FT. AT THIS TIME IT LOOKS LIKE SNOW AMOUNTS WILL BE BETWEEN
6 AND 12 INCHES FOR THE LA/VTU/SBA MOUNTAINS ABOVE 5500 FT...WITH
LESSER AMOUNTS BELOW. THE I-5 CORRIDOR COULD BE AFFECTED WITH SNOW
AND ICY CONDS BY LATE SATURDAY AFTERNOON THROUGH MONDAY.

AS FAR AS TEMPS GO OVER THE NEXT FEW DAYS...IT WILL BE MUCH COOLER
WITH MOST AREAS WEST OF THE MOUNTAINS IN THE UPPER 50S TO MID 60S.
OF COURSE IT WILL BE MUCH COLDER ACROSS THE MOUNTAINS AND INTERIOR
LOCATIONS. THE COLDEST DAY LOOKS TO BE SUNDAY.

.LONG TERM (MON-THU)...THE UPPER TROUGH AXIS WILL BE JUST SOUTH OF
THE AREA MONDAY...BUT THERE WILL BE LINGERING SHOWERS ACROSS THE
FORECAST AREA...ESPECIALLY FOR AREAS S OF POINT CONCEPTION.
HOWEVER...ANOTHER SHORT WAVE DISTURBANCE IS POISED TO MOVE IN OVER
THE FORECAST AREA BY MONDAY NIGHT INTO TUE MORNING. THIS WILL ALLOW
FOR SOME ADDITIONAL SHOWERS TO OCCUR WITH CONTINUED COLDER THAN
NORMAL TEMPS ON TUESDAY. EXCEPT FOR A FEW LINGERING CLOUDS AROUND
THE MOUNTAINS...SKIES SHOULD BE MOSTLY CLEAR...WITH WEAK OFFSHORE
FLOW FOR INTERIOR AREAS BOTH WED/THU. WARMEST DAY WILL BE THURDAY
FOR COAST AND VALLEYS WITH HIGHS IN THE LOWER 70S.


&&

.AVIATION...27/1145Z.

AT 0910Z...THE MARINE LAYER AT KLAX WAS 1500 FEET DEEP...THE TOP
OF THE INVERSION WAS LOCATED AT 2400 FT WITH A TEMP OF 13C.

LOW CLOUDS REALLY EXPANDING IN COVERAGE ACROSS THE FCST AREA EARLY
THIS MORNING. CONDITIONS MOSTLY MVFR ACROSS COASTAL SXNS OF L.A. AND
VTU COUNTIES...HIGH IFR IN THE VLYS...AND LIFR/VLIFR ON THE CENTRAL
COAST AND IN THE SANTA YNEZ VALLEY. CIGS SHOULD CONT TO RISE...
ESPECIALLY S OF PT CONCEPTION THIS MORNING. EXPECT SLOW CLEARING
NEAR THE COAST...WITH CLOUDS POSSIBLY LINGERING INTO THE AFTERNOON.
EXPECT WIDESPREAD MVFR CIGS TO RETURN TO ALL AREAS WEST OF THE MTNS
THIS EVENING...POSSIBLY EVEN INTO THE ANTELOPE VLY. THERE IS A
CHANCE OF RAIN N OF PT CONCEPTION AFTER MIDNIGHT...WITH SOME DRIZZLE
POSSIBLE S OF PT CONCEPTION. GUSTY WINDS THRU AND BELOW PASSES AND
CANYONS OF SRN SBA COUNTY THIS EVENING WITH LLWS AND MDT UDDF.


KLAX...MODERATE CONFIDENCE IN THE 12Z TAF. THERE IS A 20 TO 30
PERCENT CHANCE THAT MVFR CIGS WILL LINGER THROUGH THE DAY.


KBUR...MODERATE CONFIDENCE IN THE 12Z TAF. THERE IS A 20 TO 30
PERCENT CHANCE THAT CIGS WILL BE IN THE IFR CATEGORY BETWEEN 12Z AND
17Z.

&&

.MARINE...27/330 AM...

FOR THE OUTER WATERS...HIGH CONFIDENCE IN THE FORCE NORTHWEST WINDS
THROUGH TONIGHT...EXCEPT DIMINISHING BELOW GALE FORCE TO SCA LEVELS
ACROSS NORTHERN SECTIONS THIS EVENING. SCA CONDS ARE EXPECTED ACROSS
THE SOUTHERN TWO OUTER WATERS ZONES SAT.

FOR THE INNER WATERS...GOOD CONFIDENCE IN SCA LEVEL WINDS ACROSS THE
NORTHERN INNER WATERS THIS AFTERNOON THROUGH THIS EVENING...AND
ACROSS THE SANTA BARBARA CHANNEL AND SOUTHERN INNER WATERS FROM LATE
THIS AFTERNOON THROUGH MID MORNING SAT. THERE IS A 20 PERCENT CHANCE
OF GALE FORCE WINDS ACROSS WESTERN PORTIONS OF THESE ZONES
TONIGHT.

SHOWERS ARE EXPECTED ACROSS THE WATERS THIS WEEKEND. FROM SATURDAY
AFTERNOON THROUGH SUNDAY EVENING...THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS WHICH COULD PRODUCE GUSTY WINDS...CHOPPY SEAS...AND
POSSIBLY AN ISOLATED WATERSPOUT.

&&

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

&&

$$

PUBLIC...KAPLAN
AVIATION/MARINE...DB

WWW.WEATHER.GOV/LOSANGELES















000
FXUS66 KLOX 271200
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
345 AM PST FRI FEB 27 2015

UPDATED AVIATION SECTION

.SYNOPSIS...

A WEATHER PATTERN CHANGE WILL BEGIN TONIGHT AS THERE WILL BE PERIODS
OF RAIN THROUGH EARLY NEXT WEEK WITH LOWER SNOW LEVELS EXPECTED
ACROSS MOUNTAIN LOCATIONS...POSSIBLY AFFECTING THE INTERSTATE 5
CORRIDOR SATURDAY THROUGH MONDAY. TEMPERATURES WILL BE BELOW NORMAL
AS WELL THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM (TODAY-SUN)...LATEST FOG PRODUCT IMAGERY INDICATED LOW
CLOUDS ACROSS THE CENTRAL COAST AND DEVELOPING ACROSS THE L.A.
COUNTY BASIN AND INTO THE SAN GABRIEL VALLEY AND ADJACENT COASTAL
SLOPES. LOW CLOUDS SHOULD SPREAD INTO THE SAN FERNANDO VALLEY BY
DAWN AND PORTIONS OF THE VENTURA COUNTY COAST AND VALLEYS...BUT
MIGHT HAVE A TOUGH TIME MAKING IT INTO THE SANTA CLARITA VALLEY AS
NORTHERLY WINDS HAVE PERSISTED ACROSS THE I-5 CORRIDOR THIS MORNING.
LATEST ACARS SOUNDING NEAR LAX INDICATED A WEAK INVERSION FROM 1300
FT UP TO 2500 FT. WITH THE INVERSION BEING SO WEAK AND INCREASING
ONSHORE FLOW TODAY...EXPECT LOW CLOUDS TO CONTINUE TO INCREASE INTO
MUCH OF LA/VTU COUNTIES LATER THIS MORNING WITH SKIES BECOMING
PARTLY TO MOSTLY CLOUDY TODAY.

A WIND ADVISORY HAS BEEN ISSUED FOR THE SANTA BARBARA COUNTY
MOUNTAINS AND ADJACENT WIND PRONE SOUTH COAST OF SANTA BARBARA FOR
GUSTY NW WINDS VALID LATE THIS AFTERNOON THROUGH THIS EVENING.
STRONGEST WIND GUSTS WILL BE BETWEEN 35 AND 45 MPH. THERE WILL BE
GUSTY SW TO W WINDS ACROSS THE ANTELOPE VALLEY AS WELL THIS
AFTERNOON...BUT SHOULD REMAIN JUST BELOW WIND ADVISORY THRESHOLDS.
EXPECT LOCAL GUSTS TO 45 MPH IN SOME LOCATIONS.

SYNOPTICALLY...AN UPPER LEVEL LOW THAT WAS OVER WASHINGTON STATE
THIS MORNING WILL CONTINUE TO TREK SOUTH TOWARDS NORTHERN CALIFORNIA
THIS AFTERNOON. THIS UPPER LEVEL FEATURE WILL THEN MOVE SLOWLY TO
THE SOUTH AND BECOME CUTOFF LATE SATURDAY INTO SUNDAY OVER SOUTHERN
CALIFORNIA...THEN PUSH OUT OF THE AREA BY MONDAY MORNING...AS
ANOTHER UPPER LEVEL DISTURBANCE QUICKLY MOVES IN BEHIND THE EXITING
LOW. THIS WEATHER PATTERN WILL BRING AN EXTENDED PERIOD OF SHOWERS
AND SNOW SHOWERS ACROSS MUCH OF SOUTHWESTERN CALIFORNIA. AS HAS BEEN
THE CASE OVER THE PAST SEVERAL STORM EVENTS...THE UPPER LOWS HAVE
BEEN MAINLY OVER LAND AS THEY RETROGRADED TOWARDS SOUTHERN
CALIFORNIA. MOST OF THE SYSTEMS HAVE HAD A TOUGH TIME TAPPING INTO
SOME MOISTURE DUE TO THE TRAJECTORY OF THESE STORM SYSTEMS.
HOWEVER...MOST MODELS ARE NOW BRINGING THIS UPPER LOW A TAD FARTHER
WEST OVER THE COASTAL WATERS AS IT REACHES SOUTHERN CALIFORNIA WHICH
SHOULD HELP TO TAP INTO SOME ADDITIONAL MOISTURE. OVERALL...AREAS TO
OUR SOUTH WILL LIKELY SEE THE BETTER PRECIP AMOUNTS DUE TO BEST
CYCLONIC FLOW AROUND THE LOW. THAT BEING SAID...MODELS ARE IN PRETTY
GOOD AGREEMENT WITH THE STORM TRACK...BUT ARE STILL QUITE VARIED
WITH PRECIP AMOUNTS.

AT THIS POINT...WILL STAY WITH WINTER STORM WATCH HOPING THAT NEXT
SET OF MODELS WILL BE A BIT CLEARER AND THE DAY SHIFT CAN MAKE A
BETTER EDUCATED DECISION TO EITHER UPGRADE THE WATCH TO A WINTER
STORM WARNING OR WINTER WEATHER ADVISORY. THE FACT THERE IS NOT AN
ORGANIZED COLD FRONT BRINGING A STEADY PERIOD OF RAIN OVER THE
REGION MAKES THE FORECAST A BIT DIFFICULT. RAINFALL TOTALS WILL VARY
WITH THIS NEXT SYSTEM. THERE WILL BE PLENTY OF COLD AIR ASSOCIATED
WITH THE UPPER LOW TO HELP CAUSE THE ATMOSPHERE TO BECOME UNSTABLE
ON SATURDAY AND BRING A SLIGHT CHANCE OF THUNDERSTORMS TO AREAS N OF
VENTURA COUNTY. AS THE UPPER LOW MOVES FARTHER SOUTH...THE ENTIRE
FORECAST AREA FROM SLO TO LA COUNTIES WILL HAVE A SLIGHT CHANCE OF
THUNDERSTORMS INCLUDING THE ADJACENT COASTAL WATERS. EXPECT MOSTLY
SHOWERY CONDITIONS FROM LATE TONIGHT THROUGH SUNDAY. PRELIMINARY
RAINFALL TOTALS CURRENTLY ARE FORECAST BETWEEN 0.10 AND 0.50
INCHES...WITH UP TO 1.00 INCH IN THE SAN GABRIEL MOUNTAINS. THERE
COULD BE HIGHER AMOUNTS NEAR THUNDERSTORMS.

ONE OF THE MAIN IMPACTS WITH THIS NEXT SYSTEM WILL BE THE LOWER SNOW
LEVELS POSSIBLY AFFECTING THE I-5 CORRIDOR AND HIGHWAY 14.SNOW
LEVELS WITH THIS SYSTEM WILL BE MUCH COLDER THAN THE LAST.
INITIALLY...SNOW LEVELS WILL BE AROUND 6500 FT FRIDAY NIGHT...THEN
LOWER TO BETWEEN 4500 AND 5000 FEET BY SATURDAY AFTERNOON. SNOW
LEVELS WILL DROP FURTHER BY SATURDAY NIGHT INTO SUNDAY DOWN TO
BETWEEN 3500 AND 4000 FT. AT THIS TIME IT LOOKS LIKE SNOW AMOUNTS
WILL BE BETWEEN 6 AND 12 INCHES FOR THE LA/VTU/SBA MOUNTAINS ABOVE
5500 FT...WITH LESSER AMOUNTS BELOW. THE I-5 CORRIDOR COULD BE
AFFECTED WITH SNOW AND ICY CONDS BY LATE SATURDAY AFTERNOON THROUGH
MONDAY.

AS FAR AS TEMPS GO OVER THE NEXT FEW DAYS...IT WILL BE MUCH COOLER
WITH MOST AREAS IN THE UPPER 50S TO MID 60S. THE COLDEST DAY WILL BE
ON SUNDAY WHERE HIGHS FOR THE COAST AND VALLEYS WILL ONLY REACH THE
LOWER 60S. OF COURSE IT WILL BE MUCH COLDER ACROSS THE MOUNTAINS AND
INTERIOR LOCATIONS.

.LONG TERM (MON-THU)...THE UPPER TROUGH AXIS WILL BE JUST SOUTH OF
THE AREA MONDAY...BUT THERE WILL BE LINGERING SHOWERS ACROSS THE
FORECAST AREA...ESPECIALLY FOR AREAS S OF POINT CONCEPTION.
HOWEVER...ANOTHER SHORT WAVE DISTURBANCE IS POISED TO MOVE IN OVER
THE FORECAST AREA BY MONDAY NIGHT INTO TUE MORNING. THIS WILL ALLOW
FOR SOME ADDITIONAL SHOWERS TO OCCUR WITH CONTINUED COLDER THAN
NORMAL TEMPS ON TUESDAY. EXCEPT FOR A FEW LINGERING CLOUDS AROUND
THE MOUNTAINS...SKIES SHOULD BE MOSTLY CLEAR...WITH WEAK OFFSHORE
FLOW FOR INTERIOR AREAS BOTH WED/THU. WARMEST DAY WILL BE THURDAY
FOR COAST AND VALLEYS WITH HIGHS IN THE LOWER 70S.


&&

.AVIATION...27/1145Z.

AT 0910Z...THE MARINE LAYER AT KLAX WAS 1500 FEET DEEP...THE TOP
OF THE INVERSION WAS LOCATED AT 2400 FT WITH A TEMP OF 13C.

LOW CLOUDS REALLY EXPANDING IN COVERAGE ACROSS THE FCST AREA EARLY
THIS MORNING. CONDITIONS MOSTLY MVFR ACROSS COASTAL SXNS OF L.A. AND
VTU COUNTIES...HIGH IFR IN THE VLYS...AND LIFR/VLIFR ON THE CENTRAL
COAST AND IN THE SANTA YNEZ VALLEY. CIGS SHOULD CONT TO RISE...
ESPECIALLY S OF PT CONCEPTION THIS MORNING. EXPECT SLOW CLEARING
NEAR THE COAST...WITH CLOUDS POSSIBLY LINGERING INTO THE AFTERNOON.
EXPECT WIDESPREAD MVFR CIGS TO RETURN TO ALL AREAS WEST OF THE MTNS
THIS EVENING...POSSIBLY EVEN INTO THE ANTELOPE VLY. THERE IS A
CHANCE OF RAIN N OF PT CONCEPTION AFTER MIDNIGHT...WITH SOME DRIZZLE
POSSIBLE S OF PT CONCEPTION. GUSTY WINDS THRU AND BELOW PASSES AND
CANYONS OF SRN SBA COUNTY THIS EVENING WITH LLWS AND MDT UDDF.


