Small Craft Advisory 722, NWS Juneau, AK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
341 PM AKST Sat Nov 19 2016

.SHORT TERM...At least one more dry and mostly sunny short term
forecast in store for most of the panhandle. Exception will be
Yakutat late tonight as short wave trough approaches tonight and
the leading edge of a front moves in from the west tomorrow. Have
a chance of snow showers moving in late tonight with flurries in
advance as clouds increase. Tomorrow, snow is likely with up to an
inch accumulation forecast. Have also included flurries for the
area near Hyder this evening. Elsewhere, dry with mostly clear
skies and another night of temperatures ranging from the low teens
to the low 30s.

High pressure remains over the Yukon and northerly winds of 10 to 20
mph will continue in Haines and Skagway. Glacial silt from the
Chilkat River has been kicked up by the gusty winds there and has
reduced visibility at times down to 1 mile at the Haines airport.
Have included this in the forecast for tonight as well. Not as
confident for this phenomena continuing tomorrow, so will have to
re-visit that tonight. Steady small craft winds over northern Lynn
Canal today with no significant decrease expected until tomorrow
mid to late morning. Point Retreat only reporting in the middle
teens for wind speed, but the sensor at Little Island indicating
solid small craft winds there, so have added a small craft
advisory for southern Lynn Canal through tonight as well. Winds
there expected to diminish sooner than over the northern part of
the Canal. Point Bishop has been steadily reporting northerly
winds around 20 kts, thus believe there are high end small craft
winds coming out of Taku Inlet as well. On the outside, a weak
barrier jet will form this evening west of Icy Bay and persist
through the day tomorrow in advance of the approaching front.

Little change to the short term forecast - tonight and tomorrow -
apart from increasing winds over southern Lynn Canal and adjusting
overnight lows and daytime highs by 1 to 3 degrees. Blowing dust
and mention of flurries is new too. Overall forecast confidence is
average trending to above average.

.LONG TERM...Increasing chances of snow and rain into early next
week as the high in Canada pulls away to the east and a new system
moves into the central gulf. Current guidance is still suggesting
that the main low will take a southern gulf track weakening as it
goes. The associated front will take a more east-west orientation
as it moves north through the panhandle Mon night and it will be
shearing apart as it comes. The results are that the heaviest
precip will be across the southern panhandle with lighter amounts
expected the farther north you go. Winds will mainly be gales for
the gulf and southern inner channels with strong wind gust
possible for the southern panhandle land areas Mon night into
Tue.

Precip type will be the other complication. The current cold air
mass will be lingering in the inner channels as the precip starts
up. The southern panhandle will be warm enough to start as rain,
but the rain/snow line will likely start out somewhere around
Kupreanof Island and will gradually move north Mon night into Tue.
Snow accumulations will be complicated by the northward movement
of the warm air and by diminishing precip as the front shears
apart. At the moment it looks like accumulations will only be
around a few inches at most before the precip turns to rain or the
precip dissipates.

For the rest of the extended the main storm track remains south of
the panhandle but it will be far enough north that the associated
fronts will make it as far north as the central panhandle at
least. Meanwhile the northern panhandle will likely still see
northernly winds through the week with a chance that some of these
fronts will make it into the northern inner channels. Forecast
retains mostly cloudy skies and chance of precip as a result for
most of the area into next weekend.

&&

.AVIATION...VMC conditions will prevail through the period for the
most part. Increasing clouds with decreasing CIGs vicinity
Yakutat. Periods of reduced vis vicinity Haines due to blowing
glacial silt off the Chilkat River. Turbulence out of interior
passes below ridgetops and over Lynn Canal still probably an
issue, though have no PIREPS to confirm this.

&&

.AJK Watches/Warnings/Advisories...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ012-013-051-052.
     Small Craft Advisory due to Seas for PKZ041-042.
&&

Fritsch/EAL

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