Area Forecast Discussion
Issued by NWS Los Angeles, CA

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000
FXUS66 KLOX 212013
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
110 PM PDT SUN SEP 21 2014

.SYNOPSIS...
WARMING TREND MONDAY THROUGH WEDNESDAY AS A RIDGE TO THE SOUTHEAST
MOVES INTO CALIFORNIA...WITH LESS MARINE LAYER AND ONSHORE FLOW. A
LARGE TROUGH WILL PUSH INTO NORTHERN CALIFORNIA BY FRIDAY...BRINGING
COOLER CONDITIONS THURSDAY THROUGH SATURDAY. OFFSHORE FLOW POSSIBLE
EARLY NEXT WEEK.

&&

.SHORT TERM (TODAY-WED)...EARLIER MARINE LYR CLEARING IS IN FACT
RESULTING IN A WARMER DAY TODAY WITH MOST PLACES UP A FEW DEGREES
OVER SATURDAY. CLOUDS HANGING TOUGH IN SBA THOUGH. WATER VAPOR SHOWS
THE UPPER LOW THAT HAS KEPT US COOL THE LAST COUPLE DAYS LIFTING
NORTHEAST TODAY. RIDGING BEHIND IT WILL BRING WARMER TEMPS AND A
SHALLOWER MARINE LYR THROUGH MID WEEK. SHOULD SEE 2-4 DEGREES OF
WARMING EACH DAY THROUGH WEDNESDAY. NAM SHOWS A LITTLE MID LEVEL
MOISTURE MOVING INTO THE AREA FROM THE REMNANTS OF POLO BUT AT THIS
POINT IT`S STILL TOO DRY AND STABLE AT LOWER LAYERS TO GET MORE THAN
JUST SOME AC.

.LONG TERM (THU-SUN)...THE RIDGE WILL QUICKLY BE REPLACED BY A
RATHER IMPRESSIVE TROF ALONG THE WEST COAST FOR THE SECOND HALF OF
THE WEEK. MODELS DIFFER WITH RESPECT TO HOW DEEP THE TROF WILL GET
WITH THE ECMWF BY FAR THE DEEPEST. HOWEVER, IT DOESN`T SHOW IT
TAPPING INTO ANY MOISTURE SOURCE SO AT BEST WE`D BE LOOKING AT A
DEEPENING MARINE LYR, POSSIBLY SOME COASTAL/VALLEY DRIZZLE, AND MUCH
COOLER TEMPS. WE SHOULD BE TURNING THE CORNER SATURDAY AS THE TROF
AXIS SLIDES EAST AND RIDGING RETURNS FROM THE WEST. GFS SHOWS SOME
OFFSHORE FLOW DEVELOPING SUNDAY SO TEMPS MAY JUMP CONSIDERABLY. GFS
HAD AT ONE TIME SHOWN OFFSHORE FLOW FOR THIS WEEKEND SO WILL KEEP
THE FORECAST RATHER CONSERVATIVE AT THIS TIME, BUT MOST AREAS
SHOULD SEE AT LEAST A FEW DEGREES OF WARMING WITH THE RIDGING.

&&

.AVIATION...21/1800Z.

MID/UPPER LEVEL TROUGH OF LOW PRESSURE OVER THE EASTERN PACIFIC AND
RIDGE OF HIGH PRESSURE CENTERED SOUTHEAST OF THE AREA WILL PERSIST.
UPPER LEVEL MODERATE SOUTHWEST WINDS AND MID LEVEL LIGHT SOUTHEAST
WINDS WILL PREVAIL OVER THE AREA. LOW LEVEL CLOUD TOPS WERE
APPROXIMATELY 2.8KFT THIS MORNING AND WILL DIFFER BY MINUS 1KFT
MONDAY MORNING. THE CLOUD FIELD WAS RELATIVELY ORGANIZED THIS
MORNING AND WILL PROBABLY DIFFER LITTLE MONDAY MORNING. WEAK TO
MODERATE ONSHORE PRESSURE GRADIENT THROUGH 22/04Z AND AFTER
22/19Z...OTHERWISE A WEAK MIXED ONSHORE AND NORTHERLY GRADIENT IS
EXPECTED.

KLAX...CHANCE SCATTERED 027 BY 21/21Z. CHANCE CIGS 013-015 BETWEEN
22/07-22/17Z AND CIGS 025 BETWEEN 22/17-22/21Z.

KBUR...SKC LIKELY BY 21/19Z THEN CHANCE CIGS 012 BY 22/11Z.

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

&&

.MARINE...21/200 PM.

IT IS LIKELY SMALL CRAFT ADVISORY CONDITIONS WILL EXIST IN THE
VICINITY OF THE CHANNEL ISLANDS THIS EVENING AND A CHANCE MONDAY AND
TUESDAY EVENING. THERE IS A CHANCE SMALL CRAFT ADVISORY CONDITIONS
WILL EXIST NORTH OF POINT CONCEPTION TO POINT SAL MONDAY AND MONDAY
NIGHT. THERE IS A CHANCE THE NORTHWEST WINDS WILL INCREASE TO GALES
FRIDAY IN THE VICINITY OF THE NORTHERN ISLANDS TO SAN NICOLAS
ISLAND. SWELLS FROM 295-305 DEGREES ORIGINATING FROM A FAST MOVING
AND SHORT LIVED GULF OF ALASKA STORM A FEW DAYS AGO LAST WEEK
THURSDAY WILL PEAK THIS EVENING. A LOW PRESSURE SYSTEM IS LIKELY
TO DEVELOP OVER THE EASTERN PACIFIC MONDAY THROUGH TUESDAY. SWELLS
GENERATED BY STORM FORCE WINDS ARE EXPECTED TO ARRIVE FROM 300-310
DEGREES WEDNESDAY EVENING AND PEAK THURSDAY AND LINGER THROUGH
FRIDAY AND SMALL CRAFT ADVISORY CONDITIONS FOR HAZARDOUS SEAS WILL
LIKELY EXIST.

&&

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

&&

$$

PUBLIC...MW
AVIATION/MARINE...30
SYNOPSIS...KITTELL

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