608
FXUS66 KLOX 211126
AFDLOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
426 AM PDT SUN JUN 21 2026
SYNOPSIS
20/229 PM.
BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH THE WEEKEND, WITH
A DEEP MARINE LAYER, AS WELL AS GUSTY WINDS OVER THE INTERIOR. A
SIGNIFICANT WARMING TREND WILL START MONDAY AND PEAK AROUND
WEDNESDAY. A PUSH OF MOISTURE MIDWEEK WILL BRING AT LEAST A LOW
CHANCE FOR RAIN.
SHORT TERM (TDY-TUE)
21/105 AM.
OVERALL, 00Z MODELS IN GOOD SYNOPTIC AGREEMENT THROUGH THE SHORT
TERM PERIOD. AT UPPER LEVELS, RIDGE WILL NOSE IN OVER THE AREA
THROUGH TUESDAY AS HIGH PRESSURE DEVELOPS OVER SOUTHERN ARIZONA
AND NEW MEXICO. AT THE SURFACE, MODERATE TO STRONG ONSHORE FLOW
WILL PREVAIL WITH SOME WEAK NORTHERLY OFFSHORE FLOW.
FORECAST-WISE, NO MAJOR CHANGES TO THINKING OF PREVIOUS SHIFTS.
WITH GRADUAL INCREASE IN H5 HEIGHTS, THE MARINE INVERSION SHOULD
BECOME A BIT MORE SHALLOW THROUGH THE PERIOD. SO, THE EXPECTED
AREAL COVERAGE OF STRATUS SHOULD GRADUALLY DIMINISH THROUGH
TUESDAY. HOWEVER, GIVEN THE CURRENT CHAOTIC NATURE OF THE STRATUS
DEVELOPMENT, CONFIDENCE IN THE EXACT BEHAVIOR OF THE MARINE LAYER
IS MODERATE AT BEST. OTHER THAN ANY STRATUS ISSUES, SKIES SHOULD
REMAIN MOSTLY CLEAR THROUGH TUESDAY.
AS FOR TEMPERATURES, THE COMBINATION OF THE RIDGE BUILDING
OVERHEAD AND LESS MARINE INFLUENCE WILL ALLOW FOR A NICE WARMING
TREND FOR ALL AREAS. FOR TODAY, THERE WILL BE ABOUT 2-5 DEGREES OF
WARMING FOR MOST AREAS. ON MONDAY AND TUESDAY, COASTAL AREAS WILL
SEE ABOUT 2-4 DEGREES OF WARMING EACH DAY WHILE THE VALLEYS AND
INTERIOR SECTIONS EXPERIENCE ABOUT 4-8 DEGREES OF WARMING EACH
DAY. WITH THIS WARMING TREND, THERE WILL BE SOME AREAS OF MODERATE
HEAT RISK ON TUESDAY, MAINLY ACROSS LA COUNTY. CURRENTLY, AN
EXCESSIVE HEAT WATCH REMAINS IN EFFECT, BEGINNING TUESDAY, FOR THE
VALLEYS, MOUNTAINS AND INTERIOR COASTAL PLAIN OF LA COUNTY. GIVEN
THE INCREASED TOURIST ACTIVITY ACROSS LA COUNTY, THE WATCH REMAINS
REASONABLE AND WILL LIKELY BE UPGRADED TO AN ADVISORY BY LATER
SHIFTS.
AS FOR WINDS, NO SIGNIFICANT ISSUES ARE EXPECTED. THE MODERATE TO
STRONG ONSHORE PRESSURE GRADIENTS WILL CONTINUE TO GENERATE GUSTY
SOUTHWESTERLY WINDS IN THE AFTERNOON/EVENING HOURS ACROSS INTERIOR
SECTIONS. HOWEVER, ANY ADVISORY-LEVEL WINDS WILL REMAIN LOCALIZED
ACROSS THE DESERT FOOTHILLS. SO, NO WIND PRODUCTS ARE EXPECTED AT
THIS TIME.
LONG TERM (WED-SAT)
21/105 AM.
THROUGH THE EXTENDED PERIOD, MODELS CONTINUE TO EXHIBIT GOOD
SYNOPTIC AGREEMENT. AT UPPER LEVELS, RIDGE SLOWLY WEAKENS
WEDNESDAY AND THURSDAY WITH BROAD CYCLONIC FLOW DEVELOPING ON
FRIDAY AND SATURDAY. AT THE SURFACE, MODERATE TO STRONG ONSHORE
FLOW WILL CONTINUE WITH SOME INCREASE IN NORTHERLY OFFSHORE FLOW
LATER IN THE PERIOD.
