384
FXUS66 KMTR 040351
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
851 PM PDT Mon Jun 3 2024

...New UPDATE...

.SYNOPSIS...
Issued at 1256 PM PDT Mon Jun 3 2024

Temperatures remain at or slightly below seasonal averages today.
Tomorrow sees a dramatic warmup with a Heat Advisory in effect for
the inland areas through Thursday. Temperatures will moderate
towards the latter part of the week.

&&

.UPDATE...
Issued at 851 PM PDT Mon Jun 3 2024

Today was the last "coolish" day of the week. Another cloudy
start this morning with a patchy marine layer, persistent onshore
flow, and filtered sunshine due to high clouds overhead, led to
another seasonably cool day. Max temps were generally 5 to 15
degrees below seasonal average or in the upper 50s to lower 70s
coast/bays and upper 60s to low 80s inland. Speaking of onshore
flow, the SFO-SAC exceeded 4mb again today. Onshore winds were
strong, but not as strong as yesterday. Peak gusts topped out in
the mid 40 mph range  - typical spots of gaps and passes.

For the rest of tonight - not update needed. The real question
tonight will be the extent of the marine layer. As noted by the
Aviation section below, the most favored location will be around
Monterey Bay and Big Sur Coast. Otherwise, as high pressure builds
in high clouds will continue to spill over the ridge.

Did made adjustments to overnight lows through midweek, especially
in the hills. The combination of hot daytime temperates and mild
overnight lows will exacerbate any HeatRisk concerns. For those
seeking relief by heading to the beach Wednesday and Thursday use
caution as building surf will lead to hazardous conditions. A
beach hazard statement is now in effect.

MM

&&

.SHORT TERM...
(This evening through Tuesday)
Issued at 1256 PM PDT Mon Jun 3 2024

The morning started pretty cloudy across the region as mid- to high
level clouds stemming from a cold front coming through the Pacific
Northwest came through the region. Several stations recorded coastal
and orographically forced drizzle this morning, but accumulations
topped out at a few hundredths of an inch. Current satellite imagery
is showing breaks in the cloud cover as the high clouds move away,
while as far as satellite imagery and observations show, lower
clouds linger mainly along the coast of western San Mateo County and
scattered throughout the coastal ranges. Breezy northwest winds will
continue today with winds gusting to 20 to 30 miles per hour at the
gaps and passes. Temperatures remain at or slightly below seasonal
averages, with highs ranging from the upper 50s to low 60s along the
coast, to the mid 60s to lower 70s at the Bayshore, and the mid 70s
to lower 80s in the inland valleys. Low temperatures will hover
between the low to mid 50s, with the upper 50s expected in the
inland portions of the North and East Bays.

Tuesday sees a pattern change as a ridge building in the eastern
pacific impacts our state. High temperatures will warm quite
dramatically with 10-20 degree increases expected across the region.
High temperatures on Tuesday will range from the mid 60s to lower
70s at the immediate coast, to the upper 70s to mid 80s along the
Bayshore, and in the 90s for the inland valleys with the warmest
locations reaching 100. A Heat Advisory comes into effect Tuesday
for the inland North Bay and East Bay, extending into Thursday.
Moderate HeatRisk (corresponding to a risk for heat-related
illnesses for sensitive populations, such as children, the elderly,
pregnant women, the ill, or those working outdoors) is expected for
most of the inland Bay Area and Central Coast, with patches of Major
HeatRisk (corresponding to a risk for heat-related illnesses for
most people without adequate cooling or hydration) for the North Bay
valleys. Here are some heat safety tips:

* Stay hydrated and drink plenty of fluids.
* Wear lightweight, light-colored clothing.
* Reduce time spent outdoors or stay in the shade.
* Never leave people or pets unattended in vehicles.
* Use sunscreen if going to the coast or the pool.

&&

.LONG TERM...
(Tuesday night through next Sunday)
Issued at 1256 PM PDT Mon Jun 3 2024

The heat event peaks on Wednesday with temperatures in the interior
expected to remain in the mid 90s to lower 100s, with highs in the
mid 60s to lower 70s expected at the coast. The Heat Advisory will
extend to the South Bay and the inland Central Coast on Wednesday.
The Southern Salinas Valley is now included in the second Heat
Advisory as confidence in heat impacts has grown.

