177
FXUS66 KLOX 090419
AFDLOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
919 PM PDT THU OCT 8 2026
SYNOPSIS
08/801 PM.
TEMPERATURES ACROSS THE REGION ARE EXPECTED TO TREND COOLER
FRIDAY INTO SUNDAY AND THERE WILL BE AN INCREASING CHANCE OF
SHOWERS AND THUNDERSTORMS DUE TO MOISTURE FROM HURRICANE RACHEL.
THESE SHOWERS COULD PERSIST INTO TUESDAY, WITH ANOTHER WARMING
TREND POSSIBLE WEDNESDAY THROUGH FRIDAY.
SHORT TERM (THU-SUN)
08/918 PM.
***UPDATE***
A FINAL DAY OF EXTREME HEAT ENDED WITH HIGHS IN THE MID 90S TO 102
DEGREES AWAY FROM THE COAST, WITH COASTAL HIGHS IN THE UPPER 70S
TO MID 80S. AN UPPER RIDGE OVER THE REGION WILL WEAKEN AS AN UPPER
LOW WEST OF MONTEREY MOVES SSE AND HEIGHTS LOWER ACROSS THE AREA.
IN ADDITION, SURFACE PRESSURE GRADIENTS ARE NOW ONSHORE AND WILL
CONTINUE TO STRENGTHEN OVER THE NEXT COUPLE OF DAYS. THE END
RESULT WILL BE MUCH COOLER WEATHER FRIDAY THROUGH EARLY NEXT WEEK.
THE HIGHS FRIDAY WILL BE IN THE MID 70S FOR THE COASTS, EXCEPT 60S
FOR THE CENTRAL COAST, WITH 80S TO MID 90S FURTHER INLAND. WITH
THE LOWERING HEIGHTS AND RETURN TO ONSHORE FLOW, THE MARINE LAYER
WILL LIKELY SHIFT FARTHER INLAND, COVERING MORE OF THE COASTAL
BASINS AND EXTENDING INTO SOME OF THE COASTAL VALLEYS.
ADDITIONAL COOLING ALONG WITH INCREASING LOW CLOUDS AND FOG IN THE
MORNING WILL BE ACCOMPANIED BY MID TO UPPER LEVEL CLOUDS MOVING
OVER THE AREA. THE UPPER LOW OFF THE COAST WILL CONTINUE TO MOVE
SOUTHWARD HEADING TOWARD TS RACHEL, AS A LONGWAVE TROUGH FORMS
ALONG THE WEST COAST. BY SATURDAY EVENING, THESE SYSTEMS ARE
FORECAST TO MERGE AND MOVE INLAND ACROSS THE SOCAL/BAJA BORDER.
THIS WILL PRODUCE A CHANCE OF SHOWERS FUELED BY TROPICAL MOISTURE
SATURDAY EVENING THROUGH EARLY TUESDAY, MAINLY SOUTH OF POINT
CONCEPTION, ALTHOUGH WITH LIGHT RAIN POSSIBLE FURTHER NORTH. WHILE
SOME UNCERTAINTY REMAINS AS TO RAIN AMOUNTS, THE TOTALS OVER
VENTURA AND LA COUNTIES WILL GENERALLY BE BETWEEN 0.25 TO 0.50
INCHES BUT UP TO 1.0 INCH IN THE MOUNTAINS. FARTHER NORTH,
AMOUNTS WILL LIKELY BE 0.10 INCH OR LESS.
BY SUNDAY, TEMPERATURES WILL BE IN THE 70S IN MOST PLACES, BUT
WITH A SIGNIFICANT INCREASE IN MOISTURE IT IS LIKELY TO FEEL VERY
MUGGY. A VERY LOW BUT NON-ZERO CHANCE OF THUNDERSTORMS WILL
ACCOMPANY THESE SHOWERS.
***FROM PREVIOUS DISCUSSION***
THE MAIN FORECAST ISSUE MOVING FORWARD IS THE UNCERTAINTY WITH THE
THE TRACK OF RACHEL AND THE POTENTIAL IMPACTS. SWELLS HAVE ALREADY
STARTED TO ARRIVE ON OUR SOUTHERN BEACHES AND IMPACTS WILL
INCREASE THROUGH SUNDAY. THE LAST FEW TRACKS OF RACHEL HAVE
TRENDED FARTHER SOUTH BUT MOST OF THE ENSEMBLE SOLUTIONS INDICATE
AT LEAST SOME TROPICAL SHOWERS SOUTH OF PT CONCEPTION BY SUNDAY,
AND AROUND 10% OF THE SOLUTIONS SHOW OVER AN INCH OF RAIN.
LATER SUNDAY INTO MONDAY AN UPPER LOW WILL MOVE SOUTH INTO
SOUTHERN CALIFORNIA AND POSSIBLY INTERACT WITH LINGERING TROPICAL
MOISTURE TO GENERATE ADDITIONAL SHOWER INTO MONDAY.
