961  
FXUS66 KMTR 110421  
AFDMTR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SAN FRANCISCO CA  
921 PM PDT SUN AUG 10 2025  
   
..NEW UPDATE
 
 
   
KEY MESSAGES
 
 
UPDATED AT 1224 PM PDT SUN AUG 10 2025  
 
- MODERATE HEATRISK CONTINUES THROUGH MONDAY FOR PORTIONS OF THE  
NORTH, EAST AND SOUTH BAY AND INTERIOR MONTEREY AND SAN BENITO  
COUNTIES.  
 
- ELEVATED FIRE WEATHER CONCERNS PERSIST GIVEN THE WARM AND DRY  
CONDITIONS, WITH BREEZY WINDS EACH AFTERNOON AND EVENING.  
 
- PATTERN CHANGE ON TUESDAY BRINGS COOLER WEATHER AND COASTAL  
DRIZZLE BACK TO THE FORECAST.  
 

 
   
UPDATE
 
 
ISSUED AT 921 PM PDT SUN AUG 10 2025  
 
A HANDFUL OF SITES IN THE HIGHER ELEVATIONS REACHED 100+ DEGREES  
TODAY (FAR NORTHERN NAPA COUNTY, EAST BAY HILLS, AND INTERIOR  
CENTRAL COAST). THE PINNACLES RAWS (ELEVATION OF 1322 FT) AND THE  
MCLAUGHLIN RESERVE/KNOXVILLE (ELEVATION OF 1320 FT) BOTH PEAKED AT  
104 DEGREES THIS AFTERNOON. ACROSS THE BAY AREA, TEMPERATURES REMAIN  
FAIRLY SIMILAR ON MONDAY WITH TEMPERATURES DROPPING 1 OR 2 DEGREES  
ACROSS THE BOARD. ACROSS THE INTERIOR CENTRAL COAST, TEMPERATURES  
LOOK TO WARM AN ADDITIONAL DEGREE OR TWO BEFORE A SLIGHT COOL DOWN  
BEGINS TUESDAY. OTHERWISE, THE FORECAST REMAINS ON TRACK.  

 
   
SHORT TERM
 
 
ISSUED AT 1224 PM PDT SUN AUG 10 2025  
(THIS EVENING THROUGH MONDAY)  
 
SATELLITE IMAGERY SHOWS STRATUS AT THE IMMEDIATE COASTLINE, WITH THE  
INTERIOR REGIONS REMAINING CLEAR FOR THE DAY UNTIL THE STRATUS  
BUILDS BACK INTO THE INLAND VALLEYS TONIGHT. SMOKE FROM THE GIFFORD  
FIRE IN SAN LUIS OBISPO COUNTY CONTINUES TO WAFT INTO MONTEREY AND  
SAN BENITO COUNTIES, AND HIGH LEVEL SMOKE WAS ALSO OBSERVED OVER THE  
BAY AREA THIS MORNING. THE SMOKE PLUME COULD CONTINUE TO IMPACT THE  
CENTRAL COAST THROUGH MONDAY. FOR FURTHER INFORMATION ON SMOKE  
IMPACTS TO AIR QUALITY, REFER TO FORECASTS ISSUED BY LOCAL AIR  
QUALITY MANAGEMENT DISTRICTS.  
 
TODAY'S WEATHER CONTINUES TO BE DOMINATED BY A RIDGE OVER THE  
NORTHEASTERN PACIFIC THAT IS BUILDING INTO THE STATE. THIS RIDGE IS  
CAUSING A HOT AND DRY PATTERN THAT SHOULD CONTINUE INTO MONDAY. HIGH  
TEMPERATURES ACROSS THE REGION TODAY RANGE FROM THE 90S TO NEAR 103  
IN THE INLAND VALLEYS, THE 70S TO THE MID 80S CLOSE TO THE BAYS AND  
IN THE NORTHERN SALINAS VALLEY, AND THE LOWER TO MIDDLE 60S ALONG  
THE PACIFIC COAST. SIMILAR TEMPERATURES ARE EXPECTED TOMORROW WITH A  
FEW DEGREES OF COOLING POSSIBLE IN THE BAYSIDE AREAS, BUT WITH  
LITTLE RELIEF FOR THE WARMEST INLAND SPOTS. LOW TEMPERATURES ON  
MONDAY MORNING RANGE FROM THE MIDDLE 50S TO LOWER 60S IN THE LOWER  
ELEVATIONS, UP TO THE MIDDLE 60S TO LOWER 70S IN THE HIGHER  
ELEVATIONS. BREEZY AND GUSTY ONSHORE WINDS SHOULD DEVELOP EACH  
AFTERNOON AND EVENING WITH THE STRONGEST GUSTS REACHING 30-35 MPH  
THROUGH FAVORED GAPS AND PASSES, WITHIN FAVORABLY ORIENTED VALLEYS,  
AND ACROSS HIGHER TERRAIN.  
 