KLAX...MODERATE CONFIDENCE IN THE 12Z TAF. THERE IS A 20 TO 30
PERCENT CHANCE THAT MVFR CIGS WILL LINGER THROUGH THE DAY.


KBUR...MODERATE CONFIDENCE IN THE 12Z TAF. THERE IS A 20 TO 30
PERCENT CHANCE THAT CIGS WILL BE IN THE IFR CATEGORY BETWEEN 12Z AND
17Z.

&&

.MARINE...27/330 AM...

FOR THE OUTER WATERS...HIGH CONFIDENCE IN THE FORCE NORTHWEST WINDS
THROUGH TONIGHT...EXCEPT DIMINISHING BELOW GALE FORCE TO SCA LEVELS
ACROSS NORTHERN SECTIONS THIS EVENING. SCA CONDS ARE EXPECTED ACROSS
THE SOUTHERN TWO OUTER WATERS ZONES SAT.

FOR THE INNER WATERS...GOOD CONFIDENCE IN SCA LEVEL WINDS ACROSS THE
NORTHERN INNER WATERS THIS AFTERNOON THROUGH THIS EVENING...AND
ACROSS THE SANTA BARBARA CHANNEL AND SOUTHERN INNER WATERS FROM LATE
THIS AFTERNOON THROUGH MID MORNING SAT. THERE IS A 20 PERCENT CHANCE
OF GALE FORCE WINDS ACROSS WESTERN PORTIONS OF THESE ZONES
TONIGHT.

SHOWERS ARE EXPECTED ACROSS THE WATERS THIS WEEKEND. FROM SATURDAY
AFTERNOON THROUGH SUNDAY EVENING...THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS WHICH COULD PRODUCE GUSTY WINDS...CHOPPY SEAS...AND
POSSIBLY AN ISOLATED WATERSPOUT.

&&

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

&&

$$

PUBLIC...KAPLAN
AVIATION/MARINE...DB

WWW.WEATHER.GOV/LOSANGELES











000
FXUS66 KLOX 271200
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
345 AM PST FRI FEB 27 2015

UPDATED AVIATION SECTION

.SYNOPSIS...

A WEATHER PATTERN CHANGE WILL BEGIN TONIGHT AS THERE WILL BE PERIODS
OF RAIN THROUGH EARLY NEXT WEEK WITH LOWER SNOW LEVELS EXPECTED
ACROSS MOUNTAIN LOCATIONS...POSSIBLY AFFECTING THE INTERSTATE 5
CORRIDOR SATURDAY THROUGH MONDAY. TEMPERATURES WILL BE BELOW NORMAL
AS WELL THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM (TODAY-SUN)...LATEST FOG PRODUCT IMAGERY INDICATED LOW
CLOUDS ACROSS THE CENTRAL COAST AND DEVELOPING ACROSS THE L.A.
COUNTY BASIN AND INTO THE SAN GABRIEL VALLEY AND ADJACENT COASTAL
SLOPES. LOW CLOUDS SHOULD SPREAD INTO THE SAN FERNANDO VALLEY BY
DAWN AND PORTIONS OF THE VENTURA COUNTY COAST AND VALLEYS...BUT
MIGHT HAVE A TOUGH TIME MAKING IT INTO THE SANTA CLARITA VALLEY AS
NORTHERLY WINDS HAVE PERSISTED ACROSS THE I-5 CORRIDOR THIS MORNING.
LATEST ACARS SOUNDING NEAR LAX INDICATED A WEAK INVERSION FROM 1300
FT UP TO 2500 FT. WITH THE INVERSION BEING SO WEAK AND INCREASING
ONSHORE FLOW TODAY...EXPECT LOW CLOUDS TO CONTINUE TO INCREASE INTO
MUCH OF LA/VTU COUNTIES LATER THIS MORNING WITH SKIES BECOMING
PARTLY TO MOSTLY CLOUDY TODAY.

A WIND ADVISORY HAS BEEN ISSUED FOR THE SANTA BARBARA COUNTY
MOUNTAINS AND ADJACENT WIND PRONE SOUTH COAST OF SANTA BARBARA FOR
GUSTY NW WINDS VALID LATE THIS AFTERNOON THROUGH THIS EVENING.
STRONGEST WIND GUSTS WILL BE BETWEEN 35 AND 45 MPH. THERE WILL BE
GUSTY SW TO W WINDS ACROSS THE ANTELOPE VALLEY AS WELL THIS
AFTERNOON...BUT SHOULD REMAIN JUST BELOW WIND ADVISORY THRESHOLDS.
EXPECT LOCAL GUSTS TO 45 MPH IN SOME LOCATIONS.

SYNOPTICALLY...AN UPPER LEVEL LOW THAT WAS OVER WASHINGTON STATE
THIS MORNING WILL CONTINUE TO TREK SOUTH TOWARDS NORTHERN CALIFORNIA
THIS AFTERNOON. THIS UPPER LEVEL FEATURE WILL THEN MOVE SLOWLY TO
THE SOUTH AND BECOME CUTOFF LATE SATURDAY INTO SUNDAY OVER SOUTHERN
CALIFORNIA...THEN PUSH OUT OF THE AREA BY MONDAY MORNING...AS
ANOTHER UPPER LEVEL DISTURBANCE QUICKLY MOVES IN BEHIND THE EXITING
LOW. THIS WEATHER PATTERN WILL BRING AN EXTENDED PERIOD OF SHOWERS
AND SNOW SHOWERS ACROSS MUCH OF SOUTHWESTERN CALIFORNIA. AS HAS BEEN
THE CASE OVER THE PAST SEVERAL STORM EVENTS...THE UPPER LOWS HAVE
BEEN MAINLY OVER LAND AS THEY RETROGRADED TOWARDS SOUTHERN
CALIFORNIA. MOST OF THE SYSTEMS HAVE HAD A TOUGH TIME TAPPING INTO
SOME MOISTURE DUE TO THE TRAJECTORY OF THESE STORM SYSTEMS.
HOWEVER...MOST MODELS ARE NOW BRINGING THIS UPPER LOW A TAD FARTHER
WEST OVER THE COASTAL WATERS AS IT REACHES SOUTHERN CALIFORNIA WHICH
SHOULD HELP TO TAP INTO SOME ADDITIONAL MOISTURE. OVERALL...AREAS TO
OUR SOUTH WILL LIKELY SEE THE BETTER PRECIP AMOUNTS DUE TO BEST
CYCLONIC FLOW AROUND THE LOW. THAT BEING SAID...MODELS ARE IN PRETTY
GOOD AGREEMENT WITH THE STORM TRACK...BUT ARE STILL QUITE VARIED
WITH PRECIP AMOUNTS.

AT THIS POINT...WILL STAY WITH WINTER STORM WATCH HOPING THAT NEXT
SET OF MODELS WILL BE A BIT CLEARER AND THE DAY SHIFT CAN MAKE A
BETTER EDUCATED DECISION TO EITHER UPGRADE THE WATCH TO A WINTER
STORM WARNING OR WINTER WEATHER ADVISORY. THE FACT THERE IS NOT AN
ORGANIZED COLD FRONT BRINGING A STEADY PERIOD OF RAIN OVER THE
REGION MAKES THE FORECAST A BIT DIFFICULT. RAINFALL TOTALS WILL VARY
WITH THIS NEXT SYSTEM. THERE WILL BE PLENTY OF COLD AIR ASSOCIATED
WITH THE UPPER LOW TO HELP CAUSE THE ATMOSPHERE TO BECOME UNSTABLE
ON SATURDAY AND BRING A SLIGHT CHANCE OF THUNDERSTORMS TO AREAS N OF
VENTURA COUNTY. AS THE UPPER LOW MOVES FARTHER SOUTH...THE ENTIRE
FORECAST AREA FROM SLO TO LA COUNTIES WILL HAVE A SLIGHT CHANCE OF
THUNDERSTORMS INCLUDING THE ADJACENT COASTAL WATERS. EXPECT MOSTLY
SHOWERY CONDITIONS FROM LATE TONIGHT THROUGH SUNDAY. PRELIMINARY
RAINFALL TOTALS CURRENTLY ARE FORECAST BETWEEN 0.10 AND 0.50
INCHES...WITH UP TO 1.00 INCH IN THE SAN GABRIEL MOUNTAINS. THERE
COULD BE HIGHER AMOUNTS NEAR THUNDERSTORMS.

ONE OF THE MAIN IMPACTS WITH THIS NEXT SYSTEM WILL BE THE LOWER SNOW
LEVELS POSSIBLY AFFECTING THE I-5 CORRIDOR AND HIGHWAY 14.SNOW
LEVELS WITH THIS SYSTEM WILL BE MUCH COLDER THAN THE LAST.
INITIALLY...SNOW LEVELS WILL BE AROUND 6500 FT FRIDAY NIGHT...THEN
LOWER TO BETWEEN 4500 AND 5000 FEET BY SATURDAY AFTERNOON. SNOW
LEVELS WILL DROP FURTHER BY SATURDAY NIGHT INTO SUNDAY DOWN TO
BETWEEN 3500 AND 4000 FT. AT THIS TIME IT LOOKS LIKE SNOW AMOUNTS
WILL BE BETWEEN 6 AND 12 INCHES FOR THE LA/VTU/SBA MOUNTAINS ABOVE
5500 FT...WITH LESSER AMOUNTS BELOW. THE I-5 CORRIDOR COULD BE
AFFECTED WITH SNOW AND ICY CONDS BY LATE SATURDAY AFTERNOON THROUGH
MONDAY.

AS FAR AS TEMPS GO OVER THE NEXT FEW DAYS...IT WILL BE MUCH COOLER
WITH MOST AREAS IN THE UPPER 50S TO MID 60S. THE COLDEST DAY WILL BE
ON SUNDAY WHERE HIGHS FOR THE COAST AND VALLEYS WILL ONLY REACH THE
LOWER 60S. OF COURSE IT WILL BE MUCH COLDER ACROSS THE MOUNTAINS AND
INTERIOR LOCATIONS.

.LONG TERM (MON-THU)...THE UPPER TROUGH AXIS WILL BE JUST SOUTH OF
THE AREA MONDAY...BUT THERE WILL BE LINGERING SHOWERS ACROSS THE
FORECAST AREA...ESPECIALLY FOR AREAS S OF POINT CONCEPTION.
HOWEVER...ANOTHER SHORT WAVE DISTURBANCE IS POISED TO MOVE IN OVER
THE FORECAST AREA BY MONDAY NIGHT INTO TUE MORNING. THIS WILL ALLOW
FOR SOME ADDITIONAL SHOWERS TO OCCUR WITH CONTINUED COLDER THAN
NORMAL TEMPS ON TUESDAY. EXCEPT FOR A FEW LINGERING CLOUDS AROUND
THE MOUNTAINS...SKIES SHOULD BE MOSTLY CLEAR...WITH WEAK OFFSHORE
FLOW FOR INTERIOR AREAS BOTH WED/THU. WARMEST DAY WILL BE THURDAY
FOR COAST AND VALLEYS WITH HIGHS IN THE LOWER 70S.


&&

.AVIATION...27/1145Z.

AT 0910Z...THE MARINE LAYER AT KLAX WAS 1500 FEET DEEP...THE TOP
OF THE INVERSION WAS LOCATED AT 2400 FT WITH A TEMP OF 13C.

LOW CLOUDS REALLY EXPANDING IN COVERAGE ACROSS THE FCST AREA EARLY
THIS MORNING. CONDITIONS MOSTLY MVFR ACROSS COASTAL SXNS OF L.A. AND
VTU COUNTIES...HIGH IFR IN THE VLYS...AND LIFR/VLIFR ON THE CENTRAL
COAST AND IN THE SANTA YNEZ VALLEY. CIGS SHOULD CONT TO RISE...
ESPECIALLY S OF PT CONCEPTION THIS MORNING. EXPECT SLOW CLEARING
NEAR THE COAST...WITH CLOUDS POSSIBLY LINGERING INTO THE AFTERNOON.
EXPECT WIDESPREAD MVFR CIGS TO RETURN TO ALL AREAS WEST OF THE MTNS
THIS EVENING...POSSIBLY EVEN INTO THE ANTELOPE VLY. THERE IS A
CHANCE OF RAIN N OF PT CONCEPTION AFTER MIDNIGHT...WITH SOME DRIZZLE
POSSIBLE S OF PT CONCEPTION. GUSTY WINDS THRU AND BELOW PASSES AND
CANYONS OF SRN SBA COUNTY THIS EVENING WITH LLWS AND MDT UDDF.


KLAX...MODERATE CONFIDENCE IN THE 12Z TAF. THERE IS A 20 TO 30
PERCENT CHANCE THAT MVFR CIGS WILL LINGER THROUGH THE DAY.


KBUR...MODERATE CONFIDENCE IN THE 12Z TAF. THERE IS A 20 TO 30
PERCENT CHANCE THAT CIGS WILL BE IN THE IFR CATEGORY BETWEEN 12Z AND
17Z.

&&

.MARINE...27/330 AM...

FOR THE OUTER WATERS...HIGH CONFIDENCE IN THE FORCE NORTHWEST WINDS
THROUGH TONIGHT...EXCEPT DIMINISHING BELOW GALE FORCE TO SCA LEVELS
ACROSS NORTHERN SECTIONS THIS EVENING. SCA CONDS ARE EXPECTED ACROSS
THE SOUTHERN TWO OUTER WATERS ZONES SAT.

FOR THE INNER WATERS...GOOD CONFIDENCE IN SCA LEVEL WINDS ACROSS THE
NORTHERN INNER WATERS THIS AFTERNOON THROUGH THIS EVENING...AND
ACROSS THE SANTA BARBARA CHANNEL AND SOUTHERN INNER WATERS FROM LATE
THIS AFTERNOON THROUGH MID MORNING SAT. THERE IS A 20 PERCENT CHANCE
OF GALE FORCE WINDS ACROSS WESTERN PORTIONS OF THESE ZONES
TONIGHT.

SHOWERS ARE EXPECTED ACROSS THE WATERS THIS WEEKEND. FROM SATURDAY
AFTERNOON THROUGH SUNDAY EVENING...THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS WHICH COULD PRODUCE GUSTY WINDS...CHOPPY SEAS...AND
POSSIBLY AN ISOLATED WATERSPOUT.

&&

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

&&

$$

PUBLIC...KAPLAN
AVIATION/MARINE...DB

WWW.WEATHER.GOV/LOSANGELES












000
FXUS66 KLOX 271109
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
305 AM PST FRI FEB 27 2015

.SYNOPSIS...

A WEATHER PATTERN CHANGE WILL BEGIN TONIGHT AS THERE WILL BE PERIODS
OF RAIN THROUGH EARLY NEXT WEEK WITH LOWER SNOW LEVELS EXPECTED
ACROSS MOUNTAIN LOCATIONS...POSSIBLY AFFECTING THE INTERSTATE 5
CORRIDOR SATURDAY THROUGH MONDAY. TEMPERATURES WILL BE BELOW NORMAL
AS WELL THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM (TODAY-SUN)...LATEST FOG PRODUCT IMAGERY INDICATED LOW
CLOUDS ACROSS THE CENTRAL COAST AND DEVELOPING ACROSS THE L.A.
COUNTY BASIN AND INTO THE SAN GABRIEL VALLEY AND ADJACENT COASTAL
SLOPES. LOW CLOUDS SHOULD SPREAD INTO THE SAN FERNANDO VALLEY BY
DAWN AND PORTIONS OF THE VENTURA COUNTY COAST AND VALLEYS...BUT
MIGHT HAVE A TOUGH TIME MAKING IT INTO THE SANTA CLARITA VALLEY AS
NORTHERLY WINDS HAVE PERSISTED ACROSS THE I-5 CORRIDOR THIS MORNING.
LATEST ACARS SOUNDING NEAR LAX INDICATED A WEAK INVERSION FROM 1300
FT UP TO 2500 FT. WITH THE INVERSION BEING SO WEAK AND INCREASING
ONSHORE FLOW TODAY...EXPECT LOW CLOUDS TO CONTINUE TO INCREASE INTO
MUCH OF LA/VTU COUNTIES LATER THIS MORNING WITH SKIES BECOMING
PARTLY TO MOSTLY CLOUDY TODAY.

