403
FXUS66 KLOX 191805
AFDLOX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1005 AM PST FRI DEC 19 2025
UPDATED AVIATION DISCUSSION
SYNOPSIS
19/307 AM.
MOSTLY CLEAR SKIES WILL COVER THE AREA TODAY AND SATURDAY SAVE FOR
SOME MORNING LOW CLOUDS. IT WILL BE COOLER EACH DAY BUT HIGH
TEMPERATURES WILL REMAIN ABOVE NORMAL. THERE WILL BE INCREASING
CLOUDS, COOLER TEMPERATURES AND A SLIGHT CHANCE OF RAIN OVER SAN
LUIS OBISPO COUNTY SUNDAY AND MONDAY. A STRONG STORM WILL BRING
MANY INCHES OF RAIN TO THE ENTIRE AREA TUESDAY THROUGH WEDNESDAY.
SHORT TERM (TDY-SUN)
19/759 AM.
***UPDATE***
LATEST SATELLITE AND SURFACE OBSERVATIONS SOME STRATUS/DENSE FOG
ALONG THE CENTRAL COAST, LA COAST AND THE SALINAS VALLEY WITH
SCATTERED HIGH CLOUDS ELSEWHERE. CURRENT SOUNDING DATA INDICATES
MARINE INVERSION AROUND 700 FEET DEEP. SOME NORTHERLY WINDS,
GUSTING 30-40 MPH, ARE CURRENTLY OBSERVED ACROSS THE WESTERN SANTA
YNEZ RANGE.
FORECAST-WISE FOR THE IMMEDIATE SHORT TERM, NO SIGNIFICANT ISSUES
ARE EXPECTED. CURRENT STRATUS AND DENSE FOG WILL DISSIPATE BY
MID-MORNING. SO, WILL LET THE DENSE FOG ADVISORIES EXPIRE AT 1000
AM OR EVEN END IT SOONER. SO, MOSTLY SUNNY SKIES WILL PREVAIL THIS
AFTERNOON WITH SCATTERED HIGH CLOUDS OVERHEAD. CURRENT WINDS
ACROSS THE WESTERN SANTA YNEZ RANGE SHOULD DIMINISH THROUGH THE
DAY. AS FOR TEMPERATURES, THE RETURN OF ONSHORE PRESSURE GRADIENTS
TODAY ALONG WITH A COOLER BOUNDARY LAYER WILL BRING COOLER
CONDITIONS TO MOST AREAS. THE ONLY EXCEPTION WILL BE THE DESERTS
WHERE SOME SLIGHT WARMING IS ANTICIPATED.
OVERALL, CURRENT FORECAST HAS GOOD HANDLE ON THE IMMEDIATE SHORT
TERM. SO, NO SIGNIFICANT UPDATES ARE EXPECTED. FOR THE AFTERNOON
FORECAST SUITE, ATTENTION WILL REMAIN FOCUSED ON PRECIPITATION
CHANCES NEXT WEEK.
