091
FXUS66 KMTR 290522
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1022 PM PDT Sun Apr 28 2024

...New AVIATION, MARINE...

.SYNOPSIS...
Issued at 1227 AM PDT Sun Apr 28 2024

High pressure brings quiet weather and slowly warming temperatures
this week. Breezy onshore winds will keep temperatures along the
coast cooler however.

&&

.SHORT TERM...
(This evening through Monday)
Issued at 225 PM PDT Sun Apr 28 2024

Almost a repeat of Saturday weather wise: ample sunshine with fair
weather cumulus, warming trend continues, and breezy to gusty
onshore flow. Warmest inland temperatures will approach 80
degrees this afternoon, but will likely fall short by a degree or
two. Closer to the coast and bays is much cooler thanks to the
persistent onshore flow off the chilly coastal waters. Onshore
flow is still showing gusts of 30-40 mph along the coast,
gaps/passes, and higher terrain. For the curious weather watcher
looking at satellite imagery this afternoon it`s always impressive
to see standing wave clouds form upwind of coastal terrain. Case
in point are the line of the clouds near Pt Reyes, San Mateo
coast, and Monterey Peninsula. For the weather geek, flow in the
marine boundary layer is forced to decelerate as it hits the
terrain causing a wave like feature to form and in this case an
undular bore or visually the standing wave cloud.

Large zonal flow remains over the region tonight and early Monday.
A tight shortwave trough will zip through the zonal flow just
north of CA early Monday. While this feature will be dry it will
however give a re-enforcing shot of northwest winds over the
coastal waters, gaps/passes, and higher terrain on Monday. While
not strong enough for a Wind Advisory, gale force conditions will
impact the coastal water. Similar to Sunday morning, patchy
stratus will once again be possible early Monday. Monday afternoon
will once again feature mostly sunny skies, patchy coastal
stratus, and mild temperatures across the interior.

&&

.LONG TERM...
(Monday night through next Sunday)
Issued at 236 PM PDT Sun Apr 28 2024

Subtle riding offshore/barely for CA develops through midweek as
an upper low digs/sweeps through the Great Basin. Pretty quiet
weather for the week as temperatures will warm gradually and
onshore winds decrease. Interior locations will see more
widespread 80s with Heat Risk values creeping into the minor
category. Patchy night and morning stratus will be possible each
day.

Heading into next week the longwave pattern begins to change and
become more amplified. An upper low will move into the PacNW by
Friday and become more of an open wave/upper trough by Saturday.
This feature will bring the tail end of a weak front across
NorCal. As such, light rain is now in the forecast for the far
North Bay Saturday night/Sunday morning. Not much QPF, but a few
hundredths possible at this point.

Taking a peak farther down the road, clusters and ensembles show a
deeper low/upper trough moving into the PacNW the first week of
May. This will likely bring cooler temperatures and increased
chances for precip. Latest CPC 8-14 day outlook follows that
thinking through May 12.

&&

.AVIATION...
(06Z TAFS)
Issued at 1022 PM PDT Sun Apr 28 2024

Generally VFR throughout the region, with isolated patches of
stratus seen on satellite not expected to impact most of the
terminals, save for MVFR ceilings developing later tonight in the
Monterey Bay region. Moderate to breezy onshore winds will gradually
diminish overnight before building again Monday afternoon, gusting
to 20 to 30 knots. Beyond the TAF period, not expecting widespread
stratus coverage to return on Monday evening into Tuesday morning.

Vicinity of SFO... VFR through the TAF period. Breezy to gusty west-
northwest winds will diminish tonight before building back again
Monday afternoon. Model output showing gusts up to 30-35 knots
through Monday evening, but would not be surprised to see gusts
exceeding 35 knots develop.

SFO Bridge Approach... Similar to SFO.

Monterey Bay Terminals... MVFR ceilings developing tonight as patchy
stratus expands. Moderate onshore flow will build Monday afternoon
with gusts up to 20-25 knots. Low confidence of stratus returning to
the region Monday evening through Tuesday morning.

&&

.MARINE...
(Tonight through next Saturday)
Issued at 1022 PM PDT Sun Apr 28 2024

Strong northerly winds over the coastal waters and bays from a
high pressure over the Eastern Pacific and low pressure inland.
Winds  will be strongest over the outer waters and along the Big
Sur  coast. The strong winds will produce fresh steep wind waves
and  hazardous conditions. Winds continue to increase during the
first  half of the week lasting through Thursday. Moderate period
northwesterly swell will continue to move through the waters
through Thursday causing wave heights up to 12 feet.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 3 AM PDT Monday for SF Bay N of Bay
     Bridge.

     Small Craft Advisory from 3 PM Monday to 3 AM PDT Tuesday for SF
     Bay N of Bay Bridge.

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

     Small Craft Advisory until 9 AM PDT Monday 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.

     Gale Warning from 9 AM Monday to 3 AM PDT Tuesday 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.

     Gale Warning until 3 AM PDT Tuesday for Pt Pinos to Pt Piedras
     Blancas 0-10 nm.

&&

$$

SHORT TERM...MM
LONG TERM....MM
AVIATION...DialH
MARINE...SO

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