A WIND ADVISORY HAS BEEN ISSUED FOR THE SANTA BARBARA COUNTY
MOUNTAINS AND ADJACENT WIND PRONE SOUTH COAST OF SANTA BARBARA FOR
GUSTY NW WINDS VALID LATE THIS AFTERNOON THROUGH THIS EVENING.
STRONGEST WIND GUSTS WILL BE BETWEEN 35 AND 45 MPH. THERE WILL BE
GUSTY SW TO W WINDS ACROSS THE ANTELOPE VALLEY AS WELL THIS
AFTERNOON...BUT SHOULD REMAIN JUST BELOW WIND ADVISORY THRESHOLDS.
EXPECT LOCAL GUSTS TO 45 MPH IN SOME LOCATIONS.

SYNOPTICALLY...AN UPPER LEVEL LOW THAT WAS OVER WASHINGTON STATE
THIS MORNING WILL CONTINUE TO TREK SOUTH TOWARDS NORTHERN CALIFORNIA
THIS AFTERNOON. THIS UPPER LEVEL FEATURE WILL THEN MOVE SLOWLY TO
THE SOUTH AND BECOME CUTOFF LATE SATURDAY INTO SUNDAY OVER SOUTHERN
CALIFORNIA...THEN PUSH OUT OF THE AREA BY MONDAY MORNING...AS
ANOTHER UPPER LEVEL DISTURBANCE QUICKLY MOVES IN BEHIND THE EXITING
LOW. THIS WEATHER PATTERN WILL BRING AN EXTENDED PERIOD OF SHOWERS
AND SNOW SHOWERS ACROSS MUCH OF SOUTHWESTERN CALIFORNIA. AS HAS BEEN
THE CASE OVER THE PAST SEVERAL STORM EVENTS...THE UPPER LOWS HAVE
BEEN MAINLY OVER LAND AS THEY RETROGRADED TOWARDS SOUTHERN
CALIFORNIA. MOST OF THE SYSTEMS HAVE HAD A TOUGH TIME TAPPING INTO
SOME MOISTURE DUE TO THE TRAJECTORY OF THESE STORM SYSTEMS.
HOWEVER...MOST MODELS ARE NOW BRINGING THIS UPPER LOW A TAD FARTHER
WEST OVER THE COASTAL WATERS AS IT REACHES SOUTHERN CALIFORNIA WHICH
SHOULD HELP TO TAP INTO SOME ADDITIONAL MOISTURE. OVERALL...AREAS TO
OUR SOUTH WILL LIKELY SEE THE BETTER PRECIP AMOUNTS DUE TO BEST
CYCLONIC FLOW AROUND THE LOW. THAT BEING SAID...MODELS ARE IN PRETTY
GOOD AGREEMENT WITH THE STORM TRACK...BUT ARE STILL QUITE VARIED
WITH PRECIP AMOUNTS.

AT THIS POINT...WILL STAY WITH WINTER STORM WATCH HOPING THAT NEXT
SET OF MODELS WILL BE A BIT CLEARER AND THE DAY SHIFT CAN MAKE A
BETTER EDUCATED DECISION TO EITHER UPGRADE THE WATCH TO A WINTER
STORM WARNING OR WINTER WEATHER ADVISORY. THE FACT THERE IS NOT AN
ORGANIZED COLD FRONT BRINGING A STEADY PERIOD OF RAIN OVER THE
REGION MAKES THE FORECAST A BIT DIFFICULT. RAINFALL TOTALS WILL VARY
WITH THIS NEXT SYSTEM. THERE WILL BE PLENTY OF COLD AIR ASSOCIATED
WITH THE UPPER LOW TO HELP CAUSE THE ATMOSPHERE TO BECOME UNSTABLE
ON SATURDAY AND BRING A SLIGHT CHANCE OF THUNDERSTORMS TO AREAS N OF
VENTURA COUNTY. AS THE UPPER LOW MOVES FARTHER SOUTH...THE ENTIRE
FORECAST AREA FROM SLO TO LA COUNTIES WILL HAVE A SLIGHT CHANCE OF
THUNDERSTORMS INCLUDING THE ADJACENT COASTAL WATERS. EXPECT MOSTLY
SHOWERY CONDITIONS FROM LATE TONIGHT THROUGH SUNDAY. PRELIMINARY
RAINFALL TOTALS CURRENTLY ARE FORECAST BETWEEN 0.10 AND 0.50
INCHES...WITH UP TO 1.00 INCH IN THE SAN GABRIEL MOUNTAINS. THERE
COULD BE HIGHER AMOUNTS NEAR THUNDERSTORMS.

ONE OF THE MAIN IMPACTS WITH THIS NEXT SYSTEM WILL BE THE LOWER SNOW
LEVELS POSSIBLY AFFECTING THE I-5 CORRIDOR AND HIGHWAY 14.SNOW
LEVELS WITH THIS SYSTEM WILL BE MUCH COLDER THAN THE LAST.
INITIALLY...SNOW LEVELS WILL BE AROUND 6500 FT FRIDAY NIGHT...THEN
LOWER TO BETWEEN 4500 AND 5000 FEET BY SATURDAY AFTERNOON. SNOW
LEVELS WILL DROP FURTHER BY SATURDAY NIGHT INTO SUNDAY DOWN TO
BETWEEN 3500 AND 4000 FT. AT THIS TIME IT LOOKS LIKE SNOW AMOUNTS
WILL BE BETWEEN 6 AND 12 INCHES FOR THE LA/VTU/SBA MOUNTAINS ABOVE
5500 FT...WITH LESSER AMOUNTS BELOW. THE I-5 CORRIDOR COULD BE
AFFECTED WITH SNOW AND ICY CONDS BY LATE SATURDAY AFTERNOON THROUGH
MONDAY.

AS FAR AS TEMPS GO OVER THE NEXT FEW DAYS...IT WILL BE MUCH COOLER
WITH MOST AREAS IN THE UPPER 50S TO MID 60S. THE COLDEST DAY WILL BE
ON SUNDAY WHERE HIGHS FOR THE COAST AND VALLEYS WILL ONLY REACH THE
LOWER 60S. OF COURSE IT WILL BE MUCH COLDER ACROSS THE MOUNTAINS AND
INTERIOR LOCATIONS.

.LONG TERM (MON-THU)...THE UPPER TROUGH AXIS WILL BE JUST SOUTH OF
THE AREA MONDAY...BUT THERE WILL BE LINGERING SHOWERS ACROSS THE
FORECAST AREA...ESPECIALLY FOR AREAS S OF POINT CONCEPTION.
HOWEVER...ANOTHER SHORT WAVE DISTURBANCE IS POISED TO MOVE IN OVER
THE FORECAST AREA BY MONDAY NIGHT INTO TUE MORNING. THIS WILL ALLOW
FOR SOME ADDITIONAL SHOWERS TO OCCUR WITH CONTINUED COLDER THAN
NORMAL TEMPS ON TUESDAY. EXCEPT FOR A FEW LINGERING CLOUDS AROUND
THE MOUNTAINS...SKIES SHOULD BE MOSTLY CLEAR...WITH WEAK OFFSHORE
FLOW FOR INTERIOR AREAS BOTH WED/THU. WARMEST DAY WILL BE THURDAY
FOR COAST AND VALLEYS WITH HIGHS IN THE LOWER 70S.


&&

.AVIATION...WILL BE UPDATED WITH 12Z TAF PACKAGE.

&&

.MARINE...26/815 PM...

FOR THE OUTER WATERS...HIGH CONFIDENCE IN THE CONTINUATION OF GALE
FORCE NORTHWEST WINDS THROUGH FRIDAY NIGHT. THE NORTHWEST WINDS WILL
DIMINISH ON SATURDAY AND SUNDAY...BUT THERE IS A CHANCE OF WINDS
REMAINING AROUND SMALL CRAFT ADVISORY LEVELS.

FOR THE INNER WATERS...OTHER THAN SOME LOCAL GUSTS TO 25 KNOTS
ACROSS THE WESTERN SANTA BARBARA CHANNEL...WINDS ARE EXPECTED TO
REMAIN BELOW SMALL CRAFT ADVISORY LEVELS TONIGHT. BY FRIDAY
AFTERNOON AND CONTINUING THROUGH SATURDAY...MODERATE CONFIDENCE
IN WEST TO NORTHWEST WINDS INCREASING TO SMALL CRAFT ADVISORY LEVELS
ESPECIALLY ACROSS WESTERN SECTIONS. EXPECT WINDS TO INCREASE FRIDAY
AFTERNOON ACROSS THE SANTA BARBARA CHANNEL...SO WILL ISSUE SMALL
CRAFT ADVISORY FOR THIS EVENING.

SHOWERS ARE EXPECTED TO DEVELOP THIS WEEKEND OVER THE COASTAL WATERS
AS A LOW PRESSURE SYSTEM IMPACTS THE AREA. BY SATURDAY AFTERNOON
AND CONTINUING THROUGH SUNDAY...THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS WHICH COULD PRODUCE GUSTY WINDS...CHOPPY SEAS...AND
POSSIBLY AN ISOLATED WATERSPOUT.

&&

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

&&

$$

PUBLIC...KAPLAN
AVIATION/MARINE...DB

WWW.WEATHER.GOV/LOSANGELES









000
FXUS66 KLOX 271109
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
305 AM PST FRI FEB 27 2015

.SYNOPSIS...

A WEATHER PATTERN CHANGE WILL BEGIN TONIGHT AS THERE WILL BE PERIODS
OF RAIN THROUGH EARLY NEXT WEEK WITH LOWER SNOW LEVELS EXPECTED
ACROSS MOUNTAIN LOCATIONS...POSSIBLY AFFECTING THE INTERSTATE 5
CORRIDOR SATURDAY THROUGH MONDAY. TEMPERATURES WILL BE BELOW NORMAL
AS WELL THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM (TODAY-SUN)...LATEST FOG PRODUCT IMAGERY INDICATED LOW
CLOUDS ACROSS THE CENTRAL COAST AND DEVELOPING ACROSS THE L.A.
COUNTY BASIN AND INTO THE SAN GABRIEL VALLEY AND ADJACENT COASTAL
SLOPES. LOW CLOUDS SHOULD SPREAD INTO THE SAN FERNANDO VALLEY BY
DAWN AND PORTIONS OF THE VENTURA COUNTY COAST AND VALLEYS...BUT
MIGHT HAVE A TOUGH TIME MAKING IT INTO THE SANTA CLARITA VALLEY AS
NORTHERLY WINDS HAVE PERSISTED ACROSS THE I-5 CORRIDOR THIS MORNING.
LATEST ACARS SOUNDING NEAR LAX INDICATED A WEAK INVERSION FROM 1300
FT UP TO 2500 FT. WITH THE INVERSION BEING SO WEAK AND INCREASING
ONSHORE FLOW TODAY...EXPECT LOW CLOUDS TO CONTINUE TO INCREASE INTO
MUCH OF LA/VTU COUNTIES LATER THIS MORNING WITH SKIES BECOMING
PARTLY TO MOSTLY CLOUDY TODAY.

A WIND ADVISORY HAS BEEN ISSUED FOR THE SANTA BARBARA COUNTY
MOUNTAINS AND ADJACENT WIND PRONE SOUTH COAST OF SANTA BARBARA FOR
GUSTY NW WINDS VALID LATE THIS AFTERNOON THROUGH THIS EVENING.
STRONGEST WIND GUSTS WILL BE BETWEEN 35 AND 45 MPH. THERE WILL BE
GUSTY SW TO W WINDS ACROSS THE ANTELOPE VALLEY AS WELL THIS
AFTERNOON...BUT SHOULD REMAIN JUST BELOW WIND ADVISORY THRESHOLDS.
EXPECT LOCAL GUSTS TO 45 MPH IN SOME LOCATIONS.

SYNOPTICALLY...AN UPPER LEVEL LOW THAT WAS OVER WASHINGTON STATE
THIS MORNING WILL CONTINUE TO TREK SOUTH TOWARDS NORTHERN CALIFORNIA
THIS AFTERNOON. THIS UPPER LEVEL FEATURE WILL THEN MOVE SLOWLY TO
THE SOUTH AND BECOME CUTOFF LATE SATURDAY INTO SUNDAY OVER SOUTHERN
CALIFORNIA...THEN PUSH OUT OF THE AREA BY MONDAY MORNING...AS
ANOTHER UPPER LEVEL DISTURBANCE QUICKLY MOVES IN BEHIND THE EXITING
LOW. THIS WEATHER PATTERN WILL BRING AN EXTENDED PERIOD OF SHOWERS
AND SNOW SHOWERS ACROSS MUCH OF SOUTHWESTERN CALIFORNIA. AS HAS BEEN
THE CASE OVER THE PAST SEVERAL STORM EVENTS...THE UPPER LOWS HAVE
BEEN MAINLY OVER LAND AS THEY RETROGRADED TOWARDS SOUTHERN
CALIFORNIA. MOST OF THE SYSTEMS HAVE HAD A TOUGH TIME TAPPING INTO
SOME MOISTURE DUE TO THE TRAJECTORY OF THESE STORM SYSTEMS.
HOWEVER...MOST MODELS ARE NOW BRINGING THIS UPPER LOW A TAD FARTHER
WEST OVER THE COASTAL WATERS AS IT REACHES SOUTHERN CALIFORNIA WHICH
SHOULD HELP TO TAP INTO SOME ADDITIONAL MOISTURE. OVERALL...AREAS TO
OUR SOUTH WILL LIKELY SEE THE BETTER PRECIP AMOUNTS DUE TO BEST
CYCLONIC FLOW AROUND THE LOW. THAT BEING SAID...MODELS ARE IN PRETTY
GOOD AGREEMENT WITH THE STORM TRACK...BUT ARE STILL QUITE VARIED
WITH PRECIP AMOUNTS.

AT THIS POINT...WILL STAY WITH WINTER STORM WATCH HOPING THAT NEXT
SET OF MODELS WILL BE A BIT CLEARER AND THE DAY SHIFT CAN MAKE A
BETTER EDUCATED DECISION TO EITHER UPGRADE THE WATCH TO A WINTER
STORM WARNING OR WINTER WEATHER ADVISORY. THE FACT THERE IS NOT AN
ORGANIZED COLD FRONT BRINGING A STEADY PERIOD OF RAIN OVER THE
REGION MAKES THE FORECAST A BIT DIFFICULT. RAINFALL TOTALS WILL VARY
WITH THIS NEXT SYSTEM. THERE WILL BE PLENTY OF COLD AIR ASSOCIATED
WITH THE UPPER LOW TO HELP CAUSE THE ATMOSPHERE TO BECOME UNSTABLE
ON SATURDAY AND BRING A SLIGHT CHANCE OF THUNDERSTORMS TO AREAS N OF
VENTURA COUNTY. AS THE UPPER LOW MOVES FARTHER SOUTH...THE ENTIRE
FORECAST AREA FROM SLO TO LA COUNTIES WILL HAVE A SLIGHT CHANCE OF
THUNDERSTORMS INCLUDING THE ADJACENT COASTAL WATERS. EXPECT MOSTLY
SHOWERY CONDITIONS FROM LATE TONIGHT THROUGH SUNDAY. PRELIMINARY
RAINFALL TOTALS CURRENTLY ARE FORECAST BETWEEN 0.10 AND 0.50
INCHES...WITH UP TO 1.00 INCH IN THE SAN GABRIEL MOUNTAINS. THERE
COULD BE HIGHER AMOUNTS NEAR THUNDERSTORMS.

