Technical NOAA Weather Discussion

FXUS66 KMTR 061859
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1059 AM PST Fri Feb 6 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 115 AM PST Fri Feb 6 2026

 - Hazardous beach conditions from swells through Saturday 
   evening at Pacific Coast beaches.

 - 20 to 40% chance of rain in the North Bay Sunday night.

 - Better chances for rain middle of next week.

&&

.SHORT TERM...
Issued at 115 AM PST Fri Feb 6 2026
(Today through Saturday)

Recent KMUX imagery shows scattered returns moving northward over
the Central Coast this morning. This is in response to mid level 
moisture moving northward along a passing upper level low that 
will travel southeastward over the ocean down the Central Coast 
today. No measurable precipitation is expected, but given that 
KMUX is getting some echos between 20-30 dBz, went ahead and threw
in mention of isolated sprinkles down the Big Sur coast for this 
morning. Regardless, the vast majority of the area will remain 
dry, with only an increase in cloud cover today. However, that 
increased cloud cover will help minimize any valley fog this 
morning. Temperatures are expected to still climb just slightly 
above seasonal norms today, but with the increased cloud cover and
cooler air moving in with the low, it should feel a little cooler
compared to recently.

Weak ridging is expected to return tonight and into Saturday. 
This should help clear some of the skies out tonight which may 
allow for radiational fog development in valley locations. 
Otherwise, the cooler airmass should provide similar temperatures 
on Saturday with highs in the 60s and upper 50s/low 60s along the 
coastline.

&&

.LONG TERM...
Issued at 115 AM PST Fri Feb 6 2026
(Saturday Night through Thursday)

The pattern begins to shift on Sunday. While the weak ridge will 
remain in place over Central California during the day on Sunday, 
a longwave trough in the northeast Pacific will begin to make it 
slow movement southward down the British Columbia coastline. This 
wave will eventually send a couple of shorter waves that can 
provide additional chances for rain through the middle of next 
week.

The first weak short wave is expected to eject away from this 
parent wave and move over the Pacific northwest Sunday evening. 
With the majority of ensemble members continuing to highlight the 
higher QPF in the Pacific northwest, blended PoPs were adjusted 
down for Sunday evening to confine the highest chances (20 to 40 
percent) to the North Bay. This left just a 15 to 20 percent 
chance that light rain makes it to the city of San Francisco with 
a less than 15 percent chance it makes it to the South Bay (and 
even then it probably would not reach the South Bay until around 
or after midnight). Regardless, the amount of rain is expected to 
be only a couple hundredths in the North Bay and less to the 
south.

Models are projecting a more stout shortwave trough to descend 
down the coastline Tuesday through Wednesday. Cluster analysis is 
highlighting that models are still struggling with the depth and 
track of the upper level trough. However, with increased moisture 
and better forcing, it looks like a better chance for rain across 
the forecast area. Higher coastal elevations could see over a 
quarter of an inch of rain, but inland areas could be impacted by 
the rain shadow and see much less. Lastly, a cooler air mass aloft
will accompany this trough, allowing for temperatures next week 
to return to more seasonable norms.

Once that trough passes there could be a break in the precip 
toward the end of next week. However, models are keeping an active
pattern aloft which may bring another rainy system to the area 
next weekend. It is still a little too early for the details, but 
something to certainly keep an eye on.

