333
FXUS66 KMTR 032325
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
425 PM PDT FRI APR 3 2026
..NEW AVIATION, MARINE
KEY MESSAGES
UPDATED AT 107 PM PDT FRI APR 3 2026
- MODERATE TO STRONG OFFSHORE FLOW THROUGH REMAINDER OF TODAY
- WARMER TEMPERATURES RETURN SATURDAY AND SUNDAY BEFORE A COOLING
TREND BEGINS NEXT WEEK
- BENEFICIAL RAIN CHANCES INCREASE MID TO LATE NEXT WEEK
SHORT TERM
ISSUED AT 107 PM PDT FRI APR 3 2026
(THIS EVENING THROUGH SATURDAY)
BREEZY OFFSHORE WINDS CONTINUE THROUGH EARLY TOMORROW MORNING. THE
STRONGEST WIND GUSTS HAVE LARGELY BEEN CONFINED TO THE HIGHER
ELEVATIONS OF THE NORTH BAY INTERIOR MOUNTAINS AND THE DIABLO RANGE.
THE STRONGEST GUST REPORTED SO FAR WAS 67 MPH AT THE MT. ST. HELENA
WEST STATION (ELEVATION OF 4340 FT) AT 7:30 AM THIS MORNING. AT THAT
TIME THE SFO-WMC PRESSURE GRADIENT PEAKED AT -10 MB. WINDS HAVE
SINCE COME DOWN SLIGHTLY BUT ARE LIKELY TO INCREASE AGAIN DURING THE
AFTERNOON AND EVENING HOURS. THE SFO-WMC GRADIENT HAS REGAINED
STRENGTHEN OVER THE LAST FEW HOURS (AFTER INITIALLY WEAKENING FROM
EARLY THIS MORNING) WITH THE 11AM OBSERVATION COMING IN AT -9.80 MB.
GFS GUIDANCE MOST CLOSELY RESEMBLES THE OBSERVED SFO-WMC GRADIENT
AND KEEPS OFFSHORE WINDS CONTINUING INTO SUNDAY. ANOTHER, BRIEF,
ROUND OF BREEZY WINDS IS POSSIBLE ACROSS THE HIGHER ELEVATIONS EARLY
SATURDAY MORNING BEFORE WINDS DECREASE THROUGH THE REMAINDER OF THE
DAY.
HIGH TEMPERATURES TODAY ARE SEASONABLY WARM IN THE 60S ALONG THE
COAST AND 70S ACROSS THE INTERIOR. THIS IS RUNNING ABOUT 5 TO 10
DEGREES ABOVE NORMAL FOR THIS TIME OF YEAR AND IS THE RESULT OF
UPPER LEVEL RIDGING AND SURFACE HIGH PRESSURE BUILDING IN. THE
WARMING TREND CONTINUES INTO SATURDAY WITH HIGH TEMPERATURES IN THE
70S TO 80S EXPECTED (15-20 DEGREES ABOVE NORMAL). CURRENTLY ONLY
MINOR HEATRISK IS FORECAST TODAY AND TOMORROW THANKS TO GOOD
OVERNIGHT COOLING. LIGHT, OFFSHORE WINDS PREVAIL ON SATURDAY WHICH
WILL PLAY A ROLE IN KEEPING COASTAL AREAS WARMER THANKS TO AN EFFECT
CALLED DOWNSLOPING. DOWNSLOPING OCCURS WHEN WIND IS FORCED DOWN THE
LEEWARD SIDE OF THE MOUNTAIN WITH AN AIR PARCEL COMPRESSING (AND
WARMING) AS IT SINKS. THIS TYPE OF SETUP IS FAVORABLE FOR BRINGING
MUCH WARMER AND DRIER TEMPERATURES DIRECTLY ALONG THE COAST COMPARED
TO THE NORMALLY COOLER TEMPERATURES WE OBSERVE. FOR THE AFTERNOON
FORECAST PACKAGE, DID ADJUST HIGH TEMPERATURES UP SLIGHTLY FOR
SATURDAY AND SUNDAY GIVEN THAT THE DETERMINISTIC NBM WAS RUNNING
MUCH COOLER THAN OTHER MODELS. GIVEN THE VERY DRY ATMOSPHERE, FOG IS
NOT EXPECTED TO DEVELOP TONIGHT WITH HREF ONLY SHOWING HIGH CLOUDS
MOVING THROUGH.