FORECAST-WISE, MAIN ISSUE IN THE EXTENDED PERIOD WILL BE
TEMPERATURES. ON WEDNESDAY, THERE WILL BE SOME SLIGHT WARMING IN
MOST AREAS. THESE WARM TEMPERATURES ON WEDNESDAY MAY BE
EXACERBATED A BIT DUE TO SOME INCREASE IN MID-LEVEL MOISTURE
ACROSS THE AREA. ON THURSDAY, THERE WILL BE SOME SLIGHT COOLING,
BUT CONDITIONS, OVERALL, WILL REMAIN QUITE WARM. SO, THE EXCESSIVE
HEAT WATCH WILL REMAIN IN EFFECT FOR PARTS OF LA COUNTY THROUGH
THURSDAY WITH A GOOD CHANCE THAT IT WILL BE UPGRADED TO AN
ADVISORY BY LATER SHIFTS. FOR FRIDAY AND SATURDAY, THERE WILL BE
SEVERAL DEGREES OF AREA-WIDE COOLING EACH DAY AS THE RIDGE
RETREATS TO THE EAST.
SECONDARY CONCERN FOR THE EXTENDED WILL BE INCREASING MID-LEVEL
MOISTURE ACROSS THE AREA ON WEDNESDAY. CURRENT DETERMINISTIC
MODELS INDICATE INCREASING PWATS ACROSS VENTURA AND LA COUNTIES
WITH VALUES ANYWHERE FROM 100-150% (GFS) AND 125-200% (ECMWF) OF
NORMAL FOR LATE JUNE. THE RESPECTIVE ENSEMBLE SOLUTIONS INDICATE
THE SAME PWAT TREND. THERE REALLY DOES NOT SEEM TO BE ANY
NOTICEABLE "TRIGGER" IN THE ATMOSPHERE TO KICK OFF ANY CONVECTIVE
ACTIVITY. HOWEVER, GIVEN THE TIME OF YEAR, WILL INDICATE 5-15%
CHANCE POPS ACROSS VENTURA AND LA COUNTIES WEDNESDAY AFTERNOON
AND EVENING WITH THE HIGHEST POPS OVER THE HIGHER TERRAIN. IF
ANYTHING DOES DEVELOP, IT WILL BE HIGH-BASED, RESULTING IN LIMITED
RAINFALL. IF ANY THUNDERSTORMS WERE TO DEVELOP, DRY LIGHTNING AND
GUSTY OUTFLOW WINDS WOULD BE THE MAIN CONCERNS. THIS WILL NEED TO
BE WATCHED CLOSELY OVER THE COMING DAYS.
AVIATION
21/1125Z.
AT 1100Z AT KLAX, THE MARINE LAYER WAS AROUND 1000 FEET DEEP. THE
TOP OF THE INVERSION WAS 4300 FEET WITH A TEMPERATURE OF 18 DEGREES
CELSIUS.
FOR THE 12Z TAF PACKAGE, HIGH CONFIDENCE IN KSBA, KBUR, KVNY,
KPMD AND KWJF.
FOR ALL OTHER SITES, LOW TO MODERATE CONFIDENCE IN 12Z TAF. TIMING
OF FLIGHT CATEGORY CHANGES COULD BE +/- 3 HOURS OF CURRENT
FORECASTS. FOR KSMO, KLAX AND KLGB, THERE IS A 40-50% CHANCE OF
MVFR CIGS THIS MORNING.
KLAX...LOW CONFIDENCE IN 12Z TAF. THERE IS A 40% CHANCE THAT MVFR
CIGS DEVELOP IN THE 12Z-18Z TIME FRAME. FOR TONIGHT, MODERATE
CONFIDENCE IN RETURN OF CIG RESTRICTIONS, BUT LOW CONFIDENCE IN
TIMING (+/- 3 HOURS OF CURRENT FORECAST). NO SIGNIFICANT EASTERLY
WIND COMPONENT IS EXPECTED.
KBUR...HIGH CONFIDENCE IN 12Z TAF AS CAVU CONDITIONS ARE EXPECTED
THROUGH THE PERIOD.
MARINE
21/105 AM.
FOR THE OUTER WATERS, MODERATE TO HIGH CONFIDENCE IN CURRENT
FORECAST. TODAY THROUGH WEDNESDAY, HIGH CONFIDENCE IN WINDS AND
SEAS REMAINING BELOW SMALL CRAFT ADVISORY (SCA) LEVELS. ON
THURSDAY, THERE IS A 30-50% CHANCE OF SCA LEVEL WINDS, BEGINNING
IN THE LATE AFTERNOON HOURS ACROSS PZZ670/673.
FOR THE INNER WATERS NORTH OF POINT SAL AND SOUTH OF POINT
CONCEPTION, HIGH CONFIDENCE IN CURRENT FORECAST. TODAY THROUGH
THURSDAY, WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SCA LEVELS.
LOX WATCHES/WARNINGS/ADVISORIES
CA...EXTREME HEAT WATCH IN EFFECT FROM TUESDAY MORNING THROUGH
THURSDAY EVENING FOR ZONES 88-368-372-373-379-380-548. (SEE LAXNPWLOX).
PZ...NONE.
PUBLIC...THOMPSON
AVIATION...RAT
MARINE...RAT
SYNOPSIS...RK
WEATHER.GOV/LOSANGELES
EXPERIMENTAL GRAPHICAL HAZARDOUS WEATHER OUTLOOK AT:
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