074
FXUS66 KSGX 260943
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
243 AM PDT WED AUG 26 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...
SHORT TERM (TODAY THROUGH FRIDAY)
HIGH TEMPERATURES WILL BE AROUND 10 DEGREES ABOVE AVERAGE WITH LOW
TEMPERATURES AS MUCH AS 15 TO 20 DEGREES ABOVE AVERAGE FOR THE
LOWER ELEVATIONS OF THE MOUNTAINS. THROUGH FRIDAY, HIGH
TEMPERATURES WILL RANGE FROM THE 80S NEAR THE COAST TO 100 TO 110
FOR THE INLAND EMPIRE WITH 112 TO 118 FOR THE LOWER DESERTS. LOW
TEMPERATURES WILL BE MOSTLY IN THE 70S FOR THE COAST, VALLEYS, AND
HIGH DESERT AND IN THE MID 80S TO MID 90S FOR THE LOWER DESERTS.
LOW TEMPERATURES WILL BE AROUND 80 FOR THE LOWER ELEVATIONS OF THE
MOUNTAINS. THE HIGHEST HEATRISK IS EXPECTED ON THURSDAY WITH
WIDESPREAD MODERATE TO EXTREME HEATRISK FOR THE VALLEYS, INLAND
COASTAL AREAS, AND LOWER DESERTS.
WHILE THE HIGH TEMPERATURES WILL MOSTLY NOT TIE OR EXCEED EXISTING
HIGH TEMPERATURE RECORDS, MANY RECORDS FOR WARMEST OVERNIGHT LOW
TEMPERATURES WILL LIKELY BE TIED OR BROKEN WITH THE GREATEST
NUMBER ON THURSDAY AND FRIDAY.
SWELL FROM TROPICAL STORM ISELLE AND FORMER TROPICAL STORM JULIO
WILL BRING ELEVATED SURF OF 4 TO 6 FEET TO THE BEACHES FOR TODAY
THROUGH THURSDAY EVENING.
THERE MAY BE ENOUGH RESIDUAL MONSOONAL MOISTURE FOR A FEW SHOWERS
OR THUNDERSTORMS FOR THE MOUNTAINS FOR THIS AFTERNOON WITH
ADDITIONAL DRYING FOR THURSDAY.
LONG TERM (SATURDAY THROUGH TUESDAY)
A COOLING TREND IS EXPECTED FOR SATURDAY INTO THE MIDDLE OF NEXT
WEEK AS HIGH PRESSURE ALOFT WEAKENS AND A DEVELOPING WEAK TROUGH
OF LOW PRESSURE NEAR THE CALIFORNIA COAST STRENGTHENS ONSHORE
LOWER-LEVEL FLOW. HIGH TEMPERATURES WILL COOL TO AROUND AVERAGE
FOR NEXT MONDAY WITH LOW TEMPERATURES COOLING TO SLIGHTLY ABOVE
AVERAGE.
THERE COULD BE SOME INCREASE IN CLOUDS AND A CHANCE OF
PRECIPITATION AROUND TUESDAY OR WEDNESDAY OF NEXT WEEK FROM
MOISTURE FROM A TROPICAL SYSTEM THAT HAS YET TO DEVELOP.
AVIATION
260600Z...COAST...PATCHY LOW CLOUDS WITH BASES 600-900 FT MSL WILL
REDEVELOP ALONG THE COAST AND BEGIN MOVING ONSHORE AROUND 08-10Z.
HIGHEST CHANCES (30-60%) FOR CIGS WILL BE IN SAN DIEGO COUNTY FROM
11-16Z. EXPECT MINOR VIS REDUCTIONS OF 2-6SM DOWN TO SEA LEVEL AND
PATCHY DENSE FG ALONG ELEVATED COASTAL TERRAIN WHERE CIGS DEVELOP.
ANY LOW CLOUDS THAT FORM WILL SCATTER OUT BY 16-17Z. LOW CLOUDS WILL
BEGIN TO REFORM AROUND 01-03Z WED, WITH SIMILAR BASES.
MOUNTAINS/DESERTS...CUMULUS BASED AROUND 9,000FT MSL WITH ISO TSRA
AND CB TOPS TO 40,000 FT OVER MOUNTAINS WILL BE POSSIBLE FOR
TOMORROW AFTERNOON WITH AROUND A 15-20% CHANCE OVER THE MOUNTAINS,
MAINLY BETWEEN 20-01Z. ANY TS THAT DEVELOP COULD PRODUCE GUSTY,
ERRATIC WINDS.
REGIONWIDE...FEW-SCT CLOUDS AOA 15,000FT MSL THROUGH THE TAF 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.
BEACH HAZARDS STATEMENT FROM 5 AM PDT EARLY THIS MORNING THROUGH
THURSDAY EVENING FOR ORANGE COUNTY COASTAL AREAS-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...17
AVIATION/MARINE/BEACHES...MM
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