Gale Warning 30, NWS Los Angeles, CA

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
200 PM PDT MON OCT 12 2009

.SYNOPSIS...THERE IS A SLIGHT CHANCE OF SHOWERS ACROSS THE AREA
TODAY. BY TUESDAY...A STRONG PACIFIC STORM MOVING INTO THE WEST COAST WILL
BRING GUSTY WINDS AND THE FIRST WIDESPREAD RAIN OF THE SEASON.
SIGNIFICANT RAINFALL IS LIKELY OVER THE AREA THROUGH WEDNESDAY. DRY
AND WARMER WEATHER WILL RETURN THURSDAY AND PERSIST INTO THE WEEKEND.

&&

.SHORT TERM (TODAY-THU)...IN THE SHORT TERM...THE MAIN FOCUS CONTINUES
TO CENTER ON UPCOMING EARLY SEASON STORM. 12Z MODELS ARE ACTUALLY IN
PRETTY GOOD AGREEMENT WITH THE DETAILS...AND ALL SIGNS POINT TO A
SIGNIFICANT OCTOBER RAIN FOR THE AREA.

IN THE NEAR TERM...SHORTWAVE TROUGH WILL SWING THROUGH THE AREA THIS
AFTERNOON AND EVENING...LIKELY BRINGING SOME SCATTERED LIGHT SHOWERS
TO THE AREA. RAINFALL AMOUNTS WITH THIS ACTIVITY WILL BE LIGHT...
LESS THAN ONE QUARTER INCH.

ON TUESDAY AND WEDNESDAY...VERY POTENT STORM WILL TAKE AIM ON THE
DISTRICT. AT THIS TIME...ALL THE INGREDIENTS NECESSARY FOR A BIG
RAIN EVENT ARE IN PLACE. PRECIPITABLE WATER VALUES BETWEEN 1.5" AND
1.8" ARE FORECAST BY ALL MODELS. A 140 KT JET WILL BE INTERACTING
WITH THIS MOISTURE PLUME. CLOSER TO THE SURFACE...STRONG SOUTH TO
SOUTHWEST FLOW (30-50KT AT 850 MB) WILL DEVELOP AHEAD OF THE STORM.
WITH ALL OF THESE VARIABLES...CONFIDENCE IS HIGH IN SIGNIFICANT
RAINFALL FOR THE AREA. AT THIS TIME...SLO/SBA COUNTIES SHOULD
RECEIVE THEIR HEAVIEST RAINFALL FROM TUESDAY MORNING THROUGH
WEDNESDAY MORNING...WITH INITIAL RAINFALL TOTALS 1-3" FOR COASTAL
AREAS AND 3-6" FOR MOUNTAINS/FOOTHILLS. FOR VENTURA COUNTY...THE
HEAVIEST RAINFALL IS EXPECTED FROM TUESDAY AFTERNOON THROUGH
WEDNESDAY AFTERNOON...WITH 1-3" FOR COASTAL AREAS AND 3-5" FOR
MOUNTAINS/FOOTHILLS. ACROSS LOS ANGELES COUNTY...THE HEAVIEST RAIN
WILL BE FROM LATE TUESDAY AFTERNOON THROUGH WEDNESDAY AFTERNOON...
WITH 1-2" FOR COASTAL AREAS AND 2-4" FOR MOUNTAINS/FOOTHILLS. GIVEN
THE WARMTH OF THIS SYSTEM...SNOW LEVELS WILL REMAIN VERY HIGH...SO
NO SNOW ISSUES ARE EXPECTED.

ALONG WITH THE RAIN...STRONG AND GUSTY SOUTHERLY WINDS ARE EXPECTED
TUESDAY AND WEDNESDAY. AT THIS POINT GIVEN THE LOW LEVEL WINDS...
HIGH WIND WARNING LEVEL GUSTS ARE NOT OUT OF THE QUESTION ACROSS
ALL OF SLO/SBA COUNTIES AND THE MOUNTAINS OF VTU/LAX COUNTIES.

