286
FXUS66 KMTR 031128
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
328 AM PST SAT JAN 3 2026
..NEW AVIATION, MARINE
KEY MESSAGES
UPDATED AT 1201 AM PST SAT JAN 3 2026
- HIGH ASTRONOMICAL TIDES COMBINED WITH STORM SURGE WILL BRING
SUBSTANTIAL TIDAL FLOODING THROUGH SUNDAY
- STRONG SOUTHERLY WINDS CONTINUE INTO SATURDAY AFTERNOON
- CHANCE OF THUNDERSTORMS THROUGH THE WEEKEND
- HAZARDOUS BEACH CONDITIONS SUNDAY
- DAILY RAIN SHOWERS EXPECTED THROUGH MONDAY
SHORT TERM
ISSUED AT 1201 AM PST SAT JAN 3 2026
(TODAY AND TONIGHT)
THE OCCLUDED FRONT IS JUST OFF THE COAST, AND THE TRIPLE
POINT SHOULD MAKE LANDFALL IN THE BAY AREA AROUND 4 AM. THE MORE
ORGANIZED BAND OF RAIN ASSOCIATED WITH THIS FRONTAL PASSAGE HAS
REACHED THE NORTH BAY AND WILL PUSH SOUTH THROUGH THE EARLY MORNING
HOURS. OVERALL THE RAIN HAS BEEN SOMEWHAT UNDERWHELMING COMPARED TO
OUR EXPECTATIONS. OUTSIDE OF THE MOUNTAINS, NOWHERE HAS RECORDED
MORE THAN 1" OF RAIN, WITH LESS THAN 1/4" ACROSS THE SF PENINSULA,
EAST BAY, AND SOUTH BAY. WHILE WE HAVEN'T SEEN THUNDERSTORMS YET,
WE'VE JUST STARTED TO SEE 40 DBZ AT THE -10C LEVEL, INCREASING
CONFIDENCE THAT WE'RE APPROACHING THE ICE CONTENT NECESSARY TO
GENERATE LIGHTNING. AFTER THE FRONT PASSES THE RAIN WILL
TRANSITION TO SCATTERED SHOWERS, SOME OF WHICH COULD BE STRONG. WE
HAVE A RENEWED CHANCE FOR THUNDERSTORMS IN THE MORE UNSTABLE
ATMOSPHERE THROUGH THE DAY SATURDAY, PARTICULARLY IN THE NORTH
BAY. A RAP13 POINT SOUNDING AT SANTA ROSA SHOWS THE INSTABILITY
PEAKING AROUND 1 PM. ACCORDING TO THIS MODEL, THE SURFACE BASED
CAPE REACHES AN IMPRESSIVE 676 J/KG, WITH STEEP LOW-LEVEL LAPSE
RATES (-7.4 C/KM), DECENT 0-1 KM SHEAR (25 KT) IN A SLIGHTLY
CURVED HODOGRAPH, AND LOW LCL HEIGHTS (394M). IF WE CAN MANAGE TO
FIND A TRIGGER TO TAP INTO THIS ENERGY IN AN ORGANIZED MANNER, A
LINE OF THUNDERSTORMS COULD DEVELOP ACROSS THE NORTH BAY IN THE
AFTERNOON AND PUSH SOUTH THROUGH THE EVENING AHEAD OF THE NEXT
FRONTAL PASSAGE SUNDAY MORNING. WITH THE MODERATE SHEAR, WE CAN'T
RULE OUT SEVERE THUNDERSTORMS. THERE IS ONLY A MARGINAL CHANCE,
BUT DAMAGING WIND GUSTS AND SHORT LIVED TORNADOES ARE THE PRIMARY
HAZARD IF ANY THUNDERSTORMS CAN MANAGE TO BECOME SEVERE.
