-- Discussion containing changed information from previous version are highlighted. --
797
FXUS66 KMTR 302121
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
221 PM PDT Thu May 30 2024

...New SYNOPSIS, SHORT TERM, LONG TERM...

.SYNOPSIS...
-- Changed Discussion --
Issued at 220 PM PDT Thu May 30 2024

Weak ridging will bring a minor warming trend to the region
through Friday. A trough will move into the Pacific Northwest
this weekend though, which will help strengthen the onshore flow
and deepen the marine layer, bringing a slight reprieve to the
warmer conditions. However, high pressure will build back across
the region by the middle of next week, bringing a much more
pronounced warming trend to the region, especially across the
inland areas. Inland areas could be upwards of 10 to 20 degrees
above normal, with a moderate heat risk by Wednesday.
-- End Changed Discussion --

&&


.SHORT TERM...
-- Changed Discussion --
(This evening through Friday)
Issued at 220 PM PDT Thu May 30 2024

Water vapor imagery continues to show relatively zonal upper
level flow across California this afternoon, with a few high
clouds still moving across the far northern portion of the state.
Meanwhile, patchy low clouds continue to linger along the Big Sur
Coast and the Monterey Peninsula. Given the sunny skies this
afternoon, temperatures are running similar or up to 5 degrees
warmer than this time yesterday. This will make for pleasant
afternoon and evening across the region. The low clouds will
likely move back into the Monterey Bay tonight, with a clouds
start to the day expected on Friday. Otherwise, the minor warming
trend that we saw today will continue into the day on Friday, with
most areas similar to or slightly warmer than where they peaked
today.
-- End Changed Discussion --

&&

.LONG TERM...
-- Changed Discussion --
(Friday night through next Wednesday)
Issued at 220 PM PDT Thu May 30 2024

Things will begin to change on Friday night though as a series of
systems take aim at the Pacific Northwest. As a result, this will
bring the return of the marine layer to most areas as well as
stronger onshore flow. Therefore, expect a cooling trend to
develop, with inland temperatures seeing the greatest decrease.
Low clouds may be hard to clear the coast each afternoon, with
unseasonably cool conditions prevailing along the immediate
coast. In fact, cannot rule out some late night or early morning
drizzle each day this weekend. A more potent system will take aim
at the Pacific Northwest and far Northern California on Sunday
into Monday. While we are still not expecting any rain from this
system this far south, expect quite a bit more cloud cover to
spread across the region late Sunday and into Monday as well as
some coastal drizzle.

The primary concern for this forecast though is with the warming
trend associated with the high pressure building over the West
starting on Tuesday. While Tuesday will be warmer, expect
significant warming to occur for Wednesday and Thursday as the
ridge axis builds over the Four Corners and potentially even more
westward than that. These days could be the hottest we have seen
this year for our inland areas, with inland regions flirting with
or even surging above 100 degrees. In fact, the probabilistic
guidance is suggesting a 75% chance of inland areas reaching 95
degrees and a 40% chance of inland areas topping 100. Therefore,
there is high confidence that the inland areas will be quite hot,
ranging between 8 to 15 degrees warmer than normal and potentially
upwards of 10 to 20 degrees above normal. CPC is even
highlighting the potential for excessive heat in the Central
Valley, especially for June 5th to 7th. While we may get some
influence of the marine layer, believe that it will be quite
shall, with inland areas seeing the greatest warm up and potential
for significant heat and a moderate heat risk.

As previously stated, the marine layer influence will be the
biggest question for the coastal areas, with ensemble spreads for
the coastal areas are upwards of 20 degrees. This high
uncertainty really has to do with the placement of the ridge axis,
and whether or not we can get some light offshore winds
developing. Until the placement of the ridge axis becomes more
clear, the uncertainty will remain high for the coastal areas.
Therefore, we will continue to watch how this event develops over
the next several days.

CPC`s 8 to 14 day outlook also shows a better chance of above
normal temperatures as well, so there is a chance that this heat
turns into a minor heatwave, extending through the remainder of
the work week. Palmer
-- End Changed Discussion --

&&

.AVIATION...
-- Changed Discussion --
(18Z TAFS)
Issued at 1013 AM PDT Thu May 30 2024

VFR through the TAF Period for all but the Monterey Bay immediate
coast, which will see LIFR/IFR CIGs and pockets of mist overnight
and into Friday morning. Breezy to gusty winds build this afternoon,
with stronger winds just off the coast. Expect winds to become light
to moderate overnight. Widespread VFR returns in the mid to late
morning on Friday, with moderate to breezy winds expected that
afternoon.

Vicinity of SFO...VFR through the TAF period. Breezy to gusty
westerly winds arrive this afternoon with peak gusts around 24 kts.
These winds reduce into the early night, but stay moderate through
the late night before becoming light. Breezy winds are expected
to return Friday afternoon.

SFO Bridge Approach...Similar to SFO

Monterey Bay Terminals...VFR Lasts through the late night with
LIFR/IFR CIGs and pockets of mist and fog forming on the immediate
coast into early Friday morning, which will move inland toward MRY
and SNS within a few hours of forming. Expect moderate west winds
build this afternoon but reduce into the late evening. Another round
of moderate west winds arrive as cloud cover erodes into late Friday
morning.
-- End Changed Discussion --&&

.MARINE...
Issued at 841 AM PDT Thu May 30 2024

Breezy to gusty winds last in the outer waters into the weekend
with gale force winds expected to return into Saturday morning.
Significant wave heights offshore build to 12 feet tonight with
but abating into Friday and through the weekend.

&&

.MARINE...
Issued at 841 AM PDT Thu May 30 2024

Breezy to gusty winds last in the outer waters into the weekend
with gale force winds expected to return into Saturday morning.
Significant wave heights offshore build to 12 feet tonight with
but abating into Friday and through the weekend.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 3 AM PDT Friday for Pt Arena to Pt
     Reyes 0-10 nm.

     Small Craft Advisory from 3 PM Friday to 3 AM PDT Saturday for
     Pt Arena to Pt Reyes 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.

     Small Craft Advisory until 3 PM PDT Friday for Pt Arena to Pt
     Reyes 10-60 NM.

     Gale Warning from 3 PM Friday to 3 AM PDT Saturday for Pt Arena
     to Pt Reyes 10-60 NM.

     Small Craft Advisory until 3 AM PDT Saturday for Pigeon Pt to Pt
     Pinos 10-60 NM.

&&

$$

SHORT TERM...Palmer
LONG TERM....Behringer
AVIATION...Murdock
MARINE...Murdock

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