Technical NOAA Weather Discussion

FXUS66 KMTR 141916
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1216 PM PDT Sat Mar 14 2026

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

.KEY MESSAGES...
Updated at 1205 PM PDT Sat Mar 14 2026

 - Above normal temperatures and Minor HeatRisk today

 - An early season, long duration heat wave will bring record
   breaking temperatures and Moderate HeatRisk through the week

 - Elevated potential for grass fires due to warm and dry
   conditions and periods of moderate offshore winds next week

&&

.SHORT TERM...
Issued at 1205 PM PDT Sat Mar 14 2026
(This evening through Sunday)

The combination of a shallow marine layer and weak, shortwave trough 
is keeping temperatures slightly cooler today. High temperatures 
across the interior will be in the 70s with the warmest locations 
(generally higher terrain) reaching the low 80s. Coastal 
temperatures are forecast to peak in the low to mid 60s. Low 
level clouds are currently clearing at a faster rate today than 
they were at this time yesterday. This is increasing confidence 
that temperatures for the coast will not need to be adjusted 
downwards to account for prolonged cloud cover like they were 
yesterday. A shallow (500 ft) marine layer is likely to redevelop 
again tonight along the coast before upper level ridging 
suppresses it next week. This will bring a low potential for fog 
along the coast tonight into early Sunday morning. High clouds 
are expected to move in across the region this afternoon and
continue into the overnight hours. Fog/low clouds are not 
expected to be widespread across the Bay Area overnight but there
may be some patchy instances of stratus/fog directly along the SF
Bay Shoreline. Overnight lows generally stay in the upper 40s to 
low 50s across.

&&

.LONG TERM...
Issued at 1205 PM PDT Sat Mar 14 2026
(Sunday night through next Friday)

Sunday marks the start of our heatwave with highs rising into the
mid to upper 80s across the interior and 60s to low 70s along the
coast. High clouds return overnight Saturday into Sunday which 
will keep afternoon temperatures a few degrees cooler than
forecast next week. On the synoptic scale, upper level ridging 
reaches the West Coast late Saturday/early Sunday and will build 
throughout the day on Sunday. This initially results in a 591 dam
upper level high centered just offshore of California. The center
of this high will slowly shift eastward Monday through Wednesday 
before strengthening to 594 dam (500 mb heights) and remaining 
almost stationary over the Southern California/Arizona border 
through late next week. 

The overall forecast for the upcoming heatwave with temperatures 
running 20-30 degrees above normal remains on track but there are a 
few changes to address. Initially, the warmest days were expected to 
be Monday through Wednesday but it now appears more likely that 
the warmest days will be Wednesday to Friday. This is largely a 
result of the ridge restrengthening mid to late next week and 
remaining nearly stationary (compared to earlier in the week) over
the desert southwest. The temperature difference between each day
is relatively small and each day will be within 1-3 degrees of 
each other. High temperatures will be in the upper 80s to mid 90s
across the interior and upper 70s to mid 80s along the coastline.
The hottest locations will be across interior Monterey and San 
Benito Counties, the Santa Cruz Mountains, the North Bay Interior 
Mountains, East Bay Hills, and potentially the southern Santa 
Clara Valley. Both daily records and potentially all time March 
records are still on the table Monday through Friday next week. 
Long range guidance suggests we could see these warmer 
temperatures extend into next weekend before we see some relief 
(still above normal but only by 10-15 degrees) the week after. 
There is the potential to break some upper air records at OAK this
week (namely 850 mb temperatures and potentially 500 mb heights).
Probabilistic guidance is showing the potential for portions of 
the higher elevations to reach the low 100s late next week. The 
most likely areas to break 100 would be the Gabilan Range but the 
NBM is showing a low (~10%) chance of portions of the Santa Cruz 
Mountains, the southern Santa Clara Valley (Gilroy/Hollister), 
and the East Bay Hills reaching 100 as well.