THE HIGH TEMPERATURES TODAY AND MONDAY ARE CAUSING MODERATE HEATRISK  
ACROSS THE INLAND PORTIONS OF THE BAY AREA, BAYSIDE REGIONS OF THE  
SOUTHEASTERN PORTIONS OF SAN MATEO COUNTY AND WESTERN ALAMEDA  
COUNTY, AND PORTIONS OF THE INLAND CENTRAL COAST. THIS MEANS THAT  
THERE IS A MODERATE RISK FOR HEAT-RELATED ILLNESSES FOR POPULATIONS  
SENSITIVE TO HEAT, INCLUDING CHILDREN, THE ELDERLY, PREGNANT WOMEN,  
PEOPLE WITH CERTAIN CHRONIC DISEASES, AND PEOPLE WHO WORK OR LIVE  
OUTDOORS WITHOUT EFFECTIVE COOLING OR ADEQUATE HYDRATION. HERE ARE  
SOME HEAT SAFETY TIPS FOR PEOPLE AT RISK FOR HEAT-RELATED ILLNESSES:  
 
* STAY HYDRATED AND DRINK PLENTY OF FLUIDS.  
* WEAR LIGHTWEIGHT, LIGHT-COLORED CLOTHING.  
* REDUCE TIME SPENT OUTDOORS OR STAY IN THE SHADE.  
* NEVER LEAVE PEOPLE OR PETS UNATTENDED IN VEHICLES.  
* USE SUNSCREEN IF GOING TO THE COAST OR THE POOL.  
 

 
   
LONG TERM
 
 
ISSUED AT 1224 PM PDT SUN AUG 10 2025  
(MONDAY NIGHT THROUGH NEXT SATURDAY)  
 
A PATTERN CHANGE BEGINS ON TUESDAY AS THE UPPER LEVEL RIDGE BREAKS  
DOWN, BEGINNING A GRADUAL COOLING TREND. A TROUGH WILL THEN BEGIN TO  
FORM OVER SOUTHWESTERN CANADA AND THE PACIFIC NORTHWEST ON  
WEDNESDAY, REINFORCING THE COOLING TREND, BUILDING THE MARINE  
LAYER, AND HELPING MAINTAIN THE BREEZY AND GUSTY ONSHORE WINDS  
EACH AFTERNOON AND EVENING THROUGH THE MIDDLE OF THE UPCOMING WORK  
WEEK. THE DEEPER MARINE LAYER WILL ALSO ENHANCE THE CHANCES FOR  
COASTAL DRIZZLE THIS UPCOMING WEEK, POTENTIALLY ENOUGH TO SEE  
ACCUMULATING DRIZZLE IN SOME AREAS. BY FRIDAY AND CONTINUING INTO  
THE UPCOMING WEEKEND, TEMPERATURES SHOULD DROP BELOW THE SEASONAL  
AVERAGES, WITH HIGH TEMPERATURES IN THE MIDDLE 70S TO MIDDLE 80S  
INLAND, THE MIDDLE 60S TO MIDDLE 70S ALONG THE BAYS, AND THE LOWER  
60S ALONG THE PACIFIC COAST.  
 
BEYOND THE 7 DAY FORECAST, ENSEMBLE MODEL CLUSTER ANALYSIS  
SUPPORTS A POTENTIAL FOR A RIDGE TO RETROGRADE INTO CALIFORNIA  
FROM THE DESERT SOUTHWEST, AND CPC OUTLOOKS LEAN TOWARDS  
TEMPERATURES ABOVE THE SEASONAL AVERAGE AND PRECIPITATION TOTALS  
BELOW SEASONAL AVERAGES INTO THE LATER PART OF AUGUST.  
 

