FXUS66 KMTR 271757
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
957 AM PST Fri Feb 27 2026
...New AVIATION...
.KEY MESSAGES...
Updated at 142 AM PST Fri Feb 27 2026
- Well above normal temperatures through Saturday
- Brief, slight cooling trend Sunday and Monday
- Near to slightly above normal temperatures Tuesday through Thursday
&&
.UPDATE...
Issued at 856 AM PST Fri Feb 27 2026
Warm conditions are forecast today across the area as offshore
flow around 5 to 10 knots persists. This offshore flow should
support well above normal temperatures (10 to almost 20 degrees
above normal) for this time of year. Widespread 70 and 80 degree
temperatures are anticipated today, especially with only a thin
veil of cirrus streaming in overhead. This cirrus does signal the
potential for a very brief pattern change this weekend with
opportunities for rain and even a low end-risk (around 10% or
less) for thunderstorms. We'll have more details on this later
this morning/early afternoon.
&&
.SHORT TERM...
Issued at 142 AM PST Fri Feb 27 2026
(Today and tonight)
The 00Z sounding observed an 850 mb temperature of 13.00 degrees
Celsius which is above the 90th percentile (12.8 degrees Celsius)
for the date and time. Upper-level shortwave ridging will get pushed
into the region today by an upper-level cutoff low on its heels. At
the surface, high pressure across the Intermountain West and a
coastal trough off the California Coast will generate light offshore
flow. All of the above will be contributing factors to temperatures
climbing to 15 degrees above normal. Today will be the warmest day
of the week and the warmest day of the forecast period. To limit
heat-realted impacts, people should increase water intake, reduce
time spent outdoors or stay in the shade when the sun is the
strongest, and open windows at night and use fans to bring cooler
air inside buildings. To put this heat into context, SJC maximum
temperature is forecast to be 78 degrees (previous record 79 degrees
set in 1932, 1972, and 2020).
&&
.LONG TERM...
Issued at 407 AM PST Fri Feb 27 2026
(Saturday through Thursday)
Heights begin to fall Saturday as the upper-level cutoff low comes
into the periphery. This will kickoff a brief, slight cooling trend;
however, temperatures on Saturday will still be ten degrees above
normal. Slight (15%) chances for precipitation remain Sunday into
Monday with the passage of the upper-level shortwave trough -
chances will be greater the farther north the location. Global
ensemble clusters generally keep us dry with less than 0.10" for the
wettest solutions. Even if it doesn't rain, an increase in cloud
cover is expected with coastal drizzle possible. Conditions will be
noticeably cooler with the return of near normal temperatures and
onshore flow. There's also a less than 10% chance for thunderstorms.
The three ingredients necessary for thunderstorm development of
lift, instability, and moisture will be present, albeit with low
CAPE (accompanied by CIN) and conditionally unstable lapse rates.
The limiting factor in this case will likely be them not aligning
spatially and/or temporally as depicted in point forecast model
soundings. Upper-level shortwave ridging will nose in from the
Eastern Pacific Ocean on Tuesday before quickly getting shoved
eastward by a following upper-level shortwave trough that will dig
into the Great Basin. Sensible weather wise this will translate to
near to slightly above normal temperatures for the end of the
forecast period.
&&
.AVIATION...
(18Z TAFS)
Issued at 957 AM PST Fri Feb 27 2026
VFR. High level clouds will continue through the remainder of the
TAF period. Some potential for low clouds overnight at STS and APC
but confidence is low that fog will develop. If fog does develop, it
is most likely along the San Pablo Bay/Delta region and may spread
northwards into the North Bay Valleys. Slight chance for drizzle at
STS overnight into early Saturday morning. Winds remain light and
onshore during the afternoon/evening to offshore/variable overnight.
Vicinity of SFO...VFR. Low chance of diminished visibility 12-18Z
but not anticipating fog to develop overnight. Winds shift onshore
during the day before becoming light and variable overnight.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...VFR. Winds shift onshore during the
afternoon/evening before easing and shifting southeasterly
overnight.
&&
.MARINE...
(Today through Wednesday)
Issued at 856 AM PST Fri Feb 27 2026
Light, northerly to northeasterly winds continue across the
coastal waters. Locally moderate to fresh gusts continue through
Friday across the southern coastal waters. Drizzle is possible
across the northernmost coastal waters this weekend into early
next week and a five percent chance of thunderstorms on Saturday.
Low to moderate seas continue into next week.
&&
.CLIMATE...
Issued at 1113 PM PST Thu Feb 26 2026
The following are the record high temperatures at the long term
sites for Friday, Feb 27th and Saturday, Feb 28th.
Location Feb 27th Record High Feb 28th Record High
Santa Rosa 90 in 1923 93 in 1923
San Rafael 74 in 1954 78 in 2025
Kentfield 79 in 1932, 1923 78 in 1929, 1923
Napa 80 in 1932 81 in 1929
Richmond 78 in 2020 77 in 1986
Livermore 79 in 1932 82 in 2022
San Francisco 78 in 2002, 1992, 1986 76 in 1992, 1986
SFO Airport 76 in 2020 73 in 1959
Redwood City 79 in 2025, 1932 77 in 2025
Half Moon Bay 78 in 1986 74 in 1954
Oakland Museum 78 in 2002 75 in 2025
San Jose 79 in 2020, 1992, 1932 77 in 2025, 1926
Salinas Airport 84 in 2025 81 in 2022
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...None.
&&
$$
SHORT TERM...Sarment
LONG TERM....Sarment
AVIATION...Kennedy
MARINE...Kennedy
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Prepared by Boulder-Creek.com Weather at: Fri Feb 27 10:30:03 PST 2026
From the National Weather Service
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