Area Forecast Discussion
Issued by NWS
FXAK67 PAJK 230002
Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
402 PM AKDT Wed Mar 22 2017
.SHORT TERM...Old low southwest of Haida Gwaii persisting through
tonight and then moving slowly northwest into the eastern gulf.
There is a fair bit of moisture moving northward over southeast
Alaska. At the mid levels there is a general trough across the
gulf with a minor closed low near Prince of Wales, though this
expected to dissipate on Thursday. This will keep a general south
to southwest flow aloft into the Southeast panhandle.
Scattered showers on Wednesday afternoon seem to be limited to the
far southern panhandle and the PoPs are expected to move
northwards some, however am not expecting much more then 30 to 60
percent chance of measurable rain and or Snow. The snow should be
limited to the night time periods and little to no accumulations.
While some patchy fog may develop overnight, think there is only
a slim chance of stations picking up any thicker/dense fog with
perhaps the Yakutat area being the more likely target. Will be
considering fog for the TAF overnight in that area.
Model agreement was generally good through Thursday, and most
edits in the short term were based on a blend of the NAM and GFS
solutions. Forecast confidence is above average.
.LONG TERM...An upper level will remain positioned just west of
the Panhandle. This invites wave after wave south into the
northern gulf to spawn weak disturbances leading south. These
waves have repeatedly interacted with the southern storm track and
tapped southern moisture to play with over the southeast gulf,
only to lead it northward into the Panhandle. This pattern has
generally led to mainly rain over the southern areas with chances
of a lighter mix across the north and central Panhandle. This
refrain repeats itself again Thursday night into Friday night as
a surface low/front approaches from the south and stalls before
attempting to move east into BC. As it nears from the south
though, the northern Panhandle will see a dry day on Friday.
Confidence falls this weekend and next week though. Ensembles for
days would have us transition to a pattern that features a longer
southwesterly track of storms into the eastern gulf. This would
steer potentially stronger storms our way, and also help moderate
our temperatures. Currently, our forecast shows a slow warming
trend, but individual days/nights could be much warmer at times.
It is conceivable that portions of Southeast will experience bands
of heavy rain and wind at times. But naming the time period is too
challenging at this stage. Therefore, the forecast is very
Another challenge will arise for the transition between patterns
this weekend. Models today have displayed increasing support for a
moderately strong low moving east across the North Pacific that
will curve northward Sunday. Most models push it northwest to
retrograde into south-central Alaska. Ensembles are characterizing
this period as one of lower confidence. Our team office in
Anchorage also has expressed skepticism on this evolution. Thus,
we have decided to forgo any changes during this time period. But
should models become more consistent, we may make changes for
Sunday into Monday. This would make for a breezier period along
the coast and likely gale force winds over the gulf waters.
Precipitation should be in the form of rain in general. Currently,
the forecast is a more generalized version of these events.
Forecast confidence is average.
.AVIATION...Most aviation sites are VFR this evening though the
southern panhandle around Ketchikan will flirt with MVFR/IFR from
ceilings and showers. The showers across the panhandle are not
very widespread so think this will be an up and down evening.
Overnight ceilings may lower to top end of the MVFR levels, though
expect them to improve again after sunrise. Winds mainly light
and pilots reporting only light turbulence near and above the
MARINE...Small Craft Advisory for PKZ012-013.
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