208
FXUS66 KLOX 192201
AFDLOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
201 PM PST FRI DEC 19 2025
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-MON)
19/139 PM.
OVERALL, 12Z MODELS IN GOOD SYNOPTIC AGREEMENT THROUGH THE SHORT
TERM PERIOD. AT UPPER LEVELS, ZONAL FLOW WILL PREVAIL THROUGH
SATURDAY THEN WILL TILT TO THE SOUTHWEST SUNDAY/MONDAY AS THE AR
BEGINS TO SAG SOUTHWARD. NEAR THE SURFACE, WEAK ONSHORE FLOW WILL
PREVAIL THROUGH MONDAY.
FORECAST-WISE FOR THE SHORT TERM, NO SIGNIFICANT ISSUES ARE
EXPECTED. WITH FALLING H5 HEIGHTS AND RETURN OF ONSHORE FLOW, THE
MARINE LAYER STRATUS WILL INCREASE IN DEPTH AND COVERAGE THROUGH
THE WEEKEND, PUSHING INTO MOST COASTAL VALLEY AREAS BY SUNDAY AND
MONDAY. OUTSIDE OF THE MARINE LAYER STRATUS, THERE WILL BE
INCREASING MID/HIGH LEVEL CLOUDS THROUGH THE WEEKEND.
AS THE AR BEGINS TO SAG SOUTHWARD, THERE WILL LIKELY BE SOME LIGHT
PRECIPITATION DEVELOPING ACROSS THE CENTRAL COAST, BEGINNING
TONIGHT AND CONTINUING THROUGH MONDAY. AT THIS TIME, MOST, IF ANY,
OF THE PRECIPITATION LOOKS TO BE OVER SAN LUIS OBISPO COUNTY.
RAINFALL TOTALS WILL GENERALLY BE AROUND 0.10 INCHES OR LESS.
HOWEVER, THE NORTHWEST CORNER OF THE COUNTY (THINK ROCKY BUTTE)
COULD RECEIVE BETWEEN 0.25 AND 0.75 INCHES.
AS FOR TEMPERATURES, THE COMBINATION OF INCREASING CLOUDS, ONSHORE
FLOW, AND LOWERING THICKNESSES WILL BRING A COOLING TREND FOR ALL
AREAS THROUGH THE WEEKEND.
FINALLY WITH RESPECT TO WINDS, NO SIGNIFICANT WINDS ARE
ANTICIPATED. NORTHERLY OFFSHORE GRADIENTS WILL CONTINUE ACROSS THE
AREA TONIGHT, BUT WILL WEAKEN. SO, THERE WILL BE SOME GUSTY NORTH
WINDS ACROSS THE SANTA YNEZ RANGE THROUGH TONIGHT, BUT EXPECT ANY
ADVISORY-LEVEL WINDS TO REMAIN LOCALIZED.
LONG TERM (TUE-FRI)
19/139 PM.
FOR THE EXTENDED, 12Z MODELS DIFFER SOMEWHAT WITH DETAILS, BUT ALL
GENERALLY HAVE THE SAME IDEA. A SIGNIFICANT WINTER STORM WILL
IMPACT THE AREA DURING THE CHRISTMAS HOLIDAY AS A PINEAPPLE
EXPRESS TAKES AIM ON THE AREA.
AS MENTIONED, MODELS ARE STILL A BIT OUT OF PHASE WITH TIMING, SO
CONFIDENCE IN DETAILS IS MODERATE AT BEST (ESPECIALLY WITH RESPECT
TO TIMING). HOWEVER FOR CURRENT FORECAST, THE PEAK OF THE AR
ASSOCIATED RAINFALL LOOKS TO OCCUR IN THE TUESDAY EVENING THROUGH
CHRISTMAS EVE NIGHT PERIOD. IN THIS PERIOD, RAIN TOTALS WILL
GENERALLY RANGE BETWEEN 1 AND 3 INCHES WITH UP TO AROUND 5 INCHES
ACROSS THE MOUNTAINS. SNOW LEVELS LOOK TO REMAIN RATHER HIGH,
ABOVE 7500 FEET, THROUGH CHRISTMAS EVE.
FROM CHRISTMAS DAY THROUGH FRIDAY EVENING, A SECONDARY SHOT WITHIN
THE AR, AS WELL AS COPIOUS SHOWER ACTIVITY, WILL BRING EVEN MORE
RAINFALL TO THE AREA. IN THIS TIME PERIOD, ADDITIONAL RAINFALL
TOTALS WILL GENERALLY RANGE BETWEEN 1.00 AND 2.50 INCHES WITH UP
TO AROUND 4.00 INCHES IN THE MOUNTAINS. SNOW LEVELS WILL DROP
DURING THIS TIME PERIOD AS COLDER AIR MOVES, DROPPING INTO THE
6000 TO 7000 FOOT RANGE.
AS FOR WINDS, STRONG AND GUSTY SOUTHEASTERLY WINDS ARE LIKELY,
BEGINNING TUESDAY AND CONTINUING THROUGH CHRISTMAS DAY. THE PEAK
WINDS LOOK TO OCCUR ON CHRISTMAS EVE. THERE IS A GOOD CHANCE THAT
MANY AREAS WILL HAVE AT LEAST ADVISORY-LEVEL WINDS WITH SOME
MOUNTAIN AREAS POSSIBLY GETTING WARNING-LEVEL GUSTS (ESPECIALLY
THE SANTA LUCIA RANGE).