ONE OF THE MAIN IMPACTS WITH THIS NEXT SYSTEM WILL BE THE LOWER SNOW
LEVELS POSSIBLY AFFECTING THE I-5 CORRIDOR AND HIGHWAY 14.SNOW
LEVELS WITH THIS SYSTEM WILL BE MUCH COLDER THAN THE LAST.
INITIALLY...SNOW LEVELS WILL BE AROUND 6500 FT FRIDAY NIGHT...THEN
LOWER TO BETWEEN 4500 AND 5000 FEET BY SATURDAY AFTERNOON. SNOW
LEVELS WILL DROP FURTHER BY SATURDAY NIGHT INTO SUNDAY DOWN TO
BETWEEN 3500 AND 4000 FT. AT THIS TIME IT LOOKS LIKE SNOW AMOUNTS
WILL BE BETWEEN 6 AND 12 INCHES FOR THE LA/VTU/SBA MOUNTAINS ABOVE
5500 FT...WITH LESSER AMOUNTS BELOW. THE I-5 CORRIDOR COULD BE
AFFECTED WITH SNOW AND ICY CONDS BY LATE SATURDAY AFTERNOON THROUGH
MONDAY.

AS FAR AS TEMPS GO OVER THE NEXT FEW DAYS...IT WILL BE MUCH COOLER
WITH MOST AREAS IN THE UPPER 50S TO MID 60S. THE COLDEST DAY WILL BE
ON SUNDAY WHERE HIGHS FOR THE COAST AND VALLEYS WILL ONLY REACH THE
LOWER 60S. OF COURSE IT WILL BE MUCH COLDER ACROSS THE MOUNTAINS AND
INTERIOR LOCATIONS.

.LONG TERM (MON-THU)...THE UPPER TROUGH AXIS WILL BE JUST SOUTH OF
THE AREA MONDAY...BUT THERE WILL BE LINGERING SHOWERS ACROSS THE
FORECAST AREA...ESPECIALLY FOR AREAS S OF POINT CONCEPTION.
HOWEVER...ANOTHER SHORT WAVE DISTURBANCE IS POISED TO MOVE IN OVER
THE FORECAST AREA BY MONDAY NIGHT INTO TUE MORNING. THIS WILL ALLOW
FOR SOME ADDITIONAL SHOWERS TO OCCUR WITH CONTINUED COLDER THAN
NORMAL TEMPS ON TUESDAY. EXCEPT FOR A FEW LINGERING CLOUDS AROUND
THE MOUNTAINS...SKIES SHOULD BE MOSTLY CLEAR...WITH WEAK OFFSHORE
FLOW FOR INTERIOR AREAS BOTH WED/THU. WARMEST DAY WILL BE THURDAY
FOR COAST AND VALLEYS WITH HIGHS IN THE LOWER 70S.


&&

.AVIATION...WILL BE UPDATED WITH 12Z TAF PACKAGE.

&&

.MARINE...26/815 PM...

FOR THE OUTER WATERS...HIGH CONFIDENCE IN THE CONTINUATION OF GALE
FORCE NORTHWEST WINDS THROUGH FRIDAY NIGHT. THE NORTHWEST WINDS WILL
DIMINISH ON SATURDAY AND SUNDAY...BUT THERE IS A CHANCE OF WINDS
REMAINING AROUND SMALL CRAFT ADVISORY LEVELS.

FOR THE INNER WATERS...OTHER THAN SOME LOCAL GUSTS TO 25 KNOTS
ACROSS THE WESTERN SANTA BARBARA CHANNEL...WINDS ARE EXPECTED TO
REMAIN BELOW SMALL CRAFT ADVISORY LEVELS TONIGHT. BY FRIDAY
AFTERNOON AND CONTINUING THROUGH SATURDAY...MODERATE CONFIDENCE
IN WEST TO NORTHWEST WINDS INCREASING TO SMALL CRAFT ADVISORY LEVELS
ESPECIALLY ACROSS WESTERN SECTIONS. EXPECT WINDS TO INCREASE FRIDAY
AFTERNOON ACROSS THE SANTA BARBARA CHANNEL...SO WILL ISSUE SMALL
CRAFT ADVISORY FOR THIS EVENING.

SHOWERS ARE EXPECTED TO DEVELOP THIS WEEKEND OVER THE COASTAL WATERS
AS A LOW PRESSURE SYSTEM IMPACTS THE AREA. BY SATURDAY AFTERNOON
AND CONTINUING THROUGH SUNDAY...THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS WHICH COULD PRODUCE GUSTY WINDS...CHOPPY SEAS...AND
POSSIBLY AN ISOLATED WATERSPOUT.

&&

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

&&

$$

PUBLIC...KAPLAN
AVIATION/MARINE...DB

WWW.WEATHER.GOV/LOSANGELES








000
FXUS66 KLOX 271105
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
126 AM PST FRI FEB 27 2015

.SYNOPSIS...

A WEATHER PATTERN CHANGE WILL BEGIN TONIGHT AS THERE WILL BE PERIODS
OF RAIN THROUGH EARLY NEXT WEEK WITH LOWER SNOW LEVELS EXPECTED
ACROSS MOUNTAIN LOCATIONS...POSSIBLY AFFECTING THE INTERSTATE 5
CORRIDOR SATURDAY THROUGH MONDAY. TEMPERATURES WILL BE BELOW NORMAL
AS WELL THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM (TODAY-SUN)...LATEST FOG PRODUCT IMAGERY INDICATED LOW
CLOUDS ACROSS THE CENTRAL COAST AND DEVELOPING ACROSS THE L.A.
COUNTY BASIN AND INTO THE SAN GABRIEL VALLEY AND ADJACENT COASTAL
SLOPES. LOW CLOUDS SHOULD SPREAD INTO THE SAN FERNANDO VALLEY BY
DAWN AND PORTIONS OF THE VENTURA COUNTY COAST AND VALLEYS...BUT
MIGHT HAVE A TOUGH TIME MAKING IT INTO THE SANTA CLARITA VALLEY AS
NORTHERLY WINDS HAVE PERSISTED ACROSS THE I-5 CORRIDOR THIS MORNING.
LATEST ACARS SOUNDING NEAR LAX INDICATED A WEAK INVERSION FROM 1300
FT UP TO 2500 FT. WITH THE INVERSION BEING SO WEAK AND INCREASING
ONSHORE FLOW TODAY...EXPECT LOW CLOUDS TO CONTINUE TO INCREASE INTO
MUCH OF LA/VTU COUNTIES LATER THIS MORNING WITH SKIES BECOMING
PARTLY TO MOSTLY CLOUDY TODAY.

SYNOPTICALLY...AN UPPER LEVEL LOW THAT WAS OVER WASHINGTON STATE
THIS MORNING WILL CONTINUE TO TREK SOUTH TOWARDS NORTHERN CALIFORNIA
THIS AFTERNOON. THIS UPPER LEVEL FEATURE WILL THEN MOVE SLOWLY TO
THE SOUTH AND BECOME CUTOFF LATE SATURDAY INTO SUNDAY OVER SOUTHERN
CALIFORNIA...THEN PUSH OUT OF THE AREA BY MONDAY MORNING...AS
ANOTHER UPPER LEVEL DISTURBANCE QUICKLY MOVES IN BEHIND THE EXITING
LOW. THIS WEATHER PATTERN WILL BRING AN EXTENDED PERIOD OF SHOWERS
AND SNOW SHOWERS ACROSS MUCH OF SOUTHWESTERN CALIFORNIA. AS HAS BEEN
THE CASE OVER THE PAST SEVERAL STORM EVENTS...THE UPPER LOWS HAVE
BEEN MAINLY OVER LAND AS THEY RETROGRADED TOWARDS SOUTHERN
CALIFORNIA. MOST OF THE SYSTEMS HAVE HAD A TOUGH TIME TAPPING INTO
SOME MOISTURE DUE TO THE TRAJECTORY OF THESE STORM SYSTEMS.
HOWEVER...MOST MODELS ARE NOW BRINGING THIS UPPER LOW A TAD FARTHER
WEST OVER THE COASTAL WATERS AS IT REACHES SOUTHERN CALIFORNIA WHICH
SHOULD HELP TO TAP INTO SOME ADDITIONAL MOISTURE. OVERALL...AREAS TO
OUR SOUTH WILL LIKELY SEE THE BETTER PRECIP AMOUNTS DUE TO BEST
CYCLONIC FLOW AROUND THE LOW. THAT BEING SAID...MODELS ARE IN PRETTY
GOOD AGREEMENT WITH THE STORM TRACK...BUT ARE STILL QUITE VARIED
WITH PRECIP AMOUNTS.

AT THIS POINT...WILL STAY WITH WINTER STORM WATCH HOPING THAT NEXT
SET OF MODELS WILL BE A BIT CLEARER AND THE DAY SHIFT CAN MAKE A
BETTER EDUCATED DECISION TO EITHER UPGRADE THE WATCH TO A WINTER
STORM WARNING OR WINTER WEATHER ADVISORY. THE FACT THERE IS NOT AN
ORGANIZED COLD FRONT BRINGING A STEADY PERIOD OF RAIN OVER THE
REGION MAKES THE FORECAST A BIT DIFFICULT. RAINFALL TOTALS WILL VARY
WITH THIS NEXT SYSTEM. THERE WILL BE PLENTY OF COLD AIR ASSOCIATED
WITH THE UPPER LOW TO HELP CAUSE THE ATMOSPHERE TO BECOME UNSTABLE
ON SATURDAY AND BRING A SLIGHT CHANCE OF THUNDERSTORMS TO AREAS N OF
VENTURA COUNTY. AS THE UPPER LOW MOVES FARTHER SOUTH...THE ENTIRE
FORECAST AREA FROM SLO TO LA COUNTIES WILL HAVE A SLIGHT CHANCE OF
THUNDERSTORMS INCLUDING THE ADJACENT COASTAL WATERS. EXPECT MOSTLY
SHOWERY CONDITIONS FROM LATE TONIGHT THROUGH SUNDAY. PRELIMINARY
RAINFALL TOTALS CURRENTLY ARE FORECAST BETWEEN 0.10 AND 0.50
INCHES...WITH UP TO 1.00 INCH IN THE SAN GABRIEL MOUNTAINS. THERE
COULD BE HIGHER AMOUNTS NEAR THUNDERSTORMS.

ONE OF THE MAIN IMPACTS WITH THIS NEXT SYSTEM WILL BE THE LOWER SNOW
LEVELS POSSIBLY AFFECTING THE I-5 CORRIDOR AND HIGHWAY 14.SNOW
LEVELS WITH THIS SYSTEM WILL BE MUCH COLDER THAN THE LAST.
INITIALLY...SNOW LEVELS WILL BE AROUND 6500 FT FRIDAY NIGHT...THEN
LOWER TO BETWEEN 4500 AND 5000 FEET BY SATURDAY AFTERNOON. SNOW
LEVELS WILL DROP FURTHER BY SATURDAY NIGHT INTO SUNDAY DOWN TO
BETWEEN 3500 AND 4000 FT. AT THIS TIME IT LOOKS LIKE SNOW AMOUNTS
WILL BE BETWEEN 6 AND 12 INCHES FOR THE LA/VTU/SBA MOUNTAINS ABOVE
5500 FT...WITH LESSER AMOUNTS BELOW. THE I-5 CORRIDOR COULD BE
AFFECTED WITH SNOW AND ICY CONDS BY LATE SATURDAY AFTERNOON THROUGH
MONDAY.

AS FAR AS TEMPS GO OVER THE NEXT FEW DAYS...IT WILL BE MUCH COOLER
WITH MOST AREAS IN THE UPPER 50S TO MID 60S. THE COLDEST DAY WILL BE
ON SUNDAY WHERE HIGHS FOR THE COAST AND VALLEYS WILL ONLY REACH THE
LOWER 60S. OF COURSE IT WILL BE MUCH COLDER ACROSS THE MOUNTAINS AND
INTERIOR LOCATIONS.

.LONG TERM (MON-THU)...THE UPPER TROUGH AXIS WILL BE JUST SOUTH OF
THE AREA MONDAY...BUT THERE WILL BE LINGERING SHOWERS ACROSS THE
FORECAST AREA...ESPECIALLY FOR AREAS S OF POINT CONCEPTION.
HOWEVER...ANOTHER SHORT WAVE DISTURBANCE IS POISED TO MOVE IN OVER
THE FORECAST AREA BY MONDAY NIGHT INTO TUE MORNING. THIS WILL ALLOW
FOR SOME ADDITIONAL SHOWERS TO OCCUR WITH CONTINUED COLDER THAN
NORMAL TEMPS ON TUESDAY. EXCEPT FOR A FEW LINGERING CLOUDS AROUND
THE MOUNTAINS...SKIES SHOULD BE MOSTLY CLEAR...WITH WEAK OFFSHORE
FLOW FOR INTERIOR AREAS BOTH WED/THU. WARMEST DAY WILL BE THURDAY
FOR COAST AND VALLEYS WITH HIGHS IN THE LOWER 70S.


&&

.AVIATION...WILL BE UPDATED WITH 12Z TAF PACKAGE.

&&

.MARINE...26/815 PM...

FOR THE OUTER WATERS...HIGH CONFIDENCE IN THE CONTINUATION OF GALE
FORCE NORTHWEST WINDS THROUGH FRIDAY NIGHT. THE NORTHWEST WINDS WILL
DIMINISH ON SATURDAY AND SUNDAY...BUT THERE IS A CHANCE OF WINDS
REMAINING AROUND SMALL CRAFT ADVISORY LEVELS.

FOR THE INNER WATERS...OTHER THAN SOME LOCAL GUSTS TO 25 KNOTS
ACROSS THE WESTERN SANTA BARBARA CHANNEL...WINDS ARE EXPECTED TO
REMAIN BELOW SMALL CRAFT ADVISORY LEVELS TONIGHT. BY FRIDAY
AFTERNOON AND CONTINUING THROUGH SATURDAY...MODERATE CONFIDENCE
IN WEST TO NORTHWEST WINDS INCREASING TO SMALL CRAFT ADVISORY LEVELS
ESPECIALLY ACROSS WESTERN SECTIONS. EXPECT WINDS TO INCREASE FRIDAY
AFTERNOON ACROSS THE SANTA BARBARA CHANNEL...SO WILL ISSUE SMALL
CRAFT ADVISORY FOR THIS EVENING.

SHOWERS ARE EXPECTED TO DEVELOP THIS WEEKEND OVER THE COASTAL WATERS
AS A LOW PRESSURE SYSTEM IMPACTS THE AREA. BY SATURDAY AFTERNOON
AND CONTINUING THROUGH SUNDAY...THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS WHICH COULD PRODUCE GUSTY WINDS...CHOPPY SEAS...AND
POSSIBLY AN ISOLATED WATERSPOUT.

&&

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

&&

$$

PUBLIC...KAPLAN
AVIATION/MARINE...DB

WWW.WEATHER.GOV/LOSANGELES






000
FXUS66 KLOX 271105 RRA
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
305 AM PST FRI FEB 27 2015

.SYNOPSIS...

A WEATHER PATTERN CHANGE WILL BEGIN TONIGHT AS THERE WILL BE PERIODS
OF RAIN THROUGH EARLY NEXT WEEK WITH LOWER SNOW LEVELS EXPECTED
ACROSS MOUNTAIN LOCATIONS...POSSIBLY AFFECTING THE INTERSTATE 5
CORRIDOR SATURDAY THROUGH MONDAY. TEMPERATURES WILL BE BELOW NORMAL
AS WELL THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM (TODAY-SUN)...LATEST FOG PRODUCT IMAGERY INDICATED LOW
CLOUDS ACROSS THE CENTRAL COAST AND DEVELOPING ACROSS THE L.A.
COUNTY BASIN AND INTO THE SAN GABRIEL VALLEY AND ADJACENT COASTAL
SLOPES. LOW CLOUDS SHOULD SPREAD INTO THE SAN FERNANDO VALLEY BY
DAWN AND PORTIONS OF THE VENTURA COUNTY COAST AND VALLEYS...BUT
MIGHT HAVE A TOUGH TIME MAKING IT INTO THE SANTA CLARITA VALLEY AS
NORTHERLY WINDS HAVE PERSISTED ACROSS THE I-5 CORRIDOR THIS MORNING.
LATEST ACARS SOUNDING NEAR LAX INDICATED A WEAK INVERSION FROM 1300
FT UP TO 2500 FT. WITH THE INVERSION BEING SO WEAK AND INCREASING
ONSHORE FLOW TODAY...EXPECT LOW CLOUDS TO CONTINUE TO INCREASE INTO
MUCH OF LA/VTU COUNTIES LATER THIS MORNING WITH SKIES BECOMING
PARTLY TO MOSTLY CLOUDY TODAY.

