Small Craft Advisory 608, NWS Juneau, AK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
337 PM AKDT SUN OCT 2 2016

.SHORT TERM...Surface low along the old occluded front from low
over the northern Bering Sea is moving east to be about 150 nm
west of northern Haida Gwaii by Monday afternoon. The main rain
shield with the low spreads into Prince of Wales island this
evening, followed shortly by southern inner channels and southern
Baranof Island. The rain should spread north to roughly Icy strait
to Juneau line on Monday.

Winds head of the frontal feature are expected to reach 30 to 35
kt, and have prompted Gale warnings for the coastal waters off
the Prince of Wales Island and then the southern part of the next
northern marine zone (42) south of Sitka. Small craft winds of 25
to 30 kt through most of the inner channels south of Icy Strait.
Gusty winds on Monday as the band gets closer to the Prince of
Wales coast will have the exposed locations gusting to 40 mph at
times Monday and Monday afternoon.

Rain fall amounts through Monday afternoon should total less than
a half inch. The larger rain amounts will be in the Hydaburg and
Klawock regions.

.LONG TERM...A plot for the long-term has begun to emerge. The
central character remains a dynamic low tracking east offshore of
Haida Gwaii by Monday afternoon. This low drops southeast, guided
by a 300 mb jet, along the Canadian West Coast Monday night into
Tuesday. Rain bands continue to pass across the southern and
south-central Panhandle Monday night but begin to weaken as early
as Tuesday morning. A complex flow pattern over the northern
Panhandle, with various components of onshore flow at different
levels yet characterized by weak forcing, necessitates a chance of
rain...or snow in the higher elevations and potentially near the
borders. However, any thing that falls will be very light. As the
low to the south pulls away, winds will diminish over the southern
Inner Channels and begin to back to the north and northwest.

Midweek, the Panhandle wide should lie under brief influence of a
ridge. However, onshore flow and a wave of energy riding across
south-central Alaska will keep skies mainly cloudy at least near
the Coast Mountains. With the potential of partly cloudy skies
elsewhere, we have lowered minimum temperatures during this time.
Winds have also been greatly decreased during this time. Fog may
be a potential for this time, but given such a dry period, we do
not anticipate significant impacts.

We still watch whether a wave will push out of the North Pacific
and arrive in the southeast gulf by Thursday, or not. The ECMWF
has maintained that this system takes a more easterly track toward
the Pacific Northwest and not towards Haida Gwaii. At this point,
the GFS, the Canadian, and their ensemble means take the system
towards Haida Gwaii. The net difference in impact is whether the
south receives more rain Thursday/Friday. But for the north, it
looks dry at least through Friday.

We used the NAM and Canadian GEM in the mid-range. Extended
changes were guided principally by WPC with some help from the
Canadian GEM and GFS. Forecast confidence average.

&&

.AJK Watches/Warnings/Advisories...
PUBLIC...STRONG WIND from Monday morning through Monday afternoon for
     AKZ027.
MARINE...Gale Warning for PKZ041-042.
     Small Craft Advisory for PKZ032>036-043.
     Small Craft Advisory due to Seas for PKZ051-052.
&&

Bezenek/JWA

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