546
FXUS66 KLOX 181100
AFDLOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
300 AM PST THU DEC 18 2025
SYNOPSIS
17/201 PM.
WELL ABOVE NORMAL TEMPERATURES WILL CONTINUE AWAY FROM THE COAST
THROUGH FRIDAY. UNSETTLED WEATHER IS POSSIBLE THIS WEEKEND ALONG
THE CENTRAL COAST, SPREADING TO ALL AREAS WITH A POTENTIALLY
SIGNIFICANT STORM NEAR THE MIDDLE PART OF NEXT WEEK.
SHORT TERM (TDY-SAT)
18/1221 AM.
THE GRADIENTS ARE TRANSITIONING FROM A STRONG N PUSH TO MORE OF A
NE PUSH. THE WINDS ARE SUBSIDING SOME AND SHOULD MOSTLY BE BELOW
ADVISORY CRITERIA BY DAWN. THE OFFSHORE WINDS HAVE PUSHED ALL OF
THE COASTAL LOW CLOUDS AWAY SAVE FOR THE WESTERN SBA COUNTY
BEACHES. THE LONG BEACH AREA MAY SEE SOME LOW CLOUDS AND DENSE FOG
FOR A FEW HOURS THIS MORNING AS THE OFFSHORE FLOW IN THAT AREA IS
WEAKEST. THE OTHERWISE SUNNY SKIES WILL TEAM UP WITH THE OFFSHORE
FLOW TO BRING WARMING TO MOST OF THE AREA, BUT ESP THE VTA/LA
COUNTY CSTS/VLYS WHERE 8 TO 12 DEGREES OF WARMING IS LIKELY. LOOK
FOR MAX TEMPS IN THE 70S ACROSS THE CSTS AND 80S IN THE VLYS OR 12
TO 18 DEGREES OVER NORMAL.
ON FRIDAY THE RIDGE WILL BE PUSHED TO THE SOUTH AND FLAT WESTERLY
FLOW SETS UP OVER THE AREA. HGTS WILL FALL TO ABOUT 585 DAM
(STILL WELL ABOVE NORMAL). LOW CLOUDS WILL BE SIMILAR TO WEDNESDAY
AND PRETTY MUCH CONFINED TO THE LONG BEACH AREA. MUCH WEAKER
OFFSHORE FLOW AT THE SFC WILL LEAD TO 3 TO 6 DEGREES OF COOLING
ACROSS THE CSTS/VLYS. THE LACK OF COOL AIR ADVECTION FROM THE
SAN JOAQUIN VLY WILL LEAD TO 2 TO 4 DEGREES OF WARMING ACROSS THE
INTERIOR.
FLAT WESTERLY FLOW CONTINUES OVER THE AREA ON SATURDAY. HGTS WILL
DIP DOWN TO 582 DAM. ONSHORE FLOW TO THE EAST WILL INCREASE FROM 1
MB IN THE MORNING TO ABOUT 3 MB IN THE AFTERNOON, THE OFFSHORE
FLOW FROM THE NORTH WILL BE 3 MB WEAKER IN THE AFTERNOON COMPARED
TO FRIDAY. THE ONSHORE FLOW AND FALLING HGTS WILL BRING SOME
COASTAL LOW CLOUDS TO THE AREA IN THE MORNING. AT THE SAME TIME THE
SOUTHERN EDGE OF AN ATMOSPHERIC RIVER (AR) AFFECTING THE NORTHERN
PORTION OF THE STATE WILL MOVE SOUTH ENOUGH TO SOUTH TO BRING
MOSTLY CLOUDY SKIES TO MOST OVER THE AREA SAVE FOR LA COUNTY WHICH
WILL END UP PARTLY CLOUDY. THE AR COULD (20 PERCENT CHC) BRING
SOME LIGHT RAIN TO SLO COUNTY. THE COOLING TREND WILL CONTINUE AS
FALLING HGTS AND BETTER ONSHORE FLOW COMBINE TO LOWER MOST TEMPS 3
TO 6 DEGREES. THE CENTRAL COAST WILL BE THE EXCEPTION WITH LITTLE
CHANGE IN TEMPS. MAX TEMPS, HOWEVER, WILL REMAIN ABOVE NORMAL
(3 TO 6 DEGREES CSTS, 5 TO 10 DEGREES VLYS AND 10 TO 15 DEGREES
MTNS AND FAR INTERIOR).
LONG TERM (SUN-WED)
18/258 AM.
