FXUS66 KMTR 141804
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
1104 AM PDT Thu May 14 2026
...New AVIATION, MARINE...
.KEY MESSAGES...
Updated at 1211 AM PDT Thu May 14 2026
- Breezy to gusty winds return Friday into the weekend
- Hazardous marine conditions expected Friday into the weekend
- Elevated fire weather conditions this weekend through Monday
with low RH and windy conditions
&&
.UPDATE...
Issued at 747 AM PDT Thu May 14 2026
Patches of stratus around Monterey Bay and the western San mateo
Peninsula should steadily dissipate through the morning with clear
skies through the day. The main forecast issue today will be
refining the strengthening winds across the region starting
tomorrow through the weekend, as an inside slider pattern develops
with an upper level low tracking from the Pacific Northwest into
the Great Basin. In particular, the need for any wind or surf
products over the weekend will be investigated.
DialH
&&
.SHORT TERM...
Issued at 1211 AM PDT Thu May 14 2026
(Today and tonight)
Not much in the way of cloud cover overnight with only two little
blips of clouds, but even those are fading. One of the main things
at play here driving the clear skies - sfc pressure gradients. SFO-
ACV is near -6mb, which is standard rule of thumb to keep stratus
outside of SF Bay/SFO. SFO-WMC is near 2mb and is forecast to
become negative by sunrise with a stronger offshore component and
not just northerly.
For Thursday day, given warming 850mb temps, rising H5, and offshore
flow expect a gradual warm up under sunny skies. About a 5 to 10
deg warm up over Wednesday and trending above normal for mid-May.
Highs will be 60s/70s bays/coast and 80s to near 90 inland. Will
say offshore flow does ease through the day and expect onshore to
kick in again with an afternoon onshore gusty push.
Thursday night - onshore flow lingers at the immediate sfc, but
higher elevations begin to shift offshore again with drier air
working in. Could see some patchy coastal stratus, but a solid
marine layer is looking less likely.
&&
.LONG TERM...
Issued at 1211 AM PDT Thu May 14 2026
(Friday through Wednesday)
Friday will feature one additional day of warming as temps tick
upwards a few more degrees. Still above normal, but nothing too
crazy and HeatRisk remains Minor. The bigger story for Friday will
be the winds. SFO-ACV gradient ramps again and this time
near -7mb. That will bring some very gusty winds over the coastal
waters making for a hazardous marine environment. Additionally,
winds increase along the immediate coast and the higher terrain.
Over the weekend winds remain high and get a helping hand from a
passing upper level trough through the PacNw/NorCal. This feature
also pauses the warming trend for Sat/Sun. The passing trough
finally deepens into a low Sun/Mon across the Great Basin. Pattern
recognition shows this is decent for offshore push by early
Monday. Hi-res guidance ramps up the SFO-WMC gradient to -11mb.
That will translate to weakening N-S winds along the coast and
coastal waters and increasing winds over the N Bay Mts and E Bay
Hills. Borderline for Wind Adv Sun night/Mon AM as winds look to
remain over the higher peaks. It goes with out saying that the
offshore flow will leading to warming temps early next week. Still
not buying the NBM output for max temps, but a return to the 80s
near 90 is plausible. Will likely be warmer at the coast too with
the offshore flow influence.
Last but not least, interior and higher terrain areas will see a
noticeable drop in RH beginning Thursday and lasting into next
week. The combo of bursts of wind (N-S and Offshore flow) and low
RH will lead to elevated fire weather concerns. Latest Energy
Release Component (ERC) charts show an upward trend toward
critical levels for mid-May. These charts are taking into account
temp/rh, but not wind.
Recapping - roller coaster for temperatures the next few days.
Winds increase and remain impactful over the coastal waters and
land. RH will decrease both day and night with a marked drying
trend.
&&
.AVIATION...
(18Z TAFS)
Issued at 1101 AM PDT Thu May 14 2026
VFR. Onshore winds are forecast to increase by early afternoon
before diminishing late in the evening and overnight. The greatest
potential for sub-VFR conditions will be along coastal sites (HAF &
MRY) late this evening and into early Friday morning. Elsewhere,
high confidence of VFR conditions prevailing through the TAF period.
Onshore winds increase once again Friday afternoon.
