415
FXUS66 KLOX 022224
AFDLOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
324 PM PDT SUN AUG 2 2026
SYNOPSIS
02/1205 AM.
TODAY WILL BE THE HOTTEST DAY OF THE WEEK. STILL, ABOVE NORMAL
TEMPERATURES ARE EXPECTED WELL INTO NEXT WEEK. DENSE FOG WILL
AFFECT SOME COASTAL AREAS.
SHORT TERM (TDY-WED)
02/1257 PM.
TEMPERATURES HAVE BEGUN TO COOL TODAY AS OUR NATURAL AIR
CONDITIONER (IE. THE OCEAN BREEZE) KICKS IN. MOST AREAS ARE ONLY
DOWN 2-4 DEGREES BUT THE EARLIER ONSET OF THE SEA BREEZE IS
BRINGING SOME OVERDUE RELIEF AT LEAST TO COAST AND VALLEYS.
UNFORTUNATELY, THAT TREND IS NOT REACHING FARTHER INTERIOR AREAS
LIKE THE DESERT, THE INTERIOR MOUNTAINS, AND INTERIOR SLO AND
SANTA BARBARA COUNTIES SO LITTLE CHANGE THERE.
GOING FORWARD, THERE WILL BE A VERY MODEST COOL DOWN FOR COAST AND
COASTAL VALLEYS THE NEXT COUPLE DAYS, BUT INTERIOR AREAS NOT SO
MUCH, AND ESPECIALLY THE DESERTS. LATEST TEMPERATURE GUIDANCE
THERE SUGGESTS MINIMAL COOL DOWN, IF ANY, THROUGH AT LEAST MID
WEEK AND POSSIBLY THROUGH NEXT WEEKEND AS 950MB TEMPS REMAIN IN
THE 38-40C RANGE, WHICH TYPICALLY MEANS CLOSING IN ON 110 ACROSS
THE DESERTS AND 100+ IN THE OTHER FAR INLAND LOCATIONS MENTIONED
ABOVE. FOR NOW HAVE GONE AHEAD AND EXTENDED THE DESERT EXTREME
HEAT WARMING THROUGH WEDNESDAY, MATCHING OUR NEIGHBORING FORECAST
OFFICES. WILL LIKELY NEED TO DO THE SAME FOR THE REST OF THE
FAR INTERIOR AREAS BUT WILL HOLD OFF UNTIL AT LEAST THE CURRENT
HEAT HAZARD ENDS THIS EVENING. NOT EXPECTING TO NEED ANY HEAT
HAZARDS FOR THE COAST OR COASTAL VALLEYS AT LEAST THROUGH MID WEEK
AS THERE WILL BE ENOUGH ONSHORE FLOW TO KEEP TEMPERATURES MORE
MODERATE (THOUGH STILL ABOVE NORMAL BY 1-5 DEGREES.
THE ONLY OTHER POTENTIAL HAZARD MAY BE SOME PATCHY DENSE FOG NEAR
THE INTERIOR EDGE OF THE MARINE STRATUS PUSH, WHICH MAY JUST
BARELY SQUEAK INTO THE COASTAL VALLEYS.
LONG TERM (THU-SUN)
02/1254 PM.
AFTER TUESDAY TEMPERATURE TRENDS ARE EXPECTED TO LEVEL OFF AND
POSSIBLY INCREASE A DEGREE OR TWO AS HIGH PRESSURE OVER AZ NUDGES
WEST AGAIN THROUGH NEXT WEEKEND. IN ADDITION, THERE ARE SOME
SIGNALS IN THE ENSEMBLE PRESSURE GRADIENTS INDICATING SOME LIGHT
OFFSHORE TRENDS TOWARDS THE END OF THIS COMING WEEK THAT COULD
RESULT IN WARMING TEMPERATURES ACROSS THE COAST AND VALLEYS AS
WELL. AND AS MENTIONED, IT WILL REMAIN VERY HOT OVER THE INTERIOR
AND WOULD ESTIMATE AT LEAST A 60% CHANCE OF EXTENDED THE DESERT
EXTREME HEAT WARNING THROUGH THE END OF THE WEEK AND AROUND A
20-30 PERCENT CHANCE OF AT LEAST HEAT ADVISORIES FOR THE COASTAL
VALLEYS. ONE FACTOR THAT WILL NEED TO BE MONITORED IS MODELS ARE
STILL INDICATING INCREASING MONSOON MOISTURE LATER IN THE WEEK,
ESPECIALLY BY THE WEEKEND, THAT COULD INTRODUCE ANOTHER HEAT RISK
FACTOR WITH HIGHER HUMIDITIES AND IN TURN WARMER OVERNIGHT LOWS.
