423
FXUS66 KLOX 051605
AFDLOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
905 AM PDT MON OCT 5 2026
SYNOPSIS
05/230 AM.
A MAJOR AND LONG LASTING HEAT WAVE WILL TO PERSIST THROUGH AT
LEAST THURSDAY WITH DANGEROUSLY HIGH TEMPERATURES. FRIDAY INTO
SUNDAY, TEMPERATURES WILL TREND COOLER EACH DAY AND THERE IS A
SMALL CHANCE OF SHOWERS AND THUNDERSTORMS DUE TO MOISTURE FROM
DISTANT HURRICANE RACHEL.
SHORT TERM (TDY-WED)
05/905 AM.
***UPDATE***
THE HEAT WAVE CONTINUES. HOWEVER, THERE IS A SMALL RAY OF HOPE
THAT AT LEAST THE BEACHES AND UP TO A FEW MILES INLAND MAY BE AS
MUCH AS 5-10 DEGREES COOLER TODAY AS OFFSHORE GRADIENTS HAVE
WEAKENED BY ALMOST A MILLIBAR. MOST AREAS ARE TRENDING COOLER SO
FAR THIS MORNING BUT BY AFTERNOON EXPECTING MOST LOCATIONS AWAY
FROM THE IMMEDIATE COAST TO BE VERY CLOSE IN TEMPERATURE TO
YESTERDAY. AND VERY LITTLE CHANGE NOW THROUGH AT LEAST THURSDAY.
***FROM PREVIOUS DISCUSSION***
VERY LITTLE CHANGE IN THE DAYS 1 TO 3 FORECAST WITH THE DANGEROUS
HEAT WAVE CONTINUING THROUGH THE PERIOD AND BEYOND. WEAK UPPER
LEVEL HIGH PRESSURE WITH HGTS AROUND 589 DAM WILL BE OVERHEAD
THROUGH THE PERIOD. AT THE SFC THERE WILL BE OFFSHORE FLOW IN THE
MORNING AND LIKELY PERSISTING INTO THE AFTERNOON (THE MDLS HAVE
BEEN OVER FORECASTING THE ONSHORE FLOW IN THE AFTERNOON).
RECORD OR NEAR RECORD HEAT WILL PERSIST. MOST HIGHS ACROSS THE
CSTS AND VLYS WILL BE 90S TO 104 DEGREES BOTH TODAY AND TUESDAY.
AREAS SOUTH OF PT CONCEPTION ARE FORECAST TO COOL SOME WITH A
SLIGHTLY BETTER SEA BREEZE, BUT AT THE SAME TIME THE CENTRAL COAST
WILL WARM TO 95 TO 104 DEGREES AS SOME OFFSHORE FLOW DEVELOPS
THERE. EVEN THE BEACHES WILL GIVE LITTLE RELIEF WITH HIGHS THERE
IN THE UPPER 80S. THESE HIGHS ARE 15 TO 22 DEGREES OVER NORMAL
OVERNIGHT LOWS WILL REMAIN WARM AS WELL. MOST LOWS WILL ONLY DIP
TO THE UPPER 60S TO MID 70S. THERE WILL BE EVEN BE SOME LOW IN THE
80S IN THE MOUNTAINS AND FOOTHILLS RIGHT AT THE TOP OF THE
INVERSION.
ALL OF THE CSTS/VLYS AS WELL AS MANY MTN AND INLAND AREAS ARE
UNDER HEAT ADVISORIES AND EXTREME HEAT WARNING THROUGH THURSDAY.
PLEASE SEE THE PRODUCT LAXNPWLOX FOR ALL OF THE DETAILS.
LONG TERM (THU-SUN)
05/229 AM.
SOME COASTAL COOLING IS FORECAST FOR THURSDAY ESP ACROSS THE
CENTRAL COAST. THIS COOLING IS DEPENDENT ON THE GRADIENT FORECAST
BEING CORRECT AND THERE IS A 30 PERCENT CHC THAT THE COOLING WILL
NOT BE AS MUCH AS FORECAST. WHATEVER THE COOLING IT WILL NOT BE
ENOUGH TO END THE HEAT THREAT AND ALL HEAT WARNINGS AND ADVISORIES
WILL CONTINUE INTO THE EVENING.
THERE IS GOOD CONSENSUS THAT ON FRIDAY THE UPPER HIGH WILL BE
REPLACED BY WEAK CYCLONIC FLOW AND HGTS WILL FALL TO 583 DAM.
MOST IMPORTANTLY THERE WILL BE ONSHORE FLOW TO THE EAST AND ONLY
WEAK OFFSHORE FLOW FROM THE NORTH. HIGHS WILL STILL BE ABOVE
NORMAL WITH 80S AND LOWER 90S ACROSS THE CSTS AND 90S IN THE VLYS.
