146
FXUS66 KMTR 020557
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
957 PM PST THU JAN 1 2026
..NEW AVIATION, MARINE
KEY MESSAGES
UPDATED AT 145 PM PST THU JAN 1 2026
- HIGH ASTRONOMICAL TIDES COMBINED WITH STORM SURGE WILL BRING
MINOR TO MODERATE COASTAL FLOODING AROUND HIGH TIDE THROUGH
SUNDAY
- STRONG SOUTHERLY WINDS EXPECTED FRIDAY NIGHT INTO SATURDAY
- SLIGHT CHANCE OF THUNDERSTORMS FRIDAY NIGHT THROUGH THE WEEKEND
- DAILY RAIN LIKELY THROUGH EARLY NEXT WEEK
UPDATE
ISSUED AT 849 PM PST THU JAN 1 2026
ISOLATED TO SCATTERED SHOWERS CONTINUE ACROSS THE REGION, WITH
SOME MORE PERSISTENT RAINFALL LINGERING ALONG THE WINDWARD SIDES
OF THE COASTAL RANGES. ANY CHANCES FOR THUNDERSTORMS THROUGH THE
NIGHT HAVE DIMINISHED WITH THE LACK OF SOLAR HEATING ROBBING THE
ATMOSPHERE OF ITS INSTABILITY, LEADING TO A PERIOD OF LIGHT
SHOWERS OVERNIGHT WITH SOME DRYING THROUGH FRIDAY MORNING, BEFORE
ANOTHER SYSTEM BRINGS INTENSE RAIN, A SLIGHT CHANCE FOR
THUNDERSTORMS, AND STRONG SOUTHERLY WINDS FRIDAY NIGHT INTO
SATURDAY. MEANWHILE, COASTAL FLOODING REMAINS A CONCERN WITH THE
COMBINED HIGH ASTRONOMICAL TIDES AND STORM SURGE CONTRIBUTING TO
THE RISK OF MINOR TO MODERATE FLOODING AROUND HIGH TIDE ON FRIDAY.
THE MAIN PIECE OF ADVICE FOR COASTAL FLOODING IS THE SAME AS FOR
FLOODING INLAND: TURN AROUND, DON'T DROWN WHEN ENCOUNTERING A
FLOODED ROADWAY OR A BARRICADE!
DIALH
SHORT TERM
ISSUED AT 145 PM PST THU JAN 1 2026
(THIS EVENING THROUGH FRIDAY)
RAIN SHOWERS WITH THE POTENTIAL FOR ISOLATED THUNDERSTORMS WILL
CONTINUE THROUGH THIS AFTERNOON AS THE ATMOSPHERE BECOMES MORE
UNSTABLE AS PEAKS OF SUN ARE STARTING TO MAKE AN APPEARANCE. THUS,
HEATING WILL RESULT IN UP TO 250-500 J/KG OF SURFACE BASED CAPE.
CONVECTION IS STARTING TO POP UP ACROSS THE CENTRAL COAST AND IN THE
SANTA CRUZ MOUNTAINS, SO THIS AFTERNOON COULD BE GET A BIT
INTERESTING. ANY HEAVIER SHOWERS AND THUNDERSTORMS THAT DO DEVELOP
WILL BE CAPABLE OF PRODUCING SMALL HAIL, GUSTY ERRATIC WINDS, AND
POSSIBLE FUNNEL CLOUDS.
AS WE HEAD INTO TONIGHT AND EARLY FRIDAY MORNING, CONDITIONS APPEAR
TO DRY OUT A BIT AS A WEAK SHORTWAVE RIDGE BUILDS INTO THE REGION.
THIS WILL BE SHORT LIVED BEFORE AN ATMOSPHERIC RIVER MOVES THROUGH
FRIDAY NIGHT INTO SATURDAY.
LONG TERM
ISSUED AT 145 PM PST THU JAN 1 2026
(FRIDAY NIGHT THROUGH NEXT WEDNESDAY)
A STRONG COLD FRONT WILL APPROACH THE COAST WITH STRONG SOUTHERLY
WINDS DEVELOPING FRIDAY AFTERNOON WITH THE STRONGEST ANTICIPATED
TO BE AHEAD OF AND ALONG THE FRONTAL BOUNDARY. THESE STRONGER
WINDS WILL ADVECT DEEPER MOISTURE WITH PWAT VALUES BETWEEN
1.00-1.25" ACROSS THE ENTIRE BAY AREA AND CENTRAL COAST THROUGH
SATURDAY MORNING. ADDITIONALLY, STRONG SHOWERS OR THUNDERSTORMS
WILL ALSO BE LIKELY THROUGH SATURDAY MORNING AS A RESULT OF THE
STRONGER WINDS AND LIFTING MECHANISM OF THE FRONTAL PASSAGE. WIND
GUSTS ARE FORECAST TO REACH BETWEEN 40-50 MPH ALONG THE COAST AND
IN THE HIGHER TERRAIN. THUS, A WIND ADVISORY REMAINS IN EFFECT FOR
THE AFOREMENTIONED AREAS FROM 1 PM FRIDAY THROUGH 1 PM SATURDAY.