LONG TERM (MON-THU)
08/1213 PM.
ON MONDAY THE UPPER LOW WILL MOVE INTO THE VCNTY OF SBA COUNTY
WITH 557 DAM HGTS. THE LOW WILL BRING CLOUDS AND CHC OF RAIN TO
THE ENTIRE 4 COUNTY FORECAST AREA FROM MIDNIGHT TO MIDNIGHT. SINCE
MOST OF THE MOISTURE WILL BE TO THE EAST OF THE AREA RAINFALL
TOTALS WILL NOT BE THAT GREAT MOST AREAS CAN EXPECT TO RECIEVE A
TENTH TO A QUARTER INCH OF RAINFALL. MAX TEMPS WILL FALL FURTHER
TO THE MID 60S TO LOWER 70S.
THERE IS SOME DISAGREEMENT ON HOW FAST THE UPPER LOW WILL MOVE OUT
OF THE AREA. ENOUGH SOLUTIONS KEEP THE UPPER LOW AROUND LONG
ENOUGH TO KEEP A 20 TO 30 PERCENT CHC OF RAIN IN THE FORECAST.
EVEN IF IT DOES RAIN THERE WILL NOT BE MUCH ADDITIONAL RAINFALL.
ASIDE FROM A SMALL CHC OF A MTN SHOWER WEDNESDAY SHOULD BE DRY AS
DRIER NW FLOW MOVES INTO AND OVER THE STATE. SUNNIER SKIES AND
RISING TEMPS WILL BRING 3 TO 6 DEGREES OF WARMING. EVEN WITH THE
WARMING MAX TEMPS WILL END UP ABOUT 6 DEGREES BLO NORMAL.
AVIATION
09/0410Z.
AT 0400Z AT KLAX, THE MARINE LAYER WAS 800 FEET DEEP. THE TOP OF
THE INVERSION WAS 3500 FEET WITH A TEMPERATURE OF 27 DEGREES
CELSIUS.
FOR 06Z TAF PACKAGE, HIGH CONFIDENCE IN KPRB, KBUR, KVNY, KPMD
AND KWJF AS CAVU CONDITIONS ARE EXPECTED THROUGH THE PERIOD.
FOR COASTAL SITES, MODERATE CONFIDENCE IN 06Z TAFS AS TIMING OF
FLIGHT CATEGORY CHANGES COULD BE +/- 3 HOURS OF CURRENT FORECASTS
AND POSSIBLY OFF BY ONE FLIGHT CATEGORY.
KLAX...MODERATE CONFIDENCE IN 06Z TAF. TIMING OF FLIGHT CATEGORY
CHANGES COULD BE +/- 3 HOURS OF CURRENT FORECASTS. THERE IS A
30-4% CHANCE OF LIFR CONDITIONS 08Z-14Z. NO SIGNIFICANT EASTERLY
WIND COMPONENT IS EXPECTED.
KBUR...HIGH CONFIDENCE IN 06Z TAF AS CAVU CONDITIONS ARE EXPECTED
THROUGH THE PERIOD.
MARINE
08/747 PM.
RELATIVELY QUIET CONDITIONS ARE EXPECTED ACROSS THE COASTAL
WATERS THROUGH MUCH OF SATURDAY. LOCALIZED SMALL CRAFT ADVISORY
(SCA) GUSTS MAY OCCUR EACH AFTERNOON AND EVENING BETWEEN POINT
CONCEPTION AND SAN NICOLAS ISLAND. NIGHT THROUGH MORNING DENSE FOG
MAY AFFECT PORTIONS OF THE COASTAL WATERS ADJACENT TO THE CENTRAL
COAST AND SOUTH TO SAN NICOLAS ISLAND ONCE THROUGH FRIDAY MORNING
(OCT 9TH).
NORTHWEST TO SOUTHWEST WINDS WILL INCREASE TO 20-30 KNOTS BY
SATURDAY AFTERNOON/EVENING, BECOMING MUCH MORE EXPANSIVE ALL OF
SUNDAY AND INTO EARLY MONDAY MORNING. THERE IS A 30-40% CHANCE OF
GALE FORCE WINDS ON SUNDAY, PRIMARILY FOCUSED ACROSS THE
NEARSHORE WATERS ADJACENT TO LOS ANGELES AND ORANGE COUNTIES.