SYNOPTICALLY...AN UPPER LEVEL LOW THAT WAS OVER WASHINGTON STATE
THIS MORNING WILL CONTINUE TO TREK SOUTH TOWARDS NORTHERN CALIFORNIA
THIS AFTERNOON. THIS UPPER LEVEL FEATURE WILL THEN MOVE SLOWLY TO
THE SOUTH AND BECOME CUTOFF LATE SATURDAY INTO SUNDAY OVER SOUTHERN
CALIFORNIA...THEN PUSH OUT OF THE AREA BY MONDAY MORNING...AS
ANOTHER UPPER LEVEL DISTURBANCE QUICKLY MOVES IN BEHIND THE EXITING
LOW. THIS WEATHER PATTERN WILL BRING AN EXTENDED PERIOD OF SHOWERS
AND SNOW SHOWERS ACROSS MUCH OF SOUTHWESTERN CALIFORNIA. AS HAS BEEN
THE CASE OVER THE PAST SEVERAL STORM EVENTS...THE UPPER LOWS HAVE
BEEN MAINLY OVER LAND AS THEY RETROGRADED TOWARDS SOUTHERN
CALIFORNIA. MOST OF THE SYSTEMS HAVE HAD A TOUGH TIME TAPPING INTO
SOME MOISTURE DUE TO THE TRAJECTORY OF THESE STORM SYSTEMS.
HOWEVER...MOST MODELS ARE NOW BRINGING THIS UPPER LOW A TAD FARTHER
WEST OVER THE COASTAL WATERS AS IT REACHES SOUTHERN CALIFORNIA WHICH
SHOULD HELP TO TAP INTO SOME ADDITIONAL MOISTURE. OVERALL...AREAS TO
OUR SOUTH WILL LIKELY SEE THE BETTER PRECIP AMOUNTS DUE TO BEST
CYCLONIC FLOW AROUND THE LOW. THAT BEING SAID...MODELS ARE IN PRETTY
GOOD AGREEMENT WITH THE STORM TRACK...BUT ARE STILL QUITE VARIED
WITH PRECIP AMOUNTS.

AT THIS POINT...WILL STAY WITH WINTER STORM WATCH HOPING THAT NEXT
SET OF MODELS WILL BE A BIT CLEARER AND THE DAY SHIFT CAN MAKE A
BETTER EDUCATED DECISION TO EITHER UPGRADE THE WATCH TO A WINTER
STORM WARNING OR WINTER WEATHER ADVISORY. THE FACT THERE IS NOT AN
ORGANIZED COLD FRONT BRINGING A STEADY PERIOD OF RAIN OVER THE
REGION MAKES THE FORECAST A BIT DIFFICULT. RAINFALL TOTALS WILL VARY
WITH THIS NEXT SYSTEM. THERE WILL BE PLENTY OF COLD AIR ASSOCIATED
WITH THE UPPER LOW TO HELP CAUSE THE ATMOSPHERE TO BECOME UNSTABLE
ON SATURDAY AND BRING A SLIGHT CHANCE OF THUNDERSTORMS TO AREAS N OF
VENTURA COUNTY. AS THE UPPER LOW MOVES FARTHER SOUTH...THE ENTIRE
FORECAST AREA FROM SLO TO LA COUNTIES WILL HAVE A SLIGHT CHANCE OF
THUNDERSTORMS INCLUDING THE ADJACENT COASTAL WATERS. EXPECT MOSTLY
SHOWERY CONDITIONS FROM LATE TONIGHT THROUGH SUNDAY. PRELIMINARY
RAINFALL TOTALS CURRENTLY ARE FORECAST BETWEEN 0.10 AND 0.50
INCHES...WITH UP TO 1.00 INCH IN THE SAN GABRIEL MOUNTAINS. THERE
COULD BE HIGHER AMOUNTS NEAR THUNDERSTORMS.

ONE OF THE MAIN IMPACTS WITH THIS NEXT SYSTEM WILL BE THE LOWER SNOW
LEVELS POSSIBLY AFFECTING THE I-5 CORRIDOR AND HIGHWAY 14.SNOW
LEVELS WITH THIS SYSTEM WILL BE MUCH COLDER THAN THE LAST.
INITIALLY...SNOW LEVELS WILL BE AROUND 6500 FT FRIDAY NIGHT...THEN
LOWER TO BETWEEN 4500 AND 5000 FEET BY SATURDAY AFTERNOON. SNOW
LEVELS WILL DROP FURTHER BY SATURDAY NIGHT INTO SUNDAY DOWN TO
BETWEEN 3500 AND 4000 FT. AT THIS TIME IT LOOKS LIKE SNOW AMOUNTS
WILL BE BETWEEN 6 AND 12 INCHES FOR THE LA/VTU/SBA MOUNTAINS ABOVE
5500 FT...WITH LESSER AMOUNTS BELOW. THE I-5 CORRIDOR COULD BE
AFFECTED WITH SNOW AND ICY CONDS BY LATE SATURDAY AFTERNOON THROUGH
MONDAY.

AS FAR AS TEMPS GO OVER THE NEXT FEW DAYS...IT WILL BE MUCH COOLER
WITH MOST AREAS IN THE UPPER 50S TO MID 60S. THE COLDEST DAY WILL BE
ON SUNDAY WHERE HIGHS FOR THE COAST AND VALLEYS WILL ONLY REACH THE
LOWER 60S. OF COURSE IT WILL BE MUCH COLDER ACROSS THE MOUNTAINS AND
INTERIOR LOCATIONS.

.LONG TERM (MON-THU)...THE UPPER TROUGH AXIS WILL BE JUST SOUTH OF
THE AREA MONDAY...BUT THERE WILL BE LINGERING SHOWERS ACROSS THE
FORECAST AREA...ESPECIALLY FOR AREAS S OF POINT CONCEPTION.
HOWEVER...ANOTHER SHORT WAVE DISTURBANCE IS POISED TO MOVE IN OVER
THE FORECAST AREA BY MONDAY NIGHT INTO TUE MORNING. THIS WILL ALLOW
FOR SOME ADDITIONAL SHOWERS TO OCCUR WITH CONTINUED COLDER THAN
NORMAL TEMPS ON TUESDAY. EXCEPT FOR A FEW LINGERING CLOUDS AROUND
THE MOUNTAINS...SKIES SHOULD BE MOSTLY CLEAR...WITH WEAK OFFSHORE
FLOW FOR INTERIOR AREAS BOTH WED/THU. WARMEST DAY WILL BE THURDAY
FOR COAST AND VALLEYS WITH HIGHS IN THE LOWER 70S.


&&

.AVIATION...WILL BE UPDATED WITH 12Z TAF PACKAGE.

&&

.MARINE...26/815 PM...

FOR THE OUTER WATERS...HIGH CONFIDENCE IN THE CONTINUATION OF GALE
FORCE NORTHWEST WINDS THROUGH FRIDAY NIGHT. THE NORTHWEST WINDS WILL
DIMINISH ON SATURDAY AND SUNDAY...BUT THERE IS A CHANCE OF WINDS
REMAINING AROUND SMALL CRAFT ADVISORY LEVELS.

FOR THE INNER WATERS...OTHER THAN SOME LOCAL GUSTS TO 25 KNOTS
ACROSS THE WESTERN SANTA BARBARA CHANNEL...WINDS ARE EXPECTED TO
REMAIN BELOW SMALL CRAFT ADVISORY LEVELS TONIGHT. BY FRIDAY
AFTERNOON AND CONTINUING THROUGH SATURDAY...MODERATE CONFIDENCE
IN WEST TO NORTHWEST WINDS INCREASING TO SMALL CRAFT ADVISORY LEVELS
ESPECIALLY ACROSS WESTERN SECTIONS. EXPECT WINDS TO INCREASE FRIDAY
AFTERNOON ACROSS THE SANTA BARBARA CHANNEL...SO WILL ISSUE SMALL
CRAFT ADVISORY FOR THIS EVENING.

SHOWERS ARE EXPECTED TO DEVELOP THIS WEEKEND OVER THE COASTAL WATERS
AS A LOW PRESSURE SYSTEM IMPACTS THE AREA. BY SATURDAY AFTERNOON
AND CONTINUING THROUGH SUNDAY...THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS WHICH COULD PRODUCE GUSTY WINDS...CHOPPY SEAS...AND
POSSIBLY AN ISOLATED WATERSPOUT.

&&

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

&&

$$

PUBLIC...KAPLAN
AVIATION/MARINE...DB

WWW.WEATHER.GOV/LOSANGELES








000
FXUS66 KLOX 271105
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
126 AM PST FRI FEB 27 2015

.SYNOPSIS...

A WEATHER PATTERN CHANGE WILL BEGIN TONIGHT AS THERE WILL BE PERIODS
OF RAIN THROUGH EARLY NEXT WEEK WITH LOWER SNOW LEVELS EXPECTED
ACROSS MOUNTAIN LOCATIONS...POSSIBLY AFFECTING THE INTERSTATE 5
CORRIDOR SATURDAY THROUGH MONDAY. TEMPERATURES WILL BE BELOW NORMAL
AS WELL THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM (TODAY-SUN)...LATEST FOG PRODUCT IMAGERY INDICATED LOW
CLOUDS ACROSS THE CENTRAL COAST AND DEVELOPING ACROSS THE L.A.
COUNTY BASIN AND INTO THE SAN GABRIEL VALLEY AND ADJACENT COASTAL
SLOPES. LOW CLOUDS SHOULD SPREAD INTO THE SAN FERNANDO VALLEY BY
DAWN AND PORTIONS OF THE VENTURA COUNTY COAST AND VALLEYS...BUT
MIGHT HAVE A TOUGH TIME MAKING IT INTO THE SANTA CLARITA VALLEY AS
NORTHERLY WINDS HAVE PERSISTED ACROSS THE I-5 CORRIDOR THIS MORNING.
LATEST ACARS SOUNDING NEAR LAX INDICATED A WEAK INVERSION FROM 1300
FT UP TO 2500 FT. WITH THE INVERSION BEING SO WEAK AND INCREASING
ONSHORE FLOW TODAY...EXPECT LOW CLOUDS TO CONTINUE TO INCREASE INTO
MUCH OF LA/VTU COUNTIES LATER THIS MORNING WITH SKIES BECOMING
PARTLY TO MOSTLY CLOUDY TODAY.

SYNOPTICALLY...AN UPPER LEVEL LOW THAT WAS OVER WASHINGTON STATE
THIS MORNING WILL CONTINUE TO TREK SOUTH TOWARDS NORTHERN CALIFORNIA
THIS AFTERNOON. THIS UPPER LEVEL FEATURE WILL THEN MOVE SLOWLY TO
THE SOUTH AND BECOME CUTOFF LATE SATURDAY INTO SUNDAY OVER SOUTHERN
CALIFORNIA...THEN PUSH OUT OF THE AREA BY MONDAY MORNING...AS
ANOTHER UPPER LEVEL DISTURBANCE QUICKLY MOVES IN BEHIND THE EXITING
LOW. THIS WEATHER PATTERN WILL BRING AN EXTENDED PERIOD OF SHOWERS
AND SNOW SHOWERS ACROSS MUCH OF SOUTHWESTERN CALIFORNIA. AS HAS BEEN
THE CASE OVER THE PAST SEVERAL STORM EVENTS...THE UPPER LOWS HAVE
BEEN MAINLY OVER LAND AS THEY RETROGRADED TOWARDS SOUTHERN
CALIFORNIA. MOST OF THE SYSTEMS HAVE HAD A TOUGH TIME TAPPING INTO
SOME MOISTURE DUE TO THE TRAJECTORY OF THESE STORM SYSTEMS.
HOWEVER...MOST MODELS ARE NOW BRINGING THIS UPPER LOW A TAD FARTHER
WEST OVER THE COASTAL WATERS AS IT REACHES SOUTHERN CALIFORNIA WHICH
SHOULD HELP TO TAP INTO SOME ADDITIONAL MOISTURE. OVERALL...AREAS TO
OUR SOUTH WILL LIKELY SEE THE BETTER PRECIP AMOUNTS DUE TO BEST
CYCLONIC FLOW AROUND THE LOW. THAT BEING SAID...MODELS ARE IN PRETTY
GOOD AGREEMENT WITH THE STORM TRACK...BUT ARE STILL QUITE VARIED
WITH PRECIP AMOUNTS.

AT THIS POINT...WILL STAY WITH WINTER STORM WATCH HOPING THAT NEXT
SET OF MODELS WILL BE A BIT CLEARER AND THE DAY SHIFT CAN MAKE A
BETTER EDUCATED DECISION TO EITHER UPGRADE THE WATCH TO A WINTER
STORM WARNING OR WINTER WEATHER ADVISORY. THE FACT THERE IS NOT AN
ORGANIZED COLD FRONT BRINGING A STEADY PERIOD OF RAIN OVER THE
REGION MAKES THE FORECAST A BIT DIFFICULT. RAINFALL TOTALS WILL VARY
WITH THIS NEXT SYSTEM. THERE WILL BE PLENTY OF COLD AIR ASSOCIATED
WITH THE UPPER LOW TO HELP CAUSE THE ATMOSPHERE TO BECOME UNSTABLE
ON SATURDAY AND BRING A SLIGHT CHANCE OF THUNDERSTORMS TO AREAS N OF
VENTURA COUNTY. AS THE UPPER LOW MOVES FARTHER SOUTH...THE ENTIRE
FORECAST AREA FROM SLO TO LA COUNTIES WILL HAVE A SLIGHT CHANCE OF
THUNDERSTORMS INCLUDING THE ADJACENT COASTAL WATERS. EXPECT MOSTLY
SHOWERY CONDITIONS FROM LATE TONIGHT THROUGH SUNDAY. PRELIMINARY
RAINFALL TOTALS CURRENTLY ARE FORECAST BETWEEN 0.10 AND 0.50
INCHES...WITH UP TO 1.00 INCH IN THE SAN GABRIEL MOUNTAINS. THERE
COULD BE HIGHER AMOUNTS NEAR THUNDERSTORMS.

ONE OF THE MAIN IMPACTS WITH THIS NEXT SYSTEM WILL BE THE LOWER SNOW
LEVELS POSSIBLY AFFECTING THE I-5 CORRIDOR AND HIGHWAY 14.SNOW
LEVELS WITH THIS SYSTEM WILL BE MUCH COLDER THAN THE LAST.
INITIALLY...SNOW LEVELS WILL BE AROUND 6500 FT FRIDAY NIGHT...THEN
LOWER TO BETWEEN 4500 AND 5000 FEET BY SATURDAY AFTERNOON. SNOW
LEVELS WILL DROP FURTHER BY SATURDAY NIGHT INTO SUNDAY DOWN TO
BETWEEN 3500 AND 4000 FT. AT THIS TIME IT LOOKS LIKE SNOW AMOUNTS
WILL BE BETWEEN 6 AND 12 INCHES FOR THE LA/VTU/SBA MOUNTAINS ABOVE
5500 FT...WITH LESSER AMOUNTS BELOW. THE I-5 CORRIDOR COULD BE
AFFECTED WITH SNOW AND ICY CONDS BY LATE SATURDAY AFTERNOON THROUGH
MONDAY.

AS FAR AS TEMPS GO OVER THE NEXT FEW DAYS...IT WILL BE MUCH COOLER
WITH MOST AREAS IN THE UPPER 50S TO MID 60S. THE COLDEST DAY WILL BE
ON SUNDAY WHERE HIGHS FOR THE COAST AND VALLEYS WILL ONLY REACH THE
LOWER 60S. OF COURSE IT WILL BE MUCH COLDER ACROSS THE MOUNTAINS AND
INTERIOR LOCATIONS.

