352
FXUS66 KSGX 241120
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
420 AM PDT MON AUG 24 2026
SYNOPSIS
MONSOONAL MOISTURE WILL MAINTAIN A SLIGHT CHANCE OF AFTERNOON
SHOWERS AND THUNDERSTORMS FOR THE MOUNTAINS AND DESERTS THROUGH
TUESDAY. A WARMING TREND WILL CONTINUE THROUGH THURSDAY WITH
WIDESPREAD MAJOR TO EXTREME HEATRISK FOR THE LOWER DESERTS,
VALLEYS, AND INLAND ORANGE COUNTY. WIDESPREAD MODERATE OR GREATER
HEATRISK EXCEPT FOR MOUNTAIN ELEVATIONS ABOVE 7000 FEET IS
EXPECTED TO CONTINUE THROUGH NEXT SATURDAY.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
..UPDATED AVIATION DISCUSSION
SHORT TERM (TODAY THROUGH WEDNESDAY)
THERE WILL BE A WARMING TREND THROUGH THURSDAY WITH HIGH
TEMPERATURES FOR TODAY AROUND 5 DEGREES ABOVE AVERAGE FOR THE
MOUNTAINS AND DESERTS AND 5 TO 10 DEGREES ABOVE AVERAGE FOR THE
COAST AND VALLEYS. HIGH TEMPERATURES FOR TODAY WILL RANGE FROM
AROUND 80 NEAR THE COAST TO THE UPPER 90S TO 106 FOR THE INLAND
EMPIRE WITH THE LOWER DESERTS AROUND 110.
PRECIPITABLE WATER VALUES WILL PEAK TODAY AND TUESDAY, THEN
DECREASE THROUGH NEXT WEEKEND. THERE IS A SLIGHT CHANCE OF SHOWERS
AND THUNDERSTORMS FOR THIS AFTERNOON AND TUESDAY AFTERNOON FOR THE
MOUNTAINS AND DESERTS.
LONG TERM (THURSDAY THROUGH SUNDAY)
THE WARMING TREND WILL CONTINUE THROUGH THURSDAY WITH HIGH
TEMPERATURES ON THURSDAY AROUND 10 DEGREES ABOVE AVERAGE FOR THE
MOUNTAINS AND DESERTS TO 10 TO 15 DEGREES ABOVE AVERAGE FOR THE
COAST AND VALLEYS. HIGH TEMPERATURES ON THURSDAY WILL RANGE FROM
THE 80S NEAR THE COAST TO 105 TO 110 FOR THE INLAND EMPIRE WITH
112 TO 116 FOR THE LOWER DESERTS. LOW TEMPERATURES ON THURSDAY
WILL BE AS MUCH AS 10 TO 15 DEGREES ABOVE AVERAGE FOR THE
MOUNTAINS AND INLAND VALLEYS. LOW TEMPERATURES FOR THE COAST AND
VALLEYS WILL BE MOSTLY IN THE 70S. THERE COULD BE A LARGE NUMBER
OF RECORDS FOR WARMEST LOW TEMPERATURES TIED OR BROKEN ON
THURSDAY AND FRIDAY.
TEMPERATURES WILL GRADUALLY COOL FOR FRIDAY THROUGH SUNDAY WITH
HIGH TEMPERATURES FOR SUNDAY AROUND 5 DEGREES ABOVE AVERAGE. HIGH
TEMPERATURES ON SUNDAY WILL RANGE FROM AROUND 80 NEAR THE COAST TO
THE MID 90S TO 103 FOR THE INLAND EMPIRE WITH 108 TO 112 FOR THE
LOWER DESERTS.
THE HEATRISK IS EXPECTED TO PEAK ON THURSDAY WITH MAJOR TO EXTREME
HEATRISK FOR THE LOWER DESERTS, VALLEYS, INLAND ORANGE COUNTY, AND
THE SANTA ANA MOUNTAINS WITH MODERATE TO MAJOR HEATRISK ELSEWHERE
EXPECTED FOR THE MOUNTAINS ABOVE 7000 FEET.
AVIATION
241130Z...COAST...PATCHY LOW CLOUDS BASED AROUND 300-800 FEET MSL
WITH VIS REDUCED 0-5SM WILL CONTINUE TEMPORARILY THROUGH 16Z. EVEN
FEWER AND PATCHIER LOW CLOUDS EXPECTED OVERNIGHT INTO TUESDAY.
MOUNTAINS/DESERTS...BUILDING CUMULUS BASED AROUND 9000 FEET MSL
LEADING TO CB CLOUDS WITH TOPS TO 45000 FEET AND SCT TSRA OVER
MOUNTAINS AND LOCALLY INTO ADJACENT DESERTS 19-02Z. ANY TS COULD
PRODUCE GUSTY, ERRATIC WINDS.
OTHERWISE...SCT TO LOCALLY BKN CLOUDS AOA 20000 FEET MSL BECOMING
MOSTLY CLEAR AFTER 03Z.
MARINE
NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED THROUGH FRIDAY.
BEACHES
A 4-5 FOOT SOUTHERLY SWELL (FROM 170 DEGREES) AT 13-15 SECONDS WILL
MOVE INTO THE AREA WEDNESDAY AND THURSDAY, LEADING TO ELEVATED SURF
FOR THE SOUTH FACING BEACHES OF NORTHERN SAN DIEGO COUNTY AND ORANGE
COUNTY. BREAKING WAVES OF 4 TO 6 FEET EXPECTED, SETS UP TO 8 FEET
POSSIBLE AT BEACHES THAT FACE DUE SOUTH. SURF GRADUALLY SUBSIDES ON
FRIDAY.
SKYWARN
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
SGX WATCHES/WARNINGS/ADVISORIES
CA...HEAT ADVISORY FROM 10 AM TUESDAY TO 8 PM PDT FRIDAY FOR ORANGE
COUNTY COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS.
HEAT ADVISORY UNTIL 10 AM PDT TUESDAY FOR ORANGE COUNTY INLAND
AREAS-SAN BERNARDINO AND RIVERSIDE COUNTY VALLEYS-THE
INLAND EMPIRE-SAN DIEGO COUNTY MOUNTAINS-SAN DIEGO COUNTY
VALLEYS-SANTA ANA MOUNTAINS AND FOOTHILLS.
EXTREME HEAT WARNING FROM 10 AM TUESDAY TO 8 PM PDT FRIDAY FOR
APPLE AND LUCERNE VALLEYS-ORANGE COUNTY INLAND AREAS-SAN
BERNARDINO AND RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE-
SAN DIEGO COUNTY MOUNTAINS-SAN DIEGO COUNTY VALLEYS-SANTA
ANA MOUNTAINS AND FOOTHILLS.
HEAT ADVISORY UNTIL 8 PM PDT FRIDAY FOR RIVERSIDE COUNTY
MOUNTAINS-SAN BERNARDINO COUNTY MOUNTAINS.
EXTREME HEAT WARNING UNTIL 8 PM PDT FRIDAY FOR COACHELLA VALLEY-
SAN DIEGO COUNTY DESERTS-SAN GORGONIO PASS NEAR BANNING.
PZ...NONE.
PUBLIC...MARTIN
AVIATION/MARINE/BEACHES...MM
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page