892
FXUS66 KMTR 030452
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
952 PM PDT MON JUN 2 2025
..NEW AVIATION, MARINE
SYNOPSIS
ISSUED AT 102 PM PDT MON JUN 2 2025
GENERALLY QUIESCENT CONDITIONS ARE ANTICIPATED THROUGH THE ENTIRE
OUTLOOK PERIOD. TEMPERATURES WILL INITIALLY BE NEAR OR JUST BELOW
NORMAL, BEFORE CONDITIONS MODERATE THROUGH THE END OF THE WEEK
AND INTO THE WEEKEND. DAILY ONSHORE BREEZES ARE FORECAST, WITH
PORTIONS OF THE WEST DELTA, WITHIN GAPS AND CHANNELS, AND ACROSS
HIGHER TERRAIN POTENTIALLY EXPERIENCING GUSTS OVER 30 MPH.
UPDATE
ISSUED AT 812 PM PDT MON JUN 2 2025
A RELATIVELY SMALL CU FIELD JUST EAST OF OUR FORECAST AREA IN
SOUTHERN MONTEREY COUNTY CAN BE SEEN ON SATELLITE EARLY THIS
EVENING. WHILE NOT OFFICIALLY IN THE FORECAST WE HAVE BEEN WATCHING
THE POTENTIAL FOR ELEVATED THUNDERSTORMS OVER THIS AREA FOR THE PAST
FEW DAYS. AS EXPECTED, THE OVERALL ENVIRONMENT IS TOO DRY FOR STORMS
TO HAVE DEVELOPED THIS AFTERNOON AND EVENING. BEYOND THAT, NO
CHANGES TO THE FORECAST TONIGHT WITH NEAR NORMAL TEMPERATURES AND
DRY CONDITIONS THROUGH THE EXTENDED FORECAST. COASTAL AREAS CAN
EXPECT SOME LOW MARINE STRATUS TO FILL IN ALONG THE SHORELINE LATE
TONIGHT THROUGH EARLY TUESDAY MORNING, WITH SOME PENETRATION FURTHER
INLAND ACROSS THE NORTH BAY WITH SOUTHERLY WINDS PROVIDING A
MOISTURE SURGE INTO THE VALLEYS AND GAPS FROM THE EAST BAY
NORTHWARD.
SHORT TERM
ISSUED AT 102 PM PDT MON JUN 2 2025
(THIS EVENING THROUGH TUESDAY)
SHORT TERM KEY MESSAGES
-JUST BELOW OR NEAR NORMAL TEMPERATURES
-INCREASED BREEZES ACROSS THE WEST DELTA/AREAS OF COMPLEX TERRAIN
-NON-ZERO RISK FOR ELEVATED CONVECTION
WATER VAPOR IMAGERY EARLY THIS AFTERNOON INDICATES AN UPPER LOW
CHURNING SOUTHWARD TOWARD THE CALIFORNIA BIGHT. IT'LL GET
ENVELOPED WITHIN THE MAIN FLOW SOUTHERN STREAM FLOW OVER THE NEXT
48 HOURS. CURRENT WATER VAPOR IMAGERY ACROSS THE EAST PAC DOES
INDICATE REMNANT MOISTURE AROUND THE FLAT H5 RIDGE WILL BE DRAWN
NORTHWARD. CURRENT INDICATIONS ARE THAT THAT FLOW AROUND THE WEST
SIDE OF THE HIGH AND EAST SIDE/AHEAD OF UPPER LOW WILL BE SUCH
THAT A MAJORITY OF THE RICHER PLUME WILL REMAIN SOUTH OF OUR AREA.
STILL, SOME GUIDANCE, MOST NOTABLY THE NAM (WHICH TYPICALLY HAS A
SLIGHT WET BIAS), INDICATES THAT PRECIPITABLE WATER (PWAT) JUST
OVER 3/4 OF AN INCH MAY EEK INTO SOUTHERN MONTEREY AND SAN BENITO
COUNTIES LATE TONIGHT INTO THE PRE-DAWN HOURS ON TUESDAY. FOR NOW,
THE MAIN TRIGGER WOULD NEED TO BE OROGRAPHIC ASCENT ACROSS THE
GABILAN RANGE. FOR NOW, I'LL ADVERTISE A 5 POP ACROSS THIS REGION
AS CONFIDENCE ISN'T HIGH (AND NOT BOLSTERED BY ANY NCEP OR PG&E
HIGH- RES NWP), BUT WE'LL KEEP MONITOR OF THIS POTENTIAL,
PARTICULARLY WITH 700-500MB LAPSE RATES FORECAST TO APPROACH OR
EXCEED 7 C/KM (AND THEY ARE ALREADY AROUND 8 C/KM PER OUR 12 UTC
OAK RAOB). OTHERWISE, POCKETS OF DRIZZLE/MIST CANNOT BE
DISCOUNTED, PARTICULARLY ALONG COASTAL REGIONS.
OTHERWISE, I EXPECT THAT WE'LL SEE AN UPTICK IN BREEZES AS THE
SFO-SAC GRADIENT INCHES TOWARD 3-4MB. THIS SHOULD FUEL A BIT MORE
ONSHORE FLOW AND I ANTICIPATE THAT THROUGH SOME OF THE
GAPS/PASSES, WIND GUSTS WILL BE ENHANCED. IN FACT, THE PROBABILITY
OF PEAK WIND GUSTS OF GREATER THAN 25-30 MPH EXCEEDS 70% FOR
PORTIONS OF THE NORTH BAY MOUNTAINS, WEST DELTA AND EAST BAY HILLS
WITH AROUND A 20-30%% CHANCE THAT PEAK WINDS COULD GUST OVER 40
MPH ON TUESDAY.
