FXUS66 KMTR 171122
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
322 AM PST Mon Nov 17 2025

...New AVIATION, MARINE...

.KEY MESSAGES...
Updated at 1218 AM PST Mon Nov 17 2025

 - A strong cold front is moving through early Monday morning,
   bringing heavy rain, strong winds, and a small chance for
   waterspouts.

 - Scattered showers will gradually decrease through Monday before
   drier weather returns Tuesday.

 - Next system brings more beneficial type rain late Wednesday
   through Thursday.

&&

.SHORT TERM...
Issued at 1218 AM PST Mon Nov 17 2025
(Today and tonight)

Full scale warning operations on the watchfloor as the cold front
comes ashore. Several cells over the coastal waters have 
displayed rotational velocity of 30kts, indicating a legitimate 
waterspout potential. Fortunately the trend has been for these 
cells to lose structure as they come ashore, but we can't rule out
our classic landfalling waterspouts causing some damage along the
coast from San Mateo to Monterey County over the next several 
hours. While narrow and fast moving, the main band of rain has 
been intense, with a weather spotter in Marin reporting over six 
tenths of an inch in less than an hour. These high rain rates
could cause some land slides, especially after the recent wet 
weather. This threat is highest over the Pickett Burn Scar, where
a flash flood warning is in effect. Winds have been gusting to 
gale force and quickly diminishing after the frontal boundary 
passes. In the post frontal environment the rain will transition 
to lighter scattered showers and persist through the day on a 
decreasing trend before drier weather moves in overnight.

&&

.LONG TERM...
Issued at 1218 AM PST Mon Nov 17 2025
(Tuesday through Sunday)

In the wake of todays exiting system to the south we'll see 
progressive, high amplitude ridging move across central California 
Tuesday and Wednesday resulting in drier conditions while 
temperatures remain cooler than normal. Tuesday will be mostly sunny 
area wide, with gradually increasing cloud cover on Wednesday. The 
remainder of the extended forecast lacks consensus for the timing 
and evolution of what appears to be a similar type storm system that 
we saw overnight and today. Rain chances begin to increase across 
the North Bay Wednesday evening, spreading across our whole area 
during the day Thursday, and exiting to the south by early Friday 
morning. Rainfall totals and winds will not be as strong as we've 
seen the last 24hrs, however the saturated soils may bring more 
risks for land/rock slides. Very high surf looks likely late
Thursday and Friday. Next weekend looks mostly dry attm, with a 
signal for another upper level low bringing increasing rain 
chances early next week.

&&

.AVIATION...
(12Z TAFS)
Issued at 322 AM PST Mon Nov 17 2025

A very difficult forecast for the upcoming TAF period as a surface 
low or series of lows moves through the region. The wind pattern, in 
particular, depends critically on the strength, location and track 
of the low with cyclonic effects expected across the region. In 
addition, the current winds are much lighter than what the high 
resolution models depicted. Thus, confidence in the wind forecasts 
is low to very low, and interests should monitor TAF updates as the 
low's evolution is refined. Ceilings remain generally MVFR to VFR 
with mid-level clouds through Monday night at least, some clearing 
is possible early Tuesday morning. Chances for showers also persist 
through the day with the low pressure moving south. Thunderstorms 
remain possible, but confidence in timing or location is too low to 
include in the TAFs.

Vicinity of SFO... MVFR to VFR with mid-level ceilings through the 
TAF period. Showers and a chance of thunderstorms persist through 
the late evening-early overnight period. The winds will be rather 
gusty, but very low confidence on wind direction, especially after 
3Z as a surface low approaches the terminal.

SFO Bridge Approach... Similar to SFO.

Monterey Bay Terminals... MVFR ceilings and a chance of showers 
through the TAF period. Winds are hard to pin down owing to the 
surface low passing through, but expect an 

&&

.MARINE...
(Today through Saturday)
Issued at 322 AM PST Mon Nov 17 2025

A cold front moved through the coastal waters overnight bringing
widespread gale force gusts. The winds have since shifted to a
moderate westerly breeze. Winds will continue to shift and
increase to a strong NW breeze through the day, building rough
seas across the coastal waters. Strong winds and rough seas will
persist through Tuesday before conditions improve for a short
window Wednesday through Thursday. A very high WNW swell will
arrive late Thursday into Friday.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 9 PM PST this evening for Mry Bay-
     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-SF Bay N of Bay Bridge.

     Small Craft Advisory until 3 AM PST Wednesday for Pt Arena to Pt 
     Reyes 10-60 NM.

     Small Craft Advisory until 3 PM PST Tuesday for Pigeon Pt to Pt 
     Pinos 10-60 NM.

&&

$$

SHORT TERM...Flynn
LONG TERM....JM
AVIATION...DialH
MARINE...Flynn

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Prepared by Boulder-Creek.com Weather at: Mon Nov 17 04:30:03 PST 2025