FXUS66 KMTR 210950
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
150 AM PST Sat Feb 21 2026

...New SHORT TERM, LONG TERM...

.KEY MESSAGES...
Updated at 150 AM PST Sat Feb 21 2026

 - Cold to very cold conditions this morning

 - Unsettled weather with periods of rain and wind through the
   long term forecast period

&&

.SHORT TERM...
Issued at 150 AM PST Sat Feb 21 2026
(Today and tonight)

Surface high pressure across the Intermountain West will dominate 
our weather today. Clear skies and light winds are allowing for 
efficient radiational cooling on top of an already cold air mass. 
The 00z sounding observed an 850 millibar temperature of -1.35 
degrees Celsius which is below the tenth percentile (-0.5 degrees 
Celsius) for the date and time. Sensible weather wise this means it 
will be another cold to very cold start to the day with temperatures 
topping out below normal this afternoon. The combination of the 
aforementioned high pressure and a developing storm force low 
pressure system off the Pacific Northwest Coast will tighten the 
pressure gradient and yield strong southerly winds. Gusts up to 40 
mph are expected along the Pacific Coast and in the higher terrain. 
The proximity to the aforementioned low will allow for pre-frontal 
rain showers beginning this afternoon, primarily for the North Bay. 
Rates will be light with no adverse impacts expected. South of the 
Golden Gate Bridge can expect an increase in cloud cover and maybe 
some drizzle. Sunday will be very similar with the most notable 
difference being temperatures rebounding to near normal.

&&

.LONG TERM...
Issued at 150 AM PST Sat Feb 21 2026
(Sunday through Friday)

ECMWF and GEFS ensembles are in agreement of heights rising through 
the first half of Monday with upper-level ridging across the 
Intermountain West and upper-level troughing off the Pacific 
Northwest Coast. The ridge will get tamped down on Tuesday; however, 
there is great agreement that the region will remain under the 
influence of the ridge and its positive height anomalies. A surface 
low pressure system off the Pacific Northwest Coast will pull 
moisture in from the tropics Monday into Tuesday. ECMWF and GEFS IVT 
ensemble mean peaks near 500 kg/ms and weakens the system as it 
sinks south. Southwesterly flow (from the tropics) will allow for 
efficient rainfall due to the fetch of moist, warm air. As a result, 
southwest facing terrain will have the highest accumulation with the 
help of orographic lift with the lee side valleys experiencing the 
rain shadow effect. Confidence is high that the North Bay will see 
the highest rainfall totals. The trend continues to be our friend as 
it shifts northward, subsequently lowering rainfall totals and 
delaying the onset as it does so. As the forecast looks right now, 
the Monday night into Tuesday system will bring widespread rainfall. 
Minor flooding of low-lying, poor drainage, and urban areas will be 
possible with ponding and slick roadways likely. Mainstem river 
flooding is not expected with a low probability (less than 5%) of 
occurrence. If rain rates do end up being high enough with this 
system, shallow landslides will be possible. A warming and drying 
trend kicks off Wednesday after the cold frontal passage with 
temperatures climbing to 10 degrees above normal by Friday.

&&

.AVIATION...
(06Z TAFS)
Issued at 913 PM PST Fri Feb 20 2026

VFR is expected to prevail through the TAF period for all 
terminals with a colder, drier airmass moving over our area. 
Surface winds will generally be light most of the overnight then 
beginning to increase after sunrise Saturday morning. By Saturday 
afternoon, southerly wind gusts may be 20-25 knots at times. 

Vicinity of SFO...VFR with gusty southerly winds up to 20-25 knots 
by Saturday afternoon through the remainder of the TAF period.

SFO Bridge Approach...Similar SFO.

Monterey Bay Terminals...VFR through the TAF period with 
south/southwest winds gusts of 10-15 knots Saturday after sunrise 
with the potential for increasing to 20-25 knots at times by late 
Saturday afternoon and evening.

&&

.MARINE...
(Tonight through next Thursday)
Issued at 913 PM PST Fri Feb 20 2026

Expect fresh to moderate southerly breezes tonight and Saturday
morning with gale force gusts developing by Saturday afternoon,
especially across the northern waters. Rough to very rough seas
will persist from Saturday night into the beginning of next week.
Rain chances increase across northern waters tonight, becoming
more widespread across the northern waters by Saturday night, then
spread farther south by Sunday and Monday. Winds begin to ease by
the middle of next week.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Cold Weather Advisory until 9 AM PST this morning for CAZ504-506-
     510-513-515-528.

     Extreme Cold Warning until 9 AM PST this morning for CAZ514-
     516>518.

PZ...Small Craft Advisory from 3 PM this afternoon to 3 AM PST Sunday 
     for SF Bay N of Bay Bridge.

     Small Craft Advisory from 3 PM this afternoon to 9 PM PST this 
     evening for Mry Bay.

     Small Craft Advisory until 3 PM PST this afternoon for Pt Arena 
     to Pt Reyes 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.

     Gale Warning from 3 PM this afternoon to 3 AM PST Sunday for 
     Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 0-10 nm-
     Pt Reyes to Pigeon Pt 0-10 nm.

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

     Gale Warning from 3 PM this afternoon to 9 PM PST this evening 
     for Pigeon Pt to Pt Pinos 0-10 nm-Pt Pinos to Pt Piedras 
     Blancas 0-10 nm.

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

     Gale Warning until 3 AM PST Sunday for Pt Arena to Pt Reyes 10-
     60 NM.

&&

$$

SHORT TERM...Sarment
LONG TERM....Sarment
AVIATION...JM
MARINE...JM

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Prepared by Boulder-Creek.com Weather at: Sat Feb 21 02:30:03 PST 2026