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NWS Technical
Weather Discussion |
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FXUS66 KMTR 070018 AAA
AFDMTR
Area Forecast Discussion...UPDATED
National Weather Service San Francisco CA
418 PM PST Fri Mar 6 2026
...New AVIATION...
.KEY MESSAGES...
Updated at 152 PM PST Fri Mar 6 2026
- Breezy winds through Saturday
- Warm weekend with high temperatures 10 to 20 degrees above
normal
- Dry conditions through the extended forecast
&&
.SHORT TERM...
Issued at 150 PM PST Fri Mar 6 2026
(This evening through Saturday)
All focus remains on the warm up over the weekend. High pressure is
dominating the Eastern Pacific while an upper trough and cutoff low
linger across the desert Southwest and Southern California. This
pattern is having a two fold affect on the Bay Area and Central
Coast forecast. First is the broad area of high pressure over the
East Pacific. While typically a summertime pattern, it is having
summerlike influences on our early spring time. Under this pattern
we expect clear skies and warming conditions. This pattern also
sets up winds out of the North along the coast. When this happens
the area can experience coastal upwelling of cooler subsurface
water. In turn this can lead to sea/land breeze circulation as
well as some low clouds and fog to form in the lowest layers in
the late day and overnight hours. The surface high pressure is
being analyzed by the ocean prediction center at 1037 mb, which is
a decently stout high for March. The second item is that of the
upper trough/cutoff low. This is more of a wind steering items
than anything else. When this pattern sets up, adjacent to the
high pressure over the East Pacific, it takes the winds that would
normally come from the North and veers them toward the Northeast.
This means we can get a bit more offshore flow across the region.
Offshore winds can bring adiabatic warming (downsloping) for many
portions of the area.
This pattern over the weekend will bring the warmth that is
associated with a strong area of high pressure combine with offshore
winds will cause temperatures for Saturday and Sunday to run
anywhere from about 10-20 degrees above normal. Models typically
handle this pattern decently well, but can run a few degrees too
cool at times. Looking at the ensemble envelope we leaned more
towards the 75th percentile of the NBM, but did this with the NBM
EXP. The place that models do not handle well in this pattern is San
Francisco. This is for a few reasons, but the biggest is being a
small piece of land surrounded by water on three sides. We look at
wind direction carefully to give us an idea of what will happen in
SF during these pattern and Saturday morning (some degree Sunday
morning) will see winds at 925 mb from the Northeast at about 30
knots. So far models have been a little weak on the 925 winds. Even
so, with 30 knots and a coupled atmosphere, high temperatures for SF
on Saturday have a good probability (greater than 70%) of
exceeding 80 degrees in a few locations. No models will pick this
up and forecast was manually adjusted to account for this. The
piece to watch will the minimum temperatures for early Saturday
and Sunday morning. If we start near 60 degrees in SF, it is
almost a sure bet that SF will pop into the low to mid 80s. If we
do it again on Sunday morning, the pattern is similar enough that
we could pop again for a short time on Sunday.
Everyone else around the Bay Area, rest assured, you were not
forgotten. Numerical models handle your locations better than they
handle SF. In short, it's going to be a warm weekend.
&&
.LONG TERM...
Issued at 150 PM PST Fri Mar 6 2026
(Saturday night through next Thursday)
By the time we get late into the weekend and into early next week,
the pattern will shift. The stout high will retreat farther
offshore, the upper trough over the Southwest will pinch off into a
cutoff low over Northern Baja, and a bagginess in the jet stream
will start to encroach upon the Northern portions of our service
area. This will be short lived though as high pressure starts to
reassert itself during the middle of next week. Model really start
to diverge late next week with a few going back to a trough and
bringing the area a chance of rain and several others holding on to
the ridge and maintaining the string of sunny days. As we get
through the weekend we'll have more to say about late next week.
&&
.AVIATION...
(00Z TAFS)
Issued at 353 PM PST Fri Mar 6 2026
VFR is forecast to prevail with largely N'ly winds through the
TAF cycle. Wind gusts at or above 25 knots are forecast to subside
at KAPC and KSTS over the next 2-3 hours. While surface winds
will subside, they should remain elevated to mitigate LLWS, but
trends will be monitored for possible inclusion in future TAFs.
Through the day on Saturday, model guidance largely advertises 10
to 15 knot N'ly winds with some of the higher end guidance
suggesting 30 knot wind gusts after 21Z Saturday. For now, will
omit gusts given the low confidence for now.
Vicinity of SFO...VFR with WNW winds becoming N-NE'ly through the
TAF period. Speeds are anticipated to peak around 10-12 knots. A
gust or two above 20 knots cannot be ruled out, but limited
duration precludes mentioning in the current TAF. These N-NE'ly
winds will persist a little longer than usual, but speeds are
anticipated to remain low enough to mitigate any crosswind issues. The
LLWS potential appears minimal, but non-zero. For now, will omit
this from the TAF and monitor trends in profilers and model
guidance.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...Light northwesterly winds in the 3-6 kt
range are forecast this afternoon. In the evening and nighttime,
winds are expected to shift to an offshore direction maintaining
its speed. At the later end of the TAF period, there is some
potential for some high level clouds, though we still anticipate
VFR conditions to persist at both airports.
&&
.MARINE...
(Today through Wednesday)
Issued at 152 PM PST Fri Mar 6 2026
Hazardous conditions will continue through this evening due to
strong northerly breezes and rough to very rough seas. Frequent
gale force gusts are expected to continue across the northern
outer waters through this evening. Conditions will briefly improve
this weekend as northerly breezes diminish and seas subside, yet
hazardous conditions will linger for the northern outer waters. By
Monday, strong northerly breezes and rough to very rough seas
return.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 9 PM PST this evening for Pigeon Pt
to Pt Pinos 0-10 nm-Pt Arena to Pt Reyes 0-10 nm-Pt Pinos
to Pt Piedras Blancas 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.
Gale Warning until 3 AM PST Saturday for Pt Arena to Pt Reyes 10-
60 NM.
Small Craft Advisory until 3 AM PST Saturday for Pigeon Pt to Pt
Pinos 10-60 NM.
&&
$$
SHORT TERM...BFG
LONG TERM....BFG
AVIATION...Bain/AN
MARINE...RGass
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Prepared by Boulder-Creek.com Weather at: Fri Mar 6 18:30:03 PST 2026
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From the National Weather
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Revised:
29 Mar 2008 09:53 -0800 GMT
(Pacific) |
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