697
FXUS66 KSGX 191840
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
1140 AM PDT SUN JUL 19 2026
SYNOPSIS
NEAR SEASONAL TEMPERATURES THROUGH THE FIRST HALF OF THE WEEK WITH
AN INCREASE IN BOTH HIGH AND LOW TEMPERATURES FOR THE MIDDLE TO END
OF THE WEEK. AN ISOLATED SHOWER OR TWO MAY DEVELOP OVER THE HIGHEST
MOUNTAIN PEAKS THIS AFTERNOON AND MONDAY AFTERNOON, NO IMPACTS
EXPECTED. DRIER CONDITIONS EXPECTED TUESDAY AND WEDNESDAY, WITH
INCREASED CHANCES FOR AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS
OVER THE MOUNTAINS THURSDAY AND FRIDAY. THROUGH THE WEEK THE MARINE
LAYER WILL REMAIN MOSTLY CONFINED TO THE COAST, REACHING INTO
PORTIONS OF THE VALLEYS AT TIMES.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
HIGHS TODAY WILL BE WITHIN A FEW DEGREES OF SATURDAY, MAINTAINING
CONDITIONS THAT ARE WITHIN 3 DEGREES OF NORMAL FOR INLAND AREAS, AND
UP TO 7 DEGREES ABOVE AVERAGE FOR THE COAST. THE ATMOSPHERE IS QUITE
STABLE THIS MORNING BASED ON THE 12Z KNKX SOUNDING. AN ISOLATED
SLIGHT CHANCE OF SHOWERS HAS BEEN MAINTAINED OVER THE SAN
BERNARDINO MOUNTAINS THIS AFTERNOON AND MONDAY AFTERNOON, BUT NO
THUNDERSTORM DEVELOPMENT IS EXPECTED. THE FORECAST HAS TRENDED
DRIER FOR TUESDAY AND WEDNESDAY SO SLIGHT CHANCES HAVE BEEN
REMOVED FROM THE FORECAST.
THE FIRST HALF OF THE WEEK WILL SEE MINOR DAY TO DAY CHANGES IN
TEMPERATURES WITH HIGHS REMAINING NEAR TO SLIGHTLY ABOVE NORMAL.
FOR THE LATTER HALF OF THE WEEK, THE UPPER LEVEL HIGH IS FORECAST
TO SHIFT SOUTH TOWARDS OKLAHOMA/TEXAS WEDNESDAY/THURSDAY, THEN
WILL SLOWLY SHIFT WESTWARD INTO NEXT WEEKEND. THE FORECAST
POSITION OF THE RIDGE INDICATES AT LEAST A MODEST WARMING FOR THE
LATTER HALF OF THE WEEK. THURSDAY IS CURRENTLY FORECAST TO BE THE
WARMEST DAY WITH HIGH TEMPERATURES 5 TO 10 DEGREES ABOVE AVERAGE.
WIDESPREAD MODERATE HEATRISK IS EXPECTED WEST OF THE MOUNTAINS
WITH AREAS OF MAJOR HEATRISK IN THE DESERTS, MAINLY DUE TO
ELEVATED LOW TEMPERATURES. LIMITED OVERNIGHT COOLING WILL
EXACERBATE IMPACTS FROM THE HEAT, ESPECIALLY FOR VULNERABLE
POPULATIONS AND THOSE WITHOUT AIR CONDITIONING. SIMILAR LEVELS OF
HEATRISK ARE EXPECTED TO BE MAINTAINED THROUGH THE UPCOMING
WEEKEND.
THE POSITION OF THE UPPER LEVEL RIDGE LOOKS MOST FAVORABLE TO
SUPPORT AN INCREASE IN PRECIPITATION FOR THURSDAY AND FRIDAY.
CURRENT FORECAST FOLLOWS THE NBM WHICH HAS INCREASED CHANCES OF
PRECIPITATION THURSDAY AND FRIDAY AFTERNOONS (20 TO 40 PERCENT
CHANCE). NBM IS SUPPORTED BY GLOBAL ENSEMBLE GUIDANCE SHOWING
MODEST INCREASES IN PRECIPITABLE WATER AND INSTABILITY. A LIMITING
FACTOR IS THE POSITION OF THE UPPER LEVEL RIDGE'S AXIS. IF THE
AXIS ENDS UP DIRECTLY OVER US, THAT WOULD LIMIT OUR
SHOWER/THUNDERSTORM CHANCES.
