612
FXUS66 KSGX 211804
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
1104 AM PDT TUE APR 21 2026
SYNOPSIS
GUSTY WINDS OVER THE MOUNTAINS AND DESERTS AND LIGHT PRECIPITATION
IN THE COASTAL BASIN EXPECTED THIS AFTERNOON INTO EARLY WEDNESDAY
MORNING. THURSDAY WILL BE A LITTLE WARMER AND DRY WITH WEAKER WINDS.
COOLER CONDITIONS LIKELY THIS WEEKEND, WITH PERIODS OF INCREASED
WINDS AND ANOTHER ROUND OF LIGHT PRECIPITATION WEST OF THE
MOUNTAINS.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
A TROUGH OF LOW PRESSURE IS EXPECTED TO MOVE EAST ACROSS CENTRAL
CALIFORNIA TODAY INTO WEDNESDAY. VISIBLE SATELLITE AT 11 AM WAS
SHOWING CLOUDS MOVING INTO ORANGE COUNTY, CLOUDS ARE EXPECTED TO
SPREAD SOUTH AND EAST ACROSS THE AREA. ADDITIONALLY, AREAS OF LIGHT
RAIN WILL SPREAD SOUTH AND EAST ACROSS THE AREA THIS AFTERNOON AND
EVENING. ACCUMULATIONS OF 0.10" OR LESS ARE EXPECTED IN THE COAST
AND VALLEYS, WITH TOTALS UP TO 0.25" ON THE COASTAL SLOPES OF THE
MOUNTAINS. THE SAN BERNARDINO COUNTY MOUNTAINS ARE THE MOST LIKELY
PLACE TO SEE ACCUMULATIONS UP TO 0.25". RAINFALL RATES ARE EXPECTED
TO BE 0.10" OR LESS PER HOUR. DRY CONDITIONS WILL RETURN BY MID-
WEDNESDAY MORNING.
SOUTHWEST TO WEST WINDS HAVE ALREADY STARTED TO WEAKEN, WITH GUSTS
TO 45 MPH BEING OBSERVED THROUGH THE SAN GORGONIO PASS AT 11 AM.
WINDS WILL PEAK IN STRENGTH THIS EVENING. STRONGEST WINDS WILL BE
OVER THE MOUNTAINS AND INTO THE DESERTS. PEAK GUSTS OF 40 TO 60 MPH
EXPECTED, WITH A FEW ISOLATED GUSTS TO 65 MPH ON THE NORTHERN SLOPES
OF THE SAN BERNARDINO MOUNTAINS. WINDS WILL DECREASE THROUGH THE DAY
WEDNESDAY WITH GUSTS MAINLY 35 TO 45 MPH, LOCALLY UP TO 55 MPH
THROUGH WIND PRONE PASSES LIKE THE SAN GORGONIO PASS.
DRY AND WARMER CONDITIONS EXPECTED ON THURSDAY. HIGHS ALONG THE
COAST WILL BE A FEW DEGREES WARMER, WITH INLAND LOCATIONS UP TO 7
DEGREES WARMER THAN WEDNESDAY. THE TEMPERATURE INCREASE WILL BRING
CONDITIONS NEAR TO SLIGHTLY ABOVE NORMAL FOR THIS TIME OF YEAR.
ANOTHER AREA OF LOW PRESSURE LOOKS LIKELY TO MOVE ACROSS THE US WEST
COAST FOR THE UPCOMING WEEKEND. WHILE THERE REMAINS SOME TIMING
DIFFERENCES BETWEEN THE GLOBAL MODELS, THE TROUGH WILL BRING ANOTHER
ROUND OF COOLER CONDITIONS, INCREASE IN WESTERLY WINDS, AND
POTENTIAL FOR LIGHT PRECIPITATION. DRY AND WARMER FOR NEXT MONDAY,
WITH HIGH TEMPERATURES FOR INLAND AREAS STILL A FEW TO AROUND 5
DEGREES BELOW AVERAGE.
AVIATION
211800Z...COAST/VALLEYS...A BAND OF LOW CLOUDS BASED 2500-5000 FEET
MSL ASSOCIATED WITH A WEAK FRONT CONTAINING WAVES OF -SHRA WILL MOVE
FROM WEST TO EAST ACROSS THE COASTAL BASIN FROM 20-07Z. ISO -SHRA
COULD BRIEFLY CREATE MVFR VIS AND CIGS 1500-2500 FT MSL AS THEY PASS
OVER SITES. CLOUDS MOSTLY CLEAR OUT FROM NORTHWEST TO SOUTHEAST
AFTER THAT BAND, FIRST AT ORANGE COUNTY COAST AND LAST INLAND SAN
DIEGO COUNTY.
MOUNTAINS/DESERTS...SOUTHWEST TO WEST WINDS INCREASE THROUGH LATE
THIS AFTERNOON WITH PEAK GUSTS 35-55 KTS, STRONGEST ON RIDGETOPS,
ALONG DESERT SLOPES, AND THROUGH MOUNTAIN PASSES. ISOLATED VIS
REDUCED BY BLDU IN THE DESERTS AND MODERATE/STRONG UP/DOWNDRAFTS IN
LEE OF MOUNTAINS. WINDS DECREASE TONIGHT BUT REMAIN BREEZY FOR THE
DESERT SLOPES AND MTN PASSES, THEN GUSTY WINDS BECOME MORE
WIDESPREAD AGAIN THOUGH NOT QUITE AS STRONG FOR WED AFTERNOON.
MARINE
WESTERLY TO NORTHWESTERLY WINDS WILL INCREASE WEDNESDAY AFTERNOON
THROUGH LATE WEDNESDAY NIGHT WITH GUSTS 20-25 KNOTS LIKELY FOR OUTER
COASTAL WATERS. THESE WINDS COULD GENERATE CHOPPY AND HAZARDOUS
CONDITIONS. WINDS DIMINISH EARLY THURSDAY MORNING BEFORE BRIEFLY
INCREASING AGAIN IN THE OUTER COASTAL WATERS THURSDAY AFTERNOON,
WITH PEAK GUSTS AROUND 20 KNOTS. OTHERWISE, NO HAZARDOUS MARINE
CONDITIONS ARE EXPECTED THROUGH SATURDAY.
SKYWARN
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
SGX WATCHES/WARNINGS/ADVISORIES
CA...WIND ADVISORY FROM 2 PM THIS AFTERNOON TO 7 AM PDT WEDNESDAY FOR
APPLE AND LUCERNE VALLEYS-RIVERSIDE COUNTY MOUNTAINS-SAN
BERNARDINO COUNTY MOUNTAINS-SAN DIEGO COUNTY DESERTS-SAN
DIEGO COUNTY MOUNTAINS-SAN GORGONIO PASS NEAR BANNING.
PZ...NONE.
PUBLIC...CO
AVIATION/MARINE...CSP
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