046
FXUS66 KMTR 030423
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
923 PM PDT SUN AUG 2 2026
..NEW AVIATION, MARINE
KEY MESSAGES
UPDATED AT 1200 PM PDT SUN AUG 2 2026
- MODERATE HEATRISK IN THE INTERIOR THROUGH MONDAY WITH SOME
PATCHES LINGERING THROUGH THE NEXT WEEK
- NEAR CRITICAL FIRE WEATHER THREAT ACROSS THE INTERIOR NORTH AND
EAST BAYS, AND THE DIABLO AND SANTA LUCIA RANGES THROUGH MONDAY
WITH ELEVATED FIRE WEATHER THREAT THROUGH THE WEEK
- STRONG AND GUSTY WINDS DEVELOP OVER COASTAL WATERS NORTH OF
POINT REYES TODAY, SOME OFFSHORE WINDS DEVELOP IN THE NORTH
BAY AND SF BAY AREA TONIGHT THROUGH MONDAY MORNING
SHORT TERM
ISSUED AT 1200 PM PDT SUN AUG 2 2026
(THIS EVENING THROUGH MONDAY NIGHT)
ANOTHER DAY, ANOTHER OTTER EDDY KEEPING THE STRATUS IN PLACE OVER
MONTEREY BAY AND THE IMMEDIATELY ADJACENT COASTLINE. CLEARING IS
EXPECTED THROUGH THE NEXT COUPLE OF HOURS WITH THE STRATUS RETURNING
TO THE IMMEDIATE COASTAL REGIONS SOUTH OF THE GOLDEN GATE AND INTO
THE SALINAS VALLEY TONIGHT.
THE HIGH PRESSURE SYSTEM CENTERED OVER THE DESERT SOUTHWEST AND
EXTENDING OVER CALIFORNIA PERSISTS, WITH A TROUGH DEFLECTED TO THE
NORTH AROUND THE PACIFIC NORTHWEST AND WESTERN CANADA, AND
WIDESPREAD TEMPERATURES ABOVE THE SEASONAL AVERAGES CONTINUE TODAY.
HIGHS TODAY RANGE FROM THE LOWER 90S TO THE TRIPLE DIGITS IN THE
INLAND VALLEYS TODAY, WITH WARM SPOTS IN THE FAR INTERIOR NORTH BAY,
THE EASTERN PART OF CONTRA COSTA COUNTY, AND SOUTHERN MONTEREY AND
SAN BENITO COUNTIES SEEING HIGHS UP TO 105 OR 107. ELSEWHERE, HIGHS
ALONG THE BAYS RANGE FROM THE MIDDLE 70S TO THE MIDDLE 80S, WHILE
THE PACIFIC COAST HOVERS IN THE MIDDLE 60S TO LOWER 70S. ON MONDAY,
MORNING LOWS RANGE FROM THE MIDDLE 50S TO LOWER 60S IN THE LOWER
ELEVATIONS, TO THE MIDDLE 60S TO THE LOWER 70S IN THE HIGHER
ELEVATIONS, AND EXPECT HIGHS TO BE BROADLY SIMILAR TO TODAY'S, WITH
THE MOST NOTABLE CHANGE BEING A COUPLE DEGREES OF COOLING OVER
SOUTHERN MONTEREY COUNTY.
A RATHER STRONG NORTH-SOUTH PRESSURE GRADIENT IS RESULTING IN GALE-
FORCE WIND GUSTS ACROSS THE COASTAL WATERS, BUT THE ORIENTATION OF
THE WINDS REMAINS GENERALLY PARALLEL TO THE COAST, SO THE STRONGEST
WINDS ARE NOT EXPECTED TO MIGRATE INLAND. BREEZY AND GUSTY WINDS ARE
EXPECTED TO DEVELOP IN THE AFTERNOON AND EVENING HOURS WITH GUSTS
REACHING 20 TO 25 MPH AT THE COAST, THROUGH GAPS AND PASSES, AND
ALONG THE RIDGELINES. TONIGHT INTO MONDAY MORNING, SOME OFFSHORE
WINDS ARE POSSIBLE AS THE TROUGH MOVES INTO THE NORTHERN ROCKIES,
BRINGING US A QUASI-INSIDE SLIDER PATTERN OVERNIGHT. THE EXPECTED
GUSTS OF 15 TO 20 MPH AREN'T STRONG ENOUGH TO ISSUE A WIND ADVISORY,
BUT THEY ARE CONTRIBUTING TO NEAR-CRITICAL FIRE WEATHER CONCERNS
ACROSS THE BAY AREA, ESPECIALLY IN THE INTERIOR REGIONS. SEE THE
FIRE WEATHER SECTION FOR MORE DETAILS. ONE LESS SPARK, ONE LESS FIRE!
