237
FXUS66 KMTR 010357
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
857 PM PDT Tue Apr 30 2024

...New UPDATE, MARINE...

.SYNOPSIS...
Issued at 133 AM PDT Tue Apr 30 2024

High pressure brings quiet weather and slowly warming temperatures
this week. Breezy onshore winds will keep temperatures along the
coast cooler however. Cooler and more unsettled conditions return
this weekend into next week with light rain chances in the forecast.

&&

.UPDATE...
Issued at 856 PM PDT Tue Apr 30 2024

Relatively quiet weather as we transition from April into May.
HREF continues to indicate minimal cloud cover overnight which
will allow overnight temperatures to cool into the mid to low
40`s. Tomorrow`s temperature forecast looks to remain on track
with inland highs in the low to mid 70`s and coastal highs in the
upper 50`s to low 60`s. Gusty northwest winds gradually becoming
more northerly will continue through the end of the work week.

No updates needed to the forecast. This concludes April 2024.

&&

.SHORT TERM...
(This evening through Wednesday)
Issued at 106 PM PDT Tue Apr 30 2024

Overnight temperatures are forecast to cool into the 40`s across
much of the region with less cloud cover. However, areas around the
Monterey Bay have the potential to see low clouds develop once
again. Once any low clouds that do develop dissipate, temperatures
will begin to warm and are likely to reach into the 60`s near the
coast (70`s in places such as Santa Cruz) with mid-to-upper 70`s
inland.

&&

.LONG TERM...
(Wednesday night through Monday)
Issued at 203 AM PDT Tue Apr 30 2024

Dry conditions prevailing through mid-week. A slowly retrograding
long wave trough along the West Coast varies in strength late
week and early next week. There is a large difference between
recent GFS (wet) and ECMWF (not nearly as wet as the GFS) in
calculating the trajectory/progression of a low pressure system
moving through the long wave trough, now well within 120 hours (5
days) forecast. QPF differences are showing up in the GEFS and EPS
as well, though recent EPS have increased a little. As of current,
it remains a low confidence forecast from a global model forecast
perspective. Given the model forecast trajectory of the low pressure
system is from near the Bering Sea/Aleutians southeastward across
the Pacific (and surface high pressure over the Pacific retrogrades)
where below normal sea surface temperatures exist including a
negative phase Pacific Decadal Oscillation (PDO) i.e. the potential
forward slowing due to local surface heating is reduced therefore
the quicker arriving QPF in the GFS solution may not be that far
off if development much closer to our forecast area verifies. The
northern hemispheric pattern remains active with the current number
of long wave troughs reflecting a winter-like circulation.

Stay tuned to latest forecast updates, as currently advertised
the official forecast shows potential for showery, cool weather
this weekend. Planning travel to the mountains? This pattern has
potential for snow accumulations, it`s a good idea to monitor the
latest forecasts. Per 30 year climatology we are of course past
peak cool season rainfall, however it can still rain in May in the
Bay Area and north Central Coast. Recalling a Lead Forecaster here
years ago mentioned it`s always a good idea to carry chains in case
needed (for Sierra Nevada travel) through Memorial Day.

July climatologically is our driest time of year since by then the
jet stream has reliably weakened and returned northward and high
pressure often sets up.

&&

.AVIATION...
(00Z TAFS)
Issued at 500 PM PDT Tue Apr 30 2024

VFR through the TAF period. Strong and gusty surface winds
continue into the early night. Winds slowly ease near the
surface into the night, but winds winds aloft turn more northerly
and increase to around 25-40 kts from roughly 1500ft to 2000ft
AGL. This will introduce directional and speed shear for most
terminals tonight, especially the North Bay. It is not until the
mid to late morning of Wednesday that wind shear diminishes.
Breezy winds build in Wednesday afternoon.

Vicinity of SFO...VFR through the TAF period. Strong northwest
winds with around 30 kt gusts linger into the late evening before
becoming lighter. Expect winds around 2000ft AGL to become more
northerly and gain strength, leading to LLWS concerns. These
concerns ease into mid Wednesday morning as winds a loft decrease.
Breezy northwest winds build into Wednesday afternoon and last
into the night.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR through the TAF period. Breezy winds
last into the night before reducing. Winds aloft over MRY stay
strong and turn more Northerly overnight, leading to LLWS
concerns, while SNS looks to stay sheltered. Expect shear concerns
to ease into mid Wednesday morning, followed by a breezy
afternoon.

&&

.MARINE...
(Tonight through next Monday)
Issued at 856 PM PDT Tue Apr 30 2024

Breezy and gusty winds last through Friday, with gale force gusts
of 40 to 45 knots possible in the outer waters through much of
the week. The strong winds will result in hazardous seas and steep
wind waves with significant wave heights reaching 10 to 14 feet
in the outer waters. Conditions will gradually improve over the
weekend and into next week as winds begin to ease. Chances of rain
begin early Saturday as a trough descends over the region.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 3 AM PDT Wednesday for Mry Bay.

     Small Craft Advisory from 9 AM to 9 PM PDT Wednesday for Mry Bay.

     Gale Warning until 3 AM PDT Wednesday for Pigeon Pt to Pt Pinos
     0-10 nm-Pt Arena to Pt Reyes 0-10 nm-Pt Reyes to Pigeon Pt
     0-10 nm.

     Gale Warning until 3 AM PDT Thursday for Pt Arena to Pt Reyes 10-
     60 NM-Pt Pinos to Pt Piedras Blancas 0-10 nm.

     Gale Warning until 9 AM PDT Thursday for Pigeon Pt to Pt Pinos
     10-60 NM.

&&

$$

SHORT TERM...RGass
LONG TERM....Canepa
AVIATION...Murdock
MARINE...Murdock

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