287
FXUS66 KSGX 171921
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
1221 PM PDT FRI JUL 17 2026
SYNOPSIS
TEMPERATURES COOLING FOR INLAND AREAS TODAY WILL BE SIMILAR INTO
MUCH OF NEXT WEEK. CHANCES OF THUNDERSTORMS ARE ELEVATED ONCE
AGAIN ACROSS THE MOUNTAINS THIS AFTERNOON. STORM CHANCES BEGIN TO
DECREASE WITH MINOR CHANCES EXPECTED FOR HIGHEST RIDGES IN THE SAN
BERNARDINO AND RIVERSIDE COUNTY MOUNTAINS EACH AFTERNOON INTO THE
FIRST HALF OF NEXT WEEK. CONFIDENCE LOWERS FOR INCREASING CHANCES
LATER IN THE WEEK. LOW CLOUDS WILL CONTINUE TO COVER COASTAL
AREAS EACH NIGHT AND MORNING INTO THE NEXT WEEK AS WELL.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
SATELLITE IMAGERY SHOES SHOWS MID-LEVEL CLOUDS OVER PARTS OF SOCAL
AND FURTHER TO THE EAST, WITH DRYING TRENDS NOTICED OVER NORTHERN
PORTIONS OF THE MOUNTAINS. CLEARING THIS MORNING WILL CREATE A
BETTER ENVIRONMENT FOR THUNDERSTORM ACTIVITY AS WE HEAD INTO THE
AFTERNOON. COMPARING YESTERDAY TO TODAY, THE ENVIRONMENT IS
SEEMINGLY A BIT LESS PRIMED WITH LESS INSTABILITY, THOUGH PWATS ARE
STILL NEAR 1.5", PLENTY MOIST ENOUGH. LATEST HI-RES MODEL GUIDANCE
AGAIN FAVORS THE RIVERSIDE AND SAN DIEGO COUNTY MOUNTAINS TO RECEIVE
THE GREATEST RAINFALL, LOCALLY NEAR 0.50"-1" PER HOUR RATES, FOR
LATER THIS AFTERNOON. STORMS WILL BEGIN TO WEAKEN BY EARLY
EVENING. OTHERWISE, TEMPERATURES TODAY WILL FEEL NOT AS HOT AS
YESTERDAY. HIGH TEMPERATURES WILL BE CLOSER TO AVERAGE WITH HIGHS
IN THE 90S ACROSS THE IE AND HIGH DESERT, AND 70S/80S FOR THE
COAST, WESTERN VALLEYS AND MOUNTAINS. ELEVATED HUMIDITY WITH
OVERNIGHT LOWS NEAR TO SLIGHTLY ABOVE AVERAGE WILL REMAIN THOUGH.
MOISTURE AROUND AN AREA OF HIGH PRESSURE OVER THE INTERMOUNTAIN WEST
DECREASES AND PUSHES FURTHER EAST BY THE WEEKEND. MOISTURE WILL
STILL REMAIN IN PLACE, SO CHANCES DO REMAIN OVER THE HIGHER
MOUNTAINS OF SBD/RIV COUNTIES ON SATURDAY. THE ATMOSPHERE LOOKS TO
DRY OUT A BIT FURTHER BY SUNDAY THROUGH TUESDAY, BRINGING CHANCES
NEAR 10-15% ALONG THE EASTERN PARTS OF THE SBD MTS. OTHER THAN THIS,
THE OVERALL WEATHER PATTERN WILL REMAIN RELATIVELY UNCHANGED WITH
TEMPERATURES NEAR AVERAGE WITH MOSTLY CLEAR CONDITIONS.
THE FORECAST IN MONSOONAL MOISTURE BECOMES LESS CERTAIN BY THE
LATTER HALF OF NEXT WEEK. MODELS STILL CONTINUE TO BE SPLIT ON THE
PLACEMENT OF THE AREA OF HIGH PRESSURE, WHICH WILL DICTATE WHERE AND
HOW MUCH MONSOONAL MOISTURE WE ARE ABLE TO RECEIVE. THIS WILL ALSO
DICTATE IF WE STAY NEAR NORMAL OR WARM SLIGHTLY ABOVE NORMAL.
AVIATION
171800Z....COAST/VALLEYS...MULTIPLE CLOUD DECKS WITH VERY PATCHY LOW
CLOUDS ALONG THE NORTHERN SAN DIEGO COUNTY COASTLINE/SOUTHERN ORANGE
COUNTY COASTLINE WITH BASES AROUND 1100-1500FT MSL ALONG WITH
INCREASING HIGH CLOUDS AOA 15,000FT MSL. LOW CLOUDS WILL CONTINUE TO
ERODE BUT HIGH CLOUDS SHOULD PREVAIL THROUGH THE AFTERNOON. LOW
CLOUDS WITH SIMILAR BASES WILL DEVELOP TONIGHT AND SPREAD INTO SAN
DIEGO COUNTY AFTER 05Z SAT BEFORE MOVING UP TO ORANGE COUNTY LIKELY
NOT UNTIL 08Z. THESE CLOUDS WILL BE VERY PATCHY WITH POTENTIALLY
INTERMITTENT CIGS AT TIMES THROUGH THE NIGHT. ANY LOW CLOUDS THAT
DEVELOP SHOULD BEGIN TO MOVE BACK TOWARDS THE COAST AROUND 16Z SAT.
MOUNTAINS/DESERTS
PERIODS OF HIGH CLOUDS AOA 15,000 FT AND VFR
CONDITIONS EXPECTED THROUGHOUT THE PERIOD. SCT CU BASED 10-12 KFT
MSL AND ISO-SCT SHRA/TSRA DEVELOP OVER THE MTNS THIS AFTERNOON, MOST
LIKELY 20Z FRI THROUGH 01Z SAT. ANY STORMS THAT DEVELOP MAY PRODUCE
LIGHTNING, GUSTY WINDS, AND VIS REDUCTIONS.
MARINE
NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED THROUGH WEDNESDAY.
SKYWARN
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
SGX WATCHES/WARNINGS/ADVISORIES
CA...HIGH SURF ADVISORY FROM 5 PM SUNDAY TO 11 PM PDT TUESDAY FOR
ORANGE COUNTY COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS.
PZ...NONE.
PUBLIC...APR
AVIATION/MARINE...ZUBER
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