614
FXUS66 KMTR 250453
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
853 PM PST SAT JAN 24 2026
..NEW AVIATION, MARINE
KEY MESSAGES
UPDATED AT 121 PM PST SAT JAN 24 2026
- CLEAR TODAY AND TONIGHT WITH COOL OVERNIGHT TEMPS IN THE
MID-30S INLAND
- OFFSHORE WINDS WEAKEN BY SUNDAY MORNING; LIGHT WINDS THEN
PREVAIL INTO MID-WEEK
- SLIGHT CHANCE OF RAIN SHOWERS LATE TUESDAY/WEDNESDAY AM ALONG
COASTAL RANGES AND THE NORTH BAY. AMOUNTS GENERALLY LESS THAN
0.1"
UPDATE
ISSUED AT 822 PM PST SAT JAN 24 2026
CLASSIC EAST COAST VS WEST COAST TEMPERATURE DIPOLE THIS
AFTERNOON. TEMPERATURES ACROSS THE WEST WERE GENERALLY ABOVE
NORMAL (INCLUDING LOCALLY), WHILE EAST OF THE ROCKIES ARE BELOW
NORMAL. NOT TOTALLY UNHEARD OF WHEN THERE IS A HIGHLY AMPLIFIED
LONGWAVE PATTERN OVER THE CONUS DURING WINTER. IN OTHER WORDS,
BIG RIDGE TO THE WEST AND DEEP TROUGH TO THE EAST. TEMPERATURES
AROUND THE BAY AREA AND CENTRAL MAXED OUT IN THE 60S TO LOWER
70S. TEMPERATURES THIS AFTERNOON DID GET A BOOST FROM THE
LINGERING OFFSHORE FLOW.
SPEAKING OF OFFSHORE FLOW, CURRENT GRADIENT FROM SFO-WMC IS STILL
HOVERING AROUND -10MB, WHICH IS YIELDING WIND GUSTS 30-50 MPH
OVER THE NORTH AND EAST BAY HIGHER TERRAIN. NO SURPRISE THAT MT ST
HELENA IS THE WINNER AT 51 MPH.
THE NEAR TERM CHALLENGE WILL BE THE COMBINATION OF OFFSHORE FLOW,
DRY AIRMASS (PWAT FROM OAK WAS 0.17"!), CHILLY TEMPS, AND LURKING
TULE FOG. THE OFFSHORE FLOW HELPED DRY OUT THE AIRMASS, WHICH
COULD SET THE STAGE FOR IDEAL RADIATIONAL COOLING. HOWEVER, WE
NEED SOME WINDS TO DIMINISH TO FULLY DECOUPLE. SHELTERED VALLEYS
WILL BE EVEN TRICKIER AS WIND PLAYS LESS OF A ROLE. AS NOTED
BELOW, WE'LL HAVE SOME POCKETS DROPPING IN THE MID 30S. FOG WILL
BE TRICKY AS WELL GIVEN HOW DRY IT IS, BUT SOME PATCHY FOG IN THE
NORTH BAY IS POSSIBLE. GIVEN THE EASTERLY FLOW TULE FOG SNEAKING
INTO THE EAST BAY IS MORE LIKELY.
NO UPDATE AT THIS TIME, BUT WE'LL BE FLIRTING WITH COLD WEATHER
ADV CONDITIONS FOR THE NORTH AND EAST BAY VALLEYS GIVEN SOME OF
THE 30S.
MM
SHORT TERM
ISSUED AT 121 PM PST SAT JAN 24 2026
(THIS EVENING THROUGH SUNDAY)
GENERALLY FAIR WEATHER ACROSS THE BOARD TODAY. TEMPERATURES
THIS AFTERNOON ARE ABOUT 10-20 DEGREES WARMER THAN 24 HOURS AGO
THANKS TO TODAY'S LACK OF TULE FOG AND STRATUS. IN FACT, THE ONLY
CLOUD COVER VISIBLE ON SATELLITE IS A BIT OF STRATUS OFF THE COAST
OF BODEGA BAY AND SOME PATCH TERRAIN-INDUCED CU ALONG THE BIG SUR
COAST. TEMPERATURES ARE EXPECTED TO BE A BIT CHILLIER TONIGHT DUE
TO THE LACK OF CLOUD COVER. SUNDAY MORNING LOWS WILL RANGE FROM
THE MID-30S (INTERIOR) TO LOW 40S (COASTAL). THE ONLY OTHER
NOTABLE MENTION IN THE SHORT TERM IS THAT WE'LL HAVE ONE MORE
NIGHT OF BREEZY OFFSHORE WINDS ALONG INTERIOR RIDGETOPS BEFORE THE
LOW PRESSURE SYSTEM RESPONSIBLE (PART THE SAME ONE WREAKING HAVOC
ON THE CENTRAL AND EASTERN US CURRENTLY) MOVES OUT AND IS REPLACED
LARGELY BY ZONAL FLOW ALOFT. THIS WILL RELAX SURFACE PRESSURE
GRADIENTS AND CAUSE ANY OFFSHORE WINDS TO DIMINISH AND BECOME
LIGHT, OR EVEN LIGHT ONSHORE IN SOME LOCATIONS BY SUNDAY
AFTERNOON.