***FROM PREVIOUS DISCUSSION***
THE STRONG 592 DAM UPPER HIGH THAT BROUGHT ALL OF THE WARM WEATHER
THIS WEEK WILL BE PUSHED TO THE SOUTH TODAY. THE FLOW ALOFT WILL
FLATTEN OUT INTO THE W TO E CONFIGURATION AND HGTS WILL FALL TO
582 DAM. THE OFFSHORE FLOW FROM THE E WILL TURN ONSHORE AND THEN
INCREASE THROUGH THE DAY. OFFSHORE FLOW FROM THE N WILL REMAIN
BUT WILL BE WEAKER THAN YDY. LOOK FOR LOW CLOUDS AND PATCHY DENSE
FOG TO DEVELOP ACROSS THE LA CST, WESTERN SBA COUNTY AND THE PASO
ROBLES AREA. SKIES, OTHERWISE WILL BE MOSTLY SUNNY. THE CHANGE IN
THE SFC FLOW AS WELL AS THE FALLING HGTS 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 WILL CONTINUE OVER THE AREA ON SATURDAY. HGTS
WILL DIP DOWN TO 579 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 TURN WEAKLY ONSHORE IN THE
AFTERNOON. THE ONSHORE FLOW AND FALLING HGTS WILL BRING PLENTY OF
LOW CLOUDS TO MOST OF THE CSTS AND LOWER VLYS IN THE MORNING. THE
INCREASING ONSHORE FLOW IN THE AFTERNOON WILL SLOW CLEARING AND
MORE THAN A FEW BEACHES MAY BE CLOUDY ALL DAY. THE SOUTHERN
PROGRESS OF THE ATMOSPHERIC RIVER (AR) AFFECTING THE NORTHERN
PORTION OF THE STATE IS NO FORECAST TO REMAIN NORTH OF THE AREA
WHICH WILL ELIMINATE THE RAIN THREAT FOR SLO COUNTY AND REDUCE THE
AMOUNT OF MID AND HIGH CLOUDS OVER THE AREA. THE COOLING TREND
WILL CONTINUE AS FALLING HGTS AND BETTER ONSHORE FLOW COMBINE TO
LOWER MOST TEMPS ANOTHER 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 INTERIOR CSTS, 5 TO 10
DEGREES VLYS AND 10 TO 15 DEGREES MTNS AND FAR INTERIOR).
LONG TERM (MON-THU)
19/300 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
NORTHWESTERN SLO COUNTY. OTHER AREAS WILL JUST SEE INCREASING
CLOUDS SUNDAY AND MOSTLY CLOUDY SKIES MONDAY. RAINFALL TOTALS
DURING THE TWO DAY PERIOD WILL MOST LIKELY BE UNDER A TENTH OF AN
INCH. 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 ABOVE NORMAL (1 TO 2 DEGREES ACROSS THE CSTS; 4 TO 8
DEGREES VLYS AND 8 TO 16 DEGREES MTNS AND INTERIOR).
DETERMINISTIC, ENSEMBLE BASED AND AI BASED MDLS HAVE BEEN IN VERY
GOOD AGREEMENT UP UNTIL NOW. ANNOYINGLY QUITE A BIT OF
DISAGREEMENT HAS NOW SHOWN UP. THE FOLLOWING FORECAST IS BASED ON
A BROAD MIXTURE OF ALL AVAILABLE MDLS, BUT NOW THE CONFIDENCE IS
LOWER ESP FOR TUE AND THU.
ON TUESDAY THE FLOW WILL TILT TO THE SW. THE SOUTHERN END OF THE
AR WILL BE SWEPT UP BY A TROF AND WILL ALSO ASSUME A SW TO NE
ORIENTATION. THE TROF WILL TRANSLATE EASTWARD AND WILL BRING RAIN
TO THE AREA. RAIN WILL BECOME LIKELY (60 TO 70 PERCENT CHC) ACROSS
THE CENTRAL COAST IN THE MORNING, WHILE A CHC (20 TO 40 PERCENT
CHC) DEVELOPS SOUTH OF PT CONCEPTION. RAIN IS A NEAR CERTAINTY
ACROSS SLO AND SBA COUNTIES IN THE AFTERNOON. VENTURA COUNTY WILL
SEE A 50 PERCENT CHC AND LA COUNTY A 40 PERCENT CHC. BY TUESDAY
EVENING THE ENTIRE 4 COUNTY AREA WILL BE ENGULFED BY RAIN. DUE TO
THE SOUTHERLY FLOW ASSOCIATED WITH THIS EVENT THE SOUTH FACING
SLOPES WILL SEE THE HIGHEST TOTALS AND RATES. RIGHT NOW FROM DAWN
TUESDAY TO DAWN WEDNESDAY IT LOOKS LIKE MOST AREAS WILL SEE ABOUT
AN INCH OF RAIN WITH THE SOUTH FACING SLOPES RECEIVING ABOUT TWO
INCHES. SNOW LEVELS DURING THIS TIME WILL BE NEAR 8000 FT. ALL
THIS SAID THERE ARE SEVERAL SOLUTIONS (NOTABLY THE GFS AND MANY OF
ITS ENSEMBLES) THAT ARE SLOWER WITH THE ARRIVAL OF THE AR - THIS
OUTCOME WOULD LEAD TO A MUCH DRIER DAY.
