437
FXUS66 KMTR 281729
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
1029 AM PDT TUE APR 28 2026
..NEW AVIATION
KEY MESSAGES
UPDATED AT 1047 PM PDT MON APR 27 2026
- MORNING STRATUS AND FOG RETURNS TO THE FORECAST
- WARMING AND DRYING TREND CONTINUES INTO THE LATE WEEK FOR AREAS
AWAY FROM THE COAST
- COOLER CONDITIONS RETURN THIS WEEKEND WITH A CHANCE OF RAIN
UPDATE
ISSUED AT 818 AM PDT TUE APR 28 2026
VERY LITTLE IN THE WAY OF DRIZZLE THIS MORNING AS LOW CLOUDS LARGELY
REMAINED CONFINED TO THE SAN FRANCISCO PENINSULA AND INLAND INTO THE
EAST BAY. THESE LOW CLOUDS ARE FORECAST TO DISSIPATE THROUGHOUT THE
DAY AND GIVE WAY TO MOSTLY SUNNY SKY CONDITIONS THIS AFTERNOON.
COASTAL LOCATIONS LOOK TO WARM INTO THE UPPER 50S TO MID 60S AND THE
INTERIOR REACHING INTO THE MID 60S TO LOWER 70S. OTHERWISE, THE
FORECAST REMAINS ON TRACK THIS MORNING WITH NO UPDATES ANTICIPATED
AT THIS TIME.
RGASS
SHORT TERM
ISSUED AT 1047 PM PDT MON APR 27 2026
(TONIGHT THROUGH WEDNESDAY)
THE EVENING STILL HAD A FEW AREAS OF RAIN IN THE NORTHERNMOST
PORTIONS OF SONOMA CO, BUT IT LOOKS LIKE THEY HAVE MOSTLY
DIMINISHED. DRIZZLE CHANCES LINGER FOR SOME OF THE COAST AND
MOUNTAINTOPS DISTRICTWIDE OVERNIGHT, WHILE THE VALLEYS SEE GOOD
CHANCES FOR FOG BUILDING IN THE LATE NIGHT AND LINGERING INTO THE
MID MORNING.
THE STEADY WARMING TREND CONTINUES FOR TUESDAY WITH MOST AREAS
GETTING CLOSE TO AVERAGE, THOUGH SLIGHTLY BELOW. COASTAL AREAS WILL
PEAK AROUND 60 DEGREES WHILE AREAS INLAND WILL SEE THE UPPER 60S TO
MID 70S. INTERIOR MOUNTAINS WILL STILL BE DEALING WITH LINGERING
MOISTURE, SO THEY'LL STILL BE ON THE COOL SIDE WITH SOME STRUGGLING
TO BREAK 50 DEGREES IN ON THE BIG SUR COAST.
THE WARMING COMES FROM A BUILDING RIDGE TO THE NORTH, BUT A CUT OFF
LOW TO THE SOUTH WILL PREVENT TOO MUCH OF A WARM UP, ESPECIALLY FOR
THE COASTAL AREAS. THE LOW LOOKS TO OFFER JUST ENOUGH INFLUENCE OVER
THE AREA THAT THE MARINE LAYER STAYS INTACT THROUGH THE WEEK, AND
KEEP CONDITIONS BREEZY OVER THE MARINE ENVIRONMENT AND IMMEDIATE
COAST. THIS MARINE INFLUENCE WON'T SPREAD TOO FAR INLAND, SO THE
MORE INTERIOR AREAS WILL SEE MORE OF A STEADY WARMING UNTIL THE
PATTERN CHANGES THIS WEEKEND.
WEDNESDAY SEES HIGH TEMPERATURES ALONG THE COAST PLATEAUING: STILL
AROUND 60 DEGREES. AREAS INLAND WILL CONTINUE WARMING AND GET BACK
ABOVE AVERAGE WITH THE MORE INTERIOR AREAS GETTING INTO THE UPPER
70S AND A FEW SPOTS BREAKING 80.
OVERNIGHT LOWS WILL ALSO SEE A SLIGHT WARMING TREND, WITH MOST AREAS
SEEING LOWS IN THE 50S BY THE MID WEEK.
LONG TERM
ISSUED AT 1047 PM PDT MON APR 27 2026
(WEDNESDAY NIGHT THROUGH NEXT MONDAY)
THE INLAND WARMING TREND LOOKS TO PEAK ON FRIDAY WITH THE 80S
EXPECTED ACROSS THE INTERIOR AREAS AND MAYBE A FEW 90S IN THE
SOUTHERN SALINAS VALLEY. THIS WILL BE WHILE THE COAST WILL
CONTINUE TO STICK TO THE 60S UNDER THE INFLUENCE OF GOOD COASTAL
BREEZES, THE MARINE LAYER, AND NIGHTLY MARINE STRATUS. THE AREAS
SLIGHTLY INLAND WILL BE A MIXED BAG. THOSE THAT SEE THE MARINE
LAYER AND STRATUS LOOK TO ONLY WARM INTO THE MID 70S, WHILE AREAS
THAT WILL BE JUST OUTSIDE OF THE MARINE INFLUENCE WILL LEAN CLOSER
TO 80 DEGREES. IT'LL BE THE KIND OF DAY WHERE YOU DRIVE FROM HALF
MOON BAY TO SAN JOSE AND EXPERIENCE AROUND A 20 DEGREE
DIFFERENCE.
