811
FXUS66 KSGX 271904
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
1204 PM PDT THU AUG 27 2026
SYNOPSIS
NEAR-RECORD HIGH PRESSURE FOR LATE AUGUST WILL CONTINUE HOT DAYS
AND NEAR-RECORD WARM NIGHTS THROUGH FRIDAY NIGHT WITH A SLIGHT
CHANCE OF SHOWERS AND THUNDERSTORMS FOR THE MOUNTAINS FOR THIS
AFTERNOON AND FRIDAY AFTERNOON. HIGH PRESSURE WILL WEAKEN FOR THE
WEEKEND INTO EARLY NEXT WEEK WITH HIGH TEMPERATURES COOLING TO
AROUND AVERAGE ON MONDAY OF NEXT WEEK. FOR TUESDAY AND WEDNESDAY
OF NEXT WEEK, THERE IS A 10 TO 20 PERCENT CHANCE FOR AN INCREASE
IN CLOUDS AND A CHANCE OF PRECIPITATION FROM A TROPICAL SYSTEM
THAT HAS YET TO DEVELOP.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
...UPDATED AVIATION DISCUSSION FOR 18Z TAF PACKAGE
SHORT TERM (TODAY THROUGH SATURDAY)
HIGH TEMPERATURES WILL REMAIN AROUND 10 DEGREES ABOVE AVERAGE
THROUGH FRIDAY WITH HIGH TEMPERATURES RANGING FROM THE 80S AT THE
BEACHES TO 100 TO 110 FOR THE INLAND EMPIRE WITH 112 TO 116 FOR
THE LOWER DESERTS. NIGHTS WILL REMAIN QUITE WARM THROUGH FRIDAY
NIGHT WITH NEAR-RECORD WARM OVERNIGHT TEMPERATURES, MOSTLY IN THE
70S FOR THE COAST AND VALLEYS AND IN THE MID 80S TO MID 90S FOR
THE LOWER DESERTS. MAJOR TO EXTREME HEATRISK WILL CONTINUE THROUGH
FRIDAY FOR THE LOWER DESERTS, INLAND VALLEYS, AND INLAND ORANGE
COUNTY.
MONSOONAL MOISTURE WILL MAINTAIN A SLIGHT CHANCE OF AFTERNOON
SHOWERS AND THUNDERSTORMS FOR THE MOUNTAINS THROUGH FRIDAY.
TEMPERATURES WILL BEGIN TO COOL A FEW DEGREES ON SATURDAY AS HIGH
PRESSURE ACROSS THE AREA BEGINS TO WEAKEN.
LONG TERM (SUNDAY THROUGH WEDNESDAY)
THE COOLING TREND WILL CONTINUE INTO EARLY NEXT WEEK, BUT WITH
INCREASING SPREAD IN THE TEMPERATURE GUIDANCE AFTER MONDAY. HIGH
TEMPERATURES AND LOW TEMPERATURES ON MONDAY WILL BE A FEW DEGREES
BELOW AVERAGE WITH HIGH TEMPERATURES ON MONDAY RANGING FROM THE
MID 70S TO LOWER 80S NEAR THE COAST TO THE 90S FOR THE INLAND
EMPIRE WITH 104 TO 108 FOR THE LOWER DESERTS.
FOR TUESDAY AND WEDNESDAY, THERE COULD BE AN INCREASE IN CLOUDS
AND A CHANCE OF PRECIPITATION FROM A TROPICAL SYSTEM THAT HAS YET
TO DEVELOP. THE CENTER OF THAT POSSIBLE TROPICAL SYSTEM WOULD
REMAIN WELL TO THE SOUTHWEST OF THE AREA, BUT A LOW PRESSURE
SYSTEM NEAR THE WEST COAST COULD DIRECT SOME MID AND HIGH LEVEL
MOISTURE AND CLOUDS FROM THAT POSSIBLE TROPICAL SYSTEM TOWARD THE
NORTHEAST AND TOWARD CALIFORNIA.