WHILE THESE WINDS WILL NOT BE STRONG AS LAST WEEK, DOWNED
TREES/LIMBS MAY RESULT IN ISOLATED TO SCATTERED POWER OUTAGES.
IN WAKE OF THE FRONTAL PASSAGE, 500 MB TEMPERATURES WILL DROP TO
AROUND -16C TO -24C ALLOWING FOR STEEPENING LAPSE RATES THAT MAY
SUPPORT DEEPER CONVECTION ON SATURDAY. ANOTHER REINFORCING FRONT IS
FORECAST TO ARRIVE SUNDAY MORNING AND INTO THE AFTERNOON AND THEN
AGAIN ON MONDAY, WHICH WILL BRING ADDITIONAL ROUNDS OF MODERATE TO
HEAVY RAIN. HOWEVER, SOUTHERLY WINDS AREN'T EXPECTED TO BE AS STRONG
AND THOSE FRIDAY NIGHT INTO SATURDAY. THERE IS STILL A BIT OF
UNCERTAINTY IN THE ENSEMBLE GUIDANCE FOR THE REST OF NEXT WEEK,
HOWEVER CONDITIONS LOOK TO REMAIN COOL AND UNSETTLED.
AVIATION
(06Z TAFS)
ISSUED AT 939 PM PST THU JAN 1 2026
MVFR/IFR CIGS EXPECTED TO PREVAIL FOR THE NORTH BAY OVERNIGHT
INTO EARLY AFTERNOON FRIDAY, BEFORE LIFTING TO VFR WHEN WINDS
BEGIN TO INCREASE WITH PREFRONTAL SHOWERS OUT AHEAD OF THE MAIN
LINE EXPECT TO BEGIN MOVING ONSHORE BY EARLY AFTERNOON.
VICINITY OF SFO...EXPECT MVFR CIGS TO PREVAIL OVERNIGHT THAT MAY
OCCASIONAL LIFT TO VFR, ALONG WITH ON-AND-OFF LIGHT RAIN. BY LATE
MORNING FRIDAY PREFRONTAL WINDS BEGIN TO INCREASE WITH SCATTERED
SHOWERS OUT AHEAD OF THE MAIN LINE SET TO ARRIVE ONSHORE BY LATE
AFTERNOON. STRONG WINDS, SCATTERED SHOWERS WITH THUNDERSTORMS ARE
EXPECTED TO PREVAIL THROUGH THE REMAINDER OF THE TAF PERIOD INTO
LATE FRIDAY NIGHT.
SFO BRIDGE APPROACH...SIMILAR TO SFO.
MONTEREY BAY TERMINALS...EXPECT CIGS TO HOVER AROUND MVFR/VFR
OVERNIGHT, THEN BECOMING VFR BY MID-MORNING. WIND, SHOWERS AND
THUNDERSTORM ACTIVITY ARRIVES LATER THAN FARTHER NORTH WITH
SLIGHTLY LESS IMPACTFUL WINDS AND THUNDER STORM COVERAGE THIS FAR
SOUTH. KSNS WINDS REMAIN ELEVATED THROUGH THE TAF PERIOD WITH
SURFACE FLOW THROUGH THE SALINAS VALLEY.
MARINE
(TONIGHT THROUGH NEXT WEDNESDAY)
ISSUED AT 939 PM PST THU JAN 1 2026
SMALL CRAFT ADVISORIES IN THE NORTHERN OUTER WATERS WILL BECOME
GALE WARNINGS LATE IN THE OVERNIGHT PERIOD TONIGHT, WITH THE
REMAINING OUTER AND INNER WATERS BECOMING GALE WARNING BY MID
MORNING FRIDAY. THE REMAINING INTERIOR BAYS WILL HAVE SMALL CRAFT
ADVISORIES BY MID- AFTERNOON FRIDAY, WITH MONTEREY BAY IN A GALE
WARNING DURING MOST OF THE OVERNIGHT PERIOD FRIDAY INTO EARLY
SATURDAY MORNING. THERE MAY BE BRIEF PERIODS WITH STORM FORCE
GUSTS IN THE FAR NORTHERN OUTER WATERS AND INNER WATERS OFF BIG
SUR FRIDAY EVENING INTO EARLY SATURDAY, BUT NOT OVER A LARGE
ENOUGH AREA OR FOR A LONG ENOUGH PERIOD OF TIME TO HOIST A STORM
WARNING AT THIS TIME. THE GALE WARNINGS OFF OF BIG SUR WILL REMAIN
IN PLACE THROUGH MID-MORNING SATURDAY, AND THE GALE WARNINGS IN
THE NORTHERN HALF OF THE OUTER WATERS WILL REMAIN PLACE THROUGH
SATURDAY AFTERNOON. ALONG WITH THE STRONG SOUTHERLY WINDS, EXPECT
ROUGH SEAS, MODERATE TO HEAVY RAIN AT TIMES AND A SLIGHT CHANCE OF
THUNDERSTORMS.
