FXUS66 KMTR 141000
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
300 AM PDT Wed Oct 14 2026

...New MARINE...

.KEY MESSAGES...
Updated at 1216 AM PDT Wed Oct 14 2026

 - Warming trend continues through the end of the work week with
   above normal temperatures peaking Friday

 - Coastal Flooding Advisory remains in effect through 4 PM today
   for bayshore locations along the San Pablo Bay

 - Elevated fire weather conditions due to moderate offshore flow
   and very dry conditions across the higher elevations mid to
   late week

&&

.SHORT TERM...
Issued at 1216 AM PDT Wed Oct 14 2026
(Today and tonight)

Upper level troughing continues to progress eastward with ridging 
building just to our west over the Pacific Ocean. The warming trend 
becomes more noticeable on Wednesday as ridging starts to push 
inland and becomes the dominate force across our region. High 
temperatures will be more seasonable in the upper 70s to low 80s 
across the interior and 60s along the coastline. Morning low 
temperatures will remain slightly chillier in the 40s to  50s 
Wednesday morning and Thursday morning. Temperatures continue to 
warm on Thursday with highs reaching into the 80s to low 90s across 
the interior (5-10 degrees above normal) and 60s to 70s along the 
coast. Little to no cloud cover is expected overnight with upper 
level ridging keeping the marine layer mixed out. This in turn is 
creating much drier daytime and overnight conditions, particularly 
across the higher elevations. 

Our main concern for the upcoming week continues to be the potential 
for multiple rounds of offshore winds in the overnight through late 
morning hours with emphasis on the North Bay Interior Mountains. In 
the short term, offshore winds are expected Tuesday night into 
Wednesday but they are expected to be weaker than what is expected 
Thursday into Friday. The SFO-WMC pressure gradient shows it peaking 
around -3 to -4 mb overnight tonight into Wednesday. This is a 
fairly weak gradient with offshore winds not anticipated to be too 
strong tonight and gusts peak around 20 mph for the North Bay 
Interior Mountains tonight. The story is a little different heading 
into Wednesday. The SFO-WMC gradient initially starts out fairly 
weak (-3 to -4 mb) but it looks to strengthen to -8 to -9 mb by late 
Thursday morning. This indicates more moderate offshore winds are 
likely across the North Bay Interior Mountains with gusts between 30 
to 35 mph likely. Why the changeup? To explain, we go back to our 
synoptic setup. As the trough exits to our east, a part of it splits 
off from the jet stream and becomes a cut-off low that gradually 
retrogrades back towards the Desert Southwest Wednesday night into 
Thursday morning. As the cut-off low settles over Southern 
California, it will force the upper level ridging over Northern 
California to take on a more positive tilt (northeast to southwest 
orientation) which is more conducive for offshore flow across the 
region. The combination of strengthening offshore winds Thursday and 
dry daytime/overnight conditions will result in elevated fire 
weather concerns for the higher elevations with emphasis on the 
North Bay Interior Mountains. Elevated fire weather concerns will 
continue through Friday with further discussion in the Long Term.

&&

.LONG TERM...
Issued at 1216 AM PDT Wed Oct 14 2026
(Thursday through Tuesday)

Moderate offshore flow continues across the higher elevations
Thursday afternoon through Friday morning with the SFO-WMC 
gradient peaking around -10 to -11 mb Thursday night into Friday 
morning. The NAM suggests further strengthening to -12 to -13 mb 
is possible which could support stronger gusts than outlined in 
the short term (currently forecast peak gusts of 30 to 40 mph). 
The driest conditions are expected overnight Thursday into Friday 
with overnight RH recoveries only reaching 25-35% across the 
highest elevations and daytime RH values dropping back into the 
10s to 20s. Winds gradually diminish late morning into the 
afternoon as the pressure gradient relaxes. Elevated fire weather 
conditions continue for the higher elevations through Friday with 
conditions improving as winds decrease. If you are participating 
in any activity involving fire be very cautious and make sure 
sparks/flames do not escape as fuels are incredibly dry and ready 
to go.

High temperatures peak Friday in the 80s to low 90s with patches of 
upper 90s across the higher elevations and southern Santa Clara 
Valley. Temperatures cool slightly into the 80s by Saturday with 
only a few hot spots reaching the low 90s as the ridge relaxes and 
troughing becomes more dominant. The cut-off low will then merge 
with the jet stream and result in widespread troughing across the 
West Coast late weekend into early next week. As this trough pushes 
inland it will bring us our first weak storm system of the season. 
Initial guidance shows a weak cold front passing through California 
early next week that will bring both a return of below normal 
temperatures in the 60s to low 70s, a chance for light rain, and 
gusty onshore winds. Fall mornings return as well with morning lows 
dropping back into the 40s again late weekend into early next week. 
Initial guidance suggests a more widespread potential for light rain 
(up to a few tenths of an inch) early to mid next week. Onshore 
winds ramp up along the coast and across mountain gaps/passes Sunday 
into mid next week. The current forecast does not currently meet 
Wind Advisory criteria but it is something to keep an eye on as this 
system approaches given the stronger winds already associated with 
it.

&&

.AVIATION...
(06Z TAFS)
Issued at 959 PM PDT Tue Oct 13 2026

Generally VFR conditions prevail through the TAF period, with some 
high resolution models depicting patchy coastal stratus developing 
Wednesday night. Low confidence in model output that shows HAF 
getting fig and low stratus tonight into Wednesday morning. If it 
does happen, the most likely period for development would be 12-16Z. 
Light to gentle winds persist through Wednesday morning before the 
onshore winds resume in the afternoon.

Vicinity of SFO... VFR at the terminal through the TAF period. Light 
winds will continue overnight into Wednesday morning before moderate 
northwest winds resume in the afternoon.

SFO Bridge Approach... Similar to SFO. 

Monterey Bay Terminals... Moderate to high confidence of VFR through 
the TAF period, with low confidence in model output that depicts 
stratus returning to the terminals Wednesday evening. Light drainage 
winds persist overnight into Wednesday morning before gentle to 
moderate northwest winds resume in the afternoon. 

&&

.MARINE...
(Today through Monday)
Issued at 259 AM PDT Wed Oct 14 2026

Seas will continue to subside today with moderate seas expected
for the offshore zones through the week while nearshore waters
observe moderate to slight seas. During this time frame gentle to
fresh northerly breezes persist. Moderate to fresh northerly winds
return for the weekend, which should lead to rough seas.

&&

.FIRE WEATHER...
Issued at 320 PM PDT Tue Oct 13 2026

Periods of gusty offshore winds will develop the overnight and 
into the early morning hours the next several nights. At this
point in time, the upper level support is marginal at best, but it
is there. Therefore, expect primary gusts of 25 to 35 mph possible
across the interior North Bay Mountains. Some of the favored
exposed ridges, gaps, and passes could see some locally higher
gusts up to 40 mph. With each burst of offshore winds, overnight 
humidity recoveries will become more poor, with widespread poor 
to moderate recoveries possible. Therefore, elevated fire weather 
conditions will be a concern the next several days. Remember, be one
less spark if you are needing to do outside work.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Coastal Flood Advisory until 4 PM PDT this afternoon for CAZ506.

PZ...None.
&&

$$

SHORT TERM...Kennedy
LONG TERM....Kennedy
AVIATION...DialH
MARINE...KR

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: Wed Oct 14 04:30:04 PDT 2026