High Wind in California, May 14, 2009

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
846 PM PDT WED MAY 13 2009

.UPDATE...WINDS ARE STARTING TO INCREASE OVER THE WARNING AREA
TONIGHT...AND WINDS WILL HAVE TO BE MONITORED FOR FURTHER
DEVELOPMENT THIS EVENING. KSBA-KSMX GRADIENTS ARE NEAR 4 MB OUT
OF THE NORTH WITH KSBA-KBFL SURFACE GRADIENTS INDICATING SOME
TIGHTENING TO NEAR 3.5 MB OUT OF THE NORTHEAST. WINDS THROUGH THE
I-5 CORRIDOR ARE ALREADY DEVELOPING ACROSS THE LOS ANGELES AND
VENTURA COUNTY MOUNTAINS...HIGH WIND WARNINGS WILL REMAIN IN
PLACE. THE MOUNTAINS OF SANTA BARBARA COUNTY WILL CONTINUE TO
INCREASE AND WILL LIKELY HIT WARNING CRITERIA BETWEEN 03Z AND 08Z
TONIGHT. LATEST PILOTS REPORTS INDICATE A STRONGER WIND PRESENCE
TONIGHT OFF THE SURFACE NEAR KSBA. WHILE NAM BUFR DATA INDICATES
38 KNOT WIND MAXIMUMS ABOUT 2000 FEET OFF THE SURFACE AROUND 06Z
AND 950 MB AND 850 MB THERMAL GRADIENTS INCREASING BETWEEN 09Z
AND 12Z TIME PERIOD OUT OF THE NORTHEAST...THE WIND EVENT WILL
LIKELY PEAK IN THE HILLS ABOVE MONTECITO. MAIN FORECAST CONCERN
IS THE SANTA MONICA RANGE...AND THE SAN FERNANDO AND VENTURA
COUNTY VALLEYS TONIGHT. NAM-WRF GIVES SOME HINTS THAT SOME WINDS
MAY PUSH INTO THESE AREAS TONIGHT AT THE BOUNDARY LAYER AND 950
MB LEVELS...BUT LATEST 13-KM RUC IS IN DISAGREEMENT. WITH LITTLE
PRESENCE OF STRONG SURFACE PRESSURE GRADIENTS AND 850 MB THERMAL
GRADIENTS CONDUCIVE FOR STRONG WINDS...THE CURRENT HEADLINES WILL
REMAIN UNTOUCHED. NEXT SHIFT SHIFT WILL BE BRIEFED ON WIND
CONCERNS AND POSSIBILITIES...AND CONDITIONS WILL HAVE TO BE
MONITORED CLOSELY.

WINDS SHOULD START TO WEAKEN OVER THE NEXT SEVERAL DAYS. THIS
SHOULD ALLOW WINDS TO WEAKEN ENOUGH TO ERASE THE DAMAGING WIND
THREAT DESPITE DECENT SURFACE PRESSURE AND 850 MB THERMAL
GRADIENTS REMAINING TIGHT. OTHERWISE...A GENERAL WARMING TREND
SHOULD START TO OCCUR OVER THE AREA THROUGH THE WEEKEND AS A
RIDGE OF HIGH PRESSURE BUILDS ALONG THE WEST COAST THROUGH
SATURDAY.

&&

.PREV DISCUSSION... /ISSUED 300 PM PDT WED MAY 13 2009/

SHORT TERM...GENERAL UPPER LEVEL RIDGE BUILDS OVER THE EASTERN
PACIFIC BEGINNING FRIDAY AND CONTINUES AND SPREADS OVER THE WEST
COAST THROUGH SUNDAY. CONSIDERABLE WARMING THROUGH THE PERIOD WITH
90S LIKELY IN THE VALLEYS BY SATURDAY AND EVEN A FEW TRIPLE
DIGITS. LIGHTER NORTHERLY OR NE WINDS...ESPECIALLY NIGHTS AND
EARLY MORNINGS...WILL ALLOW FOR WARMER TEMPS EVEN REACHING SOME
COASTAL LOCATIONS BEFORE THE SEA BREEZE INITIATES.

LONG TERM...
MODELS IN AGREEMENT UNTIL MONDAY WHEN CONSIDERABLE DIFFERENCES BEGIN
TO APPEAR. GFS ACTUALLY BRINGS PRECIPITATION TO SOUTHERN CA AROUND A
CUTOFF UPPER LOW MEANDERING OFF THE SOUTHERN CA COAST FOR MON AND
TUE. ENSEMBLES ARE NOT IN AGREEMENT ON THIS SCENARIO THUS HAVE NOT
REFLECTED THIS IN FORECAST. AT A MINIMUM COASTAL COOLING WILL BE IN
ORDER WITH ONSHORE FLOW AND LOWER TEMPS ARE REFLECTED AS WELL AS
SOME RETURN OF THE MARINE LAYER. GENERAL COOLING IS FORECAST FOR THE
MIDDLE OF NEXT WEEK AS A BROADER UPPER LEVEL TROUGH MOVES INTO THE
PACIFIC NORTHWEST AND HEIGHTS LOWER BUT REMAIN ABOVE NORMAL.

