FXUS66 KMTR 171849
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
1149 AM PDT Fri Apr 17 2026
...New SHORT TERM, LONG TERM...
.KEY MESSAGES...
Updated at 1148 AM PDT Fri Apr 17 2026
- Seasonably warm temperatures expected through the weekend
- Cooler temperatures and beneficial rain for the beginning of
next week
&&
.SHORT TERM...
Issued at 1148 AM PDT Fri Apr 17 2026
(This afternoon through Saturday)
Gusty offshore winds prevail across the Vaca Range, Mayacamas
Range, and higher elevations of the East Bay Hills (such as Mt.
Diablo). However, as the day progresses, wind speeds will
gradually diminish as high pressure builds in from the eastern
Pacific. Thus, a gradual warming trend will continue today with
temperatures reaching the mid 60s to low 70s across the interior
(potentially mid 70s in the warmest interior locations).
Overnight, temperatures will be chilly and lower into the 40s
across most of the lower elevations and near 50 degrees F closer
to the coast. However, these temperatures are near seasonal
averages. High clouds are forecast to stream in from the west
during the overnight hours.
These high clouds will persist into Saturday when we are
forecasting the warmest temperatures of the weekend to occur. This
is as the mid/upper level short wave ridge axis will become
positioned over much of the Bay Area and Central Coast. There is a
greater than 50% probability for San Jose, Gilroy, Hollister, and
King City to exceed 80 degrees F on Saturday afternoon (but near
0% of exceeding 85 degrees F). Elsewhere, we are expecting mid-to-
upper 60s on northwest facing coastal locations and low-to-upper
70s across the rest of the region.
&&
.LONG TERM...
Issued at 1148 AM PDT Fri Apr 17 2026
(Saturday night through next Thursday)
A gradual cooling trend will begin on Sunday as a mid/upper level
low drops out of the Gulf of Alaska and approaches the Pacific
Northwest and northern California coast. This will bring unsettled
weather to much of the region Monday and Tuesday with
temperatures dropping to below seasonal averages. Rain chances
begin across the North Bay late Sunday, yet rainfall amounts will
generally be light (if any occurs). There are still differences in
the deterministic models with the ECMWF bringing rain to the
North Bay late Sunday while the GFS does not bring widespread
precipitation in until Monday afternoon and evening. Southerly
winds will also increase ahead of and along the frontal boundary,
yet how strong they will be remains in question. Tuesday will be
when the Bay Area and Central Coast will have the greatest
potential for scattered showers and possible thunderstorms. We
will have a better handle on the evolution of this system once we
get in the range of the high resolution and convection-allowing
models. Post-frontal rain showers look to linger into Wednesday.
There still is no clear signal of what the pattern looks like
heading into late next week.
&&
.AVIATION...
(18Z TAFS)
Issued at 1126 AM PDT Fri Apr 17 2026
Quiet weather as light and variable winds to slightly offshore
become onshore winds this afternoon. VFR conditions expected
through the TAF period as the threat for low-level clouds is
limited, with the exception of KHAF. Around 15Z, there is a layer
of lower CIGs right off the coast that may move onshore and result
in a brief period of MVFR conditions.
Vicinity of SFO...Winds will continue to turn to the northwest and
west this afternoon, with speeds increasing to around 10-15kt and
the potential for 20kt gusts from 21-02Z. Westerly winds begin to
ease around or just after sunset, with winds becoming light and
variable around 12Z. Offshore flow returns late tomorrow morning and
into the early afternoon hours. VFR conditions are expected with
high clouds passing through.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...VFR conditions are accompanied with lighter
winds today. At MRY, there is a period around 03-04z where winds
will be variable before becoming ESE by 09Z. SNS will also
experience light and variable winds before the offshore flow settles
in. No low-level clouds are currently expected this TAF period.
&&
.MARINE...
(Today through Wednesday)
Issued at 1126 AM PDT Fri Apr 17 2026
Northwest winds and seas will gradually decrease and subside
through Saturday. On Sunday winds will shift to the south ahead
of a Pacific low pressure system that will bring rain to the area
beginning early next week.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...None.
&&
$$
SHORT TERM...RGass
LONG TERM....RGass
AVIATION...KR/AN
MARINE...KR
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Prepared by Boulder-Creek.com Weather at: Fri Apr 17 12:30:02 PDT 2026
From the National Weather Service
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