458
FXUS66 KMTR 010833
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
133 AM PDT Wed May 1 2024

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

.SYNOPSIS...
Issued at 125 AM PDT Wed May 1 2024

High pressure brings quiet weather and slowly warming temperatures
this week. Breezy onshore winds will keep temperatures along the coast
cooler however. Wet, unsettled conditions returning Friday night and
Saturday, much cooler inland Saturday. Unseasonably cool daytime highs
continuing into early next week then gradually warming by the middle
of the week.

&&

.SHORT TERM...
(Today and tonight)
Issued at 133 AM PDT Wed May 1 2024

Today`s weather will be similar to Tuesday`s weather, dry conditions
prevailing with high pressure over the offshore waters to far northern
California. Gusty northwest winds continuing over the coastal waters.
Forecast highs today 60s near the coast and bays to the 70s-80 inland.

&&

.LONG TERM...
(Thursday through Tuesday)
Issued at 133 AM PDT Wed May 1 2024

Dry Thursday and Friday, increasing clouds Friday night with rain
developing over the North Bay, rain spreading southeastward across
much of the rest of the forecast area Saturday. It`ll turn noticeably
cooler especially inland Saturday with daytime highs Saturday 10F to
18F cooler inland compared to Friday`s forecast highs.

In the last 12-24 hours global and mesoscale models are more in line
focusing on the arrival of a cold core low pressure system from the
Bering Sea/Aleutian Islands arriving in northern California Friday
night and Saturday. The southeastward trajectory takes it across
cooler than normal sea surface temperatures (negative phase PDO)
at least somewhat minimizing maritime thermal modification along
the way and for maintenance/development it`ll travel through a long
wave trough on the West Coast. The low will brush by and tap higher
levels of water vapor extending far north of Hawaii, however the
low is forecast to move through our forecast area retaining a strong
mid-latitude influence. Recent precipitable water values on the GFS
have been 1.00" to 1.10" for Saturday, not far from the max moving
average on Oakland upper air sounding climatology in early May.
Model forecast rainfall amounts vary from 0.25" to 0.70" North
Bay, 0.15"-0.25" low elevations to 0.40" hills/mountains elsewhere
across the Bay Area to around 0.10" interior north Central Coast
to 0.33" Big Sur Coast. Wet and cooler weather Saturday, gusty
northwest winds over the coast temporarily subsiding with the
passage of a surface cold front/trough. Dry weather returns
Sunday. The surface pressure pattern looks favorable for gusty
northwest winds redeveloping over the coastal waters beginning
next Tuesday. Daytime highs gradually warming by the middle of
next week.

&&

.AVIATION...
(06Z TAFS)
Issued at 1022 PM PDT Tue Apr 30 2024

Generally VFR through the TAF period with patchy stratus in the
higher elevations. Westerly flow will diminish through the night,
but northerly winds aloft remain strong, causing LLWS across the
region through Wednesday morning. Northerly winds build through
Wednesday, generally gusting through 20-25 knots.

Vicinity of SFO... VFR through the TAF period. West winds
diminishing through the night with northerly winds aloft causing
LLWS early Wednesday morning. Northwest winds build through
Wednesday gusting to 20-25 knots, before diminishing through the
evening.

SFO Bridge Approach... Similar to SFO.

Monterey Bay Terminals... VFR through the TAF period. Directional
LLWS through Wednesday morning as valley drainage flow at the
surface meets northerly flow aloft. Northwesterly flow develops on
Wednesday with gusts up to 20-25 knots, diminishing again in the
evening with directional LLWS resuming at MRY.

&&

.MARINE...
(Tonight through next Monday)
Issued at 856 PM PDT Tue Apr 30 2024

Breezy and gusty winds last through Friday, with gale force gusts
of 40 to 45 knots possible in the outer waters through much of
the week. The strong winds will result in hazardous seas and steep
wind waves with significant wave heights reaching 10 to 14 feet
in the outer waters. Conditions will gradually improve over the
weekend and into next week as winds begin to ease. Chances of rain
begin early Saturday as a trough descends over the region.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 3 AM PDT early this morning for Mry
     Bay.

     Small Craft Advisory from 9 AM this morning to 9 PM PDT this
     evening for Mry Bay.

     Gale Warning until 3 AM PDT early this morning for Pigeon Pt to
     Pt Pinos 0-10 nm-Pt Arena to Pt Reyes 0-10 nm-Pt Reyes to
     Pigeon Pt 0-10 nm.

     Gale Warning until 3 AM PDT Thursday for Pt Arena to Pt Reyes 10-
     60 NM-Pt Pinos to Pt Piedras Blancas 0-10 nm.

     Gale Warning until 9 AM PDT Thursday for Pigeon Pt to Pt Pinos
     10-60 NM.

&&

$$

SHORT TERM...Canepa
LONG TERM....Canepa
AVIATION...DialH
MARINE...Murdock

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