Technical NOAA Weather Discussion

FXUS66 KMTR 281725
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1025 AM PDT Sat Mar 28 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 1010 AM PDT Fri Mar 27 2026

 - Above normal temperatures continue through the weekend

 - Beneficial rain possible next week

&&

.SHORT TERM...
Issued at 1210 AM PDT Sat Mar 28 2026 
(Tonight through Sunday)

The longwave pattern over the region is mostly zonal flow aloft
with a few embedded ripples, which are discernible on water vapor
imagery. At the surface we're seeing a pattern shift. High
pressure over the Great Basin and troughiness at the coast led to
notable offshore flow yesterday. That has since faded as the 
surface high weakened and began to shift eastward toward the
Plains. A quick look at the satellite fog product shows the 
fading offshore flow is being replaced by a slow advancing 
southerly surge. Low clouds and fog are slowly oozing northward 
toward along the Big Sur coast. Hi-res WRF/HRRR/HREF guidance 
bring the surge northward initially to Monterey Bay and then
farther northward up the coast by mid to late morning. The surge
of clouds are predicted to hug the coast for most of the day
today. The cooler marine influence will keep coastal areas in 
check temp wise, but move a few miles inland and it will be much 
warmer with highs int he 70s and 80s. Those highs will be 10-15 
degrees above normal with a few climate sites make a run at 
records again. 

Tonight through Sunday...Shallow marine layer will hug the coast
and nose its way inland Saturday night. Given the compressed 
nature some patchy fog will be possible along the coast. Expect 
clouds/fog to linger through Sunday morning. Stronger northerly 
flow ramps up through the day Sunday with a hint of offshore flow.
As such, the marine layer clouds will dissipate and be most 
prevalent along the Central Coast. No big change in the airmass on
Sunday and less marine influence will actually lead to warmer 
temperatures around the region. Temps will be 70s and 80s with a 
few interior Central Coast spots making a run for 90. Goes with 
out saying, a few records may fall.

&&

.LONG TERM...
Issued at 1210 AM PDT Sat Mar 28 2026 
(Sunday night through next Friday)

To kick off the work week we'll begin to see a more noticeable
change in the overall sensible weather. The persistent ridge of
high pressure will get knocked down first by a weak upper level 
disturbance moving through the PacNW and much more robust upper 
trough deepening over the region by mid-week. Temperatures will 
initially drop by 5 to 10 degrees from Sunday to Monday. Despite 
the drop forecast highs on Monday are still a few above normal. 
Further cooling is expected through out the week with near normal
or seasonably cool temperatures by Wednesday. While the drop in 
temps will be welcomed sight for some much for was is being put 
on rain chances. So will it rain midweek? Previous model runs were
kinda split in two camps: one a deeper trough with more direction
impact over Central CA or less deepening of the trough and more 
impact northward. If you're looking for precip the trend isn't 
your and tonight's model trend is drier. The developing upper 
trough midweek is looking more like an inside slider with less 
"down the coast" trajectory. We were also monitoring a decent 
tropical moisture plume/tap as well. Sadly, this plume does take a
Central Coast path, but quickly gets shunted southward as the 
inside slider moves through. While rain falls amounts have lowered
we haven't completely removed rain just yet. Current forecast 
still brings light rain back to the region on Tuesday with more 
widespread/steadier rain Wednesday into Thursday. Now for the 
rainfall amounts: Interior Central Coast and far E Bay nothing to 
a trace/0.01", coast, North Bay, and Bay Area a few hundredths, 
and coastal mts up to 0.25"

&&

.AVIATION...
(18Z TAFS)
Issued at 1023 AM PDT Sat Mar 28 2026

A shallow marine layer around 500 feet in depth resulted in 
stratus along the coast with KHAF reporting LIFR conditions since 
about 12Z. This also resulted in brief LIFR/IFR conditions around 
KSNS and KMRY around the same time. Expecting VFR conditions 
primarily throughout the day with an increase in onshore winds by 
this afternoon. Winds ease late this evening and into Sunday 
morning with a moderate confidence for sub-VFR conditions late 
this evening and early Sunday morning around the aforementioned 
TAF sites. Elsewhere, moderate to high confidence for VFR 
conditions to persist through the TAF period. The one exception is
KSTS where there is a low probability for LIFR/IFR to return 
early Sunday morning. 

Vicinity of SFO...VFR. Breezy onshore winds increase this 
afternoon before easing late this evening/overnight.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR throughout much of the day with an 
increase of onshore winds by this afternoon. Moderate confidence 
for LIFR/IFR ceilings to return late this evening at KMRY and 
early Sunday morning at KSNS. However, lower confidence in how 
long they will persist as the marine layer is forecast to compress
into Sunday morning. 

&&

.MARINE...
(Today through Thursday)
Issued at 439 AM PDT Sat Mar 28 2026

Moderate to fresh northerly winds continue with localized strong 
gusts and moderate seas across the northern outer water. Light 
rain is possible early to midweek as upper level troughing returns
with winds becoming more westerly to southerly. Strong to near 
gale force gusts are expected late Thursday into the weekend. Seas
build late Thursday into Friday with significant wave heights 
between 10 to 12 feet expected across the outer waters.

&&

.CLIMATE...
Issued at 717 AM PDT Sat Mar 28 2026

Here are the record high temperatures at the long term sites for
March 28th and March 29th.

Location          March 28th          March 29th

Santa Rosa        85 in 1923          86 in 2018
San Rafael        81 in 2018          85 in 2018
Kentfield         91 in 1923          84 in 1935
Napa              83 in 2015          83 in 2018, 1968
Richmond          81 in 1969          79 in 1968
Livermore         82 in 2015          85 in 2015
San Francisco     81 in 1986          81 in 2018
SFO Airport       77 in 2018          81 in 2018
Redwood City      81 in 2018          85 in 2018, 1968
Half Moon Bay     79 in 1968          77 in 2004
Oakland           79 in 2015          79 in 2003
San Jose          84 in 1923          82 in 2018
Salinas Airport   84 in 2004          86 in 2018

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 3 PM PDT Sunday for Pt Arena to Pt 
     Reyes 10-60 NM.

&&

$$

SHORT TERM...MM
LONG TERM....MM
AVIATION...RGass
MARINE...Sarment

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Prepared by Boulder-Creek.com Weather at: Sat Mar 28 10:30:03 PDT 2026
From the National Weather Service