OVERALL, NEXT WEEK LOOKS TO BE A VERY SOGGY AND IMPACTFUL HOLIDAY
WEEK. GIVEN THE SIGNIFICANT AMOUNT OF RAINFALL, THERE WILL LIKELY
BE WIDESPREAD HYDROLOGIC ISSUES, INCLUDING POTENTIAL FOR MUD AND
DEBRIS FLOWS AND WIDESPREAD URBAN FLOODING. ALSO, THERE COULD BE
SOME SIGNIFICANT WINTER WEATHER ISSUES UP IN THE MOUNTAINS. SO, IF
TRAVELING ON CHRISTMAS EVE OR CHRISTMAS DAY, BE PREPARED FOR
IMPACTFUL WEATHER. STAY TUNED FOR THE LATEST FORECAST INFORMATION
AS THE DETAILS OF THIS PATTERN COULD CHANGE OVER THE COMING DAYS.
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
19/200 PM.
MODERATE TO HIGH CONFIDENCE IN WINDS AND SEAS PEAKING THIS
AFTERNOON AND EVENING, THEN DECREASING TO RELATIVELY CALM LEVELS
SATURDAY MORNING THROUGH MONDAY ACROSS THE ENTIRETY OF THE
COASTAL WATERS.
ON TUESDAY, WINDS AND SEAS WILL RAPIDLY INCREASE TO DANGEROUS
LEVELS, WITH WIDESPREAD GALE FORCE WINDS LIKELY, WITH VERY STRONG
GALES ALONG THE CENTRAL COAST. WINDS WILL BE FROM THE SE-SW
THROUGH THURSDAY, THEN THERE'S A MODERATE CHANCE FOR WINDS
WEAKENING AND TRANSITIONG TO NW-W 15-25 KTS FRIDAY.
A SHORT TO MODERATE PERIOD SE-SW SWELL WILL PRODUCE STEEP-CHOPPY
SEAS TUESDAY THROUGH THURSDAY, TRANSITIONING TO A LONGER PERIOD
NW-W SWELL BY FRIDAY. ALONG THE CENTRAL COAST AND ACROSS THE
OUTER WATERS WAVES THE MOST LIKELY OUTCOME ARE SEAS IN THE 10-16
FOOT RANGE. SOUTH OF POINT CONCEPTION IN THE 6-12 FOOT RANGE.
LARGER SEAS ARE EXPECTED TO ACCOMPANY THE NW SWELL COMPARED TO THE
SOUHTERLY SWELL AT THIS POINT.
IN ADDITION TO HAZARDOUS SEAS, RAIN WILL BE CONTINUOUS FROM
TUESDAY THROUGH THURSDAY, WITH CHANCES CONTINUING INTO THE
WEEKEND.
BOATERS SHOULD REMAIN IN SAFE HARBOR DURING THIS SIGNIFICANT
STORM. UNPROTECTED SOUTH FACING HARBORS MAY BE ESPECIALLY
VULNERABLE TO THE SOUTH SWELL AND WINDS.
BEACHES
19/200 PM.
A SHORT TO MODERATE PERIOD SOUTHERLY WIND SWELL WILL PRODUCE
DANGEROUS SURF AND STRONG RIP CURRENTS FROM TUESDAY THROUGH
THURSDAY. A LONGER PERIOD NW SWELL WILL TAKE OVER FRIDAY, AND
SURF WILL CONTINUE TO BE SIGNIFICANT.
THERE IS A RANGE OF OUTCOMES, BUT THE MOST LIKELY SCENARIO WILL
YIELD MAX SURF HEIGHTS OF 12-16 FEET ALONG THE CENTRAL COAST, AND
7-12 FEET SOUTH OF POINT CONCEPTION. HOWEVER, WAVE HEIGHTS COULD
BE A COUPLE FEET LARGER TUESDAY THROUGH THURSDAY AS STRONG
SOUTHERLY WINDS WILL BE OCCURING CONCURRENTLY WITH THE SOUTH
SWELL.
WHILE PEAK TIDES ARE NOT VERY HIGH, MINOR TO POTENTIALLY MODERATE
COASTAL FLOODING MAY OCCUR, ESPECIALLY FOR SOUTH FACING SHORES
TUESDAY THROUGH THURSDAY.
IT IS BEST TO REMAIN OUT OF THE WATER DURING THIS TIME.
LOX WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...SMALL CRAFT ADVISORY IN EFFECT UNTIL 9 PM PST THIS EVENING
FOR ZONES 645-650-670. (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY IN EFFECT UNTIL 9 AM PST SATURDAY FOR
ZONES 673-676. (SEE LAXMWWLOX).
PUBLIC...THOMPSON
AVIATION...LEWIS
MARINE...LEWIS
BEACHES...LEWIS
SYNOPSIS...30
WEATHER.GOV/LOSANGELES
EXPERIMENTAL GRAPHICAL HAZARDOUS WEATHER OUTLOOK AT:
HTTPS://WWW.WEATHER.GOV/ERH/GHWO?WFO=LOX
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