958
FXAK67 PAJK 292351
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
351 PM AKDT Sun Sep 29 2024

.SHORT TERM...
Key details:
1) Winds escalate Monday morning, reaching peak intensity by the
evening. High winds continue into Tuesday.

2) Periods of heavy rain are expected Monday afternoon into
Tuesday morning.

Current satellite images highlight a few areas of concern, with
the first being a frontal band west of Haida Gwaii bringing some
elevated southeast winds and a few lightning strikes. Expect this
system to slowly meander north through the evening with the
potential for some lightning in the central and south this
overnight.

Main story is cyclogenesis occurring in the north pacific, with
hefty convection in the downstream cloud layer. Satellite derived
winds agree nicely with model initialization; will continue to
see this storm amplify as it moves northeast into the Gulf. The
forecast remains on track as we are still expecting a violent
storm to impact the majority of the region, bringing high winds to
most of the coastal towns and strong winds to the inner areas.
Expect the strongest winds overnight Monday with wind speeds
slowly relaxing by Wednesday, more details in the long term.

Expect periods of heavy rainfall Monday afternoon into Tuesday
bringing 1 to 3 inches at sea level, with higher terrain likely
picking up 5 to 6 inches in 24 hours. Most rain in the south. No
significant flooding concerns at this time.

.LONG TERM.../Tuesday Afternoon through Friday/...As it progresses
into this timeframe, the aforementioned strong weather system
from the short term forecast period with its tight pressure
gradient will rapidly weaken as it approaches and moves over the
southern quarter of the Panhandle into Wednesday morning, causing
marine winds to decrease from solid mid to high end gale over the
eastern Gulf and southern half of the inner channels to only low-
end small craft(25 kt) wind values. Seas over that same area will
subside from up to 33 ft Tuesday afternoon to around 16 ft by mid
Wednesday morning. The SFC low will end up weakening from 988mb
to 1010mb over the southeastern gulf and southern Clarence Strait
areas by the middle of Wednesday morning.

&&

.AVIATION...
VFR conditions expected through the afternoon and tonight with
CIGs AoA 4000-6000ft. Isolated showers gradually dissipate into
the evening for much of the panhandle. Winds will remain around
10kts or less through the rest of the afternoon, decreasing once
more to near calm and variable moving through tonight. Flight
conditions deteriorate through Monday down to MVFR with sustained
winds increasing up to 20kts and isolated gusts up to 35kts with
strongest winds along coastal and southern panhandle TAF sites as
another system moves into the Gulf of Alaska. LLWS increases
across the panhandle from south to north after 12z as front pushes
inland. Likeliest locations for strongest mechanical turbulence
and LLWS remains across Gulf coast and interior southern panhandle
TAF sites such as Sitka, Ketchikan, and Klawock into Monday
evening afternoon.

&&

.MARINE...
Overnight Sunday some lighting possible in the southern coastal
waters and inner channels but overall low concerns.

Gulf:
Monday easterly hurricane force winds fill in across the central
gulf with violent storm force for most of the coastal waters.
Expect 30ft short period easterly seas in the Gulf Monday, before
30 to 35 ft southwest swell begins to impact the Gulf by early
Tuesday. Winds begin to relax late Tuesday into Wednesday.

Inner Channels:
Expect gale force conditions to develop in Clarence Strait Monday
morning, with winds spreading into the central regions through
the day. Most intense conditions remain in western Icy Strait and
south of Frederick Sound. With that said, expect 20 to 30 knot
winds to develop by the evening for most inner channels with some
localized areas seeing gale force.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Strong Wind from Monday morning through Monday afternoon for
     AKZ317-323.
     High Wind Watch from Monday evening through Tuesday morning for
     AKZ317-322-323-330-332.
     Strong Wind Monday afternoon for AKZ325-330.
     Strong Wind from late tonight through Monday morning for AKZ328.
     High Wind Warning from 10 AM Monday to 10 AM AKDT Tuesday for
     AKZ328.
MARINE...Storm Warning for PKZ664-671-672.
     Gale Warning for PKZ022-036-053-641>644-651-652-661>663.
     Small Craft Advisory for PKZ011>013-021-031>035.

&&

$$

SHORT TERM...AP
LONG TERM....JLC
AVIATION...NM

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