AVIATION
191800Z....COAST/VALLEYS...LOW CLOUDS MOVED OUT RELATIVELY QUICKLY
THIS MORNING, WITH CIGS CLEARING AT KSAN AND KCRQ BY 13-14Z. VFR
CONDITIONS AND MOSTLY CLEAR SKIES WILL PREVAIL THROUGH THE
AFTERNOON. LOW MARINE LAYER CLOUDS ARE EXPECTED TO REDEVELOP AND
PUSH ASHORE AFTER 00Z MONDAY, WITH CIGS FOR KSAN/KCRQ ANTICIPATED
AROUND 04Z AND 07Z FOR KSNA. SIMILAR CLOUD BASES AND INLAND EXTENT
AS THIS MORNING, WITH VIS OBSCURATIONS WHERE CLOUDS INTERSECT HIGHER
TERRAIN. CLOUDS AND CIGS EXPECTED TO CLEAR OUT 15-17Z MONDAY.
MOUNTAINS/DESERTS
VFR CONDITIONS EXPECTED THROUGH THE PERIOD WITH
FEW-SCT MID-LEVEL CLOUDS GENERALLY AOA 15,000FT MSL. FEW-SCT CU
BASED 10-12 KFT MSL MAY DEVELOP OVER THE MOUNTAIN RIDGETOPS THIS
AFTERNOON, WITH A SMALL (5-10%) CHANCE FOR ISO SHRA/TSRA, MOST
LIKELY AFTER 21Z THROUGH 01Z MONDAY. ELEVATED WEST WINDS EXPECTED
THIS AFTERNOON/EVENING FROM 00-09Z MONDAY, WITH GUSTS 20-35 KTS
ALONG DESERT SLOPES AND UP TO 45 KTS THROUGH THE BANNING PASS.
MARINE
WEDNESDAY AFTERNOON, THERE IS AROUND A 50% CHANCE FOR NORTHWESTERLY
WIND GUSTS TO EXCEED 20 KTS IN THE OUTER WATERS NEAR SAN CLEMENTE
ISLAND. OTHERWISE, NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED
THROUGH THURSDAY MORNING.
BEACHES
HIGH AMPLITUDE SOUTHERLY SWELL (4-5 FT WITH A PERIOD OF 11-13
SECONDS) IS BUILDING TODAY, AND IS SET TO BRING ELEVATED TO HIGH
SURF AND STRONG RIP AND LONGSHORE CURRENTS THROUGH TUESDAY. SURF
GENERALLY 5-7 FEET WITH SETS TO 8 FEET IS EXPECTED THROUGH TUESDAY,
WITH THE HIGHEST SURF FOCUSED ON SOUTH AND SOUTHWEST FACING BEACHES.
SURF SETS UP TO 8 FEET HAVE ALREADY BEEN REPORTED ACROSS ORANGE
COUNTY THIS MORNING AND THE HIGH SURF ADVISORY HAS BEEN TWEAKED TO
GO INTO EFFECT AS OF 11AM THIS MORNING. THIS HIGH SURF ADVISORY
REMAINS IN EFFECT UNTIL 11PM TUESDAY EVENING.
SOUTHERLY SWELL AND SURF FALLS THROUGH THE DAY ON TUESDAY, REMAINING
LOW INTO WEDNESDAY. ANOTHER INCREASED SOUTHERLY SWELL FROM A
FORECAST TROPICAL CYCLONE WELL OFF THE COAST IS EXPECTED LATER THIS
WEEK. THIS SWELL IS EXPECTED TO BE AROUND 4-5 FT WITH A PERIOD OF
~15 SECONDS WHICH WOULD ONCE AGAIN BRING HIGH SURF OF 6-8 FEET,
ESPECIALLY FOR SOUTH-SOUTHWEST FACING BEACHES.
SKYWARN
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
SGX WATCHES/WARNINGS/ADVISORIES
CA...HIGH SURF ADVISORY UNTIL 11 PM PDT TUESDAY FOR ORANGE COUNTY
COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS.
PZ...NONE.
PUBLIC...CO
AVIATION/MARINE/BEACHES...MUNYAN
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