965
FXUS66 KMTR 091703
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1003 AM PDT Thu May 9 2024

...New UPDATE, MARINE...

.SYNOPSIS...
Issued at 245 AM PDT Thu May 9 2024

A warming trend that kicked off yesterday will continue today and
persist into tomorrow across the interior. Conditions begin to cool
near the coast on Saturday with interior areas remaining 5-15
degrees above average into early next week.

&&

.UPDATE...
Issued at 958 AM PDT Thu May 9 2024

Significant warming continues today, especially in the Sonoma
County valleys, where earlier this morning, many stations
reported temperatures 15 to 20 degrees above yesterday at the same
time. The Wind Advisory has been allowed to expire for the North
Bay interior mountains, with some notable wind gusts this morning
including 74 mph at Pine Flat Road, 68 mph at Mount Saint Helena,
and 54 mph at Mount Diablo. No changes to the forecast.

DialH

&&

.SHORT TERM...
(Today and tonight)
Issued at 245 AM PDT Thu May 9 2024

Clear sky conditions prevail across the region this morning as off
shore winds continue aloft. This will result in a warming trend
today with temperatures reaching the mid-to-upper 80`s across the
interior while 70`s will be common near the coast (closer to the
lower 80`s in places such as Santa Cruz and Downtown San Fransico).
This will bring Minor HeatRisk to the coast today with Moderate
HeatRisk across the North Bay, East Bay, and South Bay both today
and Friday.

A Wind Advisory remains in effect for the North Bay Interior
Mountains with gusts expected to reach 45 mph and may exceed 55 mph
in the Mayacamas Mountains through 8 AM this morning. Gusts in the
East Bay Hills are not expected to be widespread enough to warrant
an advisory, but Mount Diablo is expected to see gusts of 40-50 mph
this morning.

Overnight lows will be warmest in the North Bay and interior part of
the East Bay given the weakening offshore flow with temperatures
only expected to cool into the mid-to-upper 50`s. Elsewhere, low-to-
mid 50`s are expected overnight. The HRRR is showing signs of a
southerly surge arriving by late afternoon and into the overnight
hours. If were to occur, expect much cooler temperatures near the
coast on Friday.

&&

.LONG TERM...
(Friday through Wednesday)
Issued at 245 AM PDT Thu May 9 2024

Friday is expected to be the warmest day of the week, especially for
inland locations. Again, a southerly surge may cool conditions at
the coast, but the interior will still warm into the mid-to-upper
80`s to lower 90`s.

With the significant warm up expected for the rest of the week,
here`s a reminder of some heat safety tips:

* Stay hydrated and drink plenty of fluids.
* Wear lightweight, light-colored clothing.
* Reduce time spent outdoors or stay in the shade.
* Never leave people or pets unattended in vehicles.
* Use sunscreen if going to the coast or the pool.

As onshore flow increases, temperatures will cool regionwide.
However, interior areas will remain 5-15 degrees above average into
early next week.

From the previous forecaster: "Ensemble models and clusters are
showing that another ridge approaches the West Coast next week,
which could help maintain temperatures above the seasonal averages.
CPC products are showing temperatures above seasonal averages
continuing into the third week of May."

&&

.AVIATION...
(12Z TAFS)
Issued at 349 AM PDT Thu May 9 2024

VFR through the TAF period. At this hour, winds are predominantly
light and N/NE. Northerly winds will increase throughout the morning
and early afternoon today to become breezy around 10-15 knots for
most terminals. By the late afternoon, winds are expected to turn to
take on a more onshore flow pattern but begin to ease. Into the
overnight of Thursday into Friday, winds become light, and coastal
stratus slowly begins to push northwards along the Monterey
coastline. Towards the end of the TAF period, stratus will begin to
filter into the southernmost terminals.

Vicinity of SFO...VFR prevailing. Light NE winds prevail through the
morning. In the afternoon, winds strengthen to become breezy and
turn to become onshore. Light and variable winds return in the later
evening.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR prevailing, though FEW-SCT low clouds
are likely to develop over the terminals towards the very end of the
TAF period. At this time, confidence in CIG development is low, with
chances currently only standing at around 20-30% at best. However,
with ongoing ridging, any clouds that do form over the terminal are
likely to be around 1000` or less, as the marine layer is
compressed. Aside from this, breezy onshore winds expected in the
afternoon today once again. Winds ease into the nighttime to become
light.

&&

.MARINE...
(Today through Tuesday)
Issued at 958 AM PDT Thu May 9 2024

High pressure to the north will maintain light to moderately
northerly winds for most of the coastal waters today. However,
winds will be locally more southerly along the Big Sur and
Monterey Bay region. Otherwise, gentle breezes out of the north
and northwest continue through the weekend first portion of the
weekend. Dry weather continues through the forecast period as high
pressure dominates.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 3 PM PDT this afternoon for Pt Pinos
     to Pt Piedras Blancas 0-10 nm.

&&

$$

SHORT TERM...RGass
LONG TERM....RGass
AVIATION...AC
MARINE...MM

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