Flash Flood Warning 19, NWS Los Angeles, CA

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
330 AM PST TUE DEC 28 2004

.SHORT TERM...
PERFECT CONVERGANCE OVER SOUTHERN SBA COUNTY AND THE SBA CHANNEL WITH
GREAT PVA AND UPPER LEVEL DIVERGANCE CAME TOGETHER TO PRODUCE A LINE
OF THUNDERSTORMS AND WAVES OF HEAVY SHOWER ACTIVITY. CURRENTLY A LARGE
DIFLUENT PATTERN HAS SPREAD RAIN FROM SBA TO LGB THE RAIN HAS LET UP
WEST OF SBA AS A LARGE SWATH OF NVA IS MOVING INTO THE AREA.

BIG WORRY TODAY STILL REMAINS THUNDER AT OR AROUND 18Z WHEN JET
DYNAMICS INTERSEC AN AREA OF PVA 1100 CAPE AND NEGITIVE LIS. GIVEN
THE ACTIVITY TONIGHT SEE NO REASON WHY IT WILL NOT BE A VERY ACTIVE
LATE MORNING TO EARLY AFTERNOON. SEVERE WEATHER CANNOT BE RULED OUT.

DUE TO IMPRESIVE DYNAMICS AND UPWARD LIFTING THE STRONG WINDS ARE NOT
REALLY SURFACING. WILL HAVE TO REEVALUATE COASTAL WIND ADVISORIES AT
600 PM. WINDS IN THE MOUNTAINS ARE DOING VERY WELL 2000 FOOT ACARS
WINDS SHOWS 40 KT AND THIS IS HITTING THE MTNS.

WINTER STORM WARNING IS DOING WELL ACARS SHOWS Z LVL AT 7500 FEET BUT
ON THE INTERIOR SLOPES SNOW IS FALLING TO ABOUT 6500 FEET. WINDS IN
THE MTNS ARE QUITE STRONG WITH FREQUENT GUSTS TO 60 MPH OR HIGHER.

THIS AFTERNOON MIGHT HAVE A LULL IN IT AS THE MAIN FRONTAL BAND MOVES
OUT OF THE AREA BUT THEN OVER NIGHT THINGS GET INTERESTING AGAIN AS
THE MAIN SURFACE LOW TRANSLATES OVER THE AREA. IN MANY WAYS THIS
CREATES A SET OF CONDITIONS SIMILAR TO TONIGHT WITH VIGOUS MOIST SOUTH
FLOW...PVA...CAPE...AND JET DYNAMICS.

WEDNESDAY WILL SEE A DEINTENSIFYING OF THE RAIN BUT PROBABLY NOT A
TOTAL CESSATION OF THE RAIN AS MOIST UNSTABLE CYCLONIC FLOW CONTINUES
OVER THE AREA.

A NEW SYSTEM MOVES IN THURSDAY GFS IS ABOUT 12 HOURS FASTER THAN THE
ETA WHICH IS ABOUT PAR FOR THE COURSE.

.LONG TERM...
EXTENDED LOOKS QUITE WET ALTHO SATURDAY LOOKS LIKE IT MIGHT TURN OUT
DRY. A THIRD SYSTEM IS PROGGED TO ARRIVE SUNDAY AND MAY LAST INTO
TUESDAY. STILL WITH THIS SORT OF FLOW PATTERN IMPULSES CAN SHIFT
TIMING AROUND. WILL KEEP THE BROAD BRUSH IN FOR NOW.

.AVIATION...
LAX STILL STILL FACING A LONG DURATION STRONG EAST WIND EVENT. ETA
SUGGESTS WINDS 09020KT FROM 12Z TO 20Z...THIS ALONG WITH MODERATE RAIN
AND TSRA. WINDS SHIFT WESTWARD DURING THE AFTERNOON...BUT ARE FOERCAST
EAST AGAIN 09Z-15Z WEDNESDAY.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING/WIND ADVISORY (SEE LAXNPWLOX)
WINTER STORM WARNING (SEE LAXWSWLOX)
FLASH FLOOD WATCH (SEE LAXFFALOX)
FLOOD ADVISORY (SEE LAXFLSLOX)
GALE WARNING (SEE LAXCWFLOX)
MARINE WEATHER STATEMENT (LAXMWSLOX)

&&

RORKE

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
600 AM PST TUE DEC 28 2004

CAZ034>041-044>047-051>054-059-087-088-291400-
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-
LOS ANGELES COUNTY VALLEYS-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-
600 AM PST TUE DEC 28 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHWESTERN CALIFORNIA.