AVIATION
02/1829Z.
AT 18Z AT KLAX, THE MARINE LAYER WAS 1400 FT DEEP. THE TOP OF THE
INVERSION WAS NEAR 2300 FEET WITH A TEMP OF 27 DEGREES CELSIUS.
HIGH CONFIDENCE IN VFR CONDS FOR KPRB, KBUR, KVNY, KPMD AND KWJF.
LOW TO MODERATE CONFIDENCE ELSEWHERE WITH TIMING OFF BY 2-3 HOURS
AND AND 20-40 PERCENT THAT VFR CONDS PREVAIL. THERE IS ALSO A
20-30 PERCENT CHANCE OF AN EARLY ARRIVAL SOMETIME 23-03Z FOR
KOXR, KLAX, KSMO.
KLAX...MODERATE CONFIDENCE IN TAF. THERE IS A 20 PERCENT CHANCE
THAT VFR CONDS WILL PREVAIL TONIGHT. NO SIGNIFICANT EAST WIND
COMPONENT EXPECTED.
KBUR...HIGH CONFIDENCE IN CAVU TAF.
MARINE
02/1116 AM.
FOR THE WESTERN PORTION OF THE SANTA BARBARA CHANNEL AND THE
INNER WATERS NORTH OF POINT SAL, THERE IS A 30-40% CHANCE OF SCA
WINDS DURING THIS AFTERNOON AND EVENING HOURS. OTHERWISE
CONDITIONS ARE EXPECTED TO REMAIN BELOW SCA LEVELS.
FOR THE OUTER WATERS, SMALL CRAFT ADVISORY (SCA) WINDS AND SEAS
WILL CONTINUE THROUGH TONIGHT BEFORE BEGINNING TO SUBSIDE EARLY
THIS COMING WEEK. WINDS WILL GENERALLY PEAK AT AROUND 30 KNOTS,
STRONGEST DURING THE EVENING HOURS.
SEAS OF 7-10 FEET WILL IMPACT THE OUTER WATERS THROUGH TODAY, DUE
TO A COMBINATION OF LONG-PERIOD SOUTHERLY SWELL FROM A DISTANT
TROPICAL CYCLONE AND SHORTER- PERIOD NORTHWESTERLY SWELL/WIND-
WAVES CAUSED BY THE PREVALENT NW WINDS. AS A RESULT, STEEP,
HAZARDOUS SEAS WILL BE COMMON, ESPECIALLY OVER THE OUTER WATERS,
EXTENDING TO NEARSHORE WATERS OFF THE CENTRAL COAST. SEAS WILL
BEGIN TO SUBSIDE AS THE WINDS WEAKEN LATE TONIGHT INTO EARLY NEXT
WEEK.
DENSE FOG WILL AFFECT SOME OF THE COASTAL WATERS EACH NIGHT AND
MORNING THROUGH MUCH OF THE WEEK.
FIRE WEATHER
02/323 PM.