WITH THE AFTERNOON PACKAGE...WILL GO WITH A FLASH FLOOD WATCH FOR
THE BURN AREAS OF SBA COUNTY (LA BREA/JESUSITA/GAP/TEA) FROM TUESDAY
MORNING THRU WEDNESDAY MORNING GIVEN THE EXPECTED TIMING OF HEAVY
RAINFALL. WILL NOT ISSUE ANY FLASH FLOOD WATCHES FOR VTU/LAX COUNTIES
AT THIS TIME AS PERIOD OF HEAVY RAIN IS FURTHER OUT. ALSO...THIS WILL
GIVE THE NEXT COUPLE OF SHIFTS TO FURTHER ANALYZE THE BURN AREAS OF
VTU/LAX COUNTIES. AS FOR THE WINDS...WILL KEEP HIGH WIND WATCH IN
EFFECT AS THE TIME PERIOD OF STRONG WINDS IS BEYOND FIRST PERIOD.
HOWEVER...WOULD NOT BE SURPRISED TO SEE THE WATCHES UPGRADED TO
WARNINGS FOR SOME AREAS.

TEMP WISE...THE CLOUDS AND RAIN WILL KEEP ALL AREAS WELL BELOW
SEASONAL NORMS ON TUESDAY/WEDNESDAY. ON THURSDAY...THE STORM IS
EAST OF THE AREA AND UPPER RIDGE BUILDS OVERHEAD. NEAR THE SURFACE
SOME WEAK OFFSHORE GRADIENTS ARE FORECAST THURSDAY MORNING. SO...
WILL EXPECT NOTICEABLY WARMING TEMPS FOR THE AREA.

.LONG TERM (FRI-MON)...UPPER RIDGE PEAKS IN STRENGTH ON FRIDAY...
SO IT SHOULD BE THE WARMEST DAY. FOR SATURDAY THROUGH MONDAY...THE
RIDGE IS PUSHED EASTWARD AS A TROUGH DEVELOPS OVER THE WEST COAST.
THIS WILL RESULT IN A COOLING TREND FOR ALL AREAS...WITH THE MARINE
LAYER POSSIBLY BECOMING REESTABLISHED WEST OF THE MOUNTAINS.

&&

.AVIATION...12/1910Z.
VFR CEILINGS CONTINUE ACROSS THE ENTIRE FORECAST AREA. EXPECTATIONS
ARE THAT THE CEILINGS WILL GRADUALLY LOWER THROUGH THE NIGHT AND
INTO TUESDAY AS THE ATMOSPHERE CONTINUES TO MOISTEN AHEAD OF THE
UPCOMING STORM. CONDITIONS WILL LIKELY DETERIORATE TO MVFR TONIGHT
DUE TO LOWERING CEILINGS AND SCATTERED LIGHT SHOWERS...AND MVFR TO
IFR ON TUESDAY DUE TO LOWER CEILINGS AND INCREASING RAIN.

KLAX AND KBUR...GOOD CONFIDENCE IN STEADY DETERIORATION OF
CONDITIONS OVER THE NEXT 24 HOURS. DUE TO LOWERING CEILINGS AND
INCREASING THREAT OF RAIN...THE CONDITIONS WILL TRANSITION FROM VFR
TO MVFR TONIGHT AND MVFR TO IFR TUESDAY.CA36

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WATCH (SEE LAXNPWLOX).
FLASH FLOOD WATCH (SEE LAXFFALOX).
GALE WARNING (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
SPECIAL WEATHER STATEMENT (SEE LAXSPSLOX).

&&

PUBLIC...THOMPSON
AVIATION...SWEET
SYNOPSIS...MEIER

WWW.WEATHER.GOV/LOSANGELES

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
205 PM PDT MON OCT 12 2009

CAZ034>041-044>046-051>054-059-087-088-547-548-131300-
SAN LUIS OBISPO COUNTY CENTRAL COAST-
SANTA BARBARA COUNTY CENTRAL COAST-SANTA YNEZ VALLEY-
SAN LUIS OBISPO COUNTY INTERIOR VALLEYS-CUYAMA VALLEY-
SANTA BARBARA COUNTY SOUTH COAST-VENTURA COUNTY COAST-
LOS ANGELES COUNTY COAST INCLUDING DOWNTOWN LOS ANGELES-
VENTURA COUNTY INTERIOR VALLEYS-VENTURA COUNTY COASTAL VALLEYS-
SANTA MONICA MOUNTAINS RECREATIONAL AREA-
SAN LUIS OBISPO COUNTY MOUNTAINS-
SANTA BARBARA COUNTY MOUNTAINS-VENTURA COUNTY MOUNTAINS-
LOS ANGELES COUNTY MOUNTAINS EXCLUDING THE SANTA MONICA RANGE-
ANTELOPE VALLEY-CATALINA ISLAND-SANTA CLARITA VALLEY-
LOS ANGELES COUNTY SAN FERNANDO VALLEY-
LOS ANGELES COUNTY SAN GABRIEL VALLEY-
205 PM PDT MON OCT 12 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHWESTERN CALIFORNIA.