SUNDAY AND MONDAY WILL BE FAIRLY SIMILAR DAYS. THE UPPER FLOW
PATTERN WILL SLOWLY TILT MORE AND MORE INTO A SW TO NE DIRECTION
ON SUNDAY AS THE AR SYSTEM SAGS A LITTLE MORE TO THE SOUTH. A
SLIGHT CHC OR CHC (20 TO 30 PERCENT) OF RAIN WILL DEVELOP OVER SLO
AND WESTERN SBA COUNTIES. OTHER AREAS WILL JUST SEE INCREASING
CLOUDS. RAINFALL TOTALS DURING THE TWO DAY PERIOD WILL MOST
LIKELY BE UNDER A TENTH OF AN INCH WITH PERHAPS THE EXCEPTION OF
THE FAR NW TIP OF SLO COUNTY WHICH COULD SEE MORE. SKIES WILL
TURN MOSTLY CLOUDY SUNDAY AND WILL PERSIST THROUGH MONDAY. MAX
TEMPS WILL FALL 2 TO 4 DEGREES ACROSS ALMOST ALL OF THE AREA
SUNDAY AND THEN WILL CHANGE LITTLE ON MONDAY. MAX TEMPS WILL
REMAIN 3 TO 6 DEGREES OVER NORMALS FOR THE CSTS AND VLYS.
TUESDAY ROMAINES THE DAY OF TRANSITION. THE AR WILL SAG SOUTH AND
THE FLOW WILL BECOME EVEN MORE SOUTHWESTERLY. RAIN CHANCES WILL
OVERSPREAD THE ENTIRE AREA. RAIN CHANCES HAVE INCREASED WITH THE
LATEST FORECAST AND NOW SIT AROUND 40 PERCENT FOR LA COUNTY, 50
PERCENT FOR VTA COUNTY, 50 TO 60 PERCENT FOR SBA COUNTY AND 60 TO
70 PERCENT FOR SLO COUNTY. THE FORECAST RAINFALL AMOUNTS HAVE ALSO
BEEN INCREASED. SBA AND SLO COUNTIES WILL NOW LIKELY SEE A HALF
INCH TO AN INCH OF RAIN, WHILE A QUARTER INCH TO A HALF INCH IS
POSSIBLE FOR VTA AND LA COUNTIES.
THERE HAS BEEN A SLIGHT CHANGE IN THE CURRENT THINKING FOR THE
WED/THU STORM. BOTH THE EC AND ESP THE GFS (AS WELL AS MOST
ENSEMBLES AND THE AI ENHANCED MDLS) ARE NOW SPEEDING UP THE SYSTEM
(HENCE THE WETTER TUESDAY FCST). THIS FORECAST (WHICH VERY WELL
MIGHT CHANGE SINCE IT IS 7 TO 8 DAYS AWAY) NOW CALL FOR THE BULK
OF THE RAIN TO FALL WEDNESDAY THROUGH THURSDAY (CHRISTMAS)
MORNING. VERY PRELIMINARY (AND SUBJECT TO CHANGE) RAINFALL TOTALS
FOR THE WED/THU TIME PERIOD CALL FOR 2 TO 4 INCHES OF RAIN
CSTS/VLYS, 4 TO 6 INCHES ACROSS THE MTNS AND 1 TO 2 INCHES FOR THE
INTERIOR SECTIONS. IT IS TOO EARLY TO GET A HANDLE ON RAINFALL
RATE PREDICTIONS. SNOW LEVELS WILL BE OVER 8000 FT BUT WILL START
TO FALL LATER THURSDAY.
MODEL AGREEMENT FALLS OFF PRETTY RAPIDLY AFTER THURSDAY, BUT THERE
IS A POTENTIAL FOR ANOTHER SYSTEM OVER THE WEEKEND OF THE 27TH AND
28TH.
AVIATION
18/1008Z.
AROUND 0815Z, THE MARINE LAYER DEPTH WAS NEAR 500 FEET DEEP AT
KLAX. THE TOP OF THE MARINE INVERSION WAS NEAR 1500 FEET WITH A
TEMPERATURE AROUND 21 DEGREES CELSIUS. THERE WAS ANOTHER INVERSION
UP TO AROUND 3000 FEET.
