Weather Service Report


041 
FXAK67 PAJK 301734 CCA
AFDAJK

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 a 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 and 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 were 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 
Sunday.

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...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ052. 

&&

$$

BC/KV

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