LARGE, STEEP, AND CHOPPY SEAS WILL DEVELOP SATURDAY, CONTINUING
THROUGH AT LEAST MONDAY. THIS FAIRLY RAPID AND SIGNIFICANT
INCREASE IN WINDS IS DUE TO A VERY COMPLEX SITUATION AS AN
UNSEASONABLY COLD TROUGH DROPS DOWN THE CALIFORNIA COAST,
INTERACTING WITH REMNANTS OF TROPICAL STORM RACHEL, WHICH WILL
SOON TURN NORTHEAST AND MOVE TOWARDS THE CALIFORNIA/MEXICO BORDER
COASTLINE OVER THE NEXT COUPLE OF DAYS. IT IS WORTH NOTING THAT
THE PROJECTED TRACK OF TROPICAL STORM RACHEL HAS SHIFTED FURTHER
SOUTH, MOST LIKELY MAKING LANDFALL IN NORTHERN BAJA CALIFORNIA.
IN ADDITION THE THE INCREASING GUSTY WINDS, WIDESPREAD LIGHT TO
MODERATE RAINFALL IS LIKELY SATURDAY EVENING THROUGH TUESDAY,
WITH HIGHEST CONFIDENCE FOR SUNDAY-MONDAY. THERE IS A 10% CHANCE
OF THUNDERSTORMS DURING THE SAME TIMEFRAME. WHILE SHOWERS OR
THUNDERSTORMS ARE POSSIBLE ANYWHERE, HIGHEST CHANCES EXIST SOUTH
OF POINT CONCEPTION.
AS THIS IS A COMPLEX AND EVOLVING SITUATION, PLEASE CONTINUE TO
MONITOR THE FORECAST.
BEACHES
08/747 PM.
A COASTAL FLOOD ADVISORY IS IN EFFECT THROUGH TUESDAY AFTERNOON
FOR LOS ANGELES AND VENTURA COUNTIES, WHILE A BEACH HAZARDS
STATEMENT (BHS) IS IN EFFECT FOR THE SANTA BARBARA SOUTH COAST AND
THE CENTRAL COAST.
A VERY COMPLEX SERIES OF SWELLS FROM THE SOUTH, WEST, AND
NORTHWEST WILL IMPACT OUR COASTLINES INTO AT LEAST EARLY NEXT
WEEK. ENERGY FROM TROPICAL STORM RACHEL, SOUTHERN HEMISPHERE
SWELLS, NORTHWEST SWELLS, AND LOCAL WIND SWELLS WILL ADD UP WITH
EACH OTHER TO PRODUCE ELEVATED SURF AND DANGEROUS RIP CURRENTS AT
TIMES. EXTREMELY HIGH TIDES WILL BE COMMON EACH MORNING, PEAKING
BETWEEN 6.8 TO 7.6 FEET MLLW, HIGHEST FURTHER SOUTH. ADDITIONALLY
SECONDARY HIGH TIDES WILL PEAK EACH EVENING, LIKELY MOST IMPACTFUL
THROUGH THE WEEKEND WITH TIDES REACHING 5.5 TO 6.5 FEET MLLW.
WHILE EACH DAY UNDER THE COASTAL FLOOD ADVISORIES OR BHS SHOULD
SEE FAIRLY SIMILAR IMPACTS, SUNDAY WILL LIKELY SEE ELEVATED
IMPACTS. RAPIDLY INCREASING WIND SPEEDS WILL LIKELY ADD TO THE
COASTAL FLOODING POTENTIAL, CREATING A WIND SWELL AS WELL AS
ELEVATING TIDES SLIGHTLY. ADDITIONALLY, IF RACHEL'S TRACK
DEVIATES A BIT MORE TO THE NORTH THAT WOULD RESULT IN LOWER
MEAN SEA LEVEL PRESSURE CONTRIBUTING TO EVEN HIGHER WATER LEVELS.
IF ALL THESE INGREDIENTS OVERLAP ON SUNDAY, A MORE SIGNIFICANT
COASTAL FLOODING EVENT WILL BE LIKELY. THIS IS A VERY NARROW
WINDOW, BUT THERE IS A LOW CHANCE FOR A TARGETED COASTAL FLOOD
WARNING TO BE ISSUED IN SOUTHERN LOS ANGELES COUNTY IF ALL FACTORS
LINE UP.
AS THIS IS A COMPLEX AND EVOLVING SITUATION, PLEASE CONTINUE TO
MONITOR THE FORECAST.
LOX WATCHES/WARNINGS/ADVISORIES
CA...COASTAL FLOOD ADVISORY IN EFFECT UNTIL 2 PM PDT TUESDAY FOR
ZONES 87-354-362-366. (SEE LAXCFWLOX).
BEACH HAZARDS STATEMENT IN EFFECT FROM SATURDAY MORNING
THROUGH MONDAY AFTERNOON FOR ZONES 340-346-349-350. (SEE LAXCFWLOX).
PZ...NONE.
PUBLIC...MW/CILIBERTI
AVIATION...RAT
MARINE...LEWIS/BLACK
BEACHES...LEWIS/BLACK
SYNOPSIS...MW/CILIBERTI
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