A FEW AREAS IN LA COUNTY MAY STILL NEED HEAT ADVISORIES, BUT
OVERALL IT WILL BE A WARM BUT NOT DANGEROUSLY HOT DAY.
ACTUAL TROFFING MOVES INTO THE STATE ON SATURDAY. ONSHORE FLOW
WILL INCREASE AS WELL. MARINE LAYER STRATUS WILL LIKELY BEGIN TO
FORM ACROSS SOME OF THE COASTS. MAX TEMPS WILL DROP 4 TO 8 DEGREES
ACROSS THE BOARD. EVEN WITH THIS COOLING MOST MAX TEMPS WILL END
UP 3 TO 6 DEGREES OVER NORMAL.
THE MOISTURE FROM HURRICANE RACHEL WILL BEGIN TO MOVE INTO THE
AREA ON SUNDAY. IT WILL PRODUCE A 20-30 PERCENT CHC OF SHOWERS
MOSTLY OVER LA COUNTY AND POINTS SOUTH. CONTINUED TROFFING AND
ONSHORE FLOW WILL BRING A MORE ROBUST MARINE LAYER CLOUD PATTERN
AND AN ADDITIONAL 4 TO 8 DEGREES OF COOLING. THIS COOLING WILL
BRING A RETURN OF BLO NORMAL MAX TEMPS.
SWELL FROM HURRICANE RACHEL WILL LIKELY ARRIVE TUESDAY.
AVIATION
05/0930Z.
AT 0822Z AT KLAX, THERE WAS NO MARINE LAYER. THERE WAS A SFC
BASED INVERSION WITH A TOP AT 800 FT WITH A TEMPERATURE OF 32 C.
MODERATE CONFIDENCE IN TAFS FOR KSMX WITH A 30 PERCENT CHC OF
VLIFR CONDS 13Z-16Z. FAIR CONFIDENCE IN TAF FOG KSBP WITH A 15
PERCENT CHC OF VLIFR CONDS 13Z-16Z.
HIGH CONFIDENCE IN THE REMAINDER OF THE CAVU TAFS.
KLAX...HIGH CONFIDENCE IN CAVU TAF. GOOD CONFIDENCE THAT ANY EAST
WIND COMPONENT WILL REMAIN BELOW 7KTS.
KBUR...HIGH CONFIDENCE IN CAVU TAF.
MARINE
05/207 AM.
GENERALLY QUIET CONDITIONS ARE EXPECTED ACROSS THE COASTAL WATERS
THROUGH THE FORECAST PERIOD. LOCALIZED SMALL CRAFT ADVISORY (SCA)
GUSTS MAY OCCUR EACH AFTERNOON AND EVENING BETWEEN POINT
CONCEPTION AND SAN NICOLAS ISLAND, OFF THE COAST OF POINT DUME,
AND ACROSS THE SAN PEDRO CHANNEL. WINDS OVER THE OUTER WATERS WILL
BEGIN TO INCREASE WEDNESDAY NIGHT THROUGH FRIDAY WITH A 30%
CHANCE OF SCA GUSTS AT TIMES, MAINLY DURING THE AFTERNOON TO
EVENING HOURS.
NIGHT THROUGH MORNING DENSE FOG MAY AFFECT PORTIONS OF THE
COASTAL WATERS WEST OF THE CHANNEL ISLANDS AND POINT CONCEPTION
THROUGH THURSDAY.
LOX WATCHES/WARNINGS/ADVISORIES
CA...EXTREME HEAT WARNING IN EFFECT UNTIL 8 PM PDT THURSDAY FOR
ZONES 38-87-88-349>358-362-366>375-548-550. (SEE LAXNPWLOX).
BEACH HAZARDS STATEMENT IN EFFECT FROM TUESDAY AFTERNOON
THROUGH FRIDAY EVENING FOR ZONES 87-354-362-366. (SEE LAXCFWLOX).
HEAT ADVISORY IN EFFECT FROM 10 AM WEDNESDAY TO 8 PM PDT
THURSDAY FOR ZONES 340-346. (SEE LAXNPWLOX).
HEAT ADVISORY IN EFFECT UNTIL 8 PM PDT THURSDAY FOR ZONES
341>345-347-348. (SEE LAXNPWLOX).
PZ...NONE.
PUBLIC...MW/RORKE
AVIATION...RORKE
MARINE...CILIBERTI
SYNOPSIS...SCHOENFELD/KL/CILIBERTI
WEATHER.GOV/LOSANGELES
EXPERIMENTAL GRAPHICAL HAZARDOUS WEATHER OUTLOOK AT:
HTTPS://WWW.WEATHER.GOV/ERH/GHWO?WFO=LOX
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