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Northern Alaska forecast discussion 
National Weather Service Fairbanks Alaska 
314 PM akdt Tuesday Oct 7 2008 


Synopsis... 
the long wave trough over Mainland Alaska will retrograde over 
western Alaska Thursday and Friday. This means below normal temperatures 
will continue through Wednesday night and then will see warming eastern 
interior as a strong Chinook develops Thursday night. 


A 972 mb low north of Banks Island will move north tonight. A low 
pressure trough from this low to Cape Halkett will move to Barter 
Island northeast by 4am Wednesday and then move east. This is causing 
snow and westerly gales in the eastern Arctic coast now that will 
decrease overnight as the trough moves east and weakens. This is 
also causing heavy surf but no significant rise in in sea heights 
has been reported. 


High pressure over the western Chukchi Sea and eastern Bering seas will 
build east over the West Coast and Arctic coast of Alaska Wednesday and 
then move north of the Arctic coast on Thursday. Winds will decrease 
through Wednesday under this high. Scattered snow showers caused by the 
cold air with this high are occurring in onshore flow, but will 
diminish Wednesday as flow turns offshore. 


A trough aloft from Ambler to Bethel will move to Ambler Glennallen 
by 4pm Wednesday and to the Brooks range by 4pm Thursday. There are flurries 
east of the trough and clearing to the southwest. 


A small low aloft over Denali will drift to Nenana tonight and 
dissipate over The Fort Yukon area Wednesday. Snow showers with this will 
diminish as it moves north, but some areas may receive up to one 
inch tonight. 


The strong low moving into the southern Bering Wednesday night will 
spread a front to the Bristol Bay coast Thursday and over the interior 
Friday. This will bring northerly gales to the northern Bering and 
West Coast Thursday into Friday while it brings strong Chinook winds to 
the Alaska Range Thursday PM into Friday. 




&& 


Discussion... 
models initialize fairly well though not quite deep enough on the 
low in northwest Alaska or the one over the Kenai Peninsula. Models 
follow same general pattern. GFS continue to move the low just 
north of Banks Island northward more quickly than the NAM. Given 
the track speed of this low favor the GFS on this feature. 


The deep low moving into the southern Bering Wednesday night is almost 
15 mb deeper and the GFS than the NAM. Again favor the GFS due to 
the strong dynamics now southwest of Shemya supporting this. 




Coastal hazard potential days 3 and 4...north gales all of West 
Coast Thursday and Friday. Will see heavy surf Bering Strait and St 
Lawrence Island. Shishmaref doesn't look as bad since winds there 
are more northeast. 


&& 


Hydrology...freeze up under way. 


&& 


Afg watches/warnings/advisories... 


Heavy freezing spray warning for pkz240-pkz245. 


Small Craft Advisory for pkz210-pkz240-pkz245. 


Gale Warning for pkz245. 
&& 


$$ 


Jb Oct 08 

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