WIDESPREAD MODERATE HEATRISK PERSISTS ACROSS THE INTERIOR REGIONS
INTO MONDAY WITH PATCHES OF MODERATE HEATRISK PERSISTING INTO THE
REST OF THE WEEK. THIS CORRESPONDS TO A MODERATE RISK FOR HEAT
RELATED ILLNESSES FOR SENSITIVE POPULATIONS, INCLUDING CHILDREN, THE
ELDERLY, PREGNANT WOMEN, PEOPLE WITH CERTAIN MEDICAL CONDITIONS, AND
PEOPLE WHO WORK OR LIVE OUTDOORS WITHOUT ADEQUATE SHELTER OR
HYDRATION. SOME PATCHES OF MAJOR HEATRISK, CORRESPONDING TO A MORE
WIDESPREAD RISK FOR HEAT-RELATED ILLNESSES, ARE ALSO EXPECTED IN THE
WARMEST PARTS OF THE INTERIOR CENTRAL COAST. FOLLOW THESE TIPS TO
AVOID HEAT-RELATED ILLNESSES:
* STAY HYDRATED AND DRINK PLENTY OF FLUIDS.
* WEAR LIGHTWEIGHT, LIGHT-COLORED CLOTHING.
* REDUCE TIME SPENT OUTDOORS OR STAY IN THE SHADE.
* NEVER LEAVE PEOPLE OR PETS UNATTENDED IN VEHICLES.
* USE SUNSCREEN IF GOING TO THE COAST OR THE POOL.
LONG TERM
ISSUED AT 1200 PM PDT SUN AUG 2 2026
(TUESDAY THROUGH NEXT SATURDAY)
SUBTLE COOLING IS POSSIBLE ON TUESDAY AND WEDNESDAY IF ONSHORE FLOW
IS ABLE TO REBUILD AS THE HIGH BEGINS TO REDEVELOP. ONE OF THE BIG
QUESTIONS IS HOW QUICKLY THE RIDGE CAN REBUILD OVER CALIFORNIA AND
THE GREAT BASIN IN THE WAKE OF THE TROUGH'S PASSAGE. THE MODELS ARE
CURRENTLY SHOWING A SLOWER REBUILDING OF THE HIGH PRESSURE SYSTEM
HEADING INTO WEDNESDAY, WHICH CORRESPONDS TO HIGHS AROUND THE MIDDLE
80S TO MIDDLE 90S IN THE INLAND VALLEYS, BUT IF THE HIGH BUILDS
FASTER THAN ANTICIPATED, THESE TEMPERATURES MAY NEED TO BE BUMPED UP
A FEW DEGREES.
IN ANY CASE, THE HIGH PRESSURE SYSTEM SHOULD BE REDEVELOPED BY THE
LATTER PART OF THE WEEK, CAUSING TEMPERATURES TO RISE AGAIN. HEAT
ADVISORIES MAY BE NECESSARY LATER THIS WEEK INTO THE UPCOMING
WEEKEND, ASSUMING THE CURRENT FORECAST TRENDS CONTINUE.
AVIATION
(06Z TAFS)
ISSUED AT 916 PM PDT SUN AUG 2 2026
VFR WILL PERSIST FOR ALL TERMINALS PAST MIDNIGHT WITH ONLY KHAF,
KMRY AND KSNS EXPECTED TO DEVELOP IFR/LIFR CEILING LATE IN THE
OVERNIGHT HOURS THROUGH LATE MONDAY MORNING.
VICINITY OF SFO...VFR IS EXPECTED THROUGH THE FORECAST PERIOD,
HOWEVER THERE IS A SLIGHT CHANCE OF MVFR/IFR CEILINGS AFTER
SUNRISE WITH A LIGHT SOUTHERLY BREEZE OVER SF BAY MONDAY MORNING.
SFO BRIDGE APPROACH...SIMILAR TO SFO.
MONTEREY BAY TERMINALS...VFR UNTIL IFR/LIFR CEILINGS DEVELOP
DURING THE OVERNIGHT HOURS (HIGH CONFIDENCE) AND PERSIST UNTIL
LATE MORNING MONDAY, THEN VFR THROUGH THE REMAINDER OF THE DAY AND
EARLY EVENING, WITH STRATUS POSSIBLY RETURNING AROUND SUNSET, BUT
LIKELY LATER IN THE EVENING.
