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FXUS66 KSGX 251753
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
1053 AM PDT TUE AUG 25 2026
SYNOPSIS
A SLIGHT CHANCE OF AFTERNOON SHOWERS AND THUNDERSTORMS WILL
CONTINUE FOR THE MOUNTAINS THROUGH WEDNESDAY AS MONSOONAL MOISTURE
SLOWLY DECREASES. HIGH AND LOW TEMPERATURES WILL CONTINUE TO WARM
THROUGH THURSDAY, TO AS MUCH AS 10 TO 15 DEGREES ABOVE AVERAGE,
WITH NOT MUCH CHANGE FOR FRIDAY. THE HIGHEST HEATRISK IS EXPECTED
FOR THURSDAY AND FRIDAY WITH WIDESPREAD EXTREME HEATRISK FOR THE
INLAND VALLEYS AND INLAND ORANGE COUNTY. THIS WILL BE FOLLOWED BY
A COOLING TREND FOR THE WEEKEND INTO EARLY NEXT WEEK WITH
STRONGER ONSHORE FLOW AND DRIER SOUTHWEST FLOW ALOFT WITH HIGH
TEMPERATURES FALLING TO AROUND AVERAGE FOR NEXT MONDAY.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
..UPDATED AVIATION DISCUSSION
SHORT TERM (TODAY THROUGH THURSDAY)
THE WARMING TREND WILL CONTINUE THROUGH THURSDAY WITH WARMER DAYS
AND WARMER NIGHTS. HIGH TEMPERATURES ON THURSDAY WILL RANGE FROM
THE 80S NEAR THE COAST TO 106 TO 112 FOR THE INLAND EMPIRE WITH
110 TO 116 FOR THE LOWER DESERTS. LOW TEMPERATURES ON THURSDAY
WILL BE MOSTLY IN THE 70S FOR THE COAST AND VALLEYS AND IN THE
MID 80S TO MID 90S FOR THE LOWER DESERTS.
THE HIGHEST HEATRISK FOR THE COAST AND VALLEYS IS EXPECTED ON
THURSDAY AND FRIDAY WITH WIDESPREAD EXTREME HEATRISK FOR THE
INLAND VALLEYS AND INLAND ORANGE COUNTY WITH MAJOR HEATRISK FOR
MOST OTHER AREAS WITH MODERATE HEATRISK LIMITED TO THE BEACHES.
MID LEVEL MONSOONAL MOISTURE WILL REMAIN IN PLACE TODAY WITH A
SLIGHT DECREASE ON WEDNESDAY AND A GREATER DECREASE ON THURSDAY. A
SLIGHT CHANCE OF AFTERNOON SHOWERS AND THUNDERSTORMS, MOSTLY FOR
THE MOUNTAINS, WILL CONTINUE THROUGH WEDNESDAY.
LONG TERM (FRIDAY THROUGH MONDAY)
FOR SATURDAY THROUGH MONDAY, HIGH PRESSURE WILL BEGIN TO WEAKEN
ACROSS THE AREA AS A LOW PRESSURE SYSTEM DEVELOPS NEAR THE
CALIFORNIA COAST, STRENGTHENING ONSHORE LOWER LEVEL FLOW. HIGH
TEMPERATURES WILL FALL TO AROUND 5 DEGREES ABOVE AVERAGE ON SUNDAY
AND A FEW DEGREES BELOW AVERAGE FOR THE MOUNTAINS AND INLAND
VALLEYS ON MONDAY. MONDAY HIGH TEMPERATURES WILL RANGE 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.
AVIATION
251800Z...COAST...VFR THROUGH EARLY WEDNESDAY MORNING. PATCHY LOW
CLOUDS BASED 600-900 FT MSL REDEVELOP OVER COASTAL AREAS STARTING 08-
10Z WED. BEST CHANCE FOR CIGS WILL BE IN SAN DIEGO COUNTY FROM 12-
15Z. MINOR VIS REDUCTIONS OF 2-6SM DOWN TO SEA LEVEL AND PATCHY
DENSE FG ALONG ELEVATED COASTAL TERRAIN WHERE CIGS DEVELOP. ANY LOW
CLOUDS SCATTER OUT BY 16Z.
MOUNTAINS/DESERTS...CUMULUS BASED AROUND 9000 FEET MSL WITH ISO TSRA
AND CB TOPS TO 40000 FEET OVER MOUNTAINS 20-01Z. ANY TS THAT
DEVELOPS COULD PRODUCE GUSTY, ERRATIC WINDS. VFR CONDITIONS PREVAIL
OTHERWISE.
REGIONWIDE...FEW-SCT CLOUDS AOA 15000 FEET MSL THROUGH THE PERIOD.
MARINE
NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED THROUGH SATURDAY.
BEACHES
A 4-5 FOOT SOUTHERLY SWELL (FROM 170 DEGREES) AT 12-14 SECONDS WILL
MOVE INTO THE AREA WEDNESDAY MORNING, LEADING TO ELEVATED SURF FOR
THE SOUTH FACING BEACHES OF NORTHERN SAN DIEGO COUNTY AND ORANGE
COUNTY THROUGH THURSDAY. SURF OF 3 TO 6 FEET, WITH SETS UP TO 7 FEET
ARE EXPECTED.
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-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...KW
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