Technical NOAA Weather Discussion

FXUS66 KMTR 010451
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
951 PM PDT Tue Jun 30 2026

...New AVIATION, MARINE...

.KEY MESSAGES...
Updated at 1207 PM PDT Tue Jun 30 2026

 - Seasonably cool temperatures along with breezy afternoon winds 
   through Thursday.

 - Gradual warming trend returns Friday and Saturday with overall 
   pleasant holiday weekend weather.

&&

.SHORT TERM...
Issued at 1217 PM PDT Tue Jun 30 2026
(This evening through Wednesday night)

GOES-West visible imagery reveals the marine stratus blanketing 
much of the Pacific Coast from Sonoma south all the way through 
Monterey Counties. Communities inland, away from the influence of 
the stratus, are enjoying the abundance of June solar this 
afternoon with overall pleasant weather conditions. Temperatures 
this afternoon will max-out in the upper 50s to near 70 along the 
immediate Pacific coast, and warming to the 70s to 80s inland. Far
interior locations in Contra Costa and Monterey Counties will 
flirt with the 90-degree mark. With these forecast highs generally
running a few to several degrees below late June climatology, the
HeatRisk today is solidly low to minor (green to yellow).

The main synoptic driver for the West Coast over the last several
days has been a persistent long-wave trough that has sagged over 
the Rocky Mountains. This trough has brought unseasonably un- 
summerlike weather to parts of western North America. For us 
locally, the trough has helped reinforce the marine layer along 
the coast and as allowed for inland areas of California to remain 
comfortably cool for this time of year. The trough will hang 
around on Wednesday with similar temperatures for the coast while
inland locations cool by a few more degrees.

&&

.LONG TERM...
Issued at 1217 PM PDT Tue Jun 30 2026
(Thursday through next Monday)

The longwave trough will gradually weaken through second half of 
the week as zonal flow develops over the North Pacific. 
Temperatures will eventually respond to the rising heights with a 
gradual warming trend for central and northern California around 
Friday/Saturday. For those looking ahead to the holiday weekend, 
HeatRisk for the Bay Area and Central California Coast is forecast
to remain low (green) along the immediate coast and minor 
(yellow) inland. Traveling for the holiday weekend? Even the 
typical heat-prone areas of California such as the Central Valley 
and deserts are only forecast to have minor (yellow) to moderate 
(orange) HeatRisk.

Cluster analysis of the ensembles for next week are trying to 
pick-up on a West Coast ridge, but still observing many 
possible outcomes of varying strength and location. While the 
Climate Prediction Center does favor the likelihood of above- 
normal temperatures of us in the 8-14 day outlook (valid July 
7-13), they do keep the slight risk of extreme heat to the east 
of the Bay Area, focusing on the Great Basin and Desert Southwest.

&&

.AVIATION...
(06Z TAFS)
Issued at 950 PM PDT Tue Jun 30 2026

MVFR CIGs last along the coast and around the Monterey Bay. The 
breezy winds across the area will reduce into the night, becoming 
light to moderate. CIGs fall to IFR levels in the late night at MRY 
and along portions of the immediate coast, with some IFR CIGs 
forming at APC. Cloud cover erodes at APC in the mid morning with 
other sites seeing clearing in the late morning and early afternoon, 
leading to widespread VFR. Winds build again into Wednesday 
afternoon, but only to moderate to breezy levels.

Vicinity of SFO...VFR through the TAF period. Breezy west winds 
reduce into the night, and become light by the early morning as 
scattered low clouds move through the area. Cloud cover thins into 
the mid morning as winds become more moderate. Expect winds to 
increase further in the mid afternoon, peaking around 16 kts before 
become light again into the night. Wednesday night stratus is 
expected to get close to SFO once again. 

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...MVFR CIGs continue to affect the terminals 
this evening. MRY CIGS looks to fall to IFR levels in the early 
morning as winds continue to reduce. CIGs erodes in the late morning 
and early afternoon around the Monterey Bay as moderate winds build. 
There is still some uncertainity on the clearing at the immediate 
coast, a repeat of Tuesday is still possible.

&&

.MARINE...
(Tonight through next Monday)
Issued at 950 PM PDT Tue Jun 30 2026

Strong northerly winds continue for the northern outer waters
while weaker, yet still gusty winds affect the rest of the waters.
Frequent gale force gusts are expected across the northern outer
waters through Wednesday, a bit weaker winds for Thursday and
Friday. Moderate northerly to westerly breezes will prevail
elsewhere. Rough to very rough seas will continue through
Wednesday before abating to become moderate to rough Thursday into
Friday.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 3 AM PDT Thursday for Pigeon Pt to Pt 
     Pinos 10-60 NM-Pt Arena to Pt Reyes 0-10 nm.

     Small Craft Advisory until 9 AM PDT Wednesday for Pt Reyes to 
     Pigeon Pt 0-10 nm.

     Gale Warning until 3 AM PDT Thursday for Pt Arena to Pt Reyes 10-
     60 NM.

&&

$$

SHORT TERM...Rowe
LONG TERM....Rowe
AVIATION...Kidwell
MARINE...Murdock

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Prepared by Boulder-Creek.com Weather at: Tue Jun 30 22:30:03 PDT 2026
From the National Weather Service