TODAY THROUGH SATURDAY, WIDESPREAD ELEVATED TO BRIEF CRITICAL
CONDITIONS WILL BE COMMON ACROSS THE INTERIOR VALLEYS, MOUNTAINS,
AND DESERTS DUE TO HOT, DRY, AND BREEZY ONSHORE CONDITIONS WITH AN
INCREASED RISK FOR LARGE PLUME DOMINATED FIRE BEHAVIOR AND RAPID
FIRE GROWTH DUE TO DEEP MIXING HEIGHTS. FOR MUCH OF THIS WEEK,
DEEP MIXING HEIGHTS OF 10,000 TO 17,000 FEET CAN BE EXPECTED
ACROSS THE INTERIOR, WITH PEAK HEIGHTS LIKELY BY MID TO LATE WEEK
AS THE ATMOSPHERE BECOMES SLIGHTLY MORE UNSTABLE. IF ANY FIRE
IGNITIONS OCCUR ACROSS THE INTERIOR, THESE DEEPER MIXING HEIGHTS
WILL ALLOW FOR LARGE VERTICAL PLUME GROWTH, ESPECIALLY IN THE
MOUNTAINS AND FOOTHILLS, WHERE LIVE FUEL MOISTURE LEVELS ARE
APPROACHING CRITICAL LEVELS.
OTHER FACTORS THAT WILL ADD TO THE FIRE WEATHER RISK ACROSS THE
INTERIOR THIS WEEK WILL BE SOUTHWEST TO NORTHWEST WINDS 10 TO 25
MPH WITH GUSTS 20 TO 35 MPH, AS WELL AS WIDESPREAD AND LONG
DURATION SINGLE DIGIT HUMIDITIES. AS A RESULT, EXPECTING AT LEAST
A FEW HOURS OF WIND/RH OVERLAP TO REACH BRIEF CRITICAL FIRE
WEATHER CONDITIONS ACROSS MANY INTERIOR AREAS EACH AFTERNOON AND
EARLY EVENING. THERE IS A 20-30 PERCENT CHANCE OF RED FLAG
DURATIONS BEING REACHED (6+ HOURS) ACROSS PORTIONS OF THE INTERIOR
SOMETIME BETWEEN TUESDAY AND SATURDAY. THE HIGHEST RISK AREAS
INCLUDE SAN LUIS OBISPO COUNTY INTERIOR MOUNTAINS/VALLEYS, CUYAMA
VALLEY, SANTA BARBARA COUNTY INTERIOR MOUNTAINS, VENTURA COUNTY
INTERIOR MOUNTAINS, AND I-5 CORRIDOR. HOT-DRY-WINDY INDEX ENSEMBLE
SOLUTIONS SHOWING SEVERAL MODEL MEMBERS EXCEEDING 95TH PERCENTILE
FOR MULTIPLE DAYS ACROSS INTERIOR SAN LUIS OBISPO, SANTA BARBARA
COUNTY INTERIOR MOUNTAINS, VENTURA COUNTY INTERIOR MOUNTAINS, AND
I-5 CORRIDOR. IN ADDITION, THERE WILL BE VERY POOR TO POOR
OVERNIGHT HUMIDITY RECOVERIES, ESPECIALLY IN THE MOUNTAINS AND
FOOTHILLS WHERE SOME LOCATIONS MAY CONTINUE TO HAVE HUMIDITIES IN
THE TEENS.
LOX WATCHES/WARNINGS/ADVISORIES
CA...EXTREME HEAT WARNING IN EFFECT UNTIL 8 PM PDT THIS EVENING
FOR ZONES 38-88-343>345-351>353-356>358-368>376-378-379-548. (SEE LAXNPWLOX).
HEAT ADVISORY IN EFFECT UNTIL 8 PM PDT THIS EVENING FOR ZONES
342-348>350-354-355-362-366-367-377-380. (SEE LAXNPWLOX).
EXTREME HEAT WARNING IN EFFECT UNTIL 8 PM PDT WEDNESDAY FOR
ZONES 381>383. (SEE LAXNPWLOX).
PZ...SMALL CRAFT ADVISORY IN EFFECT UNTIL 3 AM PDT MONDAY FOR
ZONES 670-673-676. (SEE LAXMWWLOX).
PUBLIC...MW
AVIATION...MUNROE
MARINE...CILIBERTI/RS/RM
FIRE...GOMBERG
SYNOPSIS...RK/CILIBERTI
WEATHER.GOV/LOSANGELES
EXPERIMENTAL GRAPHICAL HAZARDOUS WEATHER OUTLOOK AT:
HTTPS://WWW.WEATHER.GOV/ERH/GHWO?WFO=LOX
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