579
FXUS66 KMTR 040439
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
939 PM PDT SUN MAY 3 2026
..NEW AVIATION, MARINE
KEY MESSAGES
UPDATED AT 1004 AM PDT SUN MAY 3 2026
- COOLER TEMPERATURES THROUGH TUESDAY WITH A CHANCE FOR DRIZZLE
AND LIGHT RAIN, MAINLY ALONG THE COAST AND THE NORTH BAY
- WARMER AND DRIER CONDITIONS RETURN FOR THE MIDDLE OF THE WEEK
SHORT TERM
ISSUED AT 1004 AM PDT SUN MAY 3 2026
(THIS AFTERNOON THROUGH MONDAY)
IT'S A CLOUDY MORNING ACROSS THE BAY AREA AND CENTRAL COAST WITH THE
STRATUS DECK EXTENDING FAR INLAND, WITH A STRONG UPPER LEVEL LOW
MOVING OVER THE REGION ALLOWING FOR REMARKABLE EXPANSION OF THE
MARINE LAYER, TO THE POINT WHERE IT NO LONGER MAKES SENSE TO TALK
ABOUT A MARINE LAYER DEPTH. KMUX RADAR RETURNS ARE ALSO SHOWING
LIGHT RAIN SHOWERS AND DRIZZLE ACROSS THE SAN MATEO PENINSULA, PARTS
OF SANTA CLARA COUNTY, AND THE MONTEREY BAY REGION, WITH THE
POTENTIAL FOR ADDITIONAL DRIZZLE WHERE THE RADAR BEAM IS
OVERSHOOTING THE LOW LEVEL PROCESSES, SUCH AS THE NORTH BAY AND
SOUTHERN MONTEREY COUNTY. DRIZZLE CHANCES DIMINISH AFTER AROUND 1
PM, AND SOME BREAKS IN THE CLOUDS MAY DEVELOP ACROSS THE INLAND
REGIONS THIS AFTERNOON, BUT THIS IS A LOWER CONFIDENCE FORECAST.
HAVE DECREASED THE HIGH TEMPERATURE FORECAST ACROSS THE REGION IN
LIGHT OF THE POTENTIAL FOR CONTINUED CLOUDINESS THROUGH THE DAY.
HIGHS IN THE LOWER TO MIDDLE 60S ARE EXPECTED IN THE BAY AREA
INTERIOR VALLEYS, THE LOWER TO MIDDLE 70S IN THE SOUTHERN SALINAS
VALLEY, AND THE MIDDLE 50S TO LOWER 60S ALONG THE COAST AND BAYS.
CONDITIONS ARE BROADLY SIMILAR ON MONDAY AS THE UPPER LEVEL LOW
MOVES OVER THE STATE, WITH ADDITIONAL COOLING EXPECTED IN THE
SOUTHERN PARTS OF MONTEREY COUNTY AS HIGHS REACH THE MIDDLE TO UPPER
60S.
A BEACH HAZARDS STATEMENT REMAINS IN EFFECT THROUGH 11 PM THIS
EVENING DUE TO LONG PERIOD NORTHWESTERLY SWELL, AN INCREASING RISK
OF SNEAKER WAVES AND STRONG RIP CURRENTS. SEE THE BEACHES SECTION
FOR MORE INFORMATION.
LONG TERM
ISSUED AT 1004 AM PDT SUN MAY 3 2026
(MONDAY NIGHT THROUGH NEXT SATURDAY)
THE UPPER LEVEL LOW CONTINUES TO MOVE ACROSS CALIFORNIA THROUGH
TUESDAY, RESULTING IN A CONTINUATION OF THE COOL TEMPERATURES,
EXTENSIVE STRATUS DECKS, AND A SLIGHT CHANCE FOR LIGHT RAIN AND
DRIZZLE ACROSS THE REGION, BUT MAINLY AT THE COAST AND WITHIN
TOPOGRAPHICALLY FAVORED LOCATIONS. THE LATEST MODEL OUTPUT SHOWS THE
LOW DESCENDING INTO SOUTHERN CALIFORNIA, ALLOWING FOR A BAND OF
MOISTURE TO WRAP AROUND THE LOW AND BRING SOME WETTING RAINS TO THE
NORTH BAY MONDAY NIGHT INTO TUESDAY MORNING. THE CURRENT FORECAST
SHOWS RAIN TOTALS OF UP TO A QUARTER OF AN INCH IN THE INTERIOR
REGIONS OF THE NORTH BAY WITH TOTALS A FEW HUNDREDTHS OF AN INCH
CLOSER TO THE COAST AND EXTENDING INTO THE BAY AREA. OF NOTE, HIGH
RESOLUTION MODEL OUTPUT CONTINUES TO SHOW THE POSSIBILITY OF HIGHER
RAIN TOTALS, UP TO AROUND HALF AN INCH IN THE NORTH BAY, WHICH MIGHT
BE POSSIBLE IF THERE ARE SOME PARTICULARLY STRONG SHOWERS ACROSS THE
RAIN BAND. FLOODING CONCERNS REMAIN MINIMAL AND FOCUSED ON AREAS OF
EXCEPTIONALLY POOR DRAINAGE OR WHERE DRAINAGE PIPES ARE BLOCKED OR
CLOGGED.