Vicinity of SFO...VFR through the TAF period. High confidence of
onshore winds increasing this afternoon and will persist through
late evening before diminishing slightly overnight and into Friday
morning. Gusts are likely to exceed 30 kt this afternoon and into
early evening. Onshore winds will once again increase Friday
afternoon and evening.
SFO Bridge Approach...Weaker onshore winds this afternoon
compared to SFO. Otherwise, similar to SFO.
Monterey Bay Terminals...VFR. High confidence of onshore winds
increasing this afternoon and will persist through early evening
before diminishing into Friday morning. Moderate confidence for
sub- MVFR conditions to develop around 05Z at MRY late tonight and
potentially lower to LIFR around 09Z Friday with SNS a TEMPO
group from 12Z-16Z (IFR). Conditions are likely to return to VFR
by mid-to- late morning on Friday.
&&
.MARINE...
(Today through Tuesday)
Issued at 1101 AM PDT Thu May 14 2026
Hazardous marine conditions have become widespread with gale
force winds affecting the northern waters into Thursday afternoon.
Gale-force gusts winds become widespread Friday morning and
continue to gain strength over the weekend. Locally stronger gusts
will be possible along some of the coastal jets where storm force
winds will be possible. The strong winds will drive seas between
12 to 19 feet. Winds peak on Sunday and reduce steadily into the
next work week.
&&
.FIRE WEATHER...
Issued at 530 AM PDT Thu May 14 2026
Fire weather concerns increase in the late week. Gusty offshore
winds build on Friday and strengthen through the weekend with peak
gusts above 30 mph for most areas and around 40 to 50 mph along
the coast, through gaps and passes, and across the ridgelines.
Very low daytime humidities of 15-25% will prevail across the
interior regions and higher peaks, with reduced overnight humidity
recoveries. Strong winds persist into the early part of Monday
before diminishing, but humidities will be slow to recover as a
modest offshore flow continues into the work week.
&&
.BEACHES...
Issued at 530 AM PDT Thu May 14 2026
Strong winds build Friday and peak over the weekend over the
marine environment leading to hazardously strong wind waves and
overall rough seas. Dangerous swimming, boating, and surfing
conditions can be expected. Large breaking waves can overpower
swimmers resulting in significant physical injury and increase the
risk of drowning. Gusts will stay strong along the immediate
coast, causing blowing and drifting sand and increased sea spray.
Water rescue attempts may be hampered by reduced visibilities
from the spray and sand.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 3 PM this afternoon to 9 PM PDT this
evening for Mry Bay.
Small Craft Advisory from 9 AM Friday to 3 PM PDT Saturday for
Mry Bay.
Gale Warning from 3 PM Saturday to 9 PM PDT Sunday for Mry Bay.
Small Craft Advisory until 3 PM PDT this afternoon for Pigeon Pt
to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 0-10 nm-Pt Arena
to Pt Reyes 10-60 NM.
Gale Warning from 3 PM this afternoon to 9 PM PDT Sunday for
Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 0-10 nm-
Pt Arena to Pt Reyes 10-60 NM.
Small Craft Advisory until 9 PM PDT this evening for Pt Reyes to
Pigeon Pt 0-10 nm.
Gale Warning from 9 PM this evening to 9 PM PDT Sunday for Pt
Reyes to Pigeon Pt 0-10 nm.
Small Craft Advisory until 3 PM PDT Friday for Pigeon Pt to Pt
Pinos 0-10 nm.
Gale Warning from 3 PM Friday to 9 PM PDT Sunday for Pigeon Pt
to Pt Pinos 0-10 nm.
Small Craft Advisory until 3 AM PDT Friday for Pt Pinos to Pt
Piedras Blancas 0-10 nm.
Gale Warning from 3 AM Friday to 9 AM PDT Saturday for Pt Pinos
to Pt Piedras Blancas 0-10 nm.
Storm Watch from Saturday morning through Sunday evening for Pt
Pinos to Pt Piedras Blancas 0-10 nm.
&&
$$
SHORT TERM...MM
LONG TERM....MM
AVIATION...RGass
MARINE...RGass
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Prepared by Boulder-Creek.com Weather at: Thu May 14 12:30:03 PDT 2026
From the National Weather Service
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