A TROUGH AND LOW APPROACH THE REGION INTO FRIDAY NIGHT, INCREASING
CLOUD COVER AND EXPANDING THE MARINE LAYER BOTH IN HEIGHT AND INLAND
PUSH. MODELS ARE GOING BACK TO THE SOLUTION HINTED AT A FEW NIGHTS
AGO, WITH THIS LOW CAUSING ANOTHER DRIZZLE-FEST WITH SOME SCATTERED
LIGHT RAIN. THE TIMING OF THE BEST RAIN CHANCES IS STILL NOT FIRM
ACROSS MODELS, BUT FOR NOW IT DOES LOOK BETTER FOR DRIZZLE IN THE
MID-WEEKEND WITH MEASURABLE RAIN ARRIVING LATE SUNDAY AND INTO THE
NEXT WORK WEEK. WELCOME TO MAY-GRAY!
AVIATION
(18Z TAFS)
ISSUED AT 1015 AM PDT TUE APR 28 2026
THE MORNING LOW CLOUDS WERE MUCH MORE SCATTERED THAN I THOUGHT
THEY WOULD BE AT THIS TIME YESTERDAY. THERE IS STILL ENOUGH
INSTABILITY IN THE LOWER ATMOSPHERE TO STAY WELL MIXED. IN FACT,
WE ARE STARTING TO SEE SOME FAIR WEATHER CUMULUS CLOUDS POP UP
OVER THE SOUTHERN HILLS AS THE SURFACE TEMPERATURES WARM AND TAKE
ADVANTAGE OF THIS INSTABILITY. THAT BEING SAID, THESE MIDDAY
CLOUDS ARE NOT EXPECTED TO BRING SIGNIFICANT IMPACTS TO THE TAF
SITES, AND THERE IS HIGH CONFIDENCE IN WIDESPREAD VMC THROUGH
THROUGH DAY. CLOUDS WILL START TO ROLL IN AGAIN OVERNIGHT, BUT THE
COVERAGE WILL AGAIN BE SPOTTY. HIGH RESOLUTION MODELS ARE PRETTY
CONFIDENT THAT THE NORTH BAY WILL STAY CLEAR OF STRATUS, BUT THAT
OPENS THE POSSIBILITY FOR RADIATION FOG. THE REST OF THE BAY AREA
HAS A DECENT CHANCE FOR MVFR IMPACTS AS THE MARINE LAYER GRADUALLY
WORKS TO GAIN SOME STRUCTURE OVERNIGHT.
VICINITY OF SFO...RELATIVELY STANDARD CONDITIONS TODAY WITH CLEAR
SKIES AND MODERATE ONSHORE WINDS IN THE AFTERNOON. THE CHALLENGING
PART OF THE FORECAST IS TOMORROW MORNING. THERE IS A 6 HOUR WINDOW
BETWEEN 12Z AND 18Z WHERE THERE IS A 30-50% CHANCE OF MVFR IMPACTS
OVER THE TERMINAL. AS WE SAW THIS MORNING (OAK DEVELOPED A
CEILING FOR 6 HOURS, WHILE SFO ONLY HAD IT FOR 30 MINS) THE
STRATUS DECK DOESN'T LOOK VERY HEALTHY TOMORROW AND THE FORECAST
CONFIDENCE IS QUITE LOW.
SFO BRIDGE APPROACH...SIMILAR TO SFO
MONTEREY BAY TERMINALS...AFTER A CLEAR AFTERNOON, THE SOUTHERN
TERMINALS HAVE THE BEST CHANCE FOR BOTH MVFR AND IFR IMPACTS
OVERNIGHT DUE TO A MORE COMPRESSED BOUNDARY LAYER AND BETTER
ONSHORE FLOW. THE HIGH RES MODELS ARE FAIRLY CONFIDENT, BUT THE
PERSISTENCE FORECAST IS MORE OPTIMISTIC, SO IT'S NOT A SLAM DUNK.
MARINE
(TODAY THROUGH SUNDAY)
ISSUED AT 818 AM PDT TUE APR 28 2026
THE GRADIENT BETWEEN HIGH PRESSURE OVER THE EASTERN PACIFIC AND
LOW PRESSURE OVER CALIFORNIA WILL BUILD OVER THE NEXT FEW DAYS,
GENERATING A STRONG NW BREEZE FROM WEDNESDAY THROUGH FRIDAY. THESE
WINDS WILL BUILD ROUGH SEAS OF 8-12 FEET ACROSS EXPOSED WATERS.
MTR WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...SMALL CRAFT ADVISORY FROM 3 PM WEDNESDAY TO 3 AM PDT THURSDAY
FOR PIGEON PT TO PT PINOS 0-10 NM-PT ARENA TO PT REYES 0-10
NM-PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM.
SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 9 AM PDT
THURSDAY FOR PT ARENA TO PT REYES 10-60 NM.
SMALL CRAFT ADVISORY FROM 3 PM WEDNESDAY TO 9 AM PDT THURSDAY
FOR PIGEON PT TO PT PINOS 10-60 NM.
SHORT TERM...MURDOCK
LONG TERM....MURDOCK
AVIATION...FLYNN
MARINE...FLYNN
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