Technical NOAA Weather Discussion

FXUS66 KMTR 041133
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
433 AM PDT Sat Apr 4 2026

...New AVIATION, MARINE...

.KEY MESSAGES...
Updated at 942 PM PDT Fri Apr 3 2026

 - Winds ease into the weekend

 - Warmer temperatures return Saturday and Sunday before a cooling
   trend begins next week

 - Beneficial rain chances increase mid to late next week

&&

.SHORT TERM...
Issued at 942 PM PDT Fri Apr 3 2026
(Tonight through Sunday)

The breezier winds of the day and eased and the ridge pattern is 
building. Winds remain weak through much of the weekend because of 
the ridge, with the overall surface pattern being light but 
widespread offshore flow. Overnight lows will be around 5 to 10 
degrees warmer than previous nights, with some high-level clouds 
helping to prevent extra radiational cooling.

Saturday's forecast has shifted slightly cooler in the most recent 
model updates. While highs will still be near records, the potential 
for record breaking temperatures have reduced. It seems like models 
are picking up on the higher-level cloud cover limiting the mid-day 
warming along with a reduction of the offshore winds.

Sunday sees clearing conditions, leading to that afternoon being the 
warmest of the forecast. Predicted highs look similar to previous 
forecast runs, with good chances for record high temperatures to 
fall.

&&

.LONG TERM...
Issued at 942 PM PDT Fri Apr 3 2026
(Sunday night through next Friday)

Luckily, this ridge pattern exits into the workweek preventing any 
threats of long lasting heat. The jet stream turns to more of a 
zonal flow by Monday, allowing for better onshore winds and a 
reforming marine layer. Coastal and Valley fog and status look to 
return Monday morning as a result of this pattern change. These 
factors will lead to notably cooler conditions, with a 5 to 10 
degree drop in highs. However these temperatures will still be above 
average for this time of year.

Temperatures slowly cool into the mid and late week as the onshore 
flow increases ahead of building trough and low pressure. Models are 
in fair agreement that rain returns to the area in the mid-week as 
this low moves along the coast. The models differ in the late-week 
path of this low, with some showing rain chances lingering into the 
weekend itself as the low loses momentum. The official forecast still 
has the low and its showers exiting Thursday night, but this will be 
something that could change in following forecast updates. What 
stays the same is that this still looks to be good chances for 
widespread light rain. Most areas will struggle to get past a few 
hundredths of an inch, while the highest amounts in the area (the 
Santa Lucias) are predicted stay below a half an inch.

&&

.AVIATION...
(12Z TAFS)
Issued at 429 AM PDT Sat Apr 4 2026

Offshore flow lingers and dry airmass remains (early look at 12z
Oakland sounding). Therefore, VFR conditions remain. High clouds
continue to stream overhead and will do so through the TAF period.
High confidence.

Vicinity of SFO...VFR. NE flow this AM then onshore by later
afternoon.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR.

&&

.MARINE...
(Today through Thursday)
Issued at 429 AM PDT Sat Apr 4 2026

High pressure off the Pacific Northwest coast and low pressure
along the California coast will maintain northerly flow this
weekend. Light to moderate northerly breezes will persist into
next week. A low pressure system over the Pacific will approach
the coastal waters and bays by the middle of next week bringing a
chance of rain, strong breezes, and moderate to rough seas.

&&

.CLIMATE...
Issued at 110 PM PDT Fri Apr 3 2026

The following are the record high temperatures at the long term 
stations for April 4th and April 5th.

Location          April 4th                April 5th 

Santa Rosa        88 in 1961               90 in 1939
Kentfield         85 in 1957               88 in 1924
San Rafael        86 in 1960               87 in 1957
Napa              86 in 1985, 1960         86 in 1989, 1957
Richmond          89 in 2011               83 in 1989
Livermore         87 in 1959               84 in 1989, 1916
San Francisco     84 in 1985               88 in 1989
SFO Airport       82 in 1985               84 in 1989
Redwood City      86 in 1960               87 in 1989
Half Moon Bay     77 in 2011               74 in 2016
Oakland Museum    85 in 1985               85 in 1989  
San Jose          87 in 1960               89 in 1989
Salinas Airport   86 in 1989, 1960, 1952   95 in 1989

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...None.
&&

$$

SHORT TERM...Murdock
LONG TERM....Murdock
AVIATION...JM
MARINE...JM

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Prepared by Boulder-Creek.com Weather at: Sat Apr 4 06:30:03 PDT 2026
From the National Weather Service