.DAY ONE... TODAY

A POWERFUL PACIFIC STORM WILL SLOWLY MOVE EASTWARD TODAY. THIS STORM
WILL PROUDCE AN ABUNDANCE OF HAZARDOUS WEATHER.

THERE WILL BE PERIODS OF RAIN...HEAVY AT TIMES...THIS MORNING. THESE
RAINS WILL CAUSE STREET FLOODING OVER THE URBAN AREAS AND FLASH
FLOODING COULD BECOME POSSIBLE IN THE MOUNTAINS AND VALLEYS BELOW
THE MOUNTAINS.

UP TO 5 INCHES OF RAIN WILL FALL OVER THE FLAT TERRAIN WHILE UP TO
12 INCHES OF RAIN IS POSSIBLE OVER THE HIGHER TERRAIN.

A STRONG JET STREAM WILL PRODUCE A CHANCE OF THUNDERSTORMS THIS
MORNING OVER LOS ANGELES AND VENTURA COUNTIES SOME OF THESE
THUNDERSTORMS MAY BRING SEVERE WEATHER TO THE AREAS.

THE DEEP SURFACE LOW ASSOCIATED WITH THIS STORM WILL PRODUCE VERY
STRONG WINDS THROUGHOUT THE AREA. WIND WARNINGS ARE POSTED FOR THE
SANTA BARBARA MOUNTAINS...WIND ADVISORIES ARE POSTED FOR THE
REMAINDER OF SANTA BARBARA COUNTY...ALL OF SAN LUIS OBISPO COUNTY...
AND THE MOUNTAINS OF VENTURA AND LOS ANGELES COUNTY INCLUDING THE
SANTA MONICA MOUNTAINS.

THIS SYSTEM WILL CAUSE ALL MANOR OF HAZARDS FOR THE MARINE INTERESTS
GALE FORCE WINDS WILL DEVELOP ACROSS THE WATERS TODAY...THESE WINDS
WILL PRODUCE A LARGE SHORT PERIOD SWELL WHICH COULD CAUSE LOCAL
COASTAL FLOODING AS WELL AS AN HIGH RISK OF RIP CURRENTS.

ANOTHER IMPULSE IS SLATED TO ARRIVE OVERNIGHT AND WILL REINTENSIFY
THE RAIN AND THUNDER THREAT.

* WINTER STORM WARNING.......SEE WWUS46 KLOX - WSWLOX FOR DETAILS *

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

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

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

* GALE WARNING...............SEE FZUS56 KLOX - CWFLOX FOR DETAILS *

* HIGH RIP CURRENT RISK......SEE FZUS56 KLOX - SRFLOX FOR DETAILS *

* MARINE WEATHER STATEMENT...SEE FZUS76 KLOX - MWSLOX FOR DETAILS *

.DAYS TWO THROUGH SEVEN... WEDNESDAY THROUGH MONDAY

THE STORM WILL WIND DOWN WEDNESDAY MORNING. IT WILL BE FOLLOWED BY A
UNSETTLED COOL AND BREEZY DAY.

THE REST OF THE WEEK WILL HAVE PERIODS OF RAIN BUT THE WEATHER
SHOULD BE MUCH LESS HAZARDOUS.

* WINTER STORM WARNING.......SEE WWUS46 KLOX - WSWLOX FOR DETAILS *

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

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

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

* GALE WARNING...............SEE FZUS56 KLOX - CWFLOX FOR DETAILS *

* MARINE WEATHER STATEMENT...SEE FZUS76 KLOX - MWSLOX FOR DETAILS *

.SPOTTER INFORMATION STATEMENT...

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

RORKE