BEACHES
ISSUED AT 900 AM PST THU JAN 1 2026
PERIGEAN SPRING TIDES (KING TIDES) WILL IMPACT THE REGION THROUGH
SUNDAY. THIS IS DUE TO THE COMBINATION OF THE FULL MOON ON 1/3,
LUNAR PERIGEE ON 1/1, AND PERIHELION ON 1/3. IN OTHER WORDS ALL
THREE PLANETARY BODIES ARE LINED UP AND CLOSE TO EACH OTHER. IN
ADDITION TO THE HIGH ASTRONOMICAL TIDE, THE INCOMING LOW PRESSURE
SYSTEM WILL BRING STRONG SOUTHERLY WINDS, GENERATING SOME STORM
SURGE. THE COMBINATION OF THESE FACTORS WILL BRING MINOR TO
MODERATE COASTAL FLOODING TO THE LOW-LYING AREAS NEAR SHORELINES
AND TIDAL WATERWAYS DURING HIGH TIDE THROUGH SUNDAY. AT THE SAN
FRANCISCO TIDAL GAUGE, HIGH TIDE IS EXPECTED TO BE 2.2 FT ABOVE
NORMAL AT 9:34 AM FRIDAY, 2.5 FT ABOVE NORMAL AT 10:26 AM
SATURDAY, AND 1.8 FT ABOVE NORMAL AT 11:18 AM SUNDAY. THESE
PREDICTIONS INCLUDE UP TO 1.3 FEET OF STORM SURGE THAT WILL
ENHANCE THE ASTRONOMICAL TIDE AND FLOODING THREAT. HIGH TIDE
VARIES UP TO 90 MINUTES EARLIER OR LATER ALONG THE PACIFIC COAST
AND THROUGH THE SAN FRANCISCO BAY, RESPECTIVELY.
MTR WATCHES/WARNINGS/ADVISORIES
CA...COASTAL FLOOD ADVISORY UNTIL 2 PM PST SUNDAY FOR CAZ006-505-506-
508-509-529-530.
WIND ADVISORY FROM 1 PM FRIDAY TO 1 PM PST SATURDAY FOR CAZ006-
502>505-509-512-515>518-528>530.
PZ...SMALL CRAFT ADVISORY FROM 3 PM FRIDAY TO 3 AM PST SATURDAY FOR
SF BAY N OF BAY BRIDGE.
SMALL CRAFT ADVISORY UNTIL 9 PM PST FRIDAY FOR MRY BAY.
GALE WARNING FROM 9 PM FRIDAY TO 3 AM PST SATURDAY FOR MRY BAY.
SMALL CRAFT ADVISORY UNTIL 9 AM PST FRIDAY FOR PIGEON PT TO PT
PINOS 0-10 NM-PIGEON PT TO PT PINOS 10-60 NM-PT ARENA TO PT
REYES 0-10 NM-PT REYES TO PIGEON PT 0-10 NM.
GALE WARNING FROM 9 AM FRIDAY TO 3 AM PST SATURDAY FOR PIGEON PT
TO PT PINOS 0-10 NM-PIGEON PT TO PT PINOS 10-60 NM-PT ARENA
TO PT REYES 0-10 NM-PT REYES TO PIGEON PT 0-10 NM.
SMALL CRAFT ADVISORY UNTIL 3 AM PST FRIDAY FOR PT ARENA TO PT
REYES 10-60 NM-PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM.
GALE WARNING FROM 3 AM FRIDAY TO 9 AM PST SATURDAY FOR PT PINOS
TO PT PIEDRAS BLANCAS 0-10 NM.
GALE WARNING FROM 3 AM FRIDAY TO 3 PM PST SATURDAY FOR PT ARENA
TO PT REYES 10-60 NM.
SHORT TERM...RGASS
LONG TERM....RGASS
AVIATION...JM
MARINE...JM
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK, X, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
X.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page