&&

.AVIATION...
(18Z TAFS)
Issued at 942 AM PST Fri Feb 6 2026

Currently skies are a mostly SKC with a few sites seeing FEW-SCT
at 9 kft or above. Winds AOB 10kts for most sites with VRB winds.
Surface high pressure is just beginning to build in from the 
west, turning some sites NW. This trend will continue, with most 
terminals seeing NW winds this afternoon and evening, remaining 
AOB 10kts. Satellite shows some stratus off shore this afternoon. 
As onshore winds continue into the evening, marine stratus will 
eventually advect inland tonight into early Saturday morning. 
MVFR/IFR cigs will impact most terminals, trending more IFR after 
12Z for North Bay and Bay Area terminals. Some chances for fog 
formation after 10Z over these terminals. Winds remain light, with
directions becoming VRB during this time. Impacts will linger 
through the end of the period for most sites. Zooming in on
North Bay Terminals; low clouds associated with the marine layer 
with high IFR / low MVFR ceilings move through the Petaluma Gap 
this evening, 01-03z Saturday. Clouds slowly progress into the 
North Bay Valleys through 06-08z with low to moderate confidence 
for patchy radiation fog to develop, generally after 11z, more 
likely around KSTS than KAPC, lowing visibility to 1/4-1SM 
locally. Visibility obscuration also expected where clouds meet 
terrain. Low clouds begin to retreat in the mid-morning Saturday.

Vicinity of SFO...High confidence VFR will persist through 06Z
with winds AOB 10kts. Onshore flow will eventually advect marine
stratus inland after 06Z. Times of MVFR cigs through 10Z until
skies become mostly OVC009. Some BR/FG possible from 12Z through
16Z, however vis should remain AOA 3SM. Winds remain light and
VRB. Moderate confidence impacts will linger through 20Z, then
skies should lift and scatter after. 


SFO Bridge Approach...Some lingering HZ around Bay Area is seen
this afternoon and could lower slant range visibilities near
sunset. Similar to SFO. 

Vicinity of SJC and OAK... Increasing confidence with MVFR stratus
moving in with onshore flow tonight and early Saturday morning.
Lower confidence in IFR impacts from cigs/vis, especially down the
Santa Clara Valley. Times for HZ/BR possible after 12Z, with vis
likely remaining AOA 4SM.


Monterey Bay Terminals... VFR through 00z Saturday. Low clouds with 
IFR/MVFR ceilings develop in the Monterey Bay and push onshore over 
coastal Monterey County (including KMRY and KSNS) around 01-03z this 
evening. Clouds gradually surge into the Salinas Valley tonight with 
low confidence for patchy fog formation (and visibility below 1SM) 
in the valley locally. Visibility obscuration also expected where
clouds meet terrain. Otherwise, mist from the marine layer could 
lower visibility to 4-6SM in coastal areas. Clouds begin to 
scatter out around 17z Saturday morning.

&&

.MARINE...
(Today through Wednesday)
Issued at 836 AM PST Fri Feb 6 2026

A light northwest wind will become more northerly this evening
into tomorrow. Northerly winds will increase in the Northern
Monterey Bay zone on Saturday morning, with seas then diminishing
into Saturday evening. A cold front moves southeastward over the 
coastal waters and bays gradually during the day Sunday and Sunday
night, resulting in an increase in north-northwesterly winds 
Monday and Tuesday.

&&

.BEACHES...
Issued at 247 AM PST Fri Feb 6 2026

A High Surf Advisory will be in effect beginning 4 AM PST today 
at all Pacific Coast beaches, the High Surf Advisory continues 
through 9 PM Saturday. Westerly swell will bring an increased risk
for sneaker waves and strong rip currents with breaking waves 17 to
22 feet.

Remember to stay off of jetties, piers, rocks, and other waterside
infrastructure, remain out of the water, and never turn your back
on the ocean!

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...High Surf Advisory until 9 PM PST Saturday for CAZ006-505-509-
     529-530.

PZ...Small Craft Advisory until 3 AM PST Saturday for Mry Bay-Pigeon 
     Pt to Pt Pinos 0-10 nm-Pt Arena to Pt Reyes 0-10 nm-Pt 
     Arena to Pt Reyes 10-60 NM-Pt Reyes to Pigeon Pt 0-10 nm.

     Small Craft Advisory until 9 AM PST Saturday for Pigeon Pt to Pt 
     Pinos 10-60 NM-Pt Pinos to Pt Piedras Blancas 0-10 nm.

&&

$$

SHORT TERM...DK
LONG TERM....DK
AVIATION...DeLizio/Westerink
MARINE...Camden

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Prepared by Boulder-Creek.com Weather at: Fri Feb 6 12:30:03 PST 2026
From the National Weather Service