024
FXUS66 KMTR 251759
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1059 AM PDT Tue Jun 25 2024

...New AVIATION, MARINE...

.SYNOPSIS...
Issued at 315 AM PDT Tue Jun 25 2024

Elevated thunderstorms, with isolated to scattered coverage may
produce lightning strikes capable of igniting grass fires today
into the early evening hours.

&&

.UPDATE...
Issued at 925 AM PDT Tue Jun 25 2024

Potential for high based thunderstorms continues over the Bay
Area through this evening. Current radar (as of 9AM) shows some
weaker cells moving through the North and South Bay. Given how
high based the convection is, precipitation is unlikely to reach
the ground but any precipitation that does reach the surface is
likely to be only a few hundredths of an inch. We will continue to
monitor these cells as they move through the Bay Area for any
potential thunderstorm developments that may occur. Otherwise, the
forecast remains on track.

&&

.SHORT TERM...
(Today and tonight)
Issued at 315 AM PDT Tue Jun 25 2024

Lift associated with an upper level low approaching the Pacific
Northwest over the next couple of days, is producing scattered
showers over the open water to our west. Lightning even farther west
and closer to the base of the trough can currently be seen tracking
northeast overnight. The persistent ridging over the desert
southwest will deflect the strongest energy associated with the
trough to our north over the next twenty four hours. Scattered
showers that develop this afternoon in an area of upper level
diffluent flow (mainly across Monterey Bay and points north) will be
capable of producing primarily elevated thunderstorms with limited
coverage. There is some concern for any elevated storms producing
lightning strikes across the northern half of our area being capable
of igniting a grassfire. However, instability is weak with little
to no CAPE evident. Later tonight into early Wednesday, upper
level flow across our latitude becomes more zonal as the upper
level low moves onshore into Washington state. Normal to slightly
above normal max temperatures inland today will cool a few degrees
tomorrow.

&&

.LONG TERM...
(Wednesday through Monday)
Issued at 315 AM PDT Tue Jun 25 2024

The southern extent of an upper level trough axis will shift east
across our area Thursday morning, as upper level flow shifts from
zonal to northwest and shortwave ridging over the Pacific Northwest
takes shape in the wake of the trough. The more amplified portion of
the upper ridge will remain north of our area and another upper
trough moves onshore over the weekend. Temperatures will cool nicely
from today`s peak, for the end of the week into the weekend as
cooler temperatures aloft spread over our region. A warmup looks
likely for the beginning of next week as broad troughing is
established across western CONUS.

&&

.AVIATION...
(18Z TAFS)
Issued at 1059 AM PDT Tue Jun 25 2024

High-level clouds with a few embedded storm cells are moving across
the region through the region. Chances for storms linger into the
evening but more of the focus will be to the north and east of the
region. Expect breezy conditions through the afternoon that ease into
the evening. As winds reduce, IFR/MVFR CIGs begin to move inland
affecting the Monterey Bay TAF sites this evening, with OAK and SFO
affected late into the night. Winds stay light to moderate through
Wednesday morning, with CIGs dissipating in the mid to late morning.
Expect widespread VFR by Wednesday afternoon with gusty and breezy
winds.


Vicinity of SFO...Broken high-level clouds become scattered into the
evening and exit overnight. Winds become breezy this afternoon with
gusts around 22 kts. Winds reduce into the night with MVFR CIGs
filling over the terminal. These CIGs erode into mid Wednesday
morning with gustier west winds arriving into Wednesday morning.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VF lasts into the evening with passing high
clouds. Moderate to breezy westerly winds build this afternoon.
Winds reduce into the evening as IFR CIGS move inland and fill over
MRY, with SNS filling later into the night. CIGS erode in the mid to
late morning on Wednesday as moderate to breezy winds arrive.

&&

.MARINE...
(Today through Sunday)
Issued at 1059 AM PDT Tue Jun 25 2024

Moderate to breezy northwesterly continue. Stronger northwesterly
breezes arrive into Wednesday morning creating hazardous
conditions for small crafts across all the waters. Significant
wave heights will continue to abate below 10 feet through the
period.

&&

.FIRE WEATHER...
Issued at 315 AM PDT Tue Jun 25 2024

There is a slight chance of thunderstorms this afternoon, with
limited coverage. Given the elevated nature of any storms that
may develop, any rainfall amounts, if any, will be light with
some VIRGA possible and subsequent gusty winds. Any strikes that
do occur may cause a fire start in the fine fuels.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 3 PM to 9 PM PDT Wednesday for Mry Bay-
     Pt Arena to Pt Reyes 10-60 NM-Pt Reyes to Pigeon Pt 0-10 nm.

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

&&

$$

SHORT TERM...JM
LONG TERM....JM
AVIATION...Murdock
MARINE...Murdock

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