THE BEST CONFIDENCE REMAINS ON WEDNESDAY WHEN THE AR SHOULD MOVE
ACROSS THE ENTIRE AREA. WEDNESDAY SHOULD FEATURE THE MOST RAINFALL
AND THE HIGHEST RAINFALL RATE. IT SHOULD RAIN ALL DAY ACROSS ALL
OF THE AREA. IT IS LIKELY THAT 1 TO 2 INCHES OF RAIN WILL FALL
ACROSS THE CSTS/VLYS AND 2 TO 4 INCHES ACROSS THE FOOTHILLS AND
MTNS. THE INTERIOR AS USUAL WILL SEE LESS RAIN LIKELY AROUND AN
INCH TO AN INCH AND HALF. DUE TO THE STRONG SOUTH FLOW SNOW LEVELS
WILL REMAIN NEAR 8000 FT.
PRETTY LOW CONFIDENCE FOR THE CHRISTMAS FORECAST. MANY MDLS MOVE
THE BULK OF THE RAIN OUT OF THE AREA IN THE MORNING WITH MUCH
LIGHTER RAIN IN THE AFTERNOON. THERE IS STILL THE POTENTIAL FOR 1
TO 2 INCHES OF ADDITIONAL RAIN, BUT THIS MIGHT BE ON THE HIGH SIDE
OF POTENTIAL OUTCOMES. WILL HAVE TO WAIT AND SEE WHICH WAY THE
MDLS TAKE THIS DAYS FORECAST. COLDER AIR WILL BE USHERED IN BEHIND
THE AR AND SNOW LEVELS WILL FALL THROUGH THE DAY ENDING UP AROUND
7000 FT LATE IN THE AFTERNOON AND THEN FALLING TO 6000 FT
OVERNIGHT. IT WILL BE A COOLISH DAY WITH MAX TEMPS ONLY IN THE
LOWER TO MID 60S FOR MOST OF THE CSTS/VLYS.
MODEL AGREEMENT FALLS OFF PRETTY RAPIDLY AFTER THURSDAY, BUT THERE
IS A POTENTIAL FOR MORE RAIN FRI SAT AND SUN.
AVIATION
19/1804Z.
AROUND 09Z, THE MARINE LAYER DEPTH WAS 700 FEET. THE INVERSION UP
TO 4600 FEET WITH A TEMPERATURE OF 20 DEGREES C.
HIGH CONFIDENCE IN VFR TAFS FOR KPMD AND KWJF. WINDS MAY GUSTS UP
TO 10 KT HIGHER THAN FORECAST.
MODERATE CONFIDENCE IN TAFS FOR KLAX, KLGB, AND KSMO. TIMING OF
FLIGHT CAT CHANGES MAY BE OFF +/- 3 HOURS. 20% CHANCE FOR VSBYS
LOWER THAN 1/2SM FROM 06Z-16Z. LOW CHANCE FOR SOME IFR TO MVFR
CONDS THROUGH THE AFTERNOON AS THE FOG BANK WILL LINGER ALONG THE
COAST.
HIGH CONFIDENCE IN REMAINING TAFS THROUGH 00Z, THEN LOW
CONFIDENCE THEREAFTER. TIMING OF FLIGHT CAT CHANGES MAY BE OFF
+/- 4 HOURS. CHANCE FOR VFR CONDS TO PREVAIL AT KSBP (50%), KSMX
(30%), KSBA (30%), KOXR (20%), KCMA (25%), KBUR (30%), AND KVNY
(30%). LOW CONFIDENCE IN MINIMUM FLIGHT CAT, BUT VLIFR- IFR IS
LIKELY.