Heat impacts will continue through Thursday, especially in the
interior where moderate HeatRisk continues through the day, but most
people should start to see a gradual cooldown as the ridge moves
towards the north and east, allowing a weak trough to impact our
region. A more noticeable cooldown begins on Friday, and by the
upcoming weekend, high temperatures are expected to moderate to the
mid 80s to lower 90s for the inland valleys and the upper 50s to mid
60s closer to the coast. CPC outlooks continue to show a lean
towards temperatures above seasonal averages into the middle part of
June.

&&

.AVIATION...
(00Z TAFS)
Issued at 445 PM PDT Mon Jun 3 2024

A mix of low and high clouds are spanning the Bay Area and Central
Coast this evening. Terminals north of the Monterey Bay are
expected to remain VFR through the TAF period, but there is a
small chance of MVFR stratus development at the favored
locations, particularly SFO. Otherwise the main story remains
strong NW winds in the afternoon, decreasing overnight and
returning Tuesday afternoon. LLWS was removed from all TAFs due to
a lack of reports last night and weaker winds aloft tonight.

Vicinity of SFO...Currently VFR with strong NW winds. Winds will
gradually decrease overnight. The VFR conditions are expected to
hold, though SFO has a 20% chance of developing an MVFR ceiling in
the early morning. OAK and SJC are less likely to be impacted by
any coastal stratus.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...After a brief improvement this afternoon,
stratus is starting to return this evening and will likely lower
to IFR or LIFR by early morning. The visibility may also drop, but
shouldn`t be the limiting issue due to moderate surface winds.

&&

.MARINE...
(Tonight through next Saturday)
Issued at 445 PM PDT Mon Jun 3 2024

A storm force low pressure system in the NE Pacific is centered
approximately 500 NM west of British Colombia. Meanwhile the
dominant feature locally is a ridge extending NE from subtropical
high pressure towards the Oregon coast. The gradient between this
high pressure and lower pressure over Arizona is supporting a
fresh to strong NW breeze this evening. Over the next 48 hours,
conditions will gradually worsen as the high pressure pushes
closer to the coast, tightening the gradient. While the winds are
increasing to a strong breeze on Tuesday, large NW swell from the
storm force low will also arrive in the coastal waters. Conditions
will gradually improve going into the weekend.

&&

.CLIMATE...
Issued at 127 AM PDT Sat Jun 1 2024

Record high temperatures at the long term climate stations for
June 4th and 5th:

Station             June 4th             June 5th

Santa Rosa          98 in 1949           102 in 1926
Kentfield          101 in 1981           102 in 1926
Napa               102 in 1981           105 in 1903
Richmond            90 in 1955            86 in 1983
Livermore          105 in 1960           104 in 1926
San Francisco       92 in 1949            95 in 1883
SFO Airport         92 in 1955, 1949      89 in 1972
Redwood City       100 in 1981            97 in 2002, 1972
Half Moon Bay       71 in 1955            74 in 1958
Oakland downtown    96 in 1981            87 in 2002
San Jose            98 in 1904           100 in 1926
Salinas Airport     92 in 1949            87 in 1949
King City          102 in 1981, 1957     105 in 1926

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement from Wednesday morning through Thursday
     evening for CAZ006-505-509-530.

     Heat Advisory from 8 AM Tuesday to midnight PDT Thursday night
     for CAZ503-504-506-510-515.

     Heat Advisory from 8 AM Wednesday to midnight PDT Thursday night
     for CAZ513-514-516-518.

PZ...Small Craft Advisory from 3 PM to 9 PM PDT Tuesday for Mry Bay-
     SF Bay N of Bay Bridge.

     Small Craft Advisory until 9 PM PDT this evening for Mry Bay.

     Small Craft Advisory until 9 AM PDT Wednesday for Pigeon Pt to
     Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 0-10 nm-Pt Arena to
     Pt Reyes 10-60 NM-Pt Pinos to Pt Piedras Blancas 0-10 nm.

     Small Craft Advisory until 3 AM PDT Tuesday for Pigeon Pt to Pt
     Pinos 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.

     Small Craft Advisory from 9 AM Tuesday to 3 AM PDT Wednesday for
     Pigeon Pt to Pt Pinos 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.

&&

$$

SHORT TERM...Canepa
LONG TERM....Canepa
AVIATION...Flynn
MARINE...Flynn

Visit us at www.weather.gov/sanfrancisco

Follow us on Facebook, Twitter, and YouTube at:
www.facebook.com/nwsbayarea
www.twitter.com/nwsbayarea
www.youtube.com/nwsbayarea