Storm Warning 27, NWS Juneau, AK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
308 PM AKDT Fri Sep 25 2020

.SHORT TERM...Fri night through Mon morning...For early Sat
morning, patchy fog with visibilities to around 1 mile, once
again, may occur due to recent rainfall moistening up the
boundary layer and anticipated breaks in the cloud deck between
the convective showers, which is what has been seen during the
early morning hours over the past couple of days. The global and
regional models are in general agreement about the location and
strength of the coming 965mb deep sfc low and associated front
that will be impacting the AK Panhandle and Gulf waters Sat night
through Mon morning. The system will have good mid and upper-level
support throughout the period due to a strong associated vort max
and favorable positioning of a strong jet-streak removing mass
from the system and providing good lift. Winds up to storm force
are expected over the outside waters & over the Gulf and up to
Gale force with locally higher gusts over the inner channels, due
to a strong pressure gradient with the upcoming system. Heavy rain
is anticipated with this system with storm total rainfall amounts
ranging from 1.5 inches in the northern Panhandle up to around 3
inches in the extreme southern Panhandle. For Sat night through
Sun night, Integrated Water Vapor Transport(IVT) values of around
1,000 will approach SE AK, giving support for the aforementioned
increased forecast rainfall totals, especially over the southern
third of the Panhandle. As for temperatures, mainly cloudy
conditions with few breaks after Fri night will keep a narrow
diurnal temperature curve throughout the period.

.LONG TERM...Sunday through Thursday...As of 10 PM Thu...Models
have come into better agreement with a storm force low moving into
the gulf at the beginning the period. Winds and seas over the gulf
were increased Sun. As this front pushes inland, an atmospheric
river takes aim at the panhandle. Ensembles and AR tools indicate
the southern panhandle as the favored target, but much of the
panhandle will see a period of moderate to heavy rain early next
week. Beyond Tue, models continue to show a long wave trough over
the AK pen and upper ridge anchored over W North America. This
will maintain an active pattern with SWly mid level flow through
the extended with continued chances from precip but normal to
above normal temps. Overall forecast confidence remains about
average.

&&

.AJK Watches/Warnings/Advisories...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ041>043-051.

&&

JLC/BC

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Special Weather Statement
National Weather Service Juneau AK
320 AM AKDT Sat Sep 26 2020

AKZ017>029-270100-
Cape Fairweather to Cape Suckling Coastal Area-
Taiya Inlet and Klondike Highway-Haines Borough and Lynn Canal-
Glacier Bay-Eastern Chichagof Island-
Salisbury Sound to Cape Fairweather Coastal Area-
Cape Decision to Salisbury Sound Coastal Area-
Eastern Baranof Island and Southern Admiralty Island-
Juneau Borough and Northern Admiralty Island-
Inner Channels from Kupreanof Island to Etolin Island-
Dixon Entrance to Cape Decision Coastal Area-
Southern Inner Channels-Misty Fjords-
Including the cities of Yakutat, Skagway, Haines, Gustavus,
Hoonah, Elfin Cove, Pelican, Sitka, Port Alexander, Angoon,
Juneau, Petersburg, Wrangell, Kake, Craig, Klawock, Ketchikan,
Metlakatla, and Hyder
320 AM AKDT Sat Sep 26 2020

...A STRONG FRONTAL SYSTEM WILL MOVE INTO THE AK GULF AND
PANHANDLE SAT NIGHT THROUGH MON MORNING....

A strong frontal system approaching the eastern Gulf and
Panhandle will bring strong winds to the area up to around 60
knots over the northern Gulf and northern Panhandle coastal
waters Sunday morning. Sustained winds over land areas near the
inner channels and near outside waters of 15 to 30 mph with gusts
up to near 50 mph may occur. Wave heights of up to around 35 feet
over the Gulf and up to to around 5 to 7 feet over the inner
channels are likely with these winds. Widespread heavy rain will
occur with this system with rainfall totals ranging from 1.5
inches over the northern Panhandle to near 3 inches over the
extreme southern Panhandle.