Technical NOAA Weather Discussion

FXUS66 KMTR 290453
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
953 PM PDT Sat Mar 28 2026

...New AVIATION, MARINE...

.KEY MESSAGES...
Updated at 1212 PM PDT Sat Mar 28 2026

 - Above normal temperatures over the weekend

 - Cooler conditions return Monday with beneficial, light rain 
   Tuesday through Thursday

&&

.SHORT TERM...
Issued at 1212 PM PDT Sat Mar 28 2026
(This evening through Sunday)

The 12Z sounding observed an 850 millibar temperature of 14.15 
degrees Celsius which is above the 90th percentile (13.5 degrees 
Celsius) for the date and time. This warm air mass will result in 
above normal temperatures that will contend with daily high 
temperature records this weekend. Stratus that was advected via a 
southerly surge is beginning to pull back to the coast where it is 
expected to stay throughout the day. The shallow marine layer of 500 
feet will likely undergo further compression as southerly flow veers 
to become northerly, promoting dry northerly flow. Stratus and 
patchy fog is expected to return to coastal locations tonight.

&&

.LONG TERM...
Issued at 1212 PM PDT Sat Mar 28 2026
(Sunday night through next Friday)

A passing upper-level shortwave trough and its associated dying cold 
front will encroach from the northwest Monday. This will crack the 
storm door open. Unfortunately, we will be far removed from the 
parent system in the Northern Great Plains; thus, only cooler 
conditions and wind are expected in the absence of rainfall. A gale 
force low pressure system in the Gulf of Alaska will head towards 
the Pacific Northwest on Tuesday. As it does so, it will pull in 
tropical moisture from the Northwestern Pacific Ocean that will 
overtop strong high pressure centered in the Northern Pacific Ocean. 
The strength of the aforementioned low will allow it to cut through 
the aforementioned high, renewing our chances for rainfall. The 
associated cold front will pass Wednesday into Thursday, bringing 
beneficial, light rainfall to the North Bay and locations along the 
bayshore and Pacific Coast. Interior higher terrain may get 
measurable rainfall with the help of orographic lift, otherwise the 
interior will remain dry. To put the month of March's precipitation 
into context we'll use San Francisco Downtown as an example. It has 
not rained there since March 2nd. If it rains on Tuesday, it'll tie 
1923 for the longest dry stretch in March. 1923 is the driest March 
on record with 0.03", 2026 is the second driest on record so far 
with 0.06". Surface high pressure will nose in from the Eastern 
Pacific Ocean on Friday, rebounding temperatures near to slightly 
above normal.

&&

.AVIATION...
(06Z TAFS)
Issued at 952 PM PDT Sat Mar 28 2026

VFR with a few high clouds across the region. Gentle onshore winds 
will diminish to light winds through Sunday morning. A shallow 
marine layer results in a moderate confidence for IFR-LIFR stratus 
overnight across the immediate coastal region, with patchy fog 
possible, especially at HAF. At STS, low probability and confidence 
for LIFR-IFR conditions early Sunday morning. Elsewhere, VFR 
conditions prevail through Sunday with breezy onshore flow resuming 
in the afternoon, with high resolution model data depicting stratus 
retreating away from the Bay Area coastline. 

Vicinity of SFO... VFR with thin high clouds through the TAF period. 
Gentle west-northwest winds gradually diminish through the next 
couple of hours with light winds Sunday morning, before the breezy 
west-northwest winds resume during the afternoon. Confidence in 
stratus impacts tonight, already low to very low, has decreased at 
the terminal, as well as to the east including at OAK.

SFO Bridge Approach... Similar to SFO.

Monterey Bay Terminals... The stratus layer has not developed as 
robustly across the region as the earlier forecast had expected. 
Thus, confidence in stratus impacts tonight has decreased, and some 
model output suggests that MRY could remain VFR overnight. A 
compressing marine layer also results in the possibility of the 
stratus dissipating early, especially at MRY where some offshore 
flow could contribute to clearing. Any stratus that does develop in 
the region should clear late Sunday morning with breezy northwest 
winds resuming in the afternoon. Stratus return is considered 
unlikely on Sunday night through Monday morning.

&&

.MARINE...
(Tonight through next Friday)
Issued at 952 PM PDT Sat Mar 28 2026

Hazardous conditions for small craft persist across the northern
outer waters due to moderate to fresh northerly breezes. This
spreads into the inner waters and the rest of the outer waters on
Sunday, when infrequent strong gusts are expected. Moderate
northwesterly breezes on Tuesday will back to become southerly by
Wednesday. Light rain returns Tuesday and Wednesday. Moderate seas
will prevail through Thursday.

&&

.CLIMATE...
Issued at 952 PM PDT Sat Mar 28 2026

Here are the record high temperatures at the long term sites for
March 29th.

Location          March 29th

Santa Rosa        86 in 2018
San Rafael        85 in 2018
Kentfield         84 in 1935
Napa              83 in 2018, 1968
Richmond          79 in 1968
Livermore         85 in 2015
San Francisco     81 in 2018
SFO Airport       81 in 2018
Redwood City      85 in 2018, 1968
Half Moon Bay     77 in 2004
Oakland           79 in 2003
San Jose          82 in 2018
Salinas Airport   86 in 2018

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 3 PM to 9 PM PDT Sunday for Pt Arena 
     to Pt Reyes 0-10 nm.

     Small Craft Advisory until 9 PM PDT Sunday for Pt Arena to Pt 
     Reyes 10-60 NM.

&&

$$

SHORT TERM...Sarment
LONG TERM....Sarment
AVIATION...DialH
MARINE...DialH

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Prepared by Boulder-Creek.com Weather at: Sat Mar 28 22:30:03 PDT 2026
From the National Weather Service