KLAX...MODERATE CONFIDENCE IN TAF. LOW CHANCE FOR SOME IFR TO MVFR
CONDS THROUGH THE AFTERNOON AS THE FOG BANK WILL LINGER ALONG THE
COAST. OTHERWISE FLIGHT CAT CHANGES MAY BE OFF +/- 3 HOURS. 20%
CHANCE FOR VSBYS UNDER 1/2SM FROM 06Z-16Z. MODERATE CONFIDENCE IN
ANY EAST WIND COMPONENT REMAINING BELOW 8 KNOTS.
KBUR...HIGH CONFIDENCE IN TAF THROUGH 06Z, THEN LOW CONFIDENCE
THEREAFTER. IF CIGS ARRIVE, 50% CHANCE FOR VSBYS LESS THAN 1/2SM.
HOWEVER, 30% CHANCE VFR CONDS PREVAIL. RELATIVELY MILD WINDS
EXPECTED.
MARINE
19/753 AM.
MODERATE CONFIDENCE IN THE CURRENT FORECAST. MODERATE CONFIDENCE
EXISTS IN THE SEA FORECAST THROUGH TONIGHT, THEN HIGHER CONFIDENCE
THEREAFTER.
LOW CLOUDS AND FOG WILL CONTINUE ACROSS PORTIONS OF THE COASTAL
WATERS THROUGH LATER THIS MORNING DUE TO THE SHALLOW MARINE
INVERSION OVER THE COASTAL WATERS.
FOR THE WATERS SOUTHWEST THROUGH NORTHWEST OF THE CHANNEL ISLANDS
AND THE NEARSHORE WATERS ALONG THE CENTRAL COAST, SMALL CRAFT
ADVISORY (SCA) LEVEL WINDS WILL LIKELY CONTINUE THROUGH TONIGHT,
HIGHEST DURING THE AFTERNOON AND EVENING HOURS AND FROM NEAR POINT
CONCPETION SOUTH TO SAN NICOLAS ISLAND. THERE IS A LOW-TO-
MODERATE (20-40 PERCENT) CHANCE OF SCA CONDITIONS OVER THE WEEKEND
AND INTO MONDAY, THEN THERE IS A LIKELY (60-80 PERCENT) CHANCE OF
WIDESPREAD SCA CONDITIONS ON TUESDAY AND TUESDAY NIGHT WITH A
MODERATE-TO-HIGH (30-50 PERCENT) CHANCE OF GALES.
INSIDE THE SOUTHERN CALIFORNIA BIGHT, THERE IS A MODERATE-TO-HIGH
(30-50 PERCENT) CHANCE OF SCA LEVEL WINDS THIS AFTERNOON AND
EVENING, HIGHEST ACROSS THE WESTERN PORTION OF THE SANTA BARBARA
CHANNEL. WINDS AND SEAS SHOULD DROP BELOW SCA LEVELS OVER THE
WEEKEND AND INTO MONDAY, THERE IS A HIGH-TO-LIKELY (50-60 PERCENT)
CHANCE OF WIDESPREAD SCA CONDITIONS ON TUESDAY AND TUESDAY NIGHT.
LOX WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...SMALL CRAFT ADVISORY IN EFFECT UNTIL 9 PM PST THIS EVENING
FOR ZONES 645-670. (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY IN EFFECT FROM 2 PM THIS AFTERNOON TO 9
PM PST THIS EVENING FOR ZONE 650. (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY IN EFFECT UNTIL 9 AM PST SATURDAY FOR
ZONES 673-676. (SEE LAXMWWLOX).
PUBLIC...RORKE/THOMPSON
AVIATION...LEWIS
MARINE...HALL/LEWIS
SYNOPSIS...30
WEATHER.GOV/LOSANGELES
EXPERIMENTAL GRAPHICAL HAZARDOUS WEATHER OUTLOOK AT:
HTTPS://WWW.WEATHER.GOV/ERH/GHWO?WFO=LOX
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page