846
FXUS66 KLOX 200458
AFDLOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
858 PM PST WED FEB 19 2025
SYNOPSIS
19/812 PM.
GUSTY NORTH TO NORTHEAST WINDS ARE EXPECTED OVER THE MOUNTAINS AND
SOME COAST AND VALLEYS TONIGHT THROUGH THE REMAINDER OF THIS
WEEK. TEMPERATURES WILL BE WARMING UP QUITE A BIT THIS WEEKEND,
TOPPING OUT IN THE 70S AND 80S IN MANY PLACES. IT WILL REMAIN DRY
THROUGH MUCH OF NEXT WEEK.
SHORT TERM (WED-SAT)
19/857 PM.
***UPDATE***
NOT MUCH CHANGE NOTED IN THE 00Z MODEL CYCLE TONIGHT. NORTHERLY
GRADIENTS ARE INCREASING TONIGHT RESULTING IN SOME GUSTY WINDS
ACROSS THE GRAPEVINE REGION AND SOUTHWEST SANTA BARBARA COUNTY.
WINDS MOSTLY IN THE 25-45 MPH RANGE IN THOSE AREAS BUT WITH SOME
VERY LOCALIZED GUSTS TO 55-60 MPH IN THE HIGHER MOUNTAIN AREAS.
WINDS WILL VEER TO THE EAST THURSDAY MORNING INTO EARLY AFTERNOON,
CREATING A VERY LOW END SANTA ANA THROUGH THE HIGHWAY 14/126
CORRIDOR WITH PEAK AROUND 30-45 MPH IN THE MOUNTAINS AND FOOTHILLS
AND 15-30 MPH ACROSS THE VALLEYS AND VENTURA COASTAL PLAIN.
CLOSER TO THE COAST THERE WILL BE SOMEWHAT RANDOM STRATUS PATCHES
WITH REDUCED VISIBILITIES. MOST LIKELY ACROSS THE LA BASIN AND
CENTRAL COAST.
ONE POTENTIAL MINOR CHANGE IN THE MODELS HAS BEEN A SLOW BUT
STEADY DECREASE IN THE OFFSHORE GRADIENTS AND UPPER SUPPORT FOR
FRIDAY. STILL EXPECTING AT LEAST SANTA ANA WINDS FRIDAY BUT
PROBABLY JUST VERY LOW END ADVISORY LEVELS.
***FROM PREVIOUS DISCUSSION***
THE TAIL-END OF A WEAKENING COLD FRONT WILL SWEEP ACROSS THE
REGION ON THURSDAY, BRINGING AN UPTICK IN OFFSHORE FLOW ESPECIALLY
OVER THE HIGH TERRAIN THROUGH THE REST OF THIS WEEK. UPPER
SUPPORT PERIPHERAL TO A VIGOROUS SHORTWAVE TROUGH TRACKING ACROSS
THE GREAT BASIN, ASSOCIATED WITH THE FRONT, WILL SUPPORT VERY
LOCALIZED GUSTS TO 60 MPH IN THE MOUNTAINS. OTHERWISE, GUSTS OF
45-55 MPH WILL BE COMMON OVER THE MOUNTAINS AND FOOTHILLS, AS LAX-
BAKERSFIELD AND SBA-BAKERSFIELD OFFSHORE PRESSURE GRADIENTS REACH
AROUND 5-6 MB -- STRONGEST THURSDAY INTO THURSDAY NIGHT. EXPECT
WINDS TO INITIALLY FAVOR A SUNDOWNER WIND REGIME OVER SOUTHERN
SANTA BARBARA COUNTY THIS AFTERNOON AND EVENING, WITH GUSTY
NORTHWEST TO NORTH WINDS OVERSPREADING MUCH OF THE REMAINDER OF
HIGH TERRAIN LATER THIS EVENING AND INTO TONIGHT AND THURSDAY.
WITH TIME, THE EASTWARD PROGRESSION OF THE SHORTWAVE TROUGH AND
UPSTREAM SURFACE HIGH PRESSURE WILL RE-ORIENT LOCAL PRESSURE
GRADIENTS TO ALIGN WITH THE LAX-DAGGETT CORRIDOR, RESULTING IN
WEAK TO MODERATE SANTA ANA WINDS GOING INTO FRIDAY. AS A RESULT
THERE IS A 60% CHANCE FOR WIND ADVISORIES TO BE EXTENDED BEYOND
CURRENT EXPIRATION TIMES FOR WIND-PRONE AREAS IN SUBSEQUENT
FORECASTS. BY SATURDAY, PRESSURE GRADIENTS AND RELATED SURFACE
WINDS WILL BE CONSIDERABLY WEAKER, AS AN UPPER RIDGE AXIS SETS UP
OVER THE FORECAST AREA.
AFTER NEAR TO SLIGHTLY ABOVE-NORMAL TEMPERATURES ON THURSDAY, THE
COMBINATION OF THE OFFSHORE FLOW AND THE BUILDING UPPER RIDGE
WILL FACILITATE AT LEAST A COUPLE DEGREES OF WARMING EACH DAY
GOING INTO FRIDAY AND SATURDAY, WITH FRIDAY AND SATURDAY HIGH
TEMPERATURES EXPECTED TO BE 5-15 DEGREES ABOVE NORMAL IN MANY
AREAS -- REACHING THE 70S TO THE LOWER 80S IN MOST PLACES.
LONG TERM (SUN-WED)
19/226 PM.
