066
FXUS66 KMTR 050015
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
515 PM PDT Tue Jun 4 2024

...New AVIATION, MARINE...

.SYNOPSIS...
Issued at 1230 PM PDT Tue Jun 4 2024

Heat to continue through midweek as the ridge strengthens aloft.
Cooler air moves in for the latter half of the week, but above
normal temps persist through the weekend.

&&

.SHORT TERM...
(This evening through Wednesday)
Issued at 1230 PM PDT Tue Jun 4 2024

Forecast on track this afternoon to kick off the heatwave. Not a
cloud to be found on satellite across the region as temperatures
soar into the upper 80s and 90s for areas outside of what is left
of a very shallow marine layer. Main change for today was
starting the Heat Advisory early for the South Bay as the warmest
days look to be today and Wednesday. All Heat Advisories continue
until midnight Thursday night. Wednesday still looks like the
overall peak of the heat event as the upper level ridge and
associated subsidence is strongest at this point. However, the
axis has shifted eastward by this time, and some degree of onshore
flow will be present by later on Wednesday. Therefore, the peak of
the heat may end up being today for coastal areas. Albeit a
couple of degrees cooler or warmer in some locations, the focus
should be on overall heat risk, which doesn`t change much from
day-to-day until we get to Thursday when stronger onshore flow is
expected. Despite the risk to those sensitive to heat-related
illness, the silver lining to this event is that there is no large
scale offshore wind expected and overnight temps cool
sufficiently, so the marginal fire threat that exists simply due
to being warm and dry in the afternoon should remain just that.
Afternoons will be dry with RH in the 20s, especially inland, but
most locations below about 2500 feet will see decent overnight
recovery in the 50-80% range. Locations above 2500 feet won`t be
critically dry, but a bit less recovery (30-40%) as thermal belts
set up above the marine layer.

&&

.LONG TERM...
(Thursday through next Monday)
Issued at 1230 PM PDT Tue Jun 4 2024

By Thursday, many locations should be a few degrees cooler with
slightly enhanced onshore flow, though still warm inland.
Afternoon highs look to be in the 85-95 degree range, 60-70 near
the coast. A few far inland locations may still see the 100 degree
mark Thursday (southern interior Monterey/San Benito, northern
Sonoma, inland Napa, and eastern Contra Costa). After Thursday,
temperatures "cool" back down to within 3-5 degrees above normal
and persist through the weekend as the large scale subsidence
associated with the ridge diminishes.

&&

.AVIATION...
(00Z TAFS)
Issued at 514 PM PDT Tue Jun 4 2024

VFR conditions expected through late tonight at all terminals.
Still some uncertainty about low cigs developing around Monterey
Bay early Wednesday, but current TAFs will show low cigs. Breezy
onshore flow will also persist through this evening. SFO finally
hit AWW criteria and as a result an AWW was issued through 05Z.

Vicinity of SFO...VFR through taf period. AWW was issued as winds
will gusts 35-40kt. Winds ease after 05Z. Winds will be gusty
again tomorrow afternoon.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR through late tonight. Low level
moisture moves inland late tonight with potential cigs less than
1k for MRY. Chc is 40-50% for a cig. SNS on the other hand is less
than 20% chc for a cig. Will keep SNS SCT. Given the shallow
nature fog will be possible for MRY. Regardless, any cigs/fog will
dissipate early Wednesday.

&&

.MARINE...
(Tonight through next Sunday)
Issued at 458 PM PDT Tue Jun 4 2024

High pressure off the California Coast and low pressure inland
will maintain breezy to gusty northerly flow over the coastal
waters and bays through Wednesday. Winds will result in hazardous
conditions with steep wind waves. Winds will ease Thursday and
Friday as the offshore high pressure moves east. A moderate period
northwest swell will build over the waters Wednesday into
Thursday.

&&

.BEACHES...
Issued at 859 PM PDT Mon Jun 3 2024

A Beach Hazards Statement is in effect from Wednesday morning
through Thursday evening.

A moderate-rough NW swell will arrive Wednesday and create large
breaking waves and an increased risk for sneaker waves. Breaking
waves will reach as high as 15-20 ft, especially along steep
beaches. Sneaker waves can run over 100 ft up a dry beach, pulling
people in the water from rocks, jetties, and beaches. Inexperienced
swimmers should stay out of the water. Observe the ocean for 20
minutes before relaxing on the beach. The hot weather inland will
lead to more people visiting the beach this week. Know where
lifeguards are, obey their instructions, and never turn your back
on the ocean!

&&

.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 until midnight PDT Thursday night for CAZ503-504-
     506-510-513>515.

     Heat Advisory from 8 AM Wednesday to midnight PDT Thursday night
     for CAZ516-518.

PZ...Small Craft Advisory until 9 PM PDT this evening for Mry Bay-SF
     Bay N of Bay Bridge.

     Gale Warning until 9 PM PDT this evening for Pigeon Pt to Pt
     Pinos 10-60 NM-Pt Arena to Pt Reyes 0-10 nm.

     Small Craft Advisory until 3 AM PDT Thursday for Pt Arena to Pt
     Reyes 10-60 NM-Pt Reyes to Pigeon Pt 0-10 nm.

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

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

     Small Craft Advisory until 9 AM PDT Wednesday for Pt Pinos to Pt
     Piedras Blancas 0-10 nm.

&&

$$

SHORT TERM...Behringer
LONG TERM....Behringer
AVIATION...MM
MARINE...MM

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