FXUS66 KMTR 101630 AAA
AFDMTR
Area Forecast Discussion...UPDATED
National Weather Service San Francisco CA
930 AM PDT Wed Jun 10 2026
...New UPDATE...
.KEY MESSAGES...
Updated at 1201 AM PDT Wed Jun 10 2026
- Warm and dry weather expected today through Saturday with a
moderate risk of heat-related illnesses for interior locations
today and Thursday
- Increased risk of sneaker waves and strong rip currents along
south and southwest facing beaches through Thursday morning
- Critical fire weather concerns for the interior North Bay and
the East Bay Mountains late tonight into Thursday morning
- Minor coastal flooding near high tide beginning this evening
for low-lying Bayshore locations
&&
.UPDATE...
Issued at 925 AM PDT Wed Jun 10 2026
The short term forecast is in good shape, so no changes
anticipated. Shallow morning fog (dense in spots) along some of
the immediate coastal regions continues to dissipate and in the
next 1-2 hours, I anticipate mostly sunny conditions. Our fire,
heat, and coastal headlines all appear on track.
We're anticipating Red Flag conditions at elevation across the
North Bay Interior Mountains and East Bay Hills starting tonight
into the pre-dawn hours on Thursday. The main highlights are
enhanced wind gusts due to building high pressure in the wake of a
diffuse trough moving to the north and east of the region. Latest
NWP has suggested a slight decrease in the MSLP/height gradient
(thereby leading to a more subdued jet across the Sacramento
Valley). Wind gusts in excess of 40 mph with gusts as great as 60
mph at the higher peaks are still anticipated. Fuels will continue
to cure and overnight RH recovery of less than 30% will translate
to a potential for fire ignitions and spread, especially with
favorable alignment. Winds will abate through the day on
Thursday, however, afternoon humidity values will remain
critically dry with values in the teens. Remember to obey any
local fire restrictions/burn bans and avoid activities that could
spark wildfires. Remember, one less spark, one less wildfire!
Regarding heat products, today will be warm, with more impactful
heat anticipated on Thursday as offshore winds limit marine layer
development (except along the immediate coastline). Be sure to
hydrate with plenty of water, limit strenuous outdoor activities
to the early morning or evening hours, and never leave children or
pets unattended in vehicles. We'll continue to examine the need
for additional heat headlines across far interior regions (East
Bay) on Friday as onshore flow may initially be very modest.
Finally, coastal hazards are in effect due to an increased risk
for sneaker waves/rip currents. If headed to the beach to seek
relief from the heat or for recreation, be sure to check
conditions before you venture out. Keep an eye on children and
pets and never turn your back on the ocean. Minor coastal flood
impacts are anticipated due to astronomical tides. While higher
than normal high tides are anticipated to occur mostly during the
overnight period later this week and into the weekend, coastal
infrastructure may experience minor, but impactful, inundation.
&&
.SHORT TERM...
Issued at 1201 AM PDT Wed Jun 10 2026
(Today and tonight)
Clear conditions will generally prevail through the night as a ridge
over the eastern Pacific moves into the region, kicking off the
first of several days of warm to hot temperatures across the region.
High temperatures today range from the upper 80s to the middle 90s
across the inland valleys, with the warmest spots reaching the
triple digits, while areas near the Bays see highs in the middle 70s
to middle 80s, perhaps the lower 70s near southern Monterey Bay, and
the coastal regions see highs in the 60s. The interior regions will
see Moderate HeatRisk develop, meaning that there is a risk for heat
related illnesses among heat sensitive populations, including
children, the elderly, pregnant women, people with chronic health
conditions, and people who work or live outdoors without adequate
shelter, cooling, or hydration.
There will be some relief tonight through Thursday morning as the
valleys cool to the middle 50s to lower 60s, while those in the
thermal belts will see low temperatures hover in the middle 60s to
lower 70s. This is also when strong north to northeast winds will
develop in the interior mountains of the Bay Area, especially across
the North and East Bays where peak wind gusts of 35 to 45 mph are
expected across the area with gusts of 60 mph or higher possible in
the ridgetops. These offshore winds will contribute to poor humidity
recoveries across the area overnight, and the combination of the
hot, dry, and windy conditions will result in critical fire weather
conditions where any fires that start could take hold and spread
rapidly. A Red Flag Warning has been issued for the North and East
Bay interior mountains, to come into effect tonight at 11 PM and
lasting through 9 AM Thursday. Fire weather concerns are also
elevated across the eastern mountains of Santa Clara County,
although the wind gusts will not be as strong. See the FIRE WEATHER
section for more information.
