407
FXUS66 KMTR 211523
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
823 AM PDT Tue May 21 2024

...New UPDATE...

.SYNOPSIS...
Issued at 1224 PM PDT Mon May 20 2024

Typical summer-like pattern to persist throughout the first half of
the week. Temperatures are forecast to dip below seasonal averages
by the upcoming weekend as an upper level trough impacts the
region.

&&

.UPDATE...
Issued at 822 AM PDT Tue May 21 2024

Clear skies over most of the region this morning with the
exception of Monterey Bay and within the Salinas Valley. Satellite
shows low stratus pretty socked in, but most of that will clear
out by late morning. Get ready for some warm temperatures today!
Forecast remains on track on expecting temperatures up to mid 80s
inland. North Bay is already seeing around 3-4 temperatures higher
compared to yesterday morning. If you plan to enjoy the warm
temperatures, be sure to hydrate!

SO

&&

.SHORT TERM...
(Today and tonight)
Issued at 321 AM PDT Tue May 21 2024

Similar to the past few days, stratus is confined to coastal regions
with the highest concentrations in the Monterey Bay, portions of the
Central Coast, and the Salinas Valley with dissipation expected by
mid-morning. The main story for tomorrow continues to be the high
temperatures and minor heat risk expected throughout the Bay Area
and portions of the Central Coast. Temperatures are still expected
to peak Tuesday before a slight cool down begins Wednesday.
Inland high temperatures will be 5 to 8 degrees above average with
increasingly northerly flow bringing drier and warmer conditions.
Temperatures will range from the 70s to 80s inland with peak
temperatures in the mid to upper 80s across the North Bay and
portions of the East Bay. Along the coast, onshore flow continues
which will keep high temperatures seasonal to slightly below average
with highs ranging from the upper 50s to mid 60s.

Minimum RH values will be between 15-35% inland with drier
conditions extending closer to the coastline as offshore flow aloft
continues. Areas directly adjacent to the will see minimum RH values
between 50-75% with onshore flow increasing atmospheric moisture.
Given Tuesday`s warmer and drier conditions, minor heat risk is
expected for almost all of the Bay Area and Central Coast. People
who are extremely sensitive to heat should take precautions while
outdoors and remember to drink plenty of water.

&&

.LONG TERM...
(Wednesday through Monday)
Issued at 321 AM PDT Tue May 21 2024

Temperatures cool slightly Wednesday and Thursday before a more
substantial cool down begins Friday into the weekend as upper level
troughing moves into the Bay Area. High temperatures are expected to
be on average 5 to 10 degrees below average next weekend with
widespread highs in the mid 60s to low 70s inland. Coastal highs
will range from the mid 50s to low 60s. Ensemble guidance is
starting to agree that some light precipitation (generally less than
0.1") may occur as upper level troughing moves through next weekend.
The Climate Prediction Center continues the trend of below average
temperatures and slightly above average precipitation through the
end of the month. To put this into context, May traditionally marks
the beginning of the dry season for our region as the Pacific High
shifts southward and deflects surface low pressure systems
northwards of us. Most stations typically observe little to no
precipitation from late May through August so any rainfall at all
can be considered above average. To sum it up, any precipitation
that does occur this weekend is expected be light and non-impactful
but can be considered above average given that we typically see

&&

.AVIATION...
(12Z TAFS)
Issued at 403 AM PDT Tue May 21 2024

VFR for most areas, with IFR-MVFR stratus through mid morning
around Monterey Bay and along the San Mateo coast. Low clouds will
likely return to these same areas by early this evening.

Vicinity of SFO...VFR. However few-sct clouds around 010 this
morning. Light onshore winds early this morning becoming breezy
this afternoon with gusts to around 25 kt.

SFO Bridge Approach... Similar to SFO.

Monterey Bay Terminals...IFR-MVFR stratus through mid Tuesday
morning with afternoon clearing. Winds modest and onshore with
periodic gustiness to around 20 kt this afternoon. Low stratus
returns early this evening and persists into Wednesday morning.

&&

.MARINE...
(Today through Sunday)
Issued at 321 AM PDT Tue May 21 2024

Strong and gusty northwest winds continue over the coastal waters
through Thursday, with gale force gusts across the outer coastal
waters. Expect hazardous conditions and steeper wind waves during
the week. Winds gradually easing later in the week.

&&

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

     Small Craft Advisory from 3 PM this afternoon to 3 PM PDT
     Wednesday for Pt Reyes to Pigeon Pt 0-10 nm.

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

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

     Gale Warning until 3 PM PDT Wednesday for Pt Arena to Pt Reyes
     10-60 NM.

     Gale Warning until 3 AM PDT Wednesday for Pigeon Pt to Pt Pinos
     10-60 NM.

&&

$$

SHORT TERM...Kennedy
LONG TERM....Kennedy
AVIATION...SPM
MARINE...SPM

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