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FXAK67 PAJK 162351
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
251 PM AKST Fri Nov 16 2018

.SHORT TERM...A warm front crossing the gulf has rain on the door
step of Sitka based on the radar at 230pm Friday. Over the outside
waters, gale force winds have been reported by a ship and nearing
gale force along the northern gulf coast at buoy 46082. Expect
rain to spread inland and become heavy at times for most
locations. The far southern panhandle around Ketchikan and Hyder
will be spared of the rain until Saturday afternoon.

Temperatures didn`t rise too much today. In face Tenakee Springs
saw a 6 degree drop when the fog finally cleared away around noon.
Most notably are locations still below freezing, since that will
likely cause precip to start off as snow when it moves in. We have
added a mix to areas as far south as the Mendenhall Valley and
Gustavus, but these areas will change to rain quickly and become
heavy at times overnight. Haines and the Skagway/Klondike Highway
will hold on to the cold temperatures through most of the night,
resulting in significant snowfall accumulations. Have increased
the snowfall amounts to around 4in in downtown Haines and up to
10in for the Haines Highway beyond the Chilkat River Bridge.
Downtown Haines will change to rain after the wind shifts to the
south, and warm up through early Saturday morning. For Skagway
there will be about 1in before things change to rain overnight and
4in for Dyea. Snow at White Pass will last the longest, through
Saturday afternoon, but expect greatest accumulations to be after
midnight through early morning. Total accumulations for there
have been increased to 14in.

The front will shift to the SE through Saturday afternoon. Then a
wave along the front will cause it shift back north across the
panhandle on Sunday. Therefore, expect wet conditions for most of
the weekend with some breaks/let up as the front wavers.

Adjusted wind speed up to small craft level 25-30kt as the front
moves across through Saturday morning. This increased was based
primarily on the NAMnest. Adjusted POP and QPF up based mainly on
the 12z NAM but kept higher POP values due to some timing
differences on when the front shifts back and forth.

.LONG TERM.../Sunday through Friday as of 10 pm Thursday/
Did not make much change to the longer range. Models still having
timing issues with system coming into the area Sun. Mainly looks
like an upper level amplitude issue for the Sun system, with
latest GFS/Canadian suggesting a more amplified pattern and
slower moving system than the ECMWF and NAM. Current forecast is
in range of those ideas, so did not want to chase timing right
now.

Further out, model differences increase, mainly due to amplitude
of upper level pattern and how energy within an upper trof to the
W distributes itself. This will affect both the timing and
strength of any lows associated with the systems further out.
Overall pattern still favors warm and wet, so little threat for
any snow at lower levels during the long term period.

&&

.AJK Watches/Warnings/Advisories...
PUBLIC...Winter Storm Warning from 9 PM this evening to 9 AM AKST
     Saturday for AKZ019.
     Winter Storm Warning from 9 PM this evening to 3 PM AKST
     Saturday for AKZ018.
MARINE...Gale Warning for PKZ042-043-051-052.
     Small Craft Advisory for PKZ012-013-021-022-031>036-041-053.

&&

$$

Ferrin/JB

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