THE SUNDAY FRONT WILL BRING SIMILAR IMPACTS TO THE ONGOING SYSTEM,
ALTHOUGH THE RAIN WILL CONTINUE PAST DAWN, SO THE IMPACT FROM THE
RAIN WILL LIKELY BE HIGHER. WINDS, ON THE OTHER HAND, WILL DECREASE
TO A MODERATE BREEZE, AND THE THUNDERSTORM THREAT WILL ABATE
THROUGH THE DAY. WHILE RIVER FLOODING ISN'T A MAJOR CONCERN, THE
USGS IS REPORTING SATURATED SOILS. IF ANY HEAVY SHOWERS BRING HIGH
RAIN RATES THEY COULD TRIGGER SHALLOW LANDSLIDES.
LONG TERM
ISSUED AT 1201 AM PST SAT JAN 3 2026
(SUNDAY THROUGH FRIDAY)
SHOWERS WITH A SLIGHT CHANCE OF THUNDERSTORMS WILL PERSIST SUNDAY
NIGHT INTO THE BEGINNING OF THE NEW WORK WEEK, ESPECIALLY FOR THE
NORTH BAY. THE UPPER LEVEL LOW CURRENTLY RESPONSIBLE FOR OUR WINDY
AND RAINY WEATHER OVERNIGHT, WILL LIFT NORTH DURING THE DAY TODAY
AND BE RE-ABSORBED BY YET ANOTHER DISTURBANCE OFF THE COAST OF THE
PACIFIC NORTHWEST. THE TROUGH ASSOCIATED WITH THE EXITING LOW, WILL
BE REINVIGORATED OVER THE NEXT 48HRS AND BRING ANOTHER ROUND OF
WIDESPREAD RAINFALL MONDAY INTO EARLY TUESDAY. THE COASTAL RANGES
WILL BE FAVORED FOR THE HIGHEST RAIN TOTALS BUT THE SPIGOT DOESN'T
APPEAR TO SHUT OFF UNTIL WEDNESDAY WHEN WE SEE AMPLIFIED RIDGING
BEGIN TO BUILD OVER THE EASTERN PACIFIC IN THE WAKE OF THE FINAL
UPPER LOW SHIFTING SOUTH OFFSHORE ON TUESDAY. THE COASTAL RANGES MAY
SEE 1-2" OF RAINFALL MONDAY INTO TUESDAY WITH LESSER AMOUNTS FOR THE
REMAINDER OF OUR AREA, AROUND 0.25"-0.75" WHERE IT DOES RAIN.
THERE'S A CHANCE NEXT WEEKEND COULD BE A GOOD ONE, WITH CLIMATE
PREDICTION CENTER HIGHLIGHTING THE POSSIBILITY IN THE 6-10 DAY
OUTLOOK.
AVIATION
(12Z TAFS)
ISSUED AT 328 AM PST SAT JAN 3 2026
IT'S VFR-MVFR EXCEPT PATCHY IFR IN FOG. A FEW SHOWERS CONTINUE
ACROSS THE FORECAST AREA WITH THE UPPER LOW MOVING BY TO THE
NORTHEAST. PATCHY FOG /LIFR-IFR/ RETURN TONIGHT AND SUNDAY
MORNING.
VICINITY OF SFO...MVFR-VFR WITH A FEW LIGHT SHOWERS CONTINUING
TODAY. SOUTH TO SOUTHEAST WIND GUSTS TO 25-30 KNOTS THROUGH THE
AFTERNOON. LIGHTER SOUTH WIND TONIGHT AND SUNDAY MORNING.
SFO BRIDGE APPROACH...SIMILAR TO SFO.
MONTEREY BAY TERMINALS...MVFR-VFR WITH A FEW SHOWERS CONTINUING
TODAY. SOUTH TO SOUTHEAST WIND GUSTS TO 15-20 KNOTS THROUGH THE
AFTERNOON. LIGHT SOUTHEAST WIND TONIGHT AND SUNDAY MORNING.
MARINE
(TODAY THROUGH THURSDAY)
ISSUED AT 322 AM PST SAT JAN 3 2026
AN UPPER LEVEL LOW PRESSURE AREA WILL RESULT IN SHOWERS AND A
SLIGHT CHANCE OF THUNDERSTORMS THROUGH THE WEEKEND. SEAS WILL
BUILD TO 12 TO 16 FEET THIS WEEKEND BEFORE ABATING EARLY NEXT
WEEK.