.LONG TERM (MON-THU)...THE UPPER TROUGH AXIS WILL BE JUST SOUTH OF
THE AREA MONDAY...BUT THERE WILL BE LINGERING SHOWERS ACROSS THE
FORECAST AREA...ESPECIALLY FOR AREAS S OF POINT CONCEPTION.
HOWEVER...ANOTHER SHORT WAVE DISTURBANCE IS POISED TO MOVE IN OVER
THE FORECAST AREA BY MONDAY NIGHT INTO TUE MORNING. THIS WILL ALLOW
FOR SOME ADDITIONAL SHOWERS TO OCCUR WITH CONTINUED COLDER THAN
NORMAL TEMPS ON TUESDAY. EXCEPT FOR A FEW LINGERING CLOUDS AROUND
THE MOUNTAINS...SKIES SHOULD BE MOSTLY CLEAR...WITH WEAK OFFSHORE
FLOW FOR INTERIOR AREAS BOTH WED/THU. WARMEST DAY WILL BE THURDAY
FOR COAST AND VALLEYS WITH HIGHS IN THE LOWER 70S.


&&

.AVIATION...WILL BE UPDATED WITH 12Z TAF PACKAGE.

&&

.MARINE...26/815 PM...

FOR THE OUTER WATERS...HIGH CONFIDENCE IN THE CONTINUATION OF GALE
FORCE NORTHWEST WINDS THROUGH FRIDAY NIGHT. THE NORTHWEST WINDS WILL
DIMINISH ON SATURDAY AND SUNDAY...BUT THERE IS A CHANCE OF WINDS
REMAINING AROUND SMALL CRAFT ADVISORY LEVELS.

FOR THE INNER WATERS...OTHER THAN SOME LOCAL GUSTS TO 25 KNOTS
ACROSS THE WESTERN SANTA BARBARA CHANNEL...WINDS ARE EXPECTED TO
REMAIN BELOW SMALL CRAFT ADVISORY LEVELS TONIGHT. BY FRIDAY
AFTERNOON AND CONTINUING THROUGH SATURDAY...MODERATE CONFIDENCE
IN WEST TO NORTHWEST WINDS INCREASING TO SMALL CRAFT ADVISORY LEVELS
ESPECIALLY ACROSS WESTERN SECTIONS. EXPECT WINDS TO INCREASE FRIDAY
AFTERNOON ACROSS THE SANTA BARBARA CHANNEL...SO WILL ISSUE SMALL
CRAFT ADVISORY FOR THIS EVENING.

SHOWERS ARE EXPECTED TO DEVELOP THIS WEEKEND OVER THE COASTAL WATERS
AS A LOW PRESSURE SYSTEM IMPACTS THE AREA. BY SATURDAY AFTERNOON
AND CONTINUING THROUGH SUNDAY...THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS WHICH COULD PRODUCE GUSTY WINDS...CHOPPY SEAS...AND
POSSIBLY AN ISOLATED WATERSPOUT.

&&

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

&&

$$

PUBLIC...KAPLAN
AVIATION/MARINE...DB

WWW.WEATHER.GOV/LOSANGELES







000
FXUS66 KLOX 271105 RRA
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
305 AM PST FRI FEB 27 2015

.SYNOPSIS...

A WEATHER PATTERN CHANGE WILL BEGIN TONIGHT AS THERE WILL BE PERIODS
OF RAIN THROUGH EARLY NEXT WEEK WITH LOWER SNOW LEVELS EXPECTED
ACROSS MOUNTAIN LOCATIONS...POSSIBLY AFFECTING THE INTERSTATE 5
CORRIDOR SATURDAY THROUGH MONDAY. TEMPERATURES WILL BE BELOW NORMAL
AS WELL THROUGH EARLY NEXT WEEK.

&&

.SHORT TERM (TODAY-SUN)...LATEST FOG PRODUCT IMAGERY INDICATED LOW
CLOUDS ACROSS THE CENTRAL COAST AND DEVELOPING ACROSS THE L.A.
COUNTY BASIN AND INTO THE SAN GABRIEL VALLEY AND ADJACENT COASTAL
SLOPES. LOW CLOUDS SHOULD SPREAD INTO THE SAN FERNANDO VALLEY BY
DAWN AND PORTIONS OF THE VENTURA COUNTY COAST AND VALLEYS...BUT
MIGHT HAVE A TOUGH TIME MAKING IT INTO THE SANTA CLARITA VALLEY AS
NORTHERLY WINDS HAVE PERSISTED ACROSS THE I-5 CORRIDOR THIS MORNING.
LATEST ACARS SOUNDING NEAR LAX INDICATED A WEAK INVERSION FROM 1300
FT UP TO 2500 FT. WITH THE INVERSION BEING SO WEAK AND INCREASING
ONSHORE FLOW TODAY...EXPECT LOW CLOUDS TO CONTINUE TO INCREASE INTO
MUCH OF LA/VTU COUNTIES LATER THIS MORNING WITH SKIES BECOMING
PARTLY TO MOSTLY CLOUDY TODAY.

SYNOPTICALLY...AN UPPER LEVEL LOW THAT WAS OVER WASHINGTON STATE
THIS MORNING WILL CONTINUE TO TREK SOUTH TOWARDS NORTHERN CALIFORNIA
THIS AFTERNOON. THIS UPPER LEVEL FEATURE WILL THEN MOVE SLOWLY TO
THE SOUTH AND BECOME CUTOFF LATE SATURDAY INTO SUNDAY OVER SOUTHERN
CALIFORNIA...THEN PUSH OUT OF THE AREA BY MONDAY MORNING...AS
ANOTHER UPPER LEVEL DISTURBANCE QUICKLY MOVES IN BEHIND THE EXITING
LOW. THIS WEATHER PATTERN WILL BRING AN EXTENDED PERIOD OF SHOWERS
AND SNOW SHOWERS ACROSS MUCH OF SOUTHWESTERN CALIFORNIA. AS HAS BEEN
THE CASE OVER THE PAST SEVERAL STORM EVENTS...THE UPPER LOWS HAVE
BEEN MAINLY OVER LAND AS THEY RETROGRADED TOWARDS SOUTHERN
CALIFORNIA. MOST OF THE SYSTEMS HAVE HAD A TOUGH TIME TAPPING INTO
SOME MOISTURE DUE TO THE TRAJECTORY OF THESE STORM SYSTEMS.
HOWEVER...MOST MODELS ARE NOW BRINGING THIS UPPER LOW A TAD FARTHER
WEST OVER THE COASTAL WATERS AS IT REACHES SOUTHERN CALIFORNIA WHICH
SHOULD HELP TO TAP INTO SOME ADDITIONAL MOISTURE. OVERALL...AREAS TO
OUR SOUTH WILL LIKELY SEE THE BETTER PRECIP AMOUNTS DUE TO BEST
CYCLONIC FLOW AROUND THE LOW. THAT BEING SAID...MODELS ARE IN PRETTY
GOOD AGREEMENT WITH THE STORM TRACK...BUT ARE STILL QUITE VARIED
WITH PRECIP AMOUNTS.

AT THIS POINT...WILL STAY WITH WINTER STORM WATCH HOPING THAT NEXT
SET OF MODELS WILL BE A BIT CLEARER AND THE DAY SHIFT CAN MAKE A
BETTER EDUCATED DECISION TO EITHER UPGRADE THE WATCH TO A WINTER
STORM WARNING OR WINTER WEATHER ADVISORY. THE FACT THERE IS NOT AN
ORGANIZED COLD FRONT BRINGING A STEADY PERIOD OF RAIN OVER THE
REGION MAKES THE FORECAST A BIT DIFFICULT. RAINFALL TOTALS WILL VARY
WITH THIS NEXT SYSTEM. THERE WILL BE PLENTY OF COLD AIR ASSOCIATED
WITH THE UPPER LOW TO HELP CAUSE THE ATMOSPHERE TO BECOME UNSTABLE
ON SATURDAY AND BRING A SLIGHT CHANCE OF THUNDERSTORMS TO AREAS N OF
VENTURA COUNTY. AS THE UPPER LOW MOVES FARTHER SOUTH...THE ENTIRE
FORECAST AREA FROM SLO TO LA COUNTIES WILL HAVE A SLIGHT CHANCE OF
THUNDERSTORMS INCLUDING THE ADJACENT COASTAL WATERS. EXPECT MOSTLY
SHOWERY CONDITIONS FROM LATE TONIGHT THROUGH SUNDAY. PRELIMINARY
RAINFALL TOTALS CURRENTLY ARE FORECAST BETWEEN 0.10 AND 0.50
INCHES...WITH UP TO 1.00 INCH IN THE SAN GABRIEL MOUNTAINS. THERE
COULD BE HIGHER AMOUNTS NEAR THUNDERSTORMS.

ONE OF THE MAIN IMPACTS WITH THIS NEXT SYSTEM WILL BE THE LOWER SNOW
LEVELS POSSIBLY AFFECTING THE I-5 CORRIDOR AND HIGHWAY 14.SNOW
LEVELS WITH THIS SYSTEM WILL BE MUCH COLDER THAN THE LAST.
INITIALLY...SNOW LEVELS WILL BE AROUND 6500 FT FRIDAY NIGHT...THEN
LOWER TO BETWEEN 4500 AND 5000 FEET BY SATURDAY AFTERNOON. SNOW
LEVELS WILL DROP FURTHER BY SATURDAY NIGHT INTO SUNDAY DOWN TO
BETWEEN 3500 AND 4000 FT. AT THIS TIME IT LOOKS LIKE SNOW AMOUNTS
WILL BE BETWEEN 6 AND 12 INCHES FOR THE LA/VTU/SBA MOUNTAINS ABOVE
5500 FT...WITH LESSER AMOUNTS BELOW. THE I-5 CORRIDOR COULD BE
AFFECTED WITH SNOW AND ICY CONDS BY LATE SATURDAY AFTERNOON THROUGH
MONDAY.

AS FAR AS TEMPS GO OVER THE NEXT FEW DAYS...IT WILL BE MUCH COOLER
WITH MOST AREAS IN THE UPPER 50S TO MID 60S. THE COLDEST DAY WILL BE
ON SUNDAY WHERE HIGHS FOR THE COAST AND VALLEYS WILL ONLY REACH THE
LOWER 60S. OF COURSE IT WILL BE MUCH COLDER ACROSS THE MOUNTAINS AND
INTERIOR LOCATIONS.

.LONG TERM (MON-THU)...THE UPPER TROUGH AXIS WILL BE JUST SOUTH OF
THE AREA MONDAY...BUT THERE WILL BE LINGERING SHOWERS ACROSS THE
FORECAST AREA...ESPECIALLY FOR AREAS S OF POINT CONCEPTION.
HOWEVER...ANOTHER SHORT WAVE DISTURBANCE IS POISED TO MOVE IN OVER
THE FORECAST AREA BY MONDAY NIGHT INTO TUE MORNING. THIS WILL ALLOW
FOR SOME ADDITIONAL SHOWERS TO OCCUR WITH CONTINUED COLDER THAN
NORMAL TEMPS ON TUESDAY. EXCEPT FOR A FEW LINGERING CLOUDS AROUND
THE MOUNTAINS...SKIES SHOULD BE MOSTLY CLEAR...WITH WEAK OFFSHORE
FLOW FOR INTERIOR AREAS BOTH WED/THU. WARMEST DAY WILL BE THURDAY
FOR COAST AND VALLEYS WITH HIGHS IN THE LOWER 70S.


&&

.AVIATION...WILL BE UPDATED WITH 12Z TAF PACKAGE.

&&

.MARINE...26/815 PM...

FOR THE OUTER WATERS...HIGH CONFIDENCE IN THE CONTINUATION OF GALE
FORCE NORTHWEST WINDS THROUGH FRIDAY NIGHT. THE NORTHWEST WINDS WILL
DIMINISH ON SATURDAY AND SUNDAY...BUT THERE IS A CHANCE OF WINDS
REMAINING AROUND SMALL CRAFT ADVISORY LEVELS.

FOR THE INNER WATERS...OTHER THAN SOME LOCAL GUSTS TO 25 KNOTS
ACROSS THE WESTERN SANTA BARBARA CHANNEL...WINDS ARE EXPECTED TO
REMAIN BELOW SMALL CRAFT ADVISORY LEVELS TONIGHT. BY FRIDAY
AFTERNOON AND CONTINUING THROUGH SATURDAY...MODERATE CONFIDENCE
IN WEST TO NORTHWEST WINDS INCREASING TO SMALL CRAFT ADVISORY LEVELS
ESPECIALLY ACROSS WESTERN SECTIONS. EXPECT WINDS TO INCREASE FRIDAY
AFTERNOON ACROSS THE SANTA BARBARA CHANNEL...SO WILL ISSUE SMALL
CRAFT ADVISORY FOR THIS EVENING.

SHOWERS ARE EXPECTED TO DEVELOP THIS WEEKEND OVER THE COASTAL WATERS
AS A LOW PRESSURE SYSTEM IMPACTS THE AREA. BY SATURDAY AFTERNOON
AND CONTINUING THROUGH SUNDAY...THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS WHICH COULD PRODUCE GUSTY WINDS...CHOPPY SEAS...AND
POSSIBLY AN ISOLATED WATERSPOUT.

&&

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

&&

$$

PUBLIC...KAPLAN
AVIATION/MARINE...DB

WWW.WEATHER.GOV/LOSANGELES







000
FXUS66 KLOX 270414
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
815 PM PST THU FEB 26 2015

.SYNOPSIS...

FRIDAY LOOKS TO STAY MOSTLY DRY AND SEVERAL DEGREES COOLER. A COLD
LOW PRESSURE SYSTEM WILL BRING EVEN COOLER TEMPERATURES...RAIN
SHOWERS AND MOUNTAIN SNOW TO OUR REGION OVER THE WEEKEND. A SECOND
WEAKER SYSTEM IS EXPECTED MONDAY THROUGH TUESDAY. THE REST OF NEXT
WEEK WILL BE DRY AND WARMER WITH LIGHT OFFSHORE BREEZES.

&&

.UPDATE...
OVERALL...RATHER QUIET EVENING ACROSS THE DISTRICT. LATEST SATELLITE
INDICATES MOSTLY CLEAR SKIES ACROSS THE AREA AS SOME CIRRUS DRIFTS
OVERHEAD. SURFACE OBS INDICATE SOME GUSTY NORTHERLY WINDS IN THE
MOUNTAINS THIS EVENING...BUT NOTHING STRONG/WIDESPREAD ENOUGH TO
WARRANT ANY ADVISORIES AT THIS TIME. WITH THE GALE FORCE NORTHWEST
WINDS OVER THE OUTER WATERS...A DECENT EDDY SHOULD SPIN UP
OVERNIGHT. THIS SHOULD ALLOW STRATUS TO REFORM OVER THE BIGHT AND
SPREAD INTO THE COASTAL AREAS OF VENTURA/LOS ANGELES COUNTIES AND
EVEN SOME OF THE COASTAL VALLEYS. ADDITIONALLY...EXPECT STRATUS TO
BECOME RATHER WIDESPREAD ACROSS THE CENTRAL COAST OVERNIGHT ALTHOUGH
CONFIDENCE IS ONLY MODERATE AT BEST FOR THIS SCENARIO AS NORTHWEST
FLOW COULD LIMIT STRATUS FORMATION.

OVERALL...CURRENT FORECAST LOOKS TO BE IN DECENT SHAPE. WILL ISSUE
AN EVENING UPDATE TO MAKE SOME SLIGHT ADJUSTMENTS TO CLOUD WORDING
AND TWEAK SOME WIND WORDING.

QUICK LOOK AT INITIAL 00Z MODEL GUIDANCE INDICATES THAT UNSETTLED
WEATHER IS STILL ANTICIPATED ACROSS THE AREA AS A COLD UPPER LEVEL
LOW IMPACTS THE AREA.

