Technical NOAA Weather Discussion

FXUS66 KMTR 161202
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
402 AM PST Sun Nov 16 2025

...New AVIATION, MARINE...

.KEY MESSAGES...
Updated at 134 AM PST Sun Nov 16 2025

 - Light rain gradually diminishes across the southern Bay Area
   and Central Coast Sunday morning

 - Next system arrives late Sunday with a strong cold front, gusty
   winds, and moderate to heavy rain expected overnight. Slight
   chance of thunderstorms (20-25%) Sunday night into Monday.

 - Drier weather returns Tuesday-Wednesday before a weak,
   beneficial system passes through Thursday.

&&

.SHORT TERM...
Issued at 134 AM PST Sun Nov 16 2025
(Today and tonight)

Widespread light, stratiform rain continues across the southern Bay 
Area and Central Coast with around 0.5-1.0" having fallen with this 
system so far. Moderate rain will gradually become more scattered 
and lighten by mid to late morning as the cut-off low progress 
eastward. Showers will become more scattered by the afternoon as 
weak, shortwave ridging moves through but this is short lived as 
another, deeper, upper level trough moves in the Bay Area. This 
system is associated with a strong surface cold front which will 
bring moderate to heavy rain, potential for thunderstorms, and 
gusty winds ahead of it. 

Compared to Saturday, we can expected a more typical north to south 
progression of the rain band ahead of this cold front. Moderate to 
heavy rain will reach the North Bay Sunday evening before spreading 
into the Bay Area and Central Coast Sunday night into early Monday 
morning. The North Bay Mountains and Santa Cruz Mountains look to 
receive an additional 1-2" of rain Sunday night into Monday while 
the Santa Lucia Range receives an additional 2-3". For the rest of 
the Bay Area and Central Coast, totals will generally range from 0.5-
1.25" Sunday night into Monday. High resolution guidance is 
relatively consistent that a period of moderate to heavy rain will 
develop ahead of the cold front as it passes through the Bay 
Area/Central Coast. Nuisance flooding and rises in small 
creeks/streams are likely as this band passes through. Given the 
amount of rain the Bay Area and Central Coast has had over the last 
week, soils are either saturated or close to saturation which 
increases surface runoff and, consequentially, the risk of nuisance 
flooding. If you encounter flooding while driving or encounter a 
road closure due to flooding, do not attempt to drive through it 
instead find a different route. 

The other two impacts to consider this evening will be winds and 
thunderstorm potential. Winds will strengthen this evening and 
remain gusty overnight. Wind gusts will generally peak between 30 to 
35 mph with locally stronger gusts across the higher terrain and 
mountain gaps/passes (Altamont Pass region). As the main rain band 
and cold front pass through, it is possible that temporarily 
stronger gusts will develop. Winds will gradually diminish 
throughout the day on Monday after peaking overnight Sunday into 
Monday. Now for thunderstorm potential, thunderstorm potential 
increases late Sunday afternoon into the evening across the marine 
environment. The NBM is highlighting a 30-35% chance of 
thunderstorms across the northern waters Sunday evening/night with a 
20-25% chance of thunderstorms throughout the Bay Area/Central Coast 
Sunday night into Monday. The NAM shows a relatively unstable 
environment with 300-500 J/kg of MUCAPE and 700-500mb lapse rates 
between 7-8C/km. Thunderstorm potential peaks ahead of of cold 
frontal passage with chances diminishing to 10-15% by Monday 
morning. This is not to knock the chances of thunderstorms in the 
post-frontal environment but know chances are highest ahead of/with 
cold frontal passage.

&&

.LONG TERM...
Issued at 134 AM PST Sun Nov 16 2025
(Monday through Saturday)

Periods of moderate rain and a slight chance of thunderstorms 
continue through Monday morning as a deep upper level trough pushes 
through the West Coast. Rain and thunderstorm chances generally 
diminish Monday afternoon into the evening with rain to fully exit 
the region Monday night into Tuesday morning. Shortwave ridging will 
build in Tuesday to Wednesday which will allow us to dry out across 
the Bay Area and Central Coast. This will be short lived before 
another trough pushes into the West Coast late Wednesday and brings 
light rain Thursday and Friday. Precipitation totals for this event 
have trended downwards over the last few days with the center of the 
upper level trough now positioned further east/inland. This system 
is still several days out so continued fluctuations in precipitation 
are likely but, for now, this storm looks to produce light, largely 
beneficial rain fall across the region. Drier conditions return by 
mid to late Friday and continue into the weekend.

In the wake of Sunday-Monday's system a much cooler airmass will 
move into the region. This will keep temperatures in the upper 50s 
to low 60s and overnight lows in the low 40s. Tuesday and Wednesday 
look to be the coldest morning's with lows in the 30s across the 
interior Central Coast. Pockets of near freezing temperatures are 
small so no frost/freeze products are likely next week at this time. 
The combination of cooler temperatures and lingering moisture in the 
Central Coast may result in some snow flakes across the Santa Lucia 

&&

.AVIATION...
(12Z TAFS)
Issued at 340 AM PST Sun Nov 16 2025

Ongoing light rain across the South Bay and Central Coast will
gradually taper off over the next few hours. There will be a brief
reprieve in rain today before a stronger cold front brings another
round this evening. Winds will increase to a strong southerly 
breeze ahead of the front before shifting to westerly towards the
end of the TAF period as the front moves through. High resolution
guidance is indicating a narrow band of heavy rain showers with 
possible thunderstorms will push though around 06-09Z.

Vicinity of SFO...The light rain has pushed south with only a
small chance for an isolated shower in the short term. Ceilings
will remain high MVFR or low VFR through the day. The approaching
cold front will start to be felt around 00Z as southerly winds
start to increase. The rain should arrive by 03Z and will come in
showers. The heaviest band looks to be around 08Z with periods of
IFR visibility, strong gusts, and thunderstorms possible. After 
the front passes, winds will quickly shift back to the more 
standard WNW direction, but remain elevated through the night.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Still dealing with light rain for the
next few hours. Most of the daylight hours will be dry with MVFR 
ceilings and increasing southerly winds. The showers are scheduled
to arrive around 03Z and last through the end of the TAF period. 
The cold front should move through around 10Z, bringing a stronger
band of showers and shifting winds back to westerly.

&&

.MARINE...
(Today through Friday)
Issued at 340 AM PST Sun Nov 16 2025

Moderate southerly winds will gradually increase in strength
through the day before a cold front will bring widespread
hazardous marine conditions this evening. Winds will shift to a
strong NW breeze with occasional gale force gusts, very rough
seas, and poor visibility in heavy rain. There is also a good
chance for thunderstorms as the front moves through. Conditions
will improve Wednesday before very high WNW swell rolls in
Thursday night through Friday.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 9 AM this morning to 3 PM PST Monday 
     for SF Bay N of Bay Bridge.

     Small Craft Advisory from 9 AM this morning to 9 PM PST Monday 
     for Mry Bay-Pigeon Pt to Pt Pinos 0-10 nm.

     Small Craft Advisory from 3 PM this afternoon to 9 PM PST Monday 
     for Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 0-
     10 nm-Pt Arena to Pt Reyes 10-60 NM-Pt Pinos to Pt Piedras 
     Blancas 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.

&&

$$

SHORT TERM...Kennedy
LONG TERM....Kennedy
AVIATION...Flynn
MARINE...Flynn

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: Sun Nov 16 06:30:03 PST 2025
From the National Weather Service