FXUS66 KMTR 061903
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
1203 PM PDT Wed May 6 2026
...New SHORT TERM, LONG TERM...
.KEY MESSAGES...
Updated at 1201 PM PDT Wed May 6 2026
- Warming and drying trend beginning today through the early part
of next week
- Temperatures peaking next Monday and Tuesday
- Moderate risk for heat-related illnesses for sensitive
populations across the inland valleys beginning this weekend
&&
.SHORT TERM...
Issued at 1201 PM PDT Wed May 6 2026
(This evening through Thursday)
Satellite imagery shows a lingering mid-level cloud deck over Napa
County and the eastern fringe of Sonoma County, with scattered
cumulus across ridgelines down to the Gabilan Range east of Salinas
and clear skies everywhere else. The clouds over Napa County may
take a few more hours to clear out, with generally clear skies
across the region through the afternoon before stratus returns to
the valley regions this evening and overnight. As of the time of
writing, there has been no clear signal of a return of the marine
layer, but we will continue to monitor the Bodega Bay profiler as
it is expected to develop over the next couple of days.
The upper level pattern is dominated by a building ridge across
the West Coast as the low pressure system that gave us the last
few days of gloomy weather has split, with part of the low's
energy moving off into the Plains and the other spinning up a cut-
off low centered over the northern half of Baja California. Thus,
today will mark the start of a warming and drying trend that
-- spoiler alert -- will continue into the upcoming weekend. High
temperatures toady will range from the middle 70s to lower 80s
across the inland valleys, with highs in the middle 80s possible
in the warmest regions of southern Monterey County, the middle 60s
to the lower 70s near the Bays, and the middle 50s to lower 60s
along the Pacific coast. The building ridge will cause
temperatures to warm tomorrow, generally a rise of a few degrees
across most of the forecast region, with the most notable
exceptions being the southern Salinas Valley, where highs jump
into the upper 80s to the lower 90s, and the vicinity of Santa
Cruz where highs rise into the upper 70s. Breezy onshore flow is
expected to develop across the region in the afternoon and evening
hours, with gusts reaching 20 to 30 miles per hour along the
coasts, through gaps and the northern Salinas Valley, and across
the ridgelines.
&&
.LONG TERM...
Issued at 1201 PM PDT Wed May 6 2026
(Thursday night through next Tuesday)
Upper level ridging continues to build through the week as
temperatures continue to rise across the region. Thursday night into
Friday, the strengthening pressure gradient will contribute to
breezier and gustier onshore flow during the afternoon and evening
hours, especially along the coast, at the ridgelines, and through
northwest-southeast oriented gaps and valleys, where wind gusts
could reach 25 to 35 mph. After persisting through the weekend,
breezy winds will diminish through the early part of next week as
the ridge expands over the state, degrading the pressure gradient.
Temperatures continue to rise across the 7 day outlook, with the
current forecast showing highs peaking next Monday and Tuesday, as
the temperatures reach the lower 90s to near 100 across the inland
valleys, the lower 80s to lower 90s along the Bays, and the middle
60s to lower 70s along the Pacific coast. Low temperatures will
hover in the 50s for the lower elevations, and will rise into the
60s and lower 70s in the higher elevations. Moderate HeatRisk will
develop in the inland valleys and warmer locations along the
Bayshore (namely eastern Marin County and southeastern San Mateo
County beginning this weekend into the early part of next week. This
corresponds to a moderate risk of heat-related illnesses, especially
for sensitive populations including children, the elderly, pregnant
women, people with chronic diseases, and people who work or live
outdoors without adequate shelter or hydration. Never leave anyone
unattended in a vehicle! It is best to avoid being outdoors during
the hottest part of the day, but if you must, make sure to drink
plenty of water and take breaks in the shade.
Towards the middle and latter parts of the next week, forecast
uncertainty begins to increase with an emerging split in the
ensemble model runs. Ensemble cluster analysis teases out around a
30-40% chance that a trough will develop and interrupt the warming
trend towards the the latter part of next week, with significant
differences among the ensemble runs as to what the nature of this
trough will be -- shortwave or synoptic, more zonal or meridional
flow. This is something that we will watch over the next few days as
we interrogate how this event will play out.
&&
.AVIATION...
(18Z TAFS)
Issued at 1012 AM PDT Wed May 6 2026
Low clouds have been clearing out quickly by mid-morning and
expect VFR conditions the remainder of the day and evening.
Marine layer and associated low stratus will begin its push
inland later this evening with MVFR ceilings expected for all
terminals through the overnight hours with clearing beginning by
mid-morning Thursday, likely VFR for all terminals by Noon
Thursday.
Vicinity of SFO...Steady fetch of onshore flow through the TAF
period with VFR conditions for the remainder of this afternoon and
early evening, and a return of MVFR cigs later this evening.
MVFR cigs will persist through the overnight hours with clearing
expected to begin by mid-morning Thursday, and VFR expected by
Noon Thursday.
SFO Bridge Approach...Similar as SFO.
Monterey Bay Terminals...VFR conditions this morning through the
afternoon accompanied by moderate WNW winds. Low MVFR ceilings from
the coastal stratus deck are expected to move onshore this evening
impacting MRY first. Overnight around 09Z Thursday, moderate
confidence that conditions will transition into IFR as the stratus
marine layer becomes more defined. These lower ceilings will begin
to lift and mix out by late morning Thursday.
&&
.MARINE...
(Today through Monday)
Issued at 1012 AM PDT Wed May 6 2026
A building ridge of high pressure over the eastern Pacific will
continue gentle to moderate northerly breezes across the coastal
waters this afternoon. Expect increasing northerly breezes by
Thursday afternoon that will persist through the weekend with
building rough seas, resulting in dangerous conditions for small
crafts.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 9 PM Thursday to 3 AM PDT Saturday for
Pt Arena to Pt Reyes 0-10 nm.
Small Craft Advisory from 3 AM Friday to 3 AM PDT Saturday for
Pigeon Pt to Pt Pinos 0-10 nm-Pigeon Pt to Pt Pinos 10-60
NM-Pt Arena to Pt Reyes 10-60 NM-Pt Reyes to Pigeon Pt 0-10
nm.
Small Craft Advisory from 9 AM Thursday to 3 AM PDT Saturday for
Pt Pinos to Pt Piedras Blancas 0-10 nm.
&&
$$
SHORT TERM...DialH
LONG TERM....DialH
AVIATION...JM
MARINE...JM
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Prepared by Boulder-Creek.com Weather at: Wed May 6 14:30:04 PDT 2026
From the National Weather Service
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