174
FXUS66 KSGX 232046
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
146 PM PDT TUE JUN 23 2026
SYNOPSIS
BUILDING HIGH PRESSURE WILL BRING A WARMING TREND THROUGH WEDNESDAY,
WITH MODERATE TO HIGH HEATRISK FOR THE DESERTS. MID LEVEL
MOISTURE IN SOUTHERLY FLOW ALOFT WILL BRING A SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS THIS AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR THE MOUNTAINS OF SAN BERNARDINO AND RIVERSIDE
COUNTIES EAST AND NORTHEASTWARD ACROSS THE DESERTS OF SOUTHERN
CALIFORNIA. THIS WILL BE FOLLOWED BY A COOLING TREND FOR THURSDAY
THROUGH THE WEEKEND. SOUTHWEST TO WEST WINDS WILL STRENGTHEN FOR
THURSDAY THROUGH SATURDAY IN THE MOUNTAINS AND DESERTS, WITH GUSTS
ON SATURDAY OF 30 TO 40 MPH LOCALLY TO 65 MPH IN THE NORTHERN
COACHELLA VALLEY BELOW THE SAN GORGONIO PASS.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
THIS AFTERNOON...MID-LEVEL MOISTURE IN SOUTHERLY FLOW ALOFT IS
PRODUCING SOME HIGH-BASED CONVECTIVE ELEMENTS ACROSS THE MTNS AND
DESERTS OF SOCAL. THIS ELEVATED CONVECTION COULD PRODUCE ISOLATED
DRY LIGHTNING STRIKES AND LOCALLY GUSTY WINDS. THIS COULD RESULT
IN FIRE STARTS. SEE THE FIRE WEATHER DISCUSSION BELOW.
THE MARINE LAYER IS ABOUT 2000-2500 FT DEEP WITH A STRONG INVERSION
SO SOME LOW CLOUDS ARE PERSISTING AT THE BEACHES. THE MOISTURE
ALOFT COULD DISRUPT THE RADIATION COOLING TONIGHT SO LOW CLOUD
COVERAGE MAY BE LESS TONIGHT THAN LAST NIGHT. TEMPERATURES ARE
NEAR OR A FEW DEGREES LOWER WEST OF THE MTNS THAN AT THIS TIME
YESTERDAY WHILE THE MTNS AND DESERTS ARE GENERALLY WARMER BY AS
MUCH AS 10 DEGREES IN A FEW LOCATIONS.
HIGH PRESSURE BUILDING IN FROM THE SOUTHEAST WILL CONTINUE THE WARMING
TREND THROUGH WEDNESDAY WITH A MINOR DROP IN DAYTIME HIGH TEMPERATURES
ON THURSDAY. HIGH TEMPERATURES ON WEDNESDAY WILL RANGE FROM A FEW
DEGREES ABOVE AVERAGE NEAR THE COAST TO 4 TO 8 DEGREES ABOVE AVERAGE
INLAND. HIGH TEMPERATURES ON WEDNESDAY WILL RANGE FROM THE LOWER
TO MID 70S NEAR THE COAST TO THE 90S FOR THE INLAND EMPIRE WITH
108 TO 112 FOR THE LOWER DESERTS. TONIGHT WILL BE MUCH WARMER AS
WELL WITH LOW TEMPERATURES WEDNESDAY MORNING MOSTLY IN THE 80S
FOR THE LOWER DESERTS. THE MARINE LAYER WILL REMAIN AROUND 2000
FEET DEEP WITH NIGHT AND MORNING COASTAL LOW CLOUDS EXTENDING
INLAND INTO PORTIONS OF THE WESTERN VALLEYS LATE EACH NIGHT. THE
MID-LEVEL MOISTURE WILL CONTINUE TO MOVE INTO SOCAL FROM THE SOUTH
BUT THE DISTURBANCE MOVING OVER US TODAY WILL BE MOSTLY TO OUR
NORTH BY TOMORROW AND THE HIGH PRESSURE WILL INCREASE STABILITY
MAKING DEEP CONVECTION LESS LIKELY TOMORROW.
A LOW PRESSURE SYSTEM MOVING SOUTHWARD OUT OF THE GULF OF AK WILL
STRENGTHEN THE ONSHORE SLOW ACROSS SOUTHERN CALIFORNIA INTO THE
WEEKEND. SOUTHWEST TO WEST WINDS FOR THE MOUNTAINS AND DESERTS
DURING THE AFTERNOON AND EVENING WILL STRENGTHEN FOR THURSDAY
THROUGH SATURDAY, WITH GUSTS ON SATURDAY OF 30 TO 40 MPH LOCALLY
TO 65 MPH IN THE NORTHERN COACHELLA VALLEY BELOW THE SAN GORGONIO
PASS. THE MARINE LAYER WILL DEEPEN WITH NIGHT AND MORNING COASTAL
LOW CLOUDS SPREADING FARTHER INTO THE VALLEYS LATE EACH NIGHT.