&&

.AVIATION...14/0000Z.
VFR CONDITIONS ARE EXPECTED THROUGHOUT THE PERIOD...EXCEPT FOR LOS
ANGELES COUNTY COASTAL TERMINALS. PERIODS OF MODERATE TO STRONG LOW
LEVEL WIND SHEAR AND TURBULENCE WILL DEVELOP BETWEEN 01Z TONIGHT AND
17Z WEDNESDAY. IFR TO MVFR CONDITIONS WILL DEVELOP AFTER 06Z TONIGHT
AS THE MARINE LAYER RETURNS AT LOS ANGELES COUNTY COASTAL TERMINALS.
VFR CONDITIONS WILL REDEVELOP AROUND 16Z.

KLAX...VFR CONDITIONS ARE EXPECTED THROUGH 10Z TONIGHT...THEN IFR TO
MVFR CONDITIONS WILL SPREAD INTO KLAX. VFR CONDITIONS SHOULD
REDEVELOP AFTER 17Z WEDNESDAY.

KBUR...VFR CONDITIONS ARE EXPECTED THROUGHOUT THE PERIOD WITH
PERIODS OF MODERATE TO STRONG LOW LEVEL WIND SHEAR AND TURBULENCE
BETWEEN 03Z TONIGHT AND 16Z WEDNESDAY. THE PERIOD FOR THE STRONGEST
LOW LEVEL WIND SHEAR AND TURBULENCE WILL LIKELY OCCUR BETWEEN 03Z
AND 07Z TONIGHT.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...

HIGH WIND WARNING (SEE LAXNPWLOX).
RED FLAG WARNING (SEE LAXRFWLOX).
GALE WARNING (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
WIND ADVISORY (SEE LAXNPWLOX).

&&

HALL/TRM

WWW.WEATHER.GOV/LOSANGELES

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
606 PM PDT WED MAY 13 2009

CAZ034>041-044>046-051>054-059-087-088-547-548-141300-
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-
606 PM PDT WED MAY 13 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHWESTERN CALIFORNIA.

.DAY ONE... TONIGHT

STRONG TO DAMAGING WINDS WILL AFFECT THE MOUNTAINS OF SANTA
BARBARA...VENTURA...AND LOS ANGELES COUNTY TONIGHT. THE STRONGEST
WINDS WILL OCCUR NEAR THE INTERSTATE 5 CORRIDOR. GUSTY WINDS WILL
AFFECT THE ANTELOPE VALLEY...THE SANTA CLARITA VALLEY AND THE
MOUNTAINS AND ADJACENT SOUTH COAST OF SANTA BARBARA COUNTY TONIGHT.
IN THE ANTELOPE VALLEY...STRONG WINDS WILL CREATE AREAS OF BLOWING
DUST AND SAND WITH VISIBILITIES LOCALLY ONE QUARTER MILE OR LESS.
DANGEROUS FIRE WEATHER CONDITIONS WILL AFFECT THE SANTA YNEZ RANGE
AND THE SOUTH COAST OF SANTA BARBARA COUNTY TONIGHT DUE TO GUSTY
WINDS AND LOW RELATIVE HUMIDITY. MARINERS WILL FACE A GALE FORCE
WINDS ACROSS ALL OF THE OUTER WATERS TONIGHT.

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

* RED FLAG WARNING...........SEE WWUS86 KLOX - RFWLOX FOR DETAILS *

* WIND ADVISORY..............SEE WWUS76 KLOX - NPWLOX FOR DETAILS *

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

.DAYS TWO THROUGH SEVEN... THURSDAY THROUGH TUESDAY

STRONG TO DAMAGING WINDS WILL AFFECT THE MOUNTAINS OF SANTA
BARBARA...VENTURA...AND LOS ANGELES COUNTY THURSDAY MORNING.
THE STRONGEST WINDS WILL OCCUR NEAR THE INTERSTATE 5 CORRIDOR. WHILE
WINDS SHOULD DIMINISH SOME LATE THURSDAY MORNING...THEY WILL LIKELY
INCREASE AGAIN LATE THURSDAY AND THURSDAY NIGHT. GUSTY WINDS WILL
AFFECT THE SANTA CLARITA VALLEY AND THE MOUNTAINS AND ADJACENT SOUTH
COAST OF SANTA BARBARA COUNTY THURSDAY MORNING. WHILE WINDS SHOULD
DIMINISH SOME LATE THURSDAY MORNING...THEY WILL LIKELY INCREASE
AGAIN LATE THURSDAY AND THURSDAY NIGHT. DANGEROUS FIRE WEATHER
CONDITIONS WILL AFFECT THE SANTA YNEZ RANGE AND THE SOUTH COAST OF
SANTA BARBARA COUNTY THROUGH AT LEAST LATE THURSDAY MORNING DUE TO
GUSTY WINDS AND LOW RELATIVE MARINERS WILL FACE A GALE FORCE WINDS
ACROSS ALL OF THE OUTER WATERS THURSDAY AND THURSDAY NIGHT...AND
POSSIBLY INTO FRIDAY.

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

* RED FLAG WARNING...........SEE WWUS86 KLOX - RFWLOX FOR DETAILS *

* WIND ADVISORY..............SEE WWUS76 KLOX - NPWLOX FOR DETAILS *

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

.SPOTTER INFORMATION STATEMENT...

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

HALL