Gale Warning 22, NWS Juneau, AK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
257 PM AKST Tue Jan 9 2024

.SHORT TERM...The outflow pattern continues as the pressure and
thermal gradient continues to strengthen. Winds came up in N/S
oriented channels including Lynn Canal and near gale conditions have
been reported in Stephens Passage. Elsewhere, calm winds and clear
skies keep temperatures low during the overnight hours with minor
warming during the day with limited solar heating due to sun angle
and lack of sunlight before cooling off in the evening. As of now,
temperatures tonight are expected to be colder than low temperatures
this morning across the region. Outflow and mountain wave winds
increasing into Wednesday. Locations such as  Skagway and downtown
Juneau will see the strongest winds. Locations with higher winds
and colder temps will produce very cold wind chills. Little
changes made to previous forecast.

.LONG TERM.../Thursday to the weekend/ The big story in the
mid range forecast remains the ongoing outflow which will continue
to bring significantly colder temperatures into the weekend. Overall
trend will be for temperatures across the Panhandle to continue
dropping as mentioned in the short  with the lowest temperatures
seen Friday morning with minor warming possible Saturday and more
warming Sunday as high pressure over the Canadian interior weakens
slightly. By Thursday, daytime highs will struggle to reach the low
to mid 20s for central and southern outer coastal communities.
Communities far from the coast will see daytime highs in the teens,
while in the far north higher elevations will be in the single
digits. For Friday and Saturday mornings, majority of the panhandle
will see low temperatures in the single digits, with the far
northern communities (especially at elevation) approaching 0.
With temperatures dropping consistently through Friday, wind chill
will be a factor for any prolonged outdoor activities in areas
that normally see outflow winds. A special weather statement has
been broadcast for this cold outbreak.

Outflow winds will continue into Friday, though should begin to
drop in magnitude as the gradient over the interior begins to
slacken and also become more parallel to the inner channels. With
persistent outflow winds along Lynn Canal, fully developed seas
of up to 9 ft will likely not begin to subside until later in the
day Thursday. Combined with the cold temperatures, freezing spray
remains likely for interior passes and Lynn Canal through Friday.
Mountain wave activity for downtown Juneau will continue from the
short range into Thursday with gusty winds up to 40 mph.

As expected, guidance is playing catch up in terms of keeping the
ridge in place for longer and pushing the return of precipitation
back, with a front now not expected to make its way to the panhandle
until later in the day Saturday or possibly Sunday. With the cold
air in place over the panhandle, initial precipitation will be snow
with some potential for a transition to mix or rain for the outer
coastal communities.

&&

.AVIATION.../Through Wednesday afternoon/...Possibility of some
late night/early morning fog in the usual fog magnet locations;
Juneau, Gustavus, and Petersburg. Otherwise, clear and 7. Thinking
that a full day of high broken clouds or clear skies will allow
the surface to dry out for the most part with any remaining
moisture frosting out before fog can form. As discussed yesterday,
tomorrow should see some mechanical turbulence below ridge tops
over Lynn Canal, Gastineau Channel, and Taku Inlet. Am adding
Lisianski Inlet and the junction of Chatham Strait, southern Lynn
Canal and Icy Strait to this list of possible turbulent areas
based on where I've been beat up in the past in similar outflow
conditions. Very cold conditions continue, so density altitudes
will be very negative and very beneficial.

&&

.MARINE...Outflow winds will continue as the pressure gradient and
thermal gradient tightens. N Lynn Canal, S Lynn, and Stephens
Passage will see gale to near gale force by tonight with small craft
winds for other N-S oriented channels with the exception of Stephens
Passage. Expecting long wind fetch to increase seas from Lynn Canal
down Chatham Strait. Arctic air moving in addition to the increased
winds will increase probability of freezing spray tonight into
Wednesday. Heavy freezing spray expected for N Lynn.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Wind Chill Advisory from 10 PM this evening to 6 AM AKST Friday
     for AKZ318.
MARINE...Heavy Freezing Spray Warning for PKZ012-031.
     Gale Warning for PKZ012.
     Small Craft Advisory for PKZ011-013-022-031>034-053-641>644-651-
     661>664-671-672.

&&

SHORT TERM...PRB
LONG TERM....STJ
AVIATION...Fritsch

Visit us at http://www.weather.gov/Juneau

Special Weather Statement
National Weather Service Juneau AK
1057 PM AKST Tue Jan 9 2024

AKZ317-319>332-102000-
City and Borough of Yakutat-Haines Borough and Klukwan-
Glacier Bay-Eastern Chichagof Island-
Cape Fairweather to Lisianski Strait-City and Borough of Sitka-
Admiralty Island-City and Borough of Juneau-Petersburg Borough-
Western Kupreanof Island and Kuiu Island-Prince of Wales Island-
City and Borough of Wrangell-Ketchikan Gateway Borough-
City of Hyder-Annette Island-
Including the cities of Yakutat, Haines, Gustavus, Hoonah,
Tenakee Springs, Elfin Cove, Pelican, Sitka, Angoon, Juneau,
Petersburg, Kake, Port Alexander, Craig, Klawock, Hydaburg,
Coffman Cove, Thorne Bay, Wrangell, Ketchikan, Hyder,
and Metlakatla
1057 PM AKST Tue Jan 9 2024

...VERY COLD TEMPERATURES AND WIND CHILLS THIS WEEK...

The first significant outflow event of this Winter season has
begun for Southeast Alaska. Overnight lows will decrease with
each passing night through at least Thursday night. Early Friday
morning temperatures will range from the middle teens on the
central outer coast to 10 degrees below zero at higher elevations
along the Haines Highway. Residents are encouraged to take
precautions early to prevent the freezing and bursting of
vulnerable plumbing both indoors and outdoors. Pets and other
animals normally maintained outdoors should also be attended to
before temperatures become dangerously cold.

In addition to the very cold temperatures, wind chill will become
a hazard as well in those locations that typically experience
windy conditions during outflow events with more northerly
locations experiencing the coldest values. Specifically, interior
passes near the coast mountains, Haines & the Haines Highway, and
downtown Juneau. As with the overnight lows, wind chill values
will become lower with each passing night until at least late
Thursday or early Friday morning. Hazardous and potentially
dangerous wind chills are most likely in more northerly locations
and close to the coast mountains.