628
FXUS66 KSGX 182350
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
450 PM PDT WED MAR 18 2026
SYNOPSIS
WELL ABOVE AVERAGE CONDITIONS WILL CONTINUE THROUGH THE END OF THE
WEEK. SOME COOLING IS EXPECTED THROUGH THE WEEKEND INTO EARLY NEXT
WEEK, BUT TEMPERATURES WILL REMAIN ABOVE AVERAGE. MARINE LAYER LOW
CLOUDS AND FOG WILL BE LARGELY ABSENT FROM THE COAST THIS WEEK,
POTENTIALLY RETURNING BY LATE THIS WEEKEND.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
..NEW AVIATION DISCUSSION BELOW
TEMPERATURES AT 11 AM WERE RUNNING 5 TO 10 DEGREES COOLER THAN
YESTERDAY FOR THE COAST AND PARTS OF THE WESTERN VALLEYS. THE
MOUNTAINS AND DESERTS WERE RUNNING 5 TO 10 DEGREES WARMER THAN
YESTERDAY. A DAILY AND MONTHLY HIGH AND LOW TEMPERATURE RECORDS WERE
BROKEN YESTERDAY WITH MORE EXPECTED TO BE BROKEN EACH DAY THROUGH
FRIDAY. A CLIMATE SECTION CAN BE FOUND BELOW WITH MORE INFORMATION.
WIDESPREAD MODERATE TO LOCALLY MAJOR HEATRISK IS EXPECTED THROUGH
FRIDAY FOR MOST LOCATIONS AND SATURDAY IN THE LOW DESERT. REDUCE
OUTDOOR ACTIVITIES IF POSSIBLE BETWEEN 10 AM AND 5 PM, SEEK SHADE,
AND STAY HYDRATED.
THE HIGH PRESSURE ALOFT WILL PEAK IN STRENGTH FRIDAY WITH HIGH
TEMPERATURES 20 TO 30 DEGREES ABOVE AVERAGE FOR THIS TIME OF YEAR.
OVERNIGHT LOWS WILL ALSO BE ELEVATED, WHICH WILL LIMIT OVERNIGHT
RELIEF FROM THE HEAT FOR MOST LOCATIONS. THROUGH FRIDAY WIDESPREAD
TEMPERATURES IN THE 90S TO LOW 100S EXPECTED FOR THE INLAND VALLEYS,
WITH HIGHS IN THE MID-80S TO LOW 90S FOR COASTAL AREAS AWAY FROM THE
IMMEDIATE COAST AND THE LOWER ELEVATIONS OF THE MOUNTAINS. IN THE
LOW DESERTS, HIGHS WILL LIKELY EXCEED 105 DEGREES IN MOST LOCATIONS
THROUGH SATURDAY. CHANCES FOR EXCEEDING 110 DEGREES ON FRIDAY ARE 70
PERCENT FOR INDIO, 30 PERCENT FOR PALM SPRINGS, AND 20 PERCENT FOR
BORREGO SPRINGS. IN THE HIGH DESERT, TEMPERATURES WILL BE IN THE MID-
90S.
WEAKENING HIGH PRESSURE ALOFT AND STRENGTHENING ONSHORE FLOW WILL
BRING 4 TO 8 DEGREES OF COOLING SATURDAY. THAT WILL BE MOST
NOTICEABLE FOR LOCATIONS WEST OF THE MOUNTAINS, BUT EVEN THE DESERTS
WILL COOL 3 TO 5 DEGREES. A WEAK LOW PRESSURE SYSTEM ALOFT WILL MOVE
EAST THROUGH SOUTHERN CALIFORNIA INTO THE GREAT BASIN SOMETIME
SUNDAY OR MONDAY. THAT WILL BRING AN UPTICK IN WESTERLY WINDS
SATURDAY, WHICH HAVE THE POTENTIAL TO TURN WEAKLY OFFSHORE BY SUNDAY
OR MONDAY. WEAK RIDGING ALOFT WILL RETURN SOMETIME NEXT TUESDAY OR
WEDNESDAY, MAINTAINING ABOVE AVERAGE TEMPERATURES. LOW CLOUDS WILL
REMAIN ABSENT FROM THE COAST THROUGH THE WORK WEEK. PATCHY LOW
CLOUDS MAY RETURN WITH THE RETURN OF ONSHORE FLOW OVER THE
WEEKEND.
AVIATION
190000Z...MOSTLY CLEAR SKIES AND VFR CONDITIONS THROUGH THURSDAY
AFTERNOON. PATCHY FOG OVER COASTAL WATERS TONIGHT INTO THURSDAY, BUT
UNLIKELY TO IMPACT COASTAL AIRPORTS.
MARINE
NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED THROUGH
SUNDAY.
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 RIVERSIDE COUNTY
MOUNTAINS-SAN BERNARDINO COUNTY MOUNTAINS-SAN DIEGO COUNTY
MOUNTAINS.
PZ...NONE.
PUBLIC...CO
AVIATION/MARINE...STEWEY
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