 
   
AVIATION
 
 
(00Z TAFS)  
ISSUED AT 434 PM PDT SUN AUG 10 2025  
 
CONDITIONS REMAIN FAVORABLE FOR LOW STRATUS DEVELOPMENT TO SPREAD  
FARTHER INLAND AROUND SUNSET TONIGHT WITH STEADY ONSHORE FLOW.  
THERE MAY BE PATCHY FOG AND DRIZZLE AT TIMES, ESPECIALLY THE  
CLOSER YOU GET TO THE SHORELINE.  
 
VICINITY OF SFO...VFR WILL CONTINUE THROUGH THE REMAINDER OF THE  
AFTERNOON AND EARLY EVENING WITH MVFR/IFR CEILINGS EXPECTED TO  
RETURN BY 10Z MONDAY MORNING. STRATUS SHOULD MIX OUT BY 17Z  
MONDAY. WEST TO NORTHWEST WIND NEAR 10 KNOTS TONIGHT AND MONDAY  
MORNING, THEN INCREASING FROM THE WEST 15 TO 20 KNOTS BY MONDAY  
AFTERNOON.  
 
SFO BRIDGE APPROACH...SIMILAR TO SFO.  
 
MONTEREY BAY TERMINALS...VFR IS EXPECTED TO PREVAIL THROUGH MUCH  
OF THE AFTERNOON AND EARLY EVENING, HOWEVER KMRY MAY SEE MVFR/IFR  
CEILING A LITTLE SOONER WITH STRATUS SEEN ENCROACHING ON THE AIR  
FIELD AS OF 00Z. PATCHY FOG AND DRIZZLE IS POSSIBLE NEAR THE  
COASTLINE TONIGHT THROUGH MONDAY MORNING AS WELL. LOST STRATUS IS  
EXPECTED TO CLEAR OUT BY EARLY MONDAY AFTERNOON.  
 

 
   
MARINE
 
 
(TONIGHT THROUGH NEXT FRIDAY)  
ISSUED AT 434 PM PDT SUN AUG 10 2025  
 
A GENTLE TO MODERATE BREEZE AND MODERATE SEAS WILL PREVAIL THROUGH  
TUESDAY WITH DIURNALLY DRIVEN AFTERNOON SEA BREEZE GUSTS UP TO 25  
KNOTS THROUGH THE DELTA. WINDS INCREASE AND SEAS BUILD WEDNESDAY  
WITH FRESH TO STRONG NORTHWESTERLY BREEZES AND ROUGH SEAS ON TAP  
FOR THE OUTER WATERS AND COASTAL JET REGIONS.  
 

 
   
FIRE WEATHER
 
 
ISSUED AT 906 AM PDT SUN AUG 10 2025  
 
NOT MUCH CHANGE TO THE FORECAST FOR THE NEXT COUPLE OF DAYS, WITH  
HOT AND DRY CONDITIONS PERSISTING THROUGH MONDAY AND BREEZY AND  
GUSTY ONSHORE WINDS EACH AFTERNOON AND EVENING, BOTH LEADING TO  
CURING FUELS AND THE POSSIBILITY OF RAPIDLY SPREADING FIRES SHOULD  
ONE START. POOR OVERNIGHT HUMIDITY RECOVERIES IN THE HIGHER  
TERRAIN WILL CONTRIBUTE TO THE FIRE WEATHER THREATS. AS AN UPPER  
LEVEL RIDGE BREAKS DOWN, THE GUSTY AFTERNOON WINDS WILL LINGER,  
POSSIBLE THROUGH THE MIDDLE OF THE UPCOMING WORK WEEK. HOWEVER,  
THE COOLING TEMPERATURES AND DEEPENING MARINE LAYER WILL HELP TO  
MITIGATE FIRE WEATHER THREATS, AND BY THE END OF THE WORK WEEK A  
TROUGH SHOULD BRING TEMPERATURES BELOW SEASONAL AVERAGES ACROSS  
THE REGION.  
 
DIALH  
 

 
   
MTR WATCHES/WARNINGS/ADVISORIES
 
 
CA...NONE.  
PZ...SMALL CRAFT ADVISORY UNTIL 11 PM PDT THIS EVENING FOR SF BAY N  
OF BAY BRIDGE.  
 
SMALL CRAFT ADVISORY FROM 1 PM TO 11 PM PDT MONDAY FOR SF BAY N  
OF BAY BRIDGE.  
 

 
 

 
 
SHORT TERM...DIALH  
LONG TERM....DIALH  
AVIATION...JM  
MARINE...CANEPA  
 
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