LOW-TO-MODERATE CONFIDENCE IN THE CURRENT FORECAST THROUGH 18Z AND
AGAIN AFTER 08Z FRIDAY FOR COASTAL TERMINALS AND KPRB, OTHERWISE
MODERATE-TO-HIGH CONFIDENCE. THERE IS A MODERATE-TO-HIGH CHANCE
OF LIFR TO IFR CONDITIONS THROUGH 18Z AND AGAIN AFTER 06Z FRIDAY
AT COASTAL TERMINALS AND KPRB, OTHERWISE VFR CONDITIONS ARE
EXPECTED THROUGH THE PERIOD.
KLAX...THERE IS A 40 PERCENT OF LIFR CONDITIONS THROUGH 16Z, AND
AGAIN AFTER 06Z FRIDAY. AN EASTERLY WINDS WILL BE LESS THAN 7
KNOTS THROUGH THE PERIOD.
KBUR...VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. NO WIND
IMPACTS ARE EXPECTED AT THIS TIME.
MARINE
18/119 AM.
MODERATE-TO-HIGH CONFIDENCE IN THE CURRENT FORECAST. HIGHER
CONFIDENCE EXISTS IN WINDS THROUGH EARLY SATURDAY MORNING, THEN
LOWER CONFIDENCE THEREAFTER. LOWER CONFIDENCE EXISTS IN THE SEA
FORECAST THROUGH FRIDAY NIGHT.
FOR THE WATERS SOUTHWEST THROUGH NORTHWEST OF THE CHANNEL ISLANDS
AND THE NEARSHORE WATERS ALONG THE CENTRAL COAST, THERE IS A
LIKELY-TO-IMMINENT (60-90 PERCENT) CHANCE OF SMALL CRAFT ADVISORY
(SCA) LEVEL WINDS THROUGH FRIDAY NIGHT, HIGHEST DURING THE
AFTERNOON AND EVENING HOURS AND FROM NEAR POINT CONCPETION SOUTH
TO SAN NICOLAS ISLAND. THERE IS A MODERATE (30-40 PERCENT) CHANCE
OF WIDESPREAD GALES THROUGH TONIGHT, BUT LOCAL GALE FORCE GUSTS
ARE POSSIBLE THIS AFTERNOON AND EVENING FROM POINT CONCEPTION
SOUTH TO SAN NICOLAS ISLAND. WINDS WILL LIKELY DIMINISH SOME WITH
SCA CHANCES DECREASING TO A MODERATE-TO-HIGH (30-50 PERCENT)
CHANCE BETWEEN FRIDAY NIGHT AND SATURDAY, THEN TO A LOW-TO-
MODERATE (20-40 PERCENT) CHANCE OVER THE WEEKEND AND INTO MONDAY.
INSIDE THE SOUTHERN CALIFORNIA BIGHT, THERE IS A MODERATE-TO-HIGH
(30-50 PERCENT) CHANCE OF SCA LEVEL WINDS EACH AFTERNOON AND
EVENING THROUGH FRIDAY EVENING, HIGHEST ACROSS THE WESTERN PORTION
OF THE SANTA BARBARA CHANNEL. OTHERWISE, WINDS AND SEAS SHOULD BE
BELOW SCA LEVELS THROUGH MONDAY.
LOX WATCHES/WARNINGS/ADVISORIES
CA...WIND ADVISORY REMAINS IN EFFECT UNTIL 3 AM PST EARLY THIS
MORNING FOR ZONES 88-356-362-369>375-383. (SEE LAXNPWLOX).
WIND ADVISORY NOW IN EFFECT UNTIL 3 AM PST EARLY THIS MORNING
FOR ZONES 349-351. (SEE LAXNPWLOX).
WIND ADVISORY NOW IN EFFECT UNTIL 6 AM PST EARLY THIS MORNING
FOR ZONES 352-353-376>381. (SEE LAXNPWLOX).
PZ...SMALL CRAFT ADVISORY IN EFFECT FROM NOON TODAY TO 9 PM PST
THIS EVENING FOR ZONE 645. (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY IN EFFECT UNTIL 3 AM PST EARLY THIS
MORNING FOR ZONES 650-655. (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY IN EFFECT UNTIL 9 PM PST FRIDAY FOR ZONE
670. (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY IN EFFECT UNTIL 3 AM PST SATURDAY FOR
ZONES 673-676. (SEE LAXMWWLOX).
PUBLIC...RORKE
AVIATION...HALL
MARINE...HALL
SYNOPSIS...RM/JLD
WEATHER.GOV/LOSANGELES
EXPERIMENTAL GRAPHICAL HAZARDOUS WEATHER OUTLOOK AT:
HTTPS://WWW.WEATHER.GOV/ERH/GHWO?WFO=LOX
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