FXUS66 KMTR 100506
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
1006 PM PDT Sat May 9 2026
...New AVIATION...
.KEY MESSAGES...
Updated at 1217 PM PDT Sat May 9 2026
- Warming and drying trend will continue through early in the
week with afternoon temperatures peaking on Monday
- Moderate risk for heat-related illnesses for sensitive
populations across the interior on Monday
- Gradual cooling trend and potential unsettled weather from
midweek through late week
&&
.UPDATE...
Issued at 906 PM PDT Sat May 9 2026
We're keeping an eye on the stratus tonight as it is behaving a
bit differently than last night. The first noteworthy item being,
the blanket of low level clouds over our coastal waters. The
second being the inland intrusion of stratus. This should put the
marine layer somewhere between 500-1000ft already. The question
then becomes, will deepen past 1000-1200ft tonight? Some of the
0Z data shows we could be between 1200-1500ft which could mean
more interior valleys see stratus tomorrow morning. We will see
more thermal belts, meaning warmer temperatures above the stratus
and in higher elevations. For areas that experience the marine
layer, tommorow's highs will likely be influenced by it keeping
things a bit cooler / similar to what we saw today.
&&
.SHORT TERM...
Issued at 1217 PM PDT Sat May 9 2026
(This evening through Sunday)
Low clouds have treated to the coast as of early this afternoon.
Thus, as high pressure aloft continues to build, inland
temperatures will be a few degrees warmer compared to yesterday.
Thus, afternoon temperatures are forecast to reach into the mid
80s to lower 90s (far inland areas) as high pressure continues to
build over the region. The coast will remain cooler, generally in
the upper 50s to 60s, thanks to onshore flow and the compressed
marine layer.
Tonight, expecting low clouds to return to the coast and adjacent
inland valleys (similar to this morning). Again, there is the
potential for mist or light drizzle again tonight into Sunday
morning, yet widespread measurable rainfall is highly unlikely.
Sunday will feature similar temperatures as Saturday as the
mid/upper level ridge shifts into southern California, Nevada, and
Arizona. Low clouds that do develop inland will quickly retreat
to the coast Sunday by midmorning giving way to mostly sunny skies
inland.
&&
.LONG TERM...
Issued at 1217 PM PDT Sat May 9 2026
(Sunday night through next Friday)
Low clouds persist near the coast and will return inland Sunday
night, however less widespread across the interior valleys. Monday
is still on track to be the warmest of the week as interior areas
reach Moderate HeatRisk as the high pressure strengthens over the
Desert Southwest. Temperatures by Monday afternoon are forecast
to be in the low to upper 90s across the interior, mid 80s to low
90s across inland away from the coast, and low 70s to mid 80s near
coastal locations. The cooler conditions near the coast will be
due to the marine layer not completely going away and continued
onshore winds.
Temperatures are forecast to cool slightly by Tuesday, however
will still remain some 5-15 degrees above seasonal averages. There
is increasing confidence that a cut-off low pressure system will
approach from the eastern Pacific by midweek, bring cooler and
unsettled weather to the region for the remainder of the upcoming
week. This will work to push the mid/upper level ridge across the
Desert Southwest farther to the east. Not expecting much
widespread measurable rainfall, however this pattern would be more
favorable for drizzle and/or light rain. There are still
differences in model guidance about the strength and southern
extent of the mid/upper level trough by midweek. Late in the week,
more zonal flow is forecast to develop over the region. Be sure
to check back for the latest forecasts as we gain more reliable
short range guidance.
&&
.AVIATION...
(06Z TAFS)
Issued at 1005 PM PDT Sat May 9 2026
Tonight, stratus is a bit more expansive, perhaps somewhere between
500-1000ft already, with IFR conditions along the coast and at KSFO
already and MVFR cigs near KOAK. Expect the stratus to continue to
move inland and deepen some, impacting North Bay terminals after
midnight and into tomorrow morning. MVFR to IFR cigs are expected
and should clear out mid to late morning. For the interior East Bay
terminals, the stratus deck will move through overnight resulting in
MVFR ceilings until Sunday morning. IFR ceilings persist at HAF
through the night with moderate NW winds. By mid-day Sunday,
ceilings will lift through the afternoon. The stratus deck is set to
return again in the evening. The high-level clouds that are expected
Sunday afternoon should also limit the development of the stratus
deck for the interior East and North Bay terminals.
Vicinity of SFO...Breezy westerly winds with gusts of 18-22kt will
be lasting through 8Z. Stratus has locked in around the Bay, with
cigs ranging from IFR to MVFR. Confidence is high that we will
remain locked in with stratus tonight; however, there is some
uncertainty with how long we will be stuck with IFR cigs. Opted to
lean more pessimistic based on satellite imagery, webcams, and the
KSFO METAR so far. We could break to MVFR cigs for a period on
Sunday morning, before VFR conditions return by mid to late morning.
Breezy westerly winds looks to be on tap again for Sunday, with
gusts to 22KT from 20-03Z. High clouds move in tomorrow afternoon
and evening. This may limit stratus development Sunday evening into
Monday morning. Opted to hint at a later arrival, but this may need
to be adjusted.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...Widespread IFR ceilings are forecast
through the night which will scatter out by late morning Sunday. MRY
will experience another return of MVFR stratus Sunday evening.
Moderate onshore winds persist through the first half of the TAF
period with a slight ease overnight before picking up again late
Sunday morning. High-level clouds will also roll in Sunday
afternoon, limiting the extent and depth of the marine layer into
the Salinas valley.&&
.MARINE...
(Tonight through next Friday)
Issued at 906 PM PDT Sat May 9 2026
Moderate seas and fresh to strong northwest breezes with
occasional near gale force gusts will continue through most of
Sunday. Locally gusty conditions are likely across the San Pablo
and San Francisco Bays where terrain promotes wind funneling.
Winds gradually ease starting late Sunday with a gentle to
moderate northwesterly breeze expected early to mid week. Breezy
conditions return to the inner waters late week and seas build mid
to late week.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 3 PM to 9 PM PDT Sunday for Mry Bay.
Small Craft Advisory until 3 AM PDT Monday for Pt Arena to Pt
Reyes 0-10 nm.
Small Craft Advisory until 9 PM PDT Sunday for Pigeon Pt to Pt
Pinos 0-10 nm-Pigeon Pt to Pt Pinos 10-60 NM-Pt Pinos to Pt
Piedras Blancas 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.
Small Craft Advisory until 9 AM PDT Monday for Pt Arena to Pt
Reyes 10-60 NM.
&&
$$
SHORT TERM...RGass
LONG TERM....RGass
AVIATION...KR/ANC
MARINE...KR
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Prepared by Boulder-Creek.com Weather at: Sat May 9 22:30:03 PDT 2026
From the National Weather Service
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