| |
|
NWS Technical
Weather Discussion |
|
|
FXUS66 KMTR 100124
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
624 PM PDT Sat May 9 2026
...New AVIATION, MARINE...
.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
&&
.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...
(00Z TAFS)
Issued at 623 PM PDT Sat May 9 2026
The picture from space this evening looks similar to the past few
evenings as stratus clings to portions of our coastline and blankets
a good portion of the waters. MVFR to IFR cigs are being reported
from coastal Marin County to the southern portion of the Monterey
Bay. The marine layer is expected to be around 1000ft tonight, which
should sneak into most terminal sites. The question will be the
timing of it, with interior locations likely seeing low clouds after
9Z. Stratus will be mixed out by mid morning tomorrow for these
sites, while coastal terminals take a bit linger or remain locked
in. Coastal stratus brings IFR ceilings to HAF once again, staying
true to the May gray season. Moderate winds will persist through the
TAF period with local gusts reaching up to 18 kts. Cloud ceilings
are expected to lift by late Sunday morning to allow for some
sunlight to peak through.
Vicinity of SFO...Breezy westerly winds continue through at least
the early evening, with gusts of 18-22kt lasting through 8Z. The
trickier part of the forecast is once again the stratus.
Yesterday it was quite humbling as we struggled to identify its
behavior. Tonight we appear to be in a similar boat, but the feed
of stratus looks a bit more persistent. Will need to monitor this
for the 3Z update as it could be the difference of being locked
into MVFR cigs or not for the night. Confidence is high that we
will see MVFR cigs overnight and into tomorrow morning, while
confidence is low if we get another break in the clouds this
evening, between 3Z-6Z. Tomorrow, breezy westerly winds looks to
be on tap again. Add gusts to 22KT after 21Z through the period.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...IFR ceilings will continue to impact the
coast through the night with the stratus deck beginning to funnel
into the SNS airspace. Moderate onshore winds with a few embedded
gusts persist before easing overnight. High confidence that
widespread IFR ceilings will impact all terminals by 04Z Sunday and
remain until Sunday morning. Winds are expected to increase by the
late morning which will help lift and scatter out the remaining low
clouds coupled with diurnal heating. SNS is on the border of IFR-
LIFR ceilings tonight, though confidence is too low to determine if
it will dip below 500 feet. Will continue to monitor how expansive
and compressed the marine layer becomes through the evening.
&&
.MARINE...
(Tonight through next Friday)
Issued at 623 PM PDT Sat May 9 2026
Moderate seas and fresh to strong northwest breezes with
occasional near gale force gusts will continue through the
remainder of the weekend. 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 until 9 PM PDT this evening for Mry Bay.
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
MARINE...Kennedy
Visit us at www.weather.gov/sanfrancisco
Follow us on Facebook, X, and YouTube at:
www.facebook.com/nwsbayarea
x.com/nwsbayarea
www.youtube.com/nwsbayarea
Prepared by Boulder-Creek.com Weather at: Sat May 9 20:30:04 PDT 2026
|
|
From the National Weather
Service |
|
|
|
Copyright © 2002 All rights
reserved Boulder-Creek.com. |
|
Revised:
29 Mar 2008 09:53 -0800 GMT
(Pacific) |
|