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FXAK67 PAJK 301257

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
457 AM AKDT Sun Apr 30 2017

.SYNOPSIS...One low moving into BC early this morning with another
front moving into the W gulf. Fair weather under the shortwave
ridge will be brief as precip moves into the N gulf coast late
this morning and progresses E. Deep onshore flow will bring a
series of storms to SE AK through the week.


.SHORT TERM...Sunday through Mon night...Surface analysis and
satellite imagery depict an low moving inland near Prince Rupert
and another low over the Aleutians pushing a front into the W
gulf. A brief period of dry wx to begin Sun as shortwave ridge
moves across the panhandle between the two systems. The front will
bring precip to AKZ017 late this morning the spread E this
afternoon and evening. This marks the beginning of a pattern
change with deep moist onshore flow becoming dominant across the
region. Strongest winds early this morning over Dixon Entrance
will diminish quickly as the low moves inland and weakens. Wly winds
over the gulf this morning will begin to veer to the SE and
increase this afternoon and evening in response to the front
moving across the waters. Expect advisory level winds to develop
over PKZ052 late tonight and expand E early Mon. Winds over the
inner channels will be 15 to 20 kt in many places Mon and
the north gulf coast barrier jet will reach 30 kt as well.
Inherited forecast represented this well and made minor changes
to reflect current conditions/trends with GFS/EC favored solutions
for guidance through the period.

.LONG TERM /Tuesday through Sunday night/...As of 1030 pm
Saturday night the models have come to a more consistent
agreement, used the GFS in the mid range through Wednesday with a
gradual increase to using WPC reaching 100 percent by the weekend.

Focused most of my time to the mid week with the gale force
system moving into the gulf Tuesday from the south. The area of
strongest winds will track north and spread across much of the
eastern gulf by Tuesday afternoon with 45 kt gales. There will be
a small break between the first system and the next as it follows
a similar track into the southern gulf. The second system is
slightly weaker but is still expected to bring gales the
southwestern half of Marine zone 310 up to the Fairweather Grounds
and Marine Zone 52, well offshore of Yakutat. The first system
will give a glancing blow to the outer coastal areas of Prince of
Wales and Southern Baranof Island Tuesday afternoon and evening.
Confidence of strong winds in these areas is increasing with
better model agreement. GFS shows good position of this system,
although it is one of the strongest. Wind speeds where reduced to
accommodate for that. With an easterly flow returning there will
also be increased winds near the Cross Sound area. The northeast
gulf coast will feel the strongest affects of the first system
late Tuesday night as the system moves quickly north northeast. By
Thursday winds will have diminished to 15-20 kt across the entire
area, it doesn`t last long as small craft advisory teases Marine
zone 41 Friday evening and then another system moves into the gulf

The precipitation is paired closely with the timing of the winds
with wet weather Tuesday and Wednesday moving up across the
panhandle. The wet pattern holds in place through Thursday and
then starts to erode from the northwest. Drier trend for the
weather for the weekend but the question is how dry. WPC keeps a
chance of rain.


.AJK Watches/Warnings/Advisories...
MARINE...Small Craft Advisory for PKZ052.




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