984
FXUS66 KSGX 181004
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
304 AM PDT WED MAR 18 2026
SYNOPSIS
RECORD STRONG HIGH PRESSURE FOR MARCH OVER A BROAD AREA WILL
CONTINUE TO WARM SOUTHWESTERN CALIFORNIA THE NEXT FEW DAYS WITH
WIDESPREAD RECORD HEAT FOR MARCH CONTINUING INTO THE WEEKEND FOR
INLAND AREAS. THROUGH FRIDAY, LOWEST DAYTIME HUMIDITY FOR INLAND
AREAS WILL RANGE FROM AROUND 10 PERCENT FOR THE DESERTS TO 10 TO
15 PERCENT FOR THE INLAND VALLEYS. FOR THE WEEKEND INTO EARLY NEXT
WEEK, HIGH PRESSURE ALOFT WILL SLOWLY WEAKEN AND WEAK ONSHORE
LOWER-LEVEL FLOW WILL RETURN WITH COOLING AND HIGHER COASTAL
HUMIDITY SPREADING INLAND. EVEN WITH THE COOLING, HIGH
TEMPERATURES FOR NEXT TUESDAY WILL RANGE FROM AROUND 5 TO 10
DEGREES ABOVE AVERAGE NEAR THE COAST TO 12 TO 18 DEGREES ABOVE
AVERAGE FOR INLAND AREAS. WIDESPREAD MODERATE OR GREATER HEAT RISK
WILL CONTINUE INTO THE WEEKEND EXCEPT NEAR THE IMMEDIATE COAST AND
IN THE HIGHER ELEVATIONS IN THE MOUNTAINS.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
SHORT TERM (TODAY THROUGH FRIDAY)
WIDESPREAD MODERATE OR GREATER HEAT RISK WILL CONTINUE INTO THE
WEEKEND EXCEPT NEAR THE IMMEDIATE COAST AND IN THE HIGHER
ELEVATIONS IN THE MOUNTAINS. FOR THURSDAY AND FRIDAY, SOME
PORTIONS OF THE LOWER DESERTS, INLAND VALLEYS, AND INLAND ORANGE
COUNTY WILL REACH MAJOR HEAT RISK WHICH CAN BE DANGEROUS TO ANYONE
WITHOUT PROPER HYDRATION OR ADEQUATE COOLING.
HIGH PRESSURE CONTINUES TO STRENGTHEN ACROSS SOUTHWEST CALIFORNIA
WITH RECORD HIGH PRESSURE FOR MARCH FOR A LARGE AREA COVERING THE
SOUTHWEST STATES AND SURROUNDING AREAS. THERE WILL CONTINUE TO BE
WIDESPREAD RECORDS TIED OR BROKEN FOR RECORD HIGH TEMPERATURES AND
RECORD WARM LOW TEMPERATURES EXCEPT NEAR THE BEACHES. THERE WILL
ALSO BE A GROWING NUMBER OF MONTHLY RECORDS FOR HEAT FOR MARCH
THAT WILL ALSO BE TIED OR BROKEN.
OUTSIDE OF THE IMMEDIATE COAST, THURSDAY AND FRIDAY ARE LIKELY TO
BE THE HOTTEST DAYS DEPENDING ON LOCATION WITH HIGH TEMPERATURES
AS MUCH AS 30 TO 35 DEGREES ABOVE AVERAGE FOR THE INLAND VALLEYS
AND LOWER ELEVATIONS OF THE MOUNTAINS. HIGH TEMPERATURES WILL
RANGE FROM THE 80S NEAR THE COAST TO THE UPPER 90S TO 104 FOR THE
INLAND EMPIRE WITH 108 TO 112 FOR THE LOWER DESERTS. THE EXISTING
RECORD HIGHEST TEMPERATURE FOR THE UNITED STATES FOR MARCH APPEARS
TO BE 108, REACHED THREE DIFFERENT TIMES ACROSS TWO LOCATIONS IN
SOUTH TEXAS.