THE LOW PRESSURE SYSTEM WILL ALSO BRING A COOLING TREND THROUGH
THE WEEKEND, WITH HIGH TEMPERATURES ON SUNDAY AS MUCH AS 15
DEGREES BELOW AVERAGE FOR THE MOUNTAINS AND INLAND VALLEYS. HIGH
TEMPERATURES ON SUNDAY WILL RANGE FROM AROUND 70 NEAR THE COAST TO
MID 70S TO LOWER 80S FOR THE INLAND EMPIRE WITH THE MID 90S TO
102 FOR THE LOWER DESERTS. HIGH TEMPERATURES FOR NEXT MONDAY AND
TUESDAY WILL BE MARGINALLY WARMER.
AVIATION
230930Z...COAST/VALLEYS...A STRONGER INVERSION HAS KEPT THE CLOUDS
IN PLACE ALONG THE COAST INTO THE LATE MORNING, BUT ALL TAF SITES
SHOULD SEE CIGS (CURRENTLY BASED AROUND 1700-1900FT MSL) CLEARING
OUT BY 1900-1930Z. LOW CLOUDS WITH BASES CLOSER TO 1400-1600FT MSL
BEGIN TO FILL BACK IN AFTER 03Z WEDNESDAY. GIVEN INCREASED MID LEVEL
MOISTURE IN PLACE, THE MARINE LAYER MAY BE PATCHIER IN COVERAGE THAN
PREVIOUS NIGHTS, AND TAKE LONGER TO FILL IN TO SOME AREAS. CLOUDS
SCATTER BACK OFF THE COASTS AROUND 18Z WEDNESDAY.
MOUNTAINS/DESERTS...VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD
WITH PERIODIC HIGH CLOUDS AOA 15000 FT MSL THIS AFTERNOON/EVENING.
MARINE
NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED THROUGH SUNDAY.
BEACHES
SURF WILL INCREASE THIS AFTERNOON WITH THE ARRIVAL OF A 3 FOOT 15 TO
18 SECOND PERIOD SOUTH SWELL FROM 190 TO 210 DEGREES. SURF OF 4 TO 6
FT IS EXPECTED THROUGH THURSDAY. EXPECT LOCALLY HAZARDOUS SWIMMING
CONDITIONS AND STRONG RIP CURRENTS THROUGH THE WEEK. PLEASE SEE THE
BEACH HAZARDS STATEMENT FOR MORE DETAILS.
FIRE WEATHER
THE WARMING TREND WILL CONTINUE THROUGH WEDNESDAY. MID-LEVEL
MOISTURE IN SOUTHERLY FLOW ALOFT WILL BRING A SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS THIS AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR THE MOUNTAINS OF SAN BERNARDINO AND RIVERSIDE
COUNTIES EAST AND NORTHEASTWARD ACROSS THE DESERTS OF SOUTHERN
CALIFORNIA. LITTLE IF ANY RAINFALL WILL REACH THE GROUND AND ANY
THUNDERSTORMS THAT DEVELOP COULD PRODUCE DRY LIGHTNING STRIKES AND
LOCALLY GUSTY AND ERRATIC WINDS. DRY LIGHTNING STRIKES COULD
RESULT IN FIRE STARTS THAT HAVE THE POTENTIAL FOR INITIALLY RAPID
GROWTH. ONSHORE FLOW WILL STRENGTHEN FOR THURSDAY INTO THE
WEEKEND, WITH SUNDAY HIGH TEMPERATURES COOLING TO AS MUCH AS 10
TO 15 DEGREES BELOW AVERAGE FOR THE MOUNTAINS AND INLAND VALLEYS.
SOUTHWEST TO WEST WINDS IN THE MOUNTAINS AND DESERTS WILL
STRENGTHEN THROUGH SATURDAY WITH GUSTS ON SATURDAY TO 30 TO 40 MPH
LOCALLY TO 65 MPH IN THE NORTHERN COACHELLA VALLEY BELOW THE SAN
GORGONIO PASS. FOR THURSDAY AND FRIDAY AFTERNOON AND EARLY
EVENING, THOSE WINDS COMBINED WITH LOWEST DAYTIME HUMIDITY OF 10
PERCENT IN THE DESERTS WILL RESULT IN NEAR CRITICAL FIRE WEATHER
CONDITIONS.
SKYWARN
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
SGX WATCHES/WARNINGS/ADVISORIES
CA...BEACH HAZARDS STATEMENT THROUGH THURSDAY EVENING FOR ORANGE
COUNTY COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS.
RED FLAG WARNING FROM 5 PM THIS AFTERNOON TO 11 AM PDT WEDNESDAY
FOR VICTOR VALLEY -APPLE VALLEY -LUCERNE VALLEY -JOHNSON
VALLEY.
EXTREME HEAT WARNING FROM 11 AM WEDNESDAY TO 8 PM PDT THURSDAY
FOR SAN DIEGO COUNTY DESERTS.
PZ...NONE.
PUBLIC/FIRE WEATHER...PG
AVIATION/MARINE...MUNYAN
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