This is our first major heatwave of the year and it is going to be a 
marathon. We are primarily expecting Moderate HeatRisk with some 
relief overnight from overnight lows in the upper 50s to low 60s. 
There are patches of Major HeatRisk (impacts most people) in the 
higher elevations of the Santa Cruz Mountains and interior Central 
Coast next week. Given the long duration of this heat event, 
susceptibility to heat related illnesses will increase throughout 
the week. If you are going to be outside for prolonged periods of 
time make sure you are drinking plenty of water and allowing time to 
rest in the shade. Never leave people or pets unattended in the car. 
If possible, avoid going outside during the peak afternoon heat 
(approx. 10AM - 4/5PM). Heat Advisories will be in effect for much 
of the Bay Area and Central Coast Monday through Friday with some 
potential to expand into next weekend. 

Expect increased potential for grass fires next week as much above 
normal temperatures cure small, fine fuels (grass). Offshore winds 
will remain light to moderate which will help mitigate how much any 
fires that do develop can grow. If you are participating in any 
outdoor activities (camping, offroading, hiking, etc) exercise 
caution when using fire and be aware that the risk of grass fires 
will be elevated next week.

&&

.AVIATION...
(18Z TAFS)
Issued at 1027 AM PDT Sat Mar 14 2026

The last of any lingering stratus this morning is currently
in the process of lifting out with VFR expected to prevail 
through the remainder the day and evening hours. Northwest winds 
will be gusty at times this afternoon for terminals closer to the 
Pacific coastline.

Vicinity of SFO...VFR is expected to prevail through the forecast
period with a slight chance late in the TAF period Sunday morning
for MVFR vis/cigs, confidence is too low for mentioning in the 
TAF attm.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR is is expected to prevail for the
remainder of the day and evening with MVFR cigs possible later
tonight into early Sunday morning. Confidence is high that MVFR
cigs will develop between 10pm and midnight PDT.

&&

.MARINE...
(Today through Thursday)
Issued at 909 AM PDT Sat Mar 14 2026

Fresh to moderate north/northwest breezes will persist today and
tomorrow, with stronger winds resulting in steep fresh swell. Seas
and winds will ease across the inner waters by Sunday afternoon
followed by the outer waters on Monday. Expect calm conditions
through the remainder of the extended forecast.

&&

.CLIMATE...
Issued at 1205 PM PDT Sat Mar 14 2026

The following are the record high temperatures at the long term
sites for March 15th, 16th, 17th, and 18th.

Location 		 Mar 15      Mar 16      Mar 17      Mar 18

Santa Rosa       88 in 2004  91 in 2004  87 in 1996  84 in 2010
San Rafael       83 in 1972  87 in 1972  84 in 1972  80 in 1996
Kentfield        85 in 2004  86 in 2004  87 in 1914  89 in 1914
Napa             86 in 2004  88 in 2004  92 in 1914  87 in 1914
Richmond         85 in 2004  84 in 1972  83 in 2004  78 in 1996
Livermore        83 in 1972  88 in 1972  87 in 1972  86 in 2004
San Francisco    82 in 2004  85 in 1914  85 in 1914  86 in 1914
SFO Airport      81 in 2004  82 in 2004  82 in 2004  77 in 2004
Redwood City     84 in 2004  84 in 2004  85 in 2004  84 in 2004
Half Moon Bay    74 in 1974  78 in 1972  83 in 2004  75 in 1978
Oakland Museum   85 in 2004  85 in 2004  85 in 2004  81 in 2004
San Jose         82 in 2004  85 in 1914  88 in 1914  87 in 1914
Salinas Airport  83 in 1972  87 in 2004  87 in 2004  84 in 1960

&&

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

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

     Small Craft Advisory until 9 AM PDT Sunday for Pigeon Pt to Pt 
     Pinos 10-60 NM.

&&

$$

SHORT TERM...Kennedy
LONG TERM....Kennedy
AVIATION...JM
MARINE...JM

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Prepared by Boulder-Creek.com Weather at: Sat Mar 14 12:30:03 PDT 2026
From the National Weather Service