LONG TERM
ISSUED AT 107 PM PDT FRI APR 3 2026
(SATURDAY NIGHT THROUGH NEXT THURSDAY)
ABOVE NORMAL TEMPERATURES CONTINUE INTO SUNDAY WITH HIGHS REMAINING
15-20 DEGREES ABOVE NORMAL. THIS KEEPS TEMPERATURES IN THE 80S
ACROSS THE INTERIOR AND 70S ALONG THE COASTLINE. THERE IS A LITTLE
MORE UNCERTAINTY WITH REGARDS TO SUNDAY'S HIGH TEMPERATURES THAN
SATURDAY'S. ON SATURDAY, THE CENTER OF THE UPPER LEVEL RIDGE IS
CENTERED MORE OVER CALIFORNIA WHILE ON SUNDAY THE RIDGE IS
PROGRESSING RAPIDLY EASTWARD. AS THE RIDGE DEPARTS, THE SFO-WMC
PRESSURE GRADIENT IS EXPECTED TO REVERSE (BECOMING POSITIVE) AND
ONSHORE FLOW RETURNS. CURRENTLY, OFFSHORE WINDS ARE LIKELY TO REMAIN
THROUGH AT LEAST SUNDAY MORNING BUT POTENTIALLY INTO EARLY SUNDAY
AFTERNOON. THE LONGER OFFSHORE WINDS STICK AROUND, THE MORE SURFACE
TEMPERATURES ARE ABLE TO WARM. THE CURRENT THINKING IS THAT
TEMPERATURES WILL PEAK EARLY TO MID AFTERNOON AND START DECREASING
AS THE SEA BREEZE/ONSHORE WINDS KICK IN. ANOTHER FACTOR IS THE
POTENTIAL FOR THE MARINE LAYER TO REDEVELOP, BRINGING A RETURN OF
COASTAL STRATUS AND FOG. THE MARINE LAYER NOW LOOKS TO RETURN
OVERNIGHT SUNDAY INTO MONDAY THAN SUNDAY AFTERNOON/EVENING. THIS
LIMITS THE IMPACT IT WOULD HAVE ON SUNDAY'S HIGH TEMPERATURES BUT
IT'S WORTHWHILE NOTING THAT THE SIGNAL IS THERE FOR THE MARINE LAYER
TO REDEVELOP HEADING INTO NEXT WEEK. THERE IS THE POTENTIAL FOR SOME
DAILY HIGH TEMPERATURE RECORDS TO BE BROKEN SATURDAY AND SUNDAY (ONE
SITE BEING HALF MOON BAY) DEPENDING ON HOW HIGH TEMPERATURES WARM.
TEMPERATURES COOL SLIGHTLY, BECOMING SEASONABLY WARM, INTO THE 70S
TO LOW 80S ACROSS THE INTERIOR MONDAY AND TUESDAY AS UPPER LEVEL
RIDGING PROGRESSES EASTWARD AND ZONAL FLOW RETURNS. THE COAST WILL
BE NOTICEABLY COOLER WITH SEASONAL HIGH TEMPERATURES IN THE 60S
EXPECTED. THE COOLING TREND CONTINUES THROUGH LATE NEXT WEEK AS AN
UPPER LEVEL TROUGH MOVES THROUGH THE WEST COAST. THIS SYSTEM WILL
BRING US OUR NEXT CHANCE OF BENEFICIAL RAIN. TOTALS ARE STILL LIGHT
WITH THE MAJORITY OF THE REGION SEEING LESS THAN A QUARTER OF AN
INCH. THE HIGHER ELEVATIONS OF THE SANTA CRUZ MOUNTAINS AND THE
SANTA LUCIA RANGE MAY SEE BETWEEN 0.25 TO 0.5" OF RAIN. THERE IS
ALSO THE POTENTIAL FOR THIS SYSTEM TO BRING LOCALLY GUSTIER ONSHORE
WINDS TO THE COAST AND ACROSS THE HIGHER ELEVATIONS ON WEDNESDAY.
AVIATION
(00Z TAFS)
ISSUED AT 424 PM PDT FRI APR 3 2026
HIGH CONFIDENCE OF VFR THROUGH THE TAF PERIOD, WITH MODERATE
CONFIDENCE OF A FEW HIGH CLOUDS TONIGHT INTO SATURDAY. GUSTY
OFFSHORE WINDS PREVAIL ACROSS THE INTERIOR REGIONS, WITH A
NORTHWESTERLY BREEZE DEVELOPING AT THE COAST. WINDS WILL DECREASE AT
THE TERMINALS OVERNIGHT WITH LIGHT WINDS THROUGH SATURDAY MORNING.