MARINE
(TONIGHT THROUGH NEXT SATURDAY)
ISSUED AT 916 PM PDT SUN AUG 2 2026
STRONG TO NEAR GALE NORTHWEST WINDS WILL PERSIST OVER THE
NORTHERN WATERS TONIGHT INTO EARLY MONDAY AND THEN BEGIN TO
GRADUALLY EASE INTO MONDAY EVENING. THE ROUGH TO VERY ROUGH
NORTHWEST SEAS (10-15 FT) WILL SUBSIDE TO MODERATE BY TUESDAY
EVENING, WITH MODERATE SEAS (4-8 FT) EXPECTED FOR THE REMAINDER
OF THE WORK WEEK.
FIRE WEATHER
ISSUED AT 1200 PM PDT SUN AUG 2 2026
NEAR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED THROUGH MONDAY
AND AFTER A PERIOD OF ELEVATED FIRE WEATHER CONDITIONS, POTENTIALLY
RETURN LATER IN THE WEEK. TEMPERATURES REMAIN AROUND 10 TO 15
DEGREES ABOVE NORMAL ACROSS THE INTERIOR THROUGH EARLY NEXT WEEK
WITH HIGHS IN THE UPPER 80S TO 90S. NO MAJOR CHANGES TO THE
FORECASTED DRY CONDITIONS. DAYTIME HUMIDITY RETENTION REMAINS POOR
ACROSS THE INTERIOR (20-30%) WITH HUMIDITY VALUES DROPPING INTO
THE 10S ACROSS THE INTERIOR CENTRAL COAST, EAST BAY HILLS/VALLEYS,
AND THE HIGHER ELEVATIONS. PORTIONS OF THE INTERIOR CENTRAL COAST
MAY SEE DAYTIME HUMIDITY VALUES DROP INTO THE SINGLE DIGITS
THROUGH THE NEXT COUPLE OF DAYS. OVERNIGHT RH RECOVERY REMAINS
POOR AT LOCATIONS ABOVE 2,000 FEET WITH VALUES BETWEEN 25 TO 40%
EXPECTED WITH SOME FAVORED LOCATIONS STRUGGLING TO REACH EVEN 25%.
THIS WILL BE PARTICULARLY TRUE ACROSS THE MAYACAMAS, HIGHEST
PEAKS OF THE EAST BAY HILLS, THE DIABLO RANGE, THE SANTA CRUZ
MOUNTAINS, THE SANTA LUCIA AND GABILAN RANGES. NOCTURNAL DRYING
(RAPID DECREASE IN RH THROUGH THE PRE- DAWN HOURS) MAY ALSO
TRANSPIRE WHICH WILL INCREASE THE BURN PERIOD OR TIME IN WHICH
FIRE BEHAVIOR MAY REMAIN ACTIVE. ENERGY RELEASE COMPONENT (ERC)
VALUES ARE PROJECTED TO CLIMB ABOVE THE THE PERCENTILE ACROSS THE
INTERIOR CENTRAL COAST, MID COAST TO MENDOCINO (NORTH BAY), AND
DIABLO- SANTA CRUZ (DIABLO MOUNTAINS AND SANTA CRUZ MOUNTAINS)
ZONES WITHIN THE NEXT TWO DAYS. DIURNALLY BREEZY ONSHORE WINDS ARE
EXPECTED ALONG THE COAST, MOUNTAIN GAPS AND PASSES, AND ALONG THE
RIDGELINES EACH AFTERNOON/EVENING. IN ADDITION, A BURST OF
OFFSHORE WIND IS FORECAST TONIGHT INTO MONDAY MORNING FOR THE SF
BAY AREA AND THE NORTH BAY, INCREASING THE RISK FOR NOCTURNAL
DRYING EVENTS ESPECIALLY IN DOWNSLOPE AREAS. WITH NEAR CRITICALLY
DRY CONDITIONS AND ABOVE NORMAL TEMPERATURES EXPECTED, INDIVIDUALS
ACROSS THESE AREAS ARE ADVISED TO AVOID ACTIVITIES THAT MAY SPARK
A FIRE. FIRE CREWS ARE URGED TO EXERCISE EXTRA CAUTION WHEN
EXECUTING ANY PRESCRIBED BURNS, ESPECIALLY WHERE FUELS,
TOPOGRAPHY, AND WEATHER ALIGN.
MTR WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...GALE WARNING UNTIL 3 AM PDT MONDAY FOR PT ARENA TO PT REYES 10-
60 NM.
SMALL CRAFT ADVISORY UNTIL 3 PM PDT MONDAY FOR PIGEON PT TO PT
PINOS 10-60 NM.
SHORT TERM...DIALH
LONG TERM....DIALH
AVIATION...JM
MARINE...JM
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