BEACHES
ISSUED AT 1201 AM PST SAT JAN 3 2026
A COASTAL FLOOD WARNING IS IN EFFECT FOR THE SAN FRANCISCO BAY
THROUGH SATURDAY. A COASTAL FLOOD ADVISORY IS IN EFFECT FOR THE
PACIFIC COAST AND MONTEREY BAY THROUGH SUNDAY. 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 THE EARTH, SUN AND MOON 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, PARTICULARLY ON SATURDAY
MORNING. THE COMBINATION OF THESE FACTORS WILL BRING MODERATE
COASTAL FLOODING TO THE LOW-LYING AREAS NEAR SHORELINES AND TIDAL
WATERWAYS DURING HIGH TIDE THROUGH SUNDAY.
ON FRIDAY, THE SAN FRANCISCO TIDAL GAUGE RECORDED 2.26 FT OF
INUNDATION. LOOKING AHEAD, HIGH TIDE IS EXPECTED TO BE 2.5 FT
ABOVE NORMAL AT 10:26 AM SATURDAY AND 1.9 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.
A REASONABLE WORSE CASE SCENARIO (10% EXCEEDANCE CHANCE) IS 2.7
FT OF INUNDATION ON SATURDAY. THE ALL TIME RECORD IS 2.8 FT FROM
1/27/1983. 2.5 FT HASN'T BEEN REACHED SINCE 1998. HIGH TIDE VARIES
UP TO 90 MINUTES EARLIER OR LATER ALONG THE PACIFIC COAST AND
THROUGH THE SAN FRANCISCO BAY, RESPECTIVELY.
A BEACH HAZARD STATEMENT IS IN EFFECT SUNDAY. LARGE SWELL WILL
IMPACT THE PACIFIC BEACHES, GENERATING LARGE BREAKING WAVES UP TO
20 FEET, STRONG RIP CURRENTS, AND SNEAKER WAVES. INEXPERIENCED
SWIMMERS SHOULD AVOID THE WATER. NOBODY SHOULD CLIMB THE COASTAL
ROCKS. NEVER TURN YOUR BACK ON THE OCEAN.
MTR WATCHES/WARNINGS/ADVISORIES
CA...COASTAL FLOOD WARNING UNTIL 2 PM PST THIS AFTERNOON FOR CAZ006-
506-508.
WIND ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR CAZ006-502>505-
509-512-514>518-528>530.
COASTAL FLOOD ADVISORY FROM 2 PM THIS AFTERNOON TO 2 PM PST
SUNDAY FOR CAZ006-506-508.
BEACH HAZARDS STATEMENT FROM SUNDAY MORNING THROUGH SUNDAY
EVENING FOR CAZ006-505-509-529-530.
COASTAL FLOOD ADVISORY UNTIL 2 PM PST SUNDAY FOR CAZ505-509-529-
530.
PZ...SMALL CRAFT ADVISORY UNTIL 9 AM PST SUNDAY FOR SF BAY N OF BAY
BRIDGE.
SMALL CRAFT ADVISORY UNTIL 3 PM PST SUNDAY FOR MRY BAY-PIGEON PT
TO PT PINOS 0-10 NM-PIGEON PT TO PT PINOS 10-60 NM-PT REYES
TO PIGEON PT 0-10 NM.
GALE WARNING UNTIL 3 PM PST THIS AFTERNOON FOR PT ARENA TO PT
REYES 0-10 NM.
GALE WARNING UNTIL 9 AM PST THIS MORNING FOR PT PINOS TO PT
PIEDRAS BLANCAS 0-10 NM.
GALE WARNING UNTIL 9 PM PST THIS EVENING FOR PT ARENA TO PT
REYES 10-60 NM.
SHORT TERM...FLYNN
LONG TERM....JM
AVIATION...CANEPA
MARINE...CANEPA
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