Area Forecast Discussion
Issued by NWS
FXAK67 PAJK 200056 CCA
Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
445 PM AKST Thu Jan 19 2017
A surface low in the northeast gulf moves across the southeast this
evening as an upper level trough moves a strong short wave inland.
Snow and rain is exepected to develop along this system this evening
along the eastern gulf waters with temperatures cooling tonight
changing precipitation over to snow. Only minor accumulations are
expected as moisture is limited due to a cold dry air mass ushering
in quickly from the north. Outflow winds increase rapidly on Friday
as a ridge builds across the Yukon.
.LONG TERM...(From previous disscussion)Upper trof will move NE of
the area Fri morning. Confluent flow aloft will help build high
pressure over the Yukon into the northern panhandle Fri and this
will last into Sat. A weak low and front will move N into the gulf
Sat night and Sun. After that, looking more active as large scale
upper troffing is established over the E Pac by midweek.
For Fri-Sat, as high builds some to the N, colder air will filter
in. This will help increase N winds especially over the N half of
the area. Looking like gale force winds are likely over the N
third of the inner channels especially Lynn Canal and Stephens
Passage beginning Fri. Should have SCA level N winds reach all
but the far southern area by Fri evening. Locally in the Juneau
area, threat for Taku winds will be on the increase especially Fri
night and Sat. NAM is the most aggressive with the cold air
moving in and has strongest cross barrier flow. Critical level and
inversion look excellent with flow aloft in mid-levels becoming
SW during Fri night. It will depend mostly on strength of cross
barrier flow to determine how strong winds will be. Due to some
uncertainty on that, will not put out any wind headlines for the
Juneau area attm.
Clouds will spread N later Sat and Sat night ahead of next low and
front. Looking like best precip threat may be over the gulf
although this will depend on strength of an upper trof moving in
from the W Sun and Sun night which may push precip inland. Should
see moderating trend with temps next week as increasing deep layer
SW flow becomes established. Later shifts may need to adjust some
temps upward especially after Mon.
MARINE... Gale Warning for PKZ012-13-31
Small craft Advisory for PKZ011-021-022-032-033-034-035-043-051-
Small Craft Advisory due to Seas for PKZ041-042-053.
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