&&

.PREVIOUS DISCUSSION...

SHORT TERM (TODAY-SUN)...A PRETTY QUIET COUPLE OF DAYS TODAY AND
FRIDAY. ONSHORE TRENDS WILL BE ON THE INCREASE TOMORROW AND WE
SHOULD SEE SLIGHTLY BETTER MARINE LYR COVERAGE IN THE MORNING THAN
TODAY, AND EVEN MORE SAT MORNING. DAYTIME HIGHS EXPECTED TO DROP
ABOUT 5 DEGREES ON AVERAGE FRIDAY AND ANOTHER 5 SATURDAY.

ANOTHER INTERESTING LITTLE WEATHER SYSTEM HEADED OUR WAY THIS
WEEKEND. THE UPSHOT IS THAT THE PROBABILITY IS HIGH THAT ALL AREAS
WILL GET AT LEAST SOME PRECIPITATION AT SOME POINT OVER THE WEEKEND.
HOWEVER, TRYING TO NAIL DOWN THE WHEN AND HOW MUCH HAS AND WILL BE A
SIGNIFICANT CHALLENGE. THE SYSTEM WILL BE COMING DOWN FROM THE NORTH
AND AS IS USUAL WITH STORMS FROM THIS DIRECTION WILL BE SOMEWHAT
MOISTURE STARVED. THE OTHER CHALLENGE WITH THIS SYSTEM IS THAT AT
LEAST FOR THE FIRST PART OF THE WEEKEND WE`RE GOING TO BE UNDER THE
INFLUENCE OF A PRETTY STRONG NORTHWEST FLOW PATTERN WHICH CREATES A
DRYING, DOWNSLOPING EFFECT TO AREAS SOUTH OF PT CONCEPTION,
ESPECIALLY VENTURA AND SRN SB COUNTIES. BY SATURDAY NIGHT INTO
SUNDAY THE SYSTEM STARTS TO PICK UP A LITTLE MORE OVER-WATER
TRAJECTORY AND OUR NORTHWEST FLOW DECREASES. SO THAT PERIOD SHOULD
PRESENT THE BEST CHANCE FOR SHOWERS, PLUS THE AIR MASS WILL BE AT
ITS COLDEST AND MOST UNSTABLE BY THAT TIME. STILL THOUGH, THIS WILL
BE A SHOWERY SYSTEM AND WE`LL LIKELY SEE SOME PLACED GETTING
DRENCHED WHILE OTHER AREAS GET VERY LITTLE. CAN`T ARGUE WITH
THUNDERSTORM CHANCES, THOUGH THE MOST UNSTABLE AIR IS ACROSS SBA/SLO
COUNTIES AND ADJACENT WATERS SAT AFTERNOON THROUGH SUNDAY.

SNOW LEVELS WILL BE IN THE 4000-5000` RANGE FOR MOST OF THIS EVENT
SO LOWER ELEVATIONS ROADS WILL LIKELY SEE SOME ACCUMULATING SNOW,
INCLUDING INTERSTATE 5 OVER THE GRAPEVINE. AGAIN, SNOW AMOUNTS WILL
VARY WITH THE RANDOMNESS OF THE HEAVIER SHOWERS, BUT THE 8-16"
MENTIONED IN THE CURRENT WINTER STORM WATCH IS WITHIN THE REALM OF
POSSIBILITY BUT NOT LIKELY THE NORM AS THOSE HIGHER NUMBERS WOULD
LIKELY REQUIRE A FEW GOOD STORMS TO DEVELOP OVER THE SAME AREAS.
3-6" IS A MORE LIKELY AREAL AVERAGE, BUT GIVEN THE IMPACT ON LOWER
ELEVATION DRIVING AND THE OUTSIDE CHANCE OF THOSE HIGHER NUMBERS
HITTING POPULAR SPOTS THE WATCH SEEMS WARRANTED AT THIS TIME.

RAIN AMOUNTS SIMILARLY DIFFICULT BUT A TENTH TO HALF SEEMS LIKE A
GOOD AREAL AVERAGE (LOWEST IN ERN SBA COUNTY AND COASTAL VENTURA
COUNTY). AND CONVECTION COULD LOCALLY BOOST TOTALS WELL OVER AN
INCH. BURN AREA PROBLEMS WOULD LIKELY REQUIRE ONE OF THESE
CONVECTIVE CELLS TO MOVE OVERHEAD AND WHILE THE CHANCES ARE LOW OVER
ANY ONE LOCATION THEY AREN`T ZERO.

LONG TERM (MON-THU)...THE TROF AXIS SHOULD BE JUST EAST OF THE AREA
MONDAY MORNING BUT THERE IS ENOUGH LINGERING MOISTURE AND COLD AIR
ALOFT TO WARRANT AT LEAST SOME PRECIP CHANCES THROUGH THE AFTERNOON,
HIGHEST OVER THE MTNS. A SECOND AND FAST MOVING SYSTEM WILL FOLLOW
QUICKLY ON THE HEELS OF THE WEEKEND STORM MONDAY NIGHT INTO EARLY
TUESDAY BUT MODELS AREN`T SHOWING TOO MUCH MOISTURE WITH THIS ONE AS
IT`S TAKING AN EVEN MORE INSIDE TRACK. THIS COULD CHANGE THOUGH AND
CAN`T ARGUE WITH SMALL RAIN CHANCES THROUGH TUESDAY. WE SHOULD SEE
RAPID CLEARING BY TUESDAY NIGHT AS WE SHIFT TO OFFSHORE FLOW WITH A
SIGNIFICANT WARMING TREND THROUGH THE END OF THE WEEK.

&&

.AVIATION...26/2310Z...

AT 2220Z...THE INVERSION AT KLAX WAS BASED AT 1400 FEET. THE TOP OF
THE INVERSION WAS 4500 FEET WITH A TEMPERATURE OF 14 DEGREES
CELSIUS.

OVERALL...MODERATE CONFIDENCE IN 00Z TAF PACKAGE. STRONG NORTHWEST
FLOW OVER THE COASTAL WATERS IS EXPECTED TO SPIN UP AN EDDY TONIGHT
WHICH WILL BRING STRATUS/FOG INTO KLAX/KLGB/KOXR LATE TONIGHT. ALSO
WILL ANTICIPATE SOME STRATUS/FOG DEVELOPING AT KSMX AND KPRB
OVERNIGHT.

KLAX...MODERATE CONFIDENCE IN 00Z TAF. HIGH CONFIDENCE IN VFR CONDS
THRU THIS EVENING. OVERNIGHT...HIGH CONFIDENCE IN RETURN OF MVFR
CIGS/VSBYS...BUT LOW CONFIDENCE IN TIMING (RETURN COULD BE +/- 2
HOURS OF CURRENT 11Z FORECAST). THERE IS A 30% CHANCE THAT MVFR CIGS
WILL REMAIN THRU FRIDAY AFTERNOON.

KBUR...MODERATE CONFIDENCE IN 00Z TAF. HIGH CONFIDENCE IN VFR CONDS
THRU THIS EVENING. LOW CONFIDENCE IN MVFR VSBYS 11Z-18Z. THERE IS A
20% CHANCE OF IFR CIGS 11Z-18Z.

&&

.MARINE...26/815 PM...

FOR THE OUTER WATERS...HIGH CONFIDENCE IN THE CONTINUATION OF GALE
FORCE NORTHWEST WINDS THROUGH FRIDAY NIGHT. THE NORTHWEST WINDS WILL
DIMINISH ON SATURDAY AND SUNDAY...BUT THERE IS A CHANCE OF WINDS
REMAINING AROUND SMALL CRAFT ADVISORY LEVELS.

FOR THE INNER WATERS...OTHER THAN SOME LOCAL GUSTS TO 25 KNOTS
ACROSS THE WESTERN SANTA BARBARA CHANNEL...WINDS ARE EXPECTED TO
REMAIN BELOW SMALL CRAFT ADVISORY LEVELS TONIGHT. BY FRIDAY
AFTERNOON AND CONTINUING THROUGH SATURDAY...MODERATE CONFIDENCE
IN WEST TO NORTHWEST WINDS INCREASING TO SMALL CRAFT ADVISORY LEVELS
ESPECIALLY ACROSS WESTERN SECTIONS. EXPECT WINDS TO INCREASE FRIDAY
AFTERNOON ACROSS THE SANTA BARBARA CHANNEL...SO WILL ISSUE SMALL
CRAFT ADVISORY FOR THIS EVENING.

SHOWERS ARE EXPECTED TO DEVELOP THIS WEEKEND OVER THE COASTAL WATERS
AS A LOW PRESSURE SYSTEM IMPACTS THE AREA. BY SATURDAY AFTERNOON
AND CONTINUING THROUGH SUNDAY...THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS WHICH COULD PRODUCE GUSTY WINDS...CHOPPY SEAS...AND
POSSIBLY AN ISOLATED WATERSPOUT.

&&

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

&&

$$

PUBLIC...MW
AVIATION...RAT
MARINE...RAT
SYNOPSIS...BARTLING

WWW.WEATHER.GOV/LOSANGELES







000
FXUS66 KLOX 270414
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
815 PM PST THU FEB 26 2015

.SYNOPSIS...

FRIDAY LOOKS TO STAY MOSTLY DRY AND SEVERAL DEGREES COOLER. A COLD
LOW PRESSURE SYSTEM WILL BRING EVEN COOLER TEMPERATURES...RAIN
SHOWERS AND MOUNTAIN SNOW TO OUR REGION OVER THE WEEKEND. A SECOND
WEAKER SYSTEM IS EXPECTED MONDAY THROUGH TUESDAY. THE REST OF NEXT
WEEK WILL BE DRY AND WARMER WITH LIGHT OFFSHORE BREEZES.

&&

.UPDATE...
OVERALL...RATHER QUIET EVENING ACROSS THE DISTRICT. LATEST SATELLITE
INDICATES MOSTLY CLEAR SKIES ACROSS THE AREA AS SOME CIRRUS DRIFTS
OVERHEAD. SURFACE OBS INDICATE SOME GUSTY NORTHERLY WINDS IN THE
MOUNTAINS THIS EVENING...BUT NOTHING STRONG/WIDESPREAD ENOUGH TO
WARRANT ANY ADVISORIES AT THIS TIME. WITH THE GALE FORCE NORTHWEST
WINDS OVER THE OUTER WATERS...A DECENT EDDY SHOULD SPIN UP
OVERNIGHT. THIS SHOULD ALLOW STRATUS TO REFORM OVER THE BIGHT AND
SPREAD INTO THE COASTAL AREAS OF VENTURA/LOS ANGELES COUNTIES AND
EVEN SOME OF THE COASTAL VALLEYS. ADDITIONALLY...EXPECT STRATUS TO
BECOME RATHER WIDESPREAD ACROSS THE CENTRAL COAST OVERNIGHT ALTHOUGH
CONFIDENCE IS ONLY MODERATE AT BEST FOR THIS SCENARIO AS NORTHWEST
FLOW COULD LIMIT STRATUS FORMATION.

OVERALL...CURRENT FORECAST LOOKS TO BE IN DECENT SHAPE. WILL ISSUE
AN EVENING UPDATE TO MAKE SOME SLIGHT ADJUSTMENTS TO CLOUD WORDING
AND TWEAK SOME WIND WORDING.

QUICK LOOK AT INITIAL 00Z MODEL GUIDANCE INDICATES THAT UNSETTLED
WEATHER IS STILL ANTICIPATED ACROSS THE AREA AS A COLD UPPER LEVEL
LOW IMPACTS THE AREA.

&&

.PREVIOUS DISCUSSION...

SHORT TERM (TODAY-SUN)...A PRETTY QUIET COUPLE OF DAYS TODAY AND
FRIDAY. ONSHORE TRENDS WILL BE ON THE INCREASE TOMORROW AND WE
SHOULD SEE SLIGHTLY BETTER MARINE LYR COVERAGE IN THE MORNING THAN
TODAY, AND EVEN MORE SAT MORNING. DAYTIME HIGHS EXPECTED TO DROP
ABOUT 5 DEGREES ON AVERAGE FRIDAY AND ANOTHER 5 SATURDAY.

ANOTHER INTERESTING LITTLE WEATHER SYSTEM HEADED OUR WAY THIS
WEEKEND. THE UPSHOT IS THAT THE PROBABILITY IS HIGH THAT ALL AREAS
WILL GET AT LEAST SOME PRECIPITATION AT SOME POINT OVER THE WEEKEND.
HOWEVER, TRYING TO NAIL DOWN THE WHEN AND HOW MUCH HAS AND WILL BE A
SIGNIFICANT CHALLENGE. THE SYSTEM WILL BE COMING DOWN FROM THE NORTH
AND AS IS USUAL WITH STORMS FROM THIS DIRECTION WILL BE SOMEWHAT
MOISTURE STARVED. THE OTHER CHALLENGE WITH THIS SYSTEM IS THAT AT
LEAST FOR THE FIRST PART OF THE WEEKEND WE`RE GOING TO BE UNDER THE
INFLUENCE OF A PRETTY STRONG NORTHWEST FLOW PATTERN WHICH CREATES A
DRYING, DOWNSLOPING EFFECT TO AREAS SOUTH OF PT CONCEPTION,
ESPECIALLY VENTURA AND SRN SB COUNTIES. BY SATURDAY NIGHT INTO
SUNDAY THE SYSTEM STARTS TO PICK UP A LITTLE MORE OVER-WATER
TRAJECTORY AND OUR NORTHWEST FLOW DECREASES. SO THAT PERIOD SHOULD
PRESENT THE BEST CHANCE FOR SHOWERS, PLUS THE AIR MASS WILL BE AT
ITS COLDEST AND MOST UNSTABLE BY THAT TIME. STILL THOUGH, THIS WILL
BE A SHOWERY SYSTEM AND WE`LL LIKELY SEE SOME PLACED GETTING
DRENCHED WHILE OTHER AREAS GET VERY LITTLE. CAN`T ARGUE WITH
THUNDERSTORM CHANCES, THOUGH THE MOST UNSTABLE AIR IS ACROSS SBA/SLO
COUNTIES AND ADJACENT WATERS SAT AFTERNOON THROUGH SUNDAY.

SNOW LEVELS WILL BE IN THE 4000-5000` RANGE FOR MOST OF THIS EVENT
SO LOWER ELEVATIONS ROADS WILL LIKELY SEE SOME ACCUMULATING SNOW,
INCLUDING INTERSTATE 5 OVER THE GRAPEVINE. AGAIN, SNOW AMOUNTS WILL
VARY WITH THE RANDOMNESS OF THE HEAVIER SHOWERS, BUT THE 8-16"
MENTIONED IN THE CURRENT WINTER STORM WATCH IS WITHIN THE REALM OF
POSSIBILITY BUT NOT LIKELY THE NORM AS THOSE HIGHER NUMBERS WOULD
LIKELY REQUIRE A FEW GOOD STORMS TO DEVELOP OVER THE SAME AREAS.
3-6" IS A MORE LIKELY AREAL AVERAGE, BUT GIVEN THE IMPACT ON LOWER
ELEVATION DRIVING AND THE OUTSIDE CHANCE OF THOSE HIGHER NUMBERS
HITTING POPULAR SPOTS THE WATCH SEEMS WARRANTED AT THIS TIME.

RAIN AMOUNTS SIMILARLY DIFFICULT BUT A TENTH TO HALF SEEMS LIKE A
GOOD AREAL AVERAGE (LOWEST IN ERN SBA COUNTY AND COASTAL VENTURA
COUNTY). AND CONVECTION COULD LOCALLY BOOST TOTALS WELL OVER AN
INCH. BURN AREA PROBLEMS WOULD LIKELY REQUIRE ONE OF THESE
CONVECTIVE CELLS TO MOVE OVERHEAD AND WHILE THE CHANCES ARE LOW OVER
ANY ONE LOCATION THEY AREN`T ZERO.