ALTHOUGH LLWS MAGNITUDES ARE NOT HIGH ENOUGH TO NOTE IN THE TAFS,
THE CONTINUING WINDS ALOFT MAY MAKE TAKEOFFS AND LANDINGS BUMPY FROM
THE INTERIOR TERMINALS. SATURDAY AFTERNOON WINDS LOOK TO BE LARGELY
A REPEAT OF TODAY'S PATTERN WITH OFFSHORE WINDS IN THE INTERIOR,
BALANCED BY AN ONSHORE BREEZE IN THE COASTAL REGIONS.
VICINITY OF SFO... HIGH CONFIDENCE OF VFR THROUGH THE TAF PERIOD
WITH POSSIBLE HIGH CLOUDS OVERNIGHT THROUGH SATURDAY. BREEZY
NORTHWEST WINDS SHOULD ARRIVE WITHIN THE NEXT HOUR OR TWO,
PERSISTING THROUGH THE LATE EVENING HOURS WHEN WINDS BECOME LIGHT
AND SOUTHEASTERLY. A SIMILAR PATTERN WITH BREEZY NORTHWEST WINDS IN
THE LATE AFTERNOON AND EVENING HOURS AND LIGHT WINDS OTHERWISE
SHOULD PERSIST THROUGH SATURDAY.
SFO BRIDGE APPROACH... SIMILAR TO SFO.
MONTEREY BAY TERMINALS... HIGH CONFIDENCE OF VFR THROUGH THE TAF
PERIOD WITH POSSIBLE HIGH CLOUDS OVERNIGHT THROUGH SATURDAY. GENTLE
TO MODERATE NORTHWEST WINDS CONTINUE THROUGH THE EVENING HOURS WITH
LIGHT DRAINAGE WINDS OVERNIGHT. AT SNS, THE SOUTHEAST WINDS WILL
PICK UP EARLY SATURDAY MORNING BEFORE TURNING NORTHWEST LATE IN THE
AFTERNOON, WHILE AT MRY, ONSHORE FLOW DEVELOPS IN THE AFTERNOON
HOURS ON SATURDAY.
MARINE
(TONIGHT THROUGH NEXT WEDNESDAY)
ISSUED AT 424 PM PDT FRI APR 3 2026
FRESH TO STRONG NORTHERLY BREEZES WILL PERSIST OVER THE NORTHERN
OUTER WATERS THROUGH LATE TONIGHT. OTHERWISE WINDS AND SEAS WILL
ABATE TONIGHT AND THROUGH THE WEEKEND. LIGHT TO MODERATE NORTHERLY
BREEZES PREVAIL THIS WEEKEND AND INTO NEXT WEEK. A LOW PRESSURE
SYSTEM OVER THE PACIFIC WILL APPROACH THE COASTAL WATERS AND BAYS
BY THE MIDDLE OF NEXT WEEK BRINGING A CHANCE OF RAIN.
CLIMATE
ISSUED AT 110 PM PDT FRI APR 3 2026
THE FOLLOWING ARE THE RECORD HIGH TEMPERATURES AT THE LONG TERM
STATIONS FOR APRIL 4TH AND APRIL 5TH.
LOCATION APRIL 4TH APRIL 5TH
SANTA ROSA 88 IN 1961 90 IN 1939
KENTFIELD 85 IN 1957 88 IN 1924
SAN RAFAEL 86 IN 1960 87 IN 1957
NAPA 86 IN 1985, 1960 86 IN 1989, 1957
RICHMOND 89 IN 2011 83 IN 1989
LIVERMORE 87 IN 1959 84 IN 1989, 1916
SAN FRANCISCO 84 IN 1985 88 IN 1989
SFO AIRPORT 82 IN 1985 84 IN 1989
REDWOOD CITY 86 IN 1960 87 IN 1989
HALF MOON BAY 77 IN 2011 74 IN 2016
OAKLAND MUSEUM 85 IN 1985 85 IN 1989
SAN JOSE 87 IN 1960 89 IN 1989
SALINAS AIRPORT 86 IN 1989, 1960, 1952 95 IN 1989
MTR WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 3 AM PDT SATURDAY FOR PT ARENA TO PT
REYES 10-60 NM.
SHORT TERM...KENNEDY
LONG TERM....KENNEDY
AVIATION...DIALH
MARINE...CANEPA
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