OTHERWISE, THE ONSHORE FLOW (WHICH ISN'T UNUSUAL FOR THIS TIME OF
YEAR) WILL SUPPORT NEAR TO JUST BELOW NORMAL TEMPERATURES DURING
THE SHORT TERM FORECAST PERIOD.
LONG TERM
ISSUED AT 102 PM PDT MON JUN 2 2025
(TUESDAY NIGHT THROUGH NEXT SUNDAY)
LONG TERM KEY MESSAGES
-GRADUAL WARMING TREND
WITH THE AFOREMENTIONED UPPER LOW KICKING EASTWARD, THE OVERALL
LONG TERM PATTERN APPEARS THAT IT'LL BE DOMINATED BY SLIGHT
LONGWAVE RIDGING ACROSS THE WESTERN CONUS. THIS WILL TRANSLATE TO
LARGELY UNEVENTFUL WEATHER (WARM AND PRECIPITATION-FREE) ACROSS
THE BAY AREA AND CENTRAL COAST. WE'LL LIKELY SEE A DIURNAL PATTERN
CHARACTERIZED BY A PUSH OF MARINE STRATUS ONSHORE DURING THE
OVERNIGHT HOURS, WITH EROSION OF THE MARINE LAYER LATE MORNING AND
INTO THE EARLY AFTERNOON HOURS.
TOWARD DAYS 5 THROUGH 7, MODEL SOLUTIONS DO BEGIN TO SHOW SOME
VARIABILITY. MOST SOLUTIONS SHOW A STRENGTHENING RIDGE ACROSS THE
PACIFIC NORTHWEST WITH SOME MODEL SOLUTIONS INDICATING THE HEART
OF THIS FEATURE WILL BE MORE CENTERED ACROSS BIG SKY COUNTRY.
THERE IS A SOLUTION CLUSTER (MOSTLY COMPRISED OF CANADIAN/GFS
ENSEMBLE MEMBERS) THAT WOULD SUPPORT MORE IN THE WAY OF TROUGHING
ACROSS THE PACNW, BUT THIS DOESN'T REALLY RESULT IN A SIGNIFICANT
CHANGE IN THE FORECAST ACROSS CALIFORNIA. FOR NOW, THE DETERMINISTIC
NBM OFFERS A VALID SOLUTION FOR ABOVE NORMAL WARMTH CONTINUING
THIS WEEKEND AND ONWARD. THIS PAIRS WELL WITH EXTENDED TEMPERATURE
OUTLOOKS.
AVIATION
(06Z TAFS)
ISSUED AT 952 PM PDT MON JUN 2 2025
IT'S CLEAR /VFR/ EXCEPT KHAF REPORTS MVFR IN MIST. ONSHORE WINDS
WILL USHER COASTAL STRATUS AND FOG /MVFR-IFR/ INLAND TONIGHT AND
TUESDAY MORNING. THE MARINE LAYER WILL COMPRESS OVERNIGHT, CEILINGS
LIKELY MVFR TO START THEN LOWERING TO IFR TONIGHT AND TUESDAY MORNING.
A FEW PATCHES OF VALLEY FOG /LIFR-IFR/ MAY ALSO DEVELOP LATE TONIGHT
AND TUESDAY MORNING.
VICINITY OF SFO...VFR CONTINUING THROUGH THE EVENING. STRATUS /IFR/
DEVELOPS BY 12Z TUESDAY, MIXING OUT TO VFR 17Z TUESDAY. WEST WIND
LOWERING TO LIGHT AND VARIABLE TO LIGHT NORTHEAST EARLY TUESDAY
MORNING. NORTHWEST TO WEST WIND REDEVELOPING TUESDAY, GUSTY TO 25
KNOTS TUESDAY AFTERNOON AND EARLY EVENING. HREF OUTPUT SHOWS STRATUS
/IFR/ REDEVELOPS BY 11Z WEDNESDAY MORNING.
SFO BRIDGE APPROACH...SIMILAR TO SFO.
MONTEREY BAY TERMINALS...VFR CONTINUING THROUGH THE EVENING, THEN
INCREASING PROBABILITY OF STRATUS /MVFR-IFR/ DEVELOPING TONIGHT
AND TUESDAY MORNING. STRATUS MIXING OUT BY LATE TUESDAY MORNING.
WEST TO NORTHWEST WINDS 5 TO 15 KNOTS EXCEPT LOCALLY LIGHT AND
VARIABLE TONIGHT AND TUESDAY MORNING. HREF OUTPUT SHOWS STRATUS
/IFR/ REDEVELOPS TUESDAY EVENING (03Z WEDNESDAY).
MARINE
(TONIGHT THROUGH NEXT SUNDAY)
ISSUED AT 941 PM PDT MON JUN 2 2025
GUSTY NORTH TO NORTHWEST WINDS WILL CONTINUE MAINLY OVER THE
NORTHERN OUTER COASTAL WATERS, WHILE SOUTHERLY WINDS CONTINUE
OVER THE REMAINDER OF THE COASTAL WATERS. ROUGH SEAS WILL CONTINUE
MAINLY ACROSS THE NORTHERN OUTER WATERS TONIGHT THROUGH MID TO
LATE WEEK.
MTR WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 3 PM PDT WEDNESDAY FOR PT ARENA TO PT
REYES 10-60 NM.
SMALL CRAFT ADVISORY UNTIL 9 AM PDT TUESDAY FOR PIGEON PT TO PT
PINOS 10-60 NM.
SHORT TERM...BAIN
LONG TERM....BAIN
AVIATION...CANEPA
MARINE...CANEPA
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