863
FXUS66 KSGX 121753
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
1053 AM PDT THU MAR 12 2026
SYNOPSIS
STRENGTHENING HIGH PRESSURE ALOFT AND WEAK OFFSHORE FLOW WILL
BRING NEAR-RECORD HIGH TEMPERATURES TO MUCH OF SOUTHWESTERN
CALIFORNIA TODAY AND INLAND FROM THE COAST ON FRIDAY. ONSHORE FLOW
FOR THE WEEKEND WILL BRING SOME COOLING FOR THE COAST INTO THE
VALLEYS BUT WITH HIGH TEMPERATURES REMAINING WELL ABOVE AVERAGE.
FOR NEXT WEEK, STRONGER HIGH PRESSURE ALOFT WILL BRING ADDITIONAL
WARMING FOR INLAND AREAS WITH RECORD OR NEAR-RECORD HEAT FOR
MARCH FOR MUCH OF NEXT WEEK. WIDESPREAD MODERATE OR GREATER HEAT
RISK IS EXPECTED FOR MUCH OF NEXT WEEK BEGINNING ON MONDAY FOR
THE VALLEYS, INLAND ORANGE COUNTY, AND THE LOWER DESERTS WITH
HEAT-RELATED ILLNESSES LIKELY FOR SENSITIVE POPULATIONS.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
..NEW AVIATION DISCUSSION FOR THE 18Z TAF PACKAGE
SHORT TERM (TODAY THROUGH SATURDAY)
THERE WILL BE WEAK OFFSHORE LOWER-LEVEL TODAY WITH HIGH PRESSURE
ALOFT CONTINUING TO STRENGTHEN. NORTHEAST WINDS WILL GUST TO 25 TO
35 MPH ALONG AND BELOW THE COASTAL SLOPES OF THE MOUNTAINS. HIGH
PRESSURE ALOFT WILL BEGIN TO WEAKEN ON FRIDAY AND CONTINUE TO
WEAKEN ON SATURDAY AS A LOW PRESSURE SYSTEM MOVES INLAND THROUGH
THE PACIFIC NORTHWEST. WEAK ONSHORE FLOW WILL RETURN FRIDAY AND
SATURDAY WITH THE LOCAL WRF SHOWING A COASTAL EDDY DEVELOPING ON
FRIDAY NIGHT AND CONTINUING FOR SATURDAY NIGHT ALONG WITH SOME
DEEPENING OF THE MARINE LAYER.
MID AND HIGH CLOUDS ARE STILL EXPECTED TO SPREAD ACROSS THE AREA
FOR LATE FRIDAY THROUGH LATE SATURDAY. THIS COULD PROVIDE SOME
DISRUPTION TO THE LOW CLOUDS AND FOG THAT MIGHT OTHERWISE RETURN
TO THE COAST FOR FRIDAY NIGHT INTO SATURDAY MORNING. AS THAT MID
AND HIGH LEVEL MOISTURE MOVES EAST OF THE AREA FOR SATURDAY NIGHT,
A RETURN OF LOW CLOUDS AND FOG ALONG THE COAST IS MORE LIKELY FOR
SATURDAY NIGHT INTO SUNDAY MORNING.
THE HEAT ADVISORY CONTINUES FOR THE COAST AND VALLEYS FOR TODAY
AND FRIDAY. HIGH TEMPERATURES FOR THE COAST AND WESTERN VALLEYS
WILL WARM 12 TO 18 DEGREES TODAY WITH HIGH TEMPERATURES FOR INLAND
COASTAL AREAS INTO THE WESTERN VALLEYS AS MUCH AS 20 TO 25
DEGREES ABOVE AVERAGE. FOR THE COAST AND VALLEYS, HIGH
TEMPERATURES WILL RANGE FROM THE LOWER TO MID 80S NEAR THE COAST
TO THE LOWER TO MID 90S FOR INLAND COASTAL AREAS INTO THE WESTERN
VALLEYS WITH THE LOWER DESERTS IN THE MID TO UPPER 90S. WIDESPREAD
MODERATE HEAT RISK IS EXPECTED TODAY FOR INLAND COASTAL AREAS
INTO THE VALLEYS. MUCH OF SOUTHWESTERN CALIFORNIA WILL HAVE HIGH
TEMPERATURES NEAR OR EXCEEDING RECORD HIGH TEMPERATURES FOR THE
DATE.