LONG TERM
ISSUED AT 121 PM PST SAT JAN 24 2026
(SUNDAY NIGHT THROUGH NEXT FRIDAY)
WITH MOSTLY BENIGN CONDITIONS THROUGH THE EARLY WEEK, WE'LL JUMP
TO SUNDAY WHEN A WEAK UPPER LEVEL SHORT WAVE TROUGH IS PROGGED TO
MOVE OVER THE REGION. THIS WILL BRING A SLIGHT CHANCE OF RAIN TO
THE AREA. HOWEVER, BASED ON THE MOST RECENT FORECAST UPDATES IT
SEEMS LIKE THIS MAY BE LIMITED TO COASTAL RANGES AS WELL AS THE
NORTH BAY. AMOUNTS ARE VERY SLIM AT A FEW HUNDREDTHS OF AN INCH
FOR MOST AND UP TO A TENTH OR TWO FROM THE GOLDEN GATE NORTHWARD.
BY NEXT FRIDAY, SOME MODEL GUIDANCE IS ADVERTISING ANOTHER CHANCE
FOR RAIN, BUT THERE IS CONSIDERABLE UNCERTAINTY AT THIS POINT TO
TALK ABOUT ANYTHING SPECIFIC.
AVIATION
(06Z TAFS)
ISSUED AT 852 PM PST SAT JAN 24 2026
CURRENTLY VFR AT ALL TERMINALS WITH SOME STRATUS OFF OF BODEGA BAY
AND SOME HIGH CLOUDS STREAMING IN FROM THE PACIFIC OCEAN. MODERATE
TO HIGH CONFIDENCE THAT OFFSHORE FLOW AND THE RESULTING WARMER AND
DRIER CONDITIONS WILL PRECLUDE SUB-VFR CONDITIONS WITH THE HELP OF RECORD
LOW PWAT AND INTERIOR DEW POINTS IN THE 20S AND 30S. THE
EXCEPTION WOULD BE IF TULE FOG CAN BE ADVECTED IN FROM THE CENTRAL
VALLEY, BUT CONFIDENCE IS LOW, ESPECIALLY WITH HOW BAD IT LOOKS
HEALTH-WISE ON SATELLITE.
VICINITY OF SFO...CURRENTLY VFR WITH SOUTHWESTERLY FLOW. MODERATE TO
HIGH CONFIDENCE IN VFR THROUGH THE TAF PERIOD. WINDS WILL BACK
THROUGH THE TAF PERIOD, BECOMING SOUTHEASTERLY TONIGHT AND
NORTHEASTERLY BY EARLY TOMORROW MORNING.
SFO BRIDGE APPROACH...SIMILAR TO SFO.
MONTEREY BAY TERMINALS...CURRENTLY VFR WITH DRAINAGE FLOW AT BOTH
TERMINALS. MODERATE TO HIGH CONFIDENCE IN VFR PREVAILING THROUGH THE
TAF PERIOD. ONSHORE FLOW WILL BRIEFLY RETURN TOMORROW AFTERNOON WITH
DRAINAGE WINDS RETURNING TOMORROW EVENING.
MARINE
(TONIGHT THROUGH NEXT FRIDAY)
ISSUED AT 852 PM PST SAT JAN 24 2026
GENTLE TO MODERATE NORTHERLY/OFFSHORE BREEZES WILL VEER TO BECOME
SOUTHERLY TOMORROW. SOUTHERLY BREEZES WILL INCREASE TO BECOME
FRESH TO STRONG OVER THE NORTHERN PORTION OF THE WATERS MONDAY AND
TUESDAY. WINDS DIMINISH AND RETURN NORTHERLY ON WEDNESDAY.
MODERATE SEAS WILL PREVAIL THROUGH TUESDAY. CONDITIONS DETERIORATE
WEDNESDAY AS SEAS BUILD TO BECOME ROUGH TO VERY ROUGH.
MTR WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...NONE.
SHORT TERM...BEHRINGER
LONG TERM....BEHRINGER
AVIATION...SARMENT
MARINE...SARMENT
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