LONG TERM (SATURDAY THROUGH TUESDAY)
HIGH PRESSURE ALOFT AND WEAK ONSHORE FLOW WILL RETURN FOR THE
WEEKEND INTO EARLY NEXT WEEK WITH COOLING SPREAD INLAND. EVEN WITH
THE COOLING, HIGH TEMPERATURES FOR NEXT TUESDAY WILL STILL BE WELL
ABOVE AVERAGE, RANGING FROM 5 TO 10 DEGREES ABOVE AVERAGE NEAR THE
COAST TO 12 TO 18 DEGREES ABOVE AVERAGE FOR INLAND AREAS. HIGH
TEMPERATURES FOR NEXT TUESDAY WILL RANGE FROM THE LOWER TO MID 70S
NEAR THE COAST TO THE MID 80S TO LOWER 90S FOR THE INLAND EMPIRE
WITH THE LOWER DESERTS AROUND 100. DAILY RECORDS FOR HEAT WILL
LIKELY CONTINUE BE SET EARLY NEXT WEEK FOR SOME LOCATIONS IN THE
MOUNAINS, DESERTS, AND INLAND VALLEYS.
NIGHT AND MORNING LOW CLOUDS WILL MOST LIKELY RETURN OVER THE
WEEKEND FOR SOME COASTAL AREAS, POSSIBLY EXTENDING INLAND INTO THE
FAR WESTERN VALLEYS AT TIMES DURING THE WEEKEND.
AVIATION
180930Z...MOSTLY CLEAR SKIES AND VFR CONDITIONS TODAY AND TONIGHT.
PATCHY FOG OVER COASTAL WATERS TONIGHT INTO THURSDAY, BUT UNLIKELY
TO IMPACT COASTAL AIRPORTS.
MARINE
NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED THROUGH
SUNDAY.
CLIMATE
FOR TUESDAY, THERE WERE 13 DAILY RECORDS FOR RECORD WARM HIGH
TEMPERATURES THAT WERE BROKEN WITH ONE TIED, WHILE 10 LOCATIONS
SET DAILY RECORDS FOR WARMEST LOW TEMPERATURE. THE 100 DEGREE HIGH
TEMPERATURES FOR ANAHEIM AND SANTA ANA WERE RECORDS FOR MARCH WITH
THE PRIOR EARLIEST 100+ DEGREE TEMPERATURE FOR BOTH LOCATIONS IN
EARLY APRIL. THE LOW TEMPERATURE OF 75 AT PALM SPRINGS WAS A
MARCH RECORD WITH THE PRIOR EARLIEST DATE FOR A LOW TEMPERATURE SO
WARM BEING APRIL 21ST.
THE 500 MB HEIGHT OF 592 DM AT NKX LATE TUESDAY AFTERNOON IS A
NEW RECORD FOR MARCH WITH RECORDS GOING BACK TO 1956. THE PRIOR
RECORD OF 590 DM OCCURRED ON MARCH 21ST. THE PRIOR EARLIEST DATE
FOR A 500 MB HEIGHT OF 592 DM OR GREATER FOR NKX WAS ON MAY 11TH.
AN INCREASING NUMBER OF MONTHLY HEAT RECORDS FOR MARCH WILL BE
BROKEN OR TIED THE NEXT FEW DAYS FOR INLAND AREAS.
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-SANTA ANA MOUNTAINS
AND FOOTHILLS.
HEAT ADVISORY FROM 10 AM THIS MORNING TO 8 PM PDT FRIDAY FOR
RIVERSIDE COUNTY MOUNTAINS-SAN BERNARDINO COUNTY MOUNTAINS-
SAN DIEGO COUNTY MOUNTAINS.
EXTREME HEAT WARNING FROM 10 AM THIS MORNING TO 8 PM PDT
SATURDAY FOR COACHELLA VALLEY-SAN DIEGO COUNTY DESERTS-SAN
GORGONIO PASS NEAR BANNING.
PZ...NONE.
PUBLIC/CLIMATE...17
AVIATION/MARINE...MM
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