FOR FRIDAY, HIGH TEMPERATURES WILL COOL SLIGHTLY FOR COASTAL AREAS
WITH THE MOUNTAINS AND DESERTS WARMING A FEW DEGREES. FOR
SATURDAY, GREATER COOLING OF HIGH TEMPERATURES OF 4 TO 8 DEGREES
IS EXPECTED FOR THE COAST AND VALLEYS ONTO THE COASTAL SLOPES OF
THE MOUNTAINS. SATURDAY HIGH TEMPERATURES WILL BE AROUND 10
DEGREES ABOVE AVERAGE NEAR THE COAST AND 15 TO 20 DEGREES ABOVE
AVERAGE FOR THE VALLEYS, MOUNTAINS, AND DESERTS WITH HIGH
TEMPERATURES RANGING FROM THE 70S NEAR THE COAST TO THE 80S FOR
THE VALLEYS AND INLAND ORANGE COUNTY WITH THE LOWER DESERTS IN THE
MID TO UPPER 90S.
LONG TERM (SUNDAY THROUGH WEDNESDAY)
FOR THE WEEKEND, HIGH PRESSURE WILL STRENGTHEN OFF THE WEST COAST
WITH STRONG HIGH PRESSURE ALOFT MOVING TO NEAR THE WEST COAST ON
MONDAY, THEN ONLY VERY SLOWLY INLAND FOR TUESDAY AND WEDNESDAY.
THE STRONGEST HIGH PRESSURE ALOFT WILL BE CENTERED OVER SOUTHERN
CALIFORNIA ON TUESDAY AND WEDNESDAY WITH SLIGHT STRENGTHENING OF
THAT HIGH PRESSURE FOR THURSDAY AND FRIDAY. ECMWF ENSEMBLE
GUIDANCE FOR INLAND AREAS IS WARMER AND TRENDING WARMER FOR THE
LATTER HALF OF NEXT WEEK.
ON SUNDAY, THE GREATEST WARMING IS EXPECTED FOR THE INLAND VALLEYS
ONTO THE LOWER COASTAL SLOPES OF THE MOUNTAINS AS HIGH PRESSURE
ALOFT BEGINS TO STRENGTHEN. WARMING OF A FEW TO AROUND 5 DEGREES
WILL OCCUR FOR MOST AREAS ON MONDAY AND AGAIN ON TUESDAY WITH HIGH
TEMPERATURES ON TUESDAY AROUND 30 DEGREES ABOVE AVERAGE FOR THE
INLAND VALLEYS ONTO THE LOWER COASTAL SLOPES OF THE MOUNTAINS.
ON TUESDAY, HIGH TEMPERATURES NEAR THE COAST WILL BE MOSTLY IN THE
LOWER TO MID 80S WITH INLAND ORANGE COUNTY AND THE SAN DIEGO
COUNTY VALLEYS MOSTLY IN THE 90S WITH THE INLAND EMPIRE IN THE
UPPER 90S TO 102. THE LOWER DESERTS WILL REACH 103 TO 107.
SEVERAL RECORD HIGH TEMPERATURES FOR THE MONTH OF MARCH COULD BE
TIED OR BROKEN, ESPECIALLY FOR THE DESERTS, INLAND VALLEYS, AND
PORTIONS OF INLAND ORANGE COUNTY.
THE MOUNTAINS AND DESERTS WILL CONTINUE TO SLOWLY WARM FOR
WEDNESDAY AND THURSDAY WHILE THERE COULD BE SOME DAY-TO-DAY
FLUCTUATIONS FOR COASTAL AREAS. NBM PROBABILITIES FOR THE THERMAL
HIGH TEMPERATURE TO EQUAL OR EXCEED 110 INCREASES TO 50 PERCENT ON
WEDNESDAY AND 65 PERCENT ON THURSDAY.
AVIATION
1218000Z...VFR WITH SKC-FEW250. LIGHT OFFSHORE AND NORTHERLY WINDS
FOR MOST LOCATIONS, WITH WIND GUSTS NEAR 20-30 KTS AT TIMES BELOW
PASSES IN THE INLAND EMPIRE THROUGH EARLY EVENING.
MARINE
NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED THROUGH
TUESDAY.
BEACHES
LONG PERIOD SOUTHERLY 2-3 FT SWELL AT 19-21 SECONDS WILL
CREATE ELEVATED SURF AND A HIGH RIP CURRENT RISK ALONG SOUTH AND
SOUTHWEST-FACING BEACHES THROUGH TONIGHT. SURF HEIGHTS PEAKING AT 3-
6 FEET WITH SETS TO 7 FEET.
SKYWARN
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
SGX WATCHES/WARNINGS/ADVISORIES
CA...HEAT ADVISORY UNTIL 8 PM PDT FRIDAY FOR ORANGE COUNTY COASTAL
AREAS-ORANGE COUNTY INLAND AREAS-SAN BERNARDINO AND
RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE-SAN DIEGO COUNTY
COASTAL AREAS-SAN DIEGO COUNTY VALLEYS.
PZ...NONE.
PUBLIC...17
AVIATION/MARINE...APR
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