THE UPPER RIDGE WILL REMAIN OVER THE LOCAL AREA INTO SUNDAY, WHEN
IT IS PROJECTED TO HAVE BUILT EVEN FURTHER, CHARACTERIZED BY
500-MB HEIGHTS NEARING OR EXCEEDING 586 DAM. AND WITH LIGHT
OFFSHORE PRESSURE GRADIENTS, TEMPERATURES WILL BE SOARING WELL
INTO THE 80S -- PERHAPS UPPER 80S IN SOME OF THE WARMER SPOTS
SUCH AS WOODLAND HILLS. EVEN NEAR THE COAST IT SHOULD BE WELL INTO
THE 70S FOR HIGHS ON SUNDAY. ALTOGETHER SUNDAY WILL BE A VERY
WARM DAY WITH HIGHS AROUND 10-20 DEGREES ABOVE NORMAL IN MOST
LOCATIONS. TEMPERATURES WILL GRADUALLY COOL OFF BY A DEGREE OR
TWO EACH DAY GOING INTO MONDAY THROUGH WEDNESDAY, AS THE UPPER
RIDGE FLATTENS OVER THE AREA PERIPHERAL TO A SHORTWAVE TROUGH
TRAVERSING THE NORTHWEST STATES. THE LOW-LEVEL MASS RESPONSE TO
THE PASSAGE OF THIS WAVE WILL BRING LIGHT TO MODERATE OFFSHORE
FLOW FOR EARLY TO MIDDLE PARTS OF NEXT WEEK, THOUGH STRONG WINDS
ARE NOT EXPECTED. IT WILL REMAIN DRY FOR THE REST OF THIS WEEKEND
INTO MIDDLE PARTS OF NEXT WEEK.
AVIATION
20/0105Z.
AROUND 00Z, THE MARINE LAYER DEPTH WAS AROUND 500 FEET DEEP AT
KLAX. THE TOP OF THE INVERSION WAS 1700 FEET WITH A TEMPERATURE
AROUND 18 DEGREES CELSIUS.
MODERATE CONFIDENCE EXISTS IN THE FORECAST. THERE IS A HIGH
CHANCE OF LIFR TO IFR CONDITIONS AT LOS ANGELES COUNTY COASTAL
TERMINALS BETWEEN 04Z AND 17Z, AND A LOW-TO-MODERATE CHANCE OF
LIFR TO IFR AT ALL OTHER TERMINALS BETWEEN 08Z AND 17Z. THERE IS A
MODERATE CHANCE OF MODERATE TO STRONG WIND SHEAR AT COASTAL AND
VALLEY TERMINALS AFTER 06Z THROUGH 20Z.
KLAX...THERE IS A 50 PERCENT CHANCE OF LIFR CONDITIONS AS SOON AS
04Z, OR AS LATE AS 08Z. THERE IS A 30 PERCENT CHANCE OF VLIFR
CONDITIONS BETWEEN 10Z AND 16Z. VFR CONDITIONS COULD DEVELOP AS
SOON AS 15Z, OR AS LATE AS 18Z. ANY EAST WINDS WILL LIKELY REMAIN
LESS THAN 7 KNOTS.
KBUR...VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD, EXCEPT FOR
A 10 PERCENT CHANCE OF LIFR CONDITIONS BETWEEN 13Z AND 15Z.
PERIODS OF MODERATE LOW-LEVEL WIND SHEAR ARE POSSIBLE BETWEEN 13Z
AND 16Z.
MARINE
19/846 PM.
DENSE FOG WILL LIKELY REFORM IN SPOTS TONIGHT INTO THURSDAY.
HIGH CONFIDENCE IN SMALL CRAFT ADVISORY (SCA) WINDS CONTINUING
THROUGH AT LEAST EARLY FRIDAY OVER THE WATERS 20 MILES OFFSHORE.
MODERATE CONFIDENCE IN LOW-END SCA WINDS TONIGHT OVER TTHE
WESTERN HALF OF THE SANTA BARBARA CHANNEL. SOME LOCAL GUSTS TO 25
KNOTS ARE POSSIBLE NEAR MALIBU THURSDAY MORNING.
THE WINDS WILL TURN NORTHEAST ON FRIDAY. THERE IS A 70 PERCENT
CHANCE OF SCA-LEVEL WINDS FROM VENTURA TO SANTA MONICA, A 20
PERCENT CHANCE FROM THE ORANGE COUNTY COAST TO CATALINA ISLAND,
AND A 30 PERCENT CHANCE NEARSHORE ON THE CENTRAL COAST. MODERATE
CONFIDENCE IN FAIRLY QUIET CONDITIONS OVER THE WEEKEND.
LOX WATCHES/WARNINGS/ADVISORIES
CA...WIND ADVISORY REMAINS IN EFFECT UNTIL NOON PST THURSDAY FOR
ZONES 88-342-345-352-353-372-375>379. (SEE LAXNPWLOX).
WIND ADVISORY REMAINS IN EFFECT UNTIL 2 AM PST THURSDAY FOR
ZONES 349-351. (SEE LAXNPWLOX).
WIND ADVISORY REMAINS IN EFFECT FROM 4 AM TO NOON PST
THURSDAY FOR ZONES 362-369>371-374. (SEE LAXNPWLOX).
PZ...SMALL CRAFT ADVISORY IN EFFECT UNTIL 9 PM PST THIS EVENING
FOR ZONE 645. (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY IN EFFECT UNTIL 3 AM PST THURSDAY FOR
ZONE 650. (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY IN EFFECT UNTIL 3 AM PST FRIDAY FOR
ZONES 670-673-676. (SEE LAXMWWLOX).
PUBLIC...MW/COHEN
AVIATION...HALL
MARINE...HALL
SYNOPSIS...MW/COHEN
WEATHER.GOV/LOSANGELES
EXPERIMENTAL GRAPHICAL HAZARDOUS WEATHER OUTLOOK AT:
HTTPS://WWW.WEATHER.GOV/ERH/GHWO?WFO=LOX
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