LONG TERM (MON-THU)...THE TROF AXIS SHOULD BE JUST EAST OF THE AREA
MONDAY MORNING BUT THERE IS ENOUGH LINGERING MOISTURE AND COLD AIR
ALOFT TO WARRANT AT LEAST SOME PRECIP CHANCES THROUGH THE AFTERNOON,
HIGHEST OVER THE MTNS. A SECOND AND FAST MOVING SYSTEM WILL FOLLOW
QUICKLY ON THE HEELS OF THE WEEKEND STORM MONDAY NIGHT INTO EARLY
TUESDAY BUT MODELS AREN`T SHOWING TOO MUCH MOISTURE WITH THIS ONE AS
IT`S TAKING AN EVEN MORE INSIDE TRACK. THIS COULD CHANGE THOUGH AND
CAN`T ARGUE WITH SMALL RAIN CHANCES THROUGH TUESDAY. WE SHOULD SEE
RAPID CLEARING BY TUESDAY NIGHT AS WE SHIFT TO OFFSHORE FLOW WITH A
SIGNIFICANT WARMING TREND THROUGH THE END OF THE WEEK.

&&

.AVIATION...26/2310Z...

AT 2220Z...THE INVERSION AT KLAX WAS BASED AT 1400 FEET. THE TOP OF
THE INVERSION WAS 4500 FEET WITH A TEMPERATURE OF 14 DEGREES
CELSIUS.

OVERALL...MODERATE CONFIDENCE IN 00Z TAF PACKAGE. STRONG NORTHWEST
FLOW OVER THE COASTAL WATERS IS EXPECTED TO SPIN UP AN EDDY TONIGHT
WHICH WILL BRING STRATUS/FOG INTO KLAX/KLGB/KOXR LATE TONIGHT. ALSO
WILL ANTICIPATE SOME STRATUS/FOG DEVELOPING AT KSMX AND KPRB
OVERNIGHT.

KLAX...MODERATE CONFIDENCE IN 00Z TAF. HIGH CONFIDENCE IN VFR CONDS
THRU THIS EVENING. OVERNIGHT...HIGH CONFIDENCE IN RETURN OF MVFR
CIGS/VSBYS...BUT LOW CONFIDENCE IN TIMING (RETURN COULD BE +/- 2
HOURS OF CURRENT 11Z FORECAST). THERE IS A 30% CHANCE THAT MVFR CIGS
WILL REMAIN THRU FRIDAY AFTERNOON.

KBUR...MODERATE CONFIDENCE IN 00Z TAF. HIGH CONFIDENCE IN VFR CONDS
THRU THIS EVENING. LOW CONFIDENCE IN MVFR VSBYS 11Z-18Z. THERE IS A
20% CHANCE OF IFR CIGS 11Z-18Z.

&&

.MARINE...26/815 PM...

FOR THE OUTER WATERS...HIGH CONFIDENCE IN THE CONTINUATION OF GALE
FORCE NORTHWEST WINDS THROUGH FRIDAY NIGHT. THE NORTHWEST WINDS WILL
DIMINISH ON SATURDAY AND SUNDAY...BUT THERE IS A CHANCE OF WINDS
REMAINING AROUND SMALL CRAFT ADVISORY LEVELS.

FOR THE INNER WATERS...OTHER THAN SOME LOCAL GUSTS TO 25 KNOTS
ACROSS THE WESTERN SANTA BARBARA CHANNEL...WINDS ARE EXPECTED TO
REMAIN BELOW SMALL CRAFT ADVISORY LEVELS TONIGHT. BY FRIDAY
AFTERNOON AND CONTINUING THROUGH SATURDAY...MODERATE CONFIDENCE
IN WEST TO NORTHWEST WINDS INCREASING TO SMALL CRAFT ADVISORY LEVELS
ESPECIALLY ACROSS WESTERN SECTIONS. EXPECT WINDS TO INCREASE FRIDAY
AFTERNOON ACROSS THE SANTA BARBARA CHANNEL...SO WILL ISSUE SMALL
CRAFT ADVISORY FOR THIS EVENING.

SHOWERS ARE EXPECTED TO DEVELOP THIS WEEKEND OVER THE COASTAL WATERS
AS A LOW PRESSURE SYSTEM IMPACTS THE AREA. BY SATURDAY AFTERNOON
AND CONTINUING THROUGH SUNDAY...THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS WHICH COULD PRODUCE GUSTY WINDS...CHOPPY SEAS...AND
POSSIBLY AN ISOLATED WATERSPOUT.

&&

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

&&

$$

PUBLIC...MW
AVIATION...RAT
MARINE...RAT
SYNOPSIS...BARTLING

WWW.WEATHER.GOV/LOSANGELES








000
FXUS66 KLOX 270414
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
815 PM PST THU FEB 26 2015

.SYNOPSIS...

FRIDAY LOOKS TO STAY MOSTLY DRY AND SEVERAL DEGREES COOLER. A COLD
LOW PRESSURE SYSTEM WILL BRING EVEN COOLER TEMPERATURES...RAIN
SHOWERS AND MOUNTAIN SNOW TO OUR REGION OVER THE WEEKEND. A SECOND
WEAKER SYSTEM IS EXPECTED MONDAY THROUGH TUESDAY. THE REST OF NEXT
WEEK WILL BE DRY AND WARMER WITH LIGHT OFFSHORE BREEZES.

&&

.UPDATE...
OVERALL...RATHER QUIET EVENING ACROSS THE DISTRICT. LATEST SATELLITE
INDICATES MOSTLY CLEAR SKIES ACROSS THE AREA AS SOME CIRRUS DRIFTS
OVERHEAD. SURFACE OBS INDICATE SOME GUSTY NORTHERLY WINDS IN THE
MOUNTAINS THIS EVENING...BUT NOTHING STRONG/WIDESPREAD ENOUGH TO
WARRANT ANY ADVISORIES AT THIS TIME. WITH THE GALE FORCE NORTHWEST
WINDS OVER THE OUTER WATERS...A DECENT EDDY SHOULD SPIN UP
OVERNIGHT. THIS SHOULD ALLOW STRATUS TO REFORM OVER THE BIGHT AND
SPREAD INTO THE COASTAL AREAS OF VENTURA/LOS ANGELES COUNTIES AND
EVEN SOME OF THE COASTAL VALLEYS. ADDITIONALLY...EXPECT STRATUS TO
BECOME RATHER WIDESPREAD ACROSS THE CENTRAL COAST OVERNIGHT ALTHOUGH
CONFIDENCE IS ONLY MODERATE AT BEST FOR THIS SCENARIO AS NORTHWEST
FLOW COULD LIMIT STRATUS FORMATION.

OVERALL...CURRENT FORECAST LOOKS TO BE IN DECENT SHAPE. WILL ISSUE
AN EVENING UPDATE TO MAKE SOME SLIGHT ADJUSTMENTS TO CLOUD WORDING
AND TWEAK SOME WIND WORDING.

QUICK LOOK AT INITIAL 00Z MODEL GUIDANCE INDICATES THAT UNSETTLED
WEATHER IS STILL ANTICIPATED ACROSS THE AREA AS A COLD UPPER LEVEL
LOW IMPACTS THE AREA.

&&

.PREVIOUS DISCUSSION...

SHORT TERM (TODAY-SUN)...A PRETTY QUIET COUPLE OF DAYS TODAY AND
FRIDAY. ONSHORE TRENDS WILL BE ON THE INCREASE TOMORROW AND WE
SHOULD SEE SLIGHTLY BETTER MARINE LYR COVERAGE IN THE MORNING THAN
TODAY, AND EVEN MORE SAT MORNING. DAYTIME HIGHS EXPECTED TO DROP
ABOUT 5 DEGREES ON AVERAGE FRIDAY AND ANOTHER 5 SATURDAY.

ANOTHER INTERESTING LITTLE WEATHER SYSTEM HEADED OUR WAY THIS
WEEKEND. THE UPSHOT IS THAT THE PROBABILITY IS HIGH THAT ALL AREAS
WILL GET AT LEAST SOME PRECIPITATION AT SOME POINT OVER THE WEEKEND.
HOWEVER, TRYING TO NAIL DOWN THE WHEN AND HOW MUCH HAS AND WILL BE A
SIGNIFICANT CHALLENGE. THE SYSTEM WILL BE COMING DOWN FROM THE NORTH
AND AS IS USUAL WITH STORMS FROM THIS DIRECTION WILL BE SOMEWHAT
MOISTURE STARVED. THE OTHER CHALLENGE WITH THIS SYSTEM IS THAT AT
LEAST FOR THE FIRST PART OF THE WEEKEND WE`RE GOING TO BE UNDER THE
INFLUENCE OF A PRETTY STRONG NORTHWEST FLOW PATTERN WHICH CREATES A
DRYING, DOWNSLOPING EFFECT TO AREAS SOUTH OF PT CONCEPTION,
ESPECIALLY VENTURA AND SRN SB COUNTIES. BY SATURDAY NIGHT INTO
SUNDAY THE SYSTEM STARTS TO PICK UP A LITTLE MORE OVER-WATER
TRAJECTORY AND OUR NORTHWEST FLOW DECREASES. SO THAT PERIOD SHOULD
PRESENT THE BEST CHANCE FOR SHOWERS, PLUS THE AIR MASS WILL BE AT
ITS COLDEST AND MOST UNSTABLE BY THAT TIME. STILL THOUGH, THIS WILL
BE A SHOWERY SYSTEM AND WE`LL LIKELY SEE SOME PLACED GETTING
DRENCHED WHILE OTHER AREAS GET VERY LITTLE. CAN`T ARGUE WITH
THUNDERSTORM CHANCES, THOUGH THE MOST UNSTABLE AIR IS ACROSS SBA/SLO
COUNTIES AND ADJACENT WATERS SAT AFTERNOON THROUGH SUNDAY.

SNOW LEVELS WILL BE IN THE 4000-5000` RANGE FOR MOST OF THIS EVENT
SO LOWER ELEVATIONS ROADS WILL LIKELY SEE SOME ACCUMULATING SNOW,
INCLUDING INTERSTATE 5 OVER THE GRAPEVINE. AGAIN, SNOW AMOUNTS WILL
VARY WITH THE RANDOMNESS OF THE HEAVIER SHOWERS, BUT THE 8-16"
MENTIONED IN THE CURRENT WINTER STORM WATCH IS WITHIN THE REALM OF
POSSIBILITY BUT NOT LIKELY THE NORM AS THOSE HIGHER NUMBERS WOULD
LIKELY REQUIRE A FEW GOOD STORMS TO DEVELOP OVER THE SAME AREAS.
3-6" IS A MORE LIKELY AREAL AVERAGE, BUT GIVEN THE IMPACT ON LOWER
ELEVATION DRIVING AND THE OUTSIDE CHANCE OF THOSE HIGHER NUMBERS
HITTING POPULAR SPOTS THE WATCH SEEMS WARRANTED AT THIS TIME.

RAIN AMOUNTS SIMILARLY DIFFICULT BUT A TENTH TO HALF SEEMS LIKE A
GOOD AREAL AVERAGE (LOWEST IN ERN SBA COUNTY AND COASTAL VENTURA
COUNTY). AND CONVECTION COULD LOCALLY BOOST TOTALS WELL OVER AN
INCH. BURN AREA PROBLEMS WOULD LIKELY REQUIRE ONE OF THESE
CONVECTIVE CELLS TO MOVE OVERHEAD AND WHILE THE CHANCES ARE LOW OVER
ANY ONE LOCATION THEY AREN`T ZERO.

LONG TERM (MON-THU)...THE TROF AXIS SHOULD BE JUST EAST OF THE AREA
MONDAY MORNING BUT THERE IS ENOUGH LINGERING MOISTURE AND COLD AIR
ALOFT TO WARRANT AT LEAST SOME PRECIP CHANCES THROUGH THE AFTERNOON,
HIGHEST OVER THE MTNS. A SECOND AND FAST MOVING SYSTEM WILL FOLLOW
QUICKLY ON THE HEELS OF THE WEEKEND STORM MONDAY NIGHT INTO EARLY
TUESDAY BUT MODELS AREN`T SHOWING TOO MUCH MOISTURE WITH THIS ONE AS
IT`S TAKING AN EVEN MORE INSIDE TRACK. THIS COULD CHANGE THOUGH AND
CAN`T ARGUE WITH SMALL RAIN CHANCES THROUGH TUESDAY. WE SHOULD SEE
RAPID CLEARING BY TUESDAY NIGHT AS WE SHIFT TO OFFSHORE FLOW WITH A
SIGNIFICANT WARMING TREND THROUGH THE END OF THE WEEK.

&&

.AVIATION...26/2310Z...

AT 2220Z...THE INVERSION AT KLAX WAS BASED AT 1400 FEET. THE TOP OF
THE INVERSION WAS 4500 FEET WITH A TEMPERATURE OF 14 DEGREES
CELSIUS.

OVERALL...MODERATE CONFIDENCE IN 00Z TAF PACKAGE. STRONG NORTHWEST
FLOW OVER THE COASTAL WATERS IS EXPECTED TO SPIN UP AN EDDY TONIGHT
WHICH WILL BRING STRATUS/FOG INTO KLAX/KLGB/KOXR LATE TONIGHT. ALSO
WILL ANTICIPATE SOME STRATUS/FOG DEVELOPING AT KSMX AND KPRB
OVERNIGHT.

KLAX...MODERATE CONFIDENCE IN 00Z TAF. HIGH CONFIDENCE IN VFR CONDS
THRU THIS EVENING. OVERNIGHT...HIGH CONFIDENCE IN RETURN OF MVFR
CIGS/VSBYS...BUT LOW CONFIDENCE IN TIMING (RETURN COULD BE +/- 2
HOURS OF CURRENT 11Z FORECAST). THERE IS A 30% CHANCE THAT MVFR CIGS
WILL REMAIN THRU FRIDAY AFTERNOON.

KBUR...MODERATE CONFIDENCE IN 00Z TAF. HIGH CONFIDENCE IN VFR CONDS
THRU THIS EVENING. LOW CONFIDENCE IN MVFR VSBYS 11Z-18Z. THERE IS A
20% CHANCE OF IFR CIGS 11Z-18Z.

&&

.MARINE...26/815 PM...

FOR THE OUTER WATERS...HIGH CONFIDENCE IN THE CONTINUATION OF GALE
FORCE NORTHWEST WINDS THROUGH FRIDAY NIGHT. THE NORTHWEST WINDS WILL
DIMINISH ON SATURDAY AND SUNDAY...BUT THERE IS A CHANCE OF WINDS
REMAINING AROUND SMALL CRAFT ADVISORY LEVELS.

FOR THE INNER WATERS...OTHER THAN SOME LOCAL GUSTS TO 25 KNOTS
ACROSS THE WESTERN SANTA BARBARA CHANNEL...WINDS ARE EXPECTED TO
REMAIN BELOW SMALL CRAFT ADVISORY LEVELS TONIGHT. BY FRIDAY
AFTERNOON AND CONTINUING THROUGH SATURDAY...MODERATE CONFIDENCE
IN WEST TO NORTHWEST WINDS INCREASING TO SMALL CRAFT ADVISORY LEVELS
ESPECIALLY ACROSS WESTERN SECTIONS. EXPECT WINDS TO INCREASE FRIDAY
AFTERNOON ACROSS THE SANTA BARBARA CHANNEL...SO WILL ISSUE SMALL
CRAFT ADVISORY FOR THIS EVENING.

SHOWERS ARE EXPECTED TO DEVELOP THIS WEEKEND OVER THE COASTAL WATERS
AS A LOW PRESSURE SYSTEM IMPACTS THE AREA. BY SATURDAY AFTERNOON
AND CONTINUING THROUGH SUNDAY...THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS WHICH COULD PRODUCE GUSTY WINDS...CHOPPY SEAS...AND
POSSIBLY AN ISOLATED WATERSPOUT.

&&

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

&&

$$

PUBLIC...MW
AVIATION...RAT
MARINE...RAT
SYNOPSIS...BARTLING

WWW.WEATHER.GOV/LOSANGELES







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