BY WEDNESDAY, THE UPPER LEVEL LOW MOVES INTO THE GREAT BASIN AND
SOUTHERN ROCKIES WITH RIDGING BUILDING BACK BEHIND IT, LEADING TO A
WARMING AND DRYING TREND IN THE REGION WITH HIGHS RISING TO THE 70S
AND 80S INLAND. THE CPC EXTENDED OUTLOOK SHOWS THAT TEMPERATURES
ABOVE THE SEASONAL AVERAGES ARE LIKELY TO PERSIST THROUGH THE MIDDLE
OF MAY, WHILE PRECIPITATION TOTALS LEAN BELOW THE SEASONAL AVERAGE.
FOR CONTEXT, THE SEASONAL AVERAGE HIGH IN DOWNTOWN SAN FRANCISCO IS
AROUND 64 DEGREES, WHILE THE SEASONAL AVERAGE PRECIPITATION TOTAL
FOR THE MAY 10 TO 16 PERIOD, AS COVERED IN THE CPC 8-14 DAY OUTLOOK,
FALLS A SHADE UNDER TWO TENTHS OF AN INCH FOR THE SAME STATION.
AVIATION
(06Z TAFS)
ISSUED AT 933 PM PDT SUN MAY 3 2026
NOT MUCH OF A DISCERNIBLE MARINE LAYER PER SE, BUT DEFINITELY A
SCT TO BKN CLOUD DECK FORMING OVER THE NEARBY TERRAIN WITH SOME
IMPACTS TO TERMINALS. TONIGHT THROUGH EARLY MONDAY WILL KEEP
MAINLY VFR CIGS WITH HEIGHTS IN THE 3000-5000 FT RANGE. TOMORROW
IS A TRICKY DAY AS MOISTURE TO THE EAST STREAMS WEST INCREASING
CHC FOR PRECIP AND LOWER CIGS. PRECIP INITIALLY LIKELY OVER THE N
BAY AND THEN SPREADING S TO SF BAY. FARTHER SOUTH THAN THAT IS
OUTSIDE OF THE TAF PERIOD. OVERALL CONF IS MEDIUM.
VICINITY OF SFO...VFR CIGS LOOKING MORE LIKELY THROUGH MUCH OF
MONDAY. LATE MONDAY INTO TUESDAY PRECIP CHC INCREASE WITH MVFR
CIGS.
SFO BRIDGE APPROACH...SIMILAR TO SFO.
MONTEREY BAY TERMINALS...MVFR CIGS SLOWLY DEVELOPING AROUND THE
PENINSULA. WILL HAVE A BETTER SHOT FILLING LATER IN THE NIGHT.
MARINE
(TONIGHT THROUGH NEXT SATURDAY)
ISSUED AT 933 PM PDT SUN MAY 3 2026
LIGHT TO GENTLE BREEZES OVER THE WATERS AS A WEAK DISTURBANCE
MOVES THROUGH THE REGION. THE LONGER PERIOD SWELL THAT ARRIVE
SUNDAY WILL CONTINUE TO DIMINISH THROUGH MONDAY. NORTHERLY WINDS
AND SEAS WILL BEGIN TO INCREASE THURSDAY AND INTO NEXT WEEKEND.
MTR WATCHES/WARNINGS/ADVISORIES
CA...BEACH HAZARDS STATEMENT UNTIL 11 PM PDT THIS EVENING FOR CAZ006-
505-509-529-530.
PZ...NONE.
SHORT TERM...DIALH
LONG TERM....DIALH
AVIATION...MM
MARINE...MM
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