High astronomical tides, combined with around half a foot of surge
driven by southerly swell and thermal expansion, will result in
minor flooding in low-lying areas near the Bayshore beginning this
evening, mainly around low-lying locations in the North Bay and
particularly eastern Marin County, and expanding to cover the rest
of the San Francisco Bayshore beginning Thursday evening. Coastal
Flood Advisories will go into effect at 6 PM tonight for the North
Bay, and on 7 PM Thursday for the rest of the San Francisco
Bayshore. At the San Francisco tidal gauge, high tide is expected to
be 0.6 ft above normal (6.58 ft MLLW) at 811 PM on Wednesday the
10th, 1.2 ft above normal (6.98 ft MLLW) at 851 PM on Thursday the
11th, and 1.5 ft above normal (7.23 ft MLLW) at 934 PM on Friday the
12th. The astronomical tide predictions will support an extension of
the Coastal Flood Advisories through the weekend and into the early
part of next week. As a final note, long-period southerly swell is
causing an increased risk for potentially dangerous sneaker waves
and rip currents. A Beach Hazards Statement is in effect for parts
of the Pacific Coast. See the BEACHES section for more
information.
&&
.LONG TERM...
Issued at 1201 AM PDT Wed Jun 10 2026
(Thursday through Tuesday)
Thursday should be the warmest day of the week as the ridge persists
across the region. Temperatures in the inland valleys will jump into
the 90s to near 102, with the warmest spots going up to around 105,
while the Bays see highs ranging from the 80s to the middle 90s and
the coastal communities range in the middle 60s to lower 80s. A Heat
Advisory will come into effect from noon to 11 PM on Thursday for
the North Bay valleys and interior mountains, the Sonoma coastal
range, the East bay, the Santa Clara valley and eastern mountains,
and the San Francisco Bay shoreline.
The current forecast shows a gradual slight cooling trend beginning
on Friday, which is a little curious given the lack of an obvious
large scale change to the upper level pattern. Once again, I've
opted to bump up the temperatures slightly on Friday owing to the
model diagnosis, but there are models that are trying to put marine
layer influence back into the region, although how far it goes
depends critically on what it can do against the high pressure
system. By Saturday, an shortwave trough tries to form over northern
California, which could bring us another burst of offshore flow.
Considered bumping temperatures up on Saturday as well, but my
confidence isn't high enough to pull the trigger as of yet. Ensemble
model cluster analysis converges on the ridge continuing to impact
the state for the early part of next week as the ridge axis builds
into the Pacific Northwest into southwestern Canada. Beyond that,
they hint at the ridge breaking down in the middle of next week,
although whether that will manifest as weaker ridging over the
western US or more zonal flow is to be determined.
&&
.AVIATION...
(12Z TAFS)
Issued at 457 AM PDT Wed Jun 10 2026
Strong high pressure remains over the forecast area. The ACV-SFO
pressure gradient is 8.5 mb and SFO-SAC is 1.8 mb. Gusty northwest
winds over the coastal waters are stirring up sea spray aerosols
resulting in mist/fog/haze/hazy conditions beneath a shallow marine
layer temperature inversion. Sea spray aerosols are condensation
nuclei for stratus and fog. Satellite shows a patch of low stratus
and fog /LIFR-IFR/ has developed near KMRY otherwise it's VFR across
the forecast area. Patches of stratus and fog will mix out during
the morning under increasing diurnal warming and mixing. Increasing
north-northeast winds in the lower levels develop tonight and
Thursday morning resulting in areas of low level wind shear.
Vicinity of SFO...VFR. Wind variable 5 knots becoming west 15
knots in the afternoon and evening. Northeast surface wind 5 knots
tonight and Thursday morning. Low level wind shear develops tonight
and Thursday morning.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...VFR except for temporary BKN-OVC stratus
and fog /LIFR-IFR/ vicinity KMRY early this morning. Variable winds
5 knots becoming west-northwest 5 to 15 knots today. Light and
variable winds tonight and Thursday morning.
&&
.MARINE...
(Today through Monday)
Issued at 403 AM PDT Wed Jun 10 2026
Gale force gusts will continue across the northern waters, with
gusty northwest winds continuing across the rest of the waters,
resulting in hazardous conditions for small craft. Winds and seas
begin to ease by Thursday evening and are expected to stay light
through the remainder of the forecast period.