.DAY ONE... TODAY

GUSTY SOUTHEAST WINDS ARE EXPECTED TO DEVELOP OVERNIGHT AS A
STRONG STORM SYSTEM APPROACHES THE WEST COAST. SUSTAINED WINDS
OF 25 TO 35 KNOTS WITH GUSTS TO 45 KNOTS ARE EXPECTED THROUGH
EARLY TUESDAY MORNING.

* GALE WARNING...............SEE WHUS76 KLOX - MWWLOX FOR DETAILS *

* SPECIAL WEATHER STATEMENT..SEE WWUS86 KLOX - SPSLOX FOR DETAILS *

.DAYS TWO THROUGH SEVEN... TUESDAY THROUGH SUNDAY

A LARGE STORM SYSTEM IS FORECAST TO IMPACT MUCH OF THE WEST COAST
TUESDAY INTO WEDNESDAY...BRINGING SIGNIFICANT RAINFALL AND GUSTY
WINDS TO ALL OF SOUTHWESTERN CALIFORNIA. THIS STORM IS EXPECTED TO
TAP INTO SUBTROPICAL MOISTURE...GIVING IT THE POTENTIAL TO BRING
MODERATE TO HEAVY RAIN. THE BEST CHANCE FOR HEAVY RAIN WILL BE
ACROSS SANTA BARBARA AND SAN LUIS OBISPO COUNTIES...BUT MODERATE TO
HEAVY RAIN IS LIKELY ACROSS VENTURA AND LOS ANGELES COUNTIES AS
WELL. THIS HEAVY RAINFALL MAY CREATE SIGNIFICANT HAZARDS IN AND
AROUND RECENT BURN AREAS...WITH A THREAT OF FLASH FLOODING AND
DEBRIS FLOWS OVER THE BURN AREAS OF SANTA BARBARA COUNTY. THE
THREAT OF FLASH FLOODING MAY SPREAD INTO THE BURN AREAS OF VENTURA
AND LOS ANGELES COUNTIES ON TUESDAY AND WEDNESDAY. RESIDENTS OF
SOUTHWESTERN CALIFORNIA...ESPECIALLY THOSE WITH PROPERTY OR
INTERESTS IN AND AROUND THE RECENT BURN AREAS SHOULD STAY TUNED TO
LATER FORECASTS AND EXPECTED IMPACTS FROM THIS STORM SYSTEM. STRONG
SOUTHEAST TO SOUTH WINDS ARE EXPECTED TO DEVELOP ACROSS SAN LUIS
OBISPO COUNTY AND MUCH OF SANTA BARBARA COUNTY TUESDAY MORNING...AND
CONTINUE INTO TUESDAY NIGHT. DAMAGING WINDS GUSTS TO 60 MPH ARE
POSSIBLE. IN THE MOUNTAINS OF VENTURA AND LOS ANGELES
COUNTIES...STRONG SOUTH WINDS ARE EXPECTED TO DEVELOP TUESDAY
AFTERNOON AND CONTINUE THROUGH NOON WEDNESDAY...WITH DAMAGING WIND
GUSTS TO 60 MPH POSSIBLE. ACROSS THE COASTAL WATERS NORTHWEST AND
WEST OF SANTA CRUZ ISLAND...SOUTHEAST TO SOUTH WINDS OF 25 TO
35 KNOTS WITH GUSTS TO 45 KNOTS ARE EXPECTED TUESDAY.

* HIGH WIND WATCH............SEE WWUS76 KLOX - NPWLOX FOR DETAILS *

* FLOOD WATCH................SEE WGUS66 KLOX - FFALOX FOR DETAILS *

* GALE WARNING...............SEE WHUS76 KLOX - MWWLOX FOR DETAILS *

* SPECIAL WEATHER STATEMENT..SEE WWUS86 KLOX - SPSLOX FOR DETAILS *

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

THOMPSON