AVIATION
271800Z...COAST...LOW CLOUDS THIS MORNING HAVE LARGELY CLEARED OUT,
BUT REMAIN RIGHT ALONG THE IMMEDIATE COAST OF EXTREME SOUTHWESTERN
SAN DIEGO COUNTY. THESE CLOUDS ARE GENERALLY BASED AROUND 500FT MSL
AND WITHIN SOUTH-SOUTHWESTERLY FLOW, WILL LINGER IN THE VICINITY OF
KSAN INTO THE AFTERNOON. GUIDANCE SUGGESTS MARINE LAYER CLOUDS WILL
BE EVEN PATCHIER TONIGHT THAN THIS MORNING, WITH ONLY STRAY PATCHES
OFF THE NORTHERN SD/ORANGE COUNTY COASTS. BEST CHANCES FOR CIGS
OVERNIGHT REMAIN ACROSS THE SOUTHERN SAN DIEGO COUNTY COASTS, WITH
KSAN HAVING A ~70% CHANCE FOR CIGS BETWEEN 11-15Z FRIDAY, WITH A
~40% CHANCE AT KCRQ. BASES FOR ANY CLOUDS WOULD BE AROUND 500FT WITH
VIS RESTRICTIONS TO 3-6 SM IN BR. ANY CLOUDS THAT DO PUSH ONSHORE
WILL CLEAR BACK OUT OFFSHORE BY 16Z.
MOUNTAINS/DESERTS...CUMULUS BASED AROUND 9000 FEET MSL OVER THE
MOUNTAINS THIS AFTERNOON WITH ISOLATED CB CLOUD TOPS RISING TO 40000
FEET MSL. THERE IS A 15-20% CHANCE OF TSRA OVER THE MOUNTAINS AND A
5-15% CHANCE IN THE DESERTS UNTIL 01Z. ANY TS THAT DEVELOPS COULD
PRODUCE GUSTY, ERRATIC WINDS.
REGIONWIDE...HIGH CLOUDS AOA 15000 FEET MSL WILL CONTINUE TODAY AND
TONIGHT, DECREASING EARLY FRIDAY.
MARINE
NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED THROUGH MONDAY.
BEACHES
A 4-FOOT SOUTHERLY SWELL (FROM 170 DEGREES) AT 12-13 SECONDS WILL
CONTINUE TO PRODUCE ELEVATED SURF THROUGH TONIGHT, PARTICULARLY FOR
SOUTH-FACING BEACHES OF ORANGE COUNTY AND NORTHERN SAN DIEGO COUNTY.
SURF OF 3 TO 5 FEET, WITH SETS UP TO 7 FEET IS EXPECTED. SEE THE
COASTAL HAZARD MESSAGE FOR DETAILS ON BEACH HAZARDS.
SGX WATCHES/WARNINGS/ADVISORIES
CA...BEACH HAZARDS STATEMENT UNTIL 11 PM PDT THIS EVENING FOR ORANGE
COUNTY COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS.
HEAT ADVISORY UNTIL 8 PM PDT FRIDAY FOR ORANGE COUNTY COASTAL
AREAS-RIVERSIDE COUNTY MOUNTAINS-SAN BERNARDINO COUNTY
MOUNTAINS-SAN DIEGO COUNTY COASTAL AREAS.
EXTREME HEAT WARNING UNTIL 8 PM PDT FRIDAY FOR APPLE AND LUCERNE
VALLEYS-COACHELLA VALLEY-ORANGE COUNTY INLAND AREAS-SAN
BERNARDINO AND RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE-
SAN DIEGO COUNTY DESERTS-SAN DIEGO COUNTY MOUNTAINS-SAN
DIEGO COUNTY VALLEYS-SAN GORGONIO PASS NEAR BANNING-SANTA
ANA MOUNTAINS AND FOOTHILLS.
PZ...NONE.
PUBLIC...MARTIN
AVIATION/MARINE/BEACHES...MUNYAN
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