&&
.FIRE WEATHER...
Issued at 750 PM PDT Tue Jun 9 2026
Hot temperatures, gusty north winds, and low humidities across the
North Bay interior mountains into the Diablo Range will raise the
fire weather threats late on Wednesday into Thursday, with a
particular emphasis on the interior mountains of Napa County. Red
Flag Warnings have been issued for the interior mountains of the
North and East Bay from 11 PM Wednesday night through 9 AM
Thursday morning as the greatest risk of rapid fire spread
arrives. Although the strongest winds will remain within the
Sacramento Valley, gusts of 30 to 40 mph are expected to spread
into Napa County and the Diablo Range south through Santa Clara
County, with stronger gusts of 50-60 mph possible along the Vaca
Mountains along Napa County's eastern edge. Meanwhile, daytime
humidity retention will be very poor with relative humidity values
as low as 10-15%, while overnight recoveries are likewise poor as
RH values top out at 20-30%. Thus, fuels are expected to dry
rapidly, leading to the elevated fire weather concerns. Also
important to note that even with the drizzle and light rain coming
through the region, wetting rains (rain totals above 0.1") are
not expected, limiting any relief that will be realized for the
midweek period. Elsewhere across the district, conditions remain
hot and dry, but we're not expecting winds to be as strong as they
are across the interior North Bay. Remember, one less spark, one
less wildfire.
DialH
&&
.BEACHES...
Issued at 750 PM PDT Tue Jun 9 2026
Long period southerly swell is moving through the waters with buoy
observations suggesting that a swell of around 4 to 6 feet is
coming from 190 degrees, just west of due south, with a period of
around 19 to 21 seconds. The long period swell will result in an
increased risk of sneaker waves and strong rip currents along
south and southwest facing beaches. As a result, a Beach Hazards
Statement has been issued for the Pacific Coast of the North Bay,
San Mateo, and Santa Cruz counties through 5 AM on Thursday.
Sneaker waves will run up the beach much farther than other waves,
potentially catching beachgoers by surprise and resulting in
people being swept into the water. Rip currents are strong enough
to pull the strongest swimmers away from shore. Swim near a
lifeguard if possible. Stay back from the beach, and away from
jetties, piers, beachside rocks, and other infrastructure near the
water. Never turn your back to the ocean!
DialH
&&
.CLIMATE...
Issued at 1235 AM PDT Wed Jun 10 2026
The following are the record highs for June 11th.
Station Record Highs June 11th
Santa Rosa 100 in 2019
San Rafael 97 in 1985
Napa 102 in 2019
Livermore 105 in 1985
San Francisco 92 in 2019, 1877
SFO Airport 98 in 2019
Redwood City 102 in 2019
Oakland Museum 99 in 2019
Half Moon Bay 85 in 2019
San Jose 99 in 2019
Monterey Airport 92 in 2019
Salinas Airport 104 in 2019
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Coastal Flood Advisory from 7 PM Thursday to 1 AM PDT Saturday
for CAZ006-508.
Heat Advisory from noon to 11 PM PDT Thursday for CAZ503-504-506-
508-510-513>515.
Red Flag Warning from 11 PM this evening to 9 AM PDT Thursday
for CAZ504-515.
Beach Hazards Statement through late tonight for CAZ505-509-529.
Coastal Flood Advisory from 6 PM this evening to 1 AM PDT
Saturday for CAZ506.
PZ...Small Craft Advisory until 9 PM PDT this evening for Mry Bay.
Small Craft Advisory until 9 AM PDT this morning for Pt Arena to
Pt Reyes 0-10 nm.
Gale Warning until 9 PM PDT this evening for Pt Arena to Pt
Reyes 0-10 nm.
Small Craft Advisory until 9 PM PDT this evening for Pigeon Pt
to Pt Pinos 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.
Small Craft Advisory until 3 AM PDT Thursday for Pt Pinos to Pt
Piedras Blancas 0-10 nm.
Gale Warning until 3 PM PDT Thursday for Pt Arena to Pt Reyes 10-
60 NM.
Small Craft Advisory until 9 AM PDT Thursday for Pigeon Pt to Pt
Pinos 10-60 NM.
&&
$$
SHORT TERM...DialH
LONG TERM....DialH
AVIATION...Canepa
MARINE...Canepa
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Prepared by Boulder-Creek.com Weather at: Wed Jun 10 12:30:02 PDT 2026
From the National Weather Service
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