692 
fxak69 pafg 211302 
afdafg 


Northern Alaska forecast discussion 
National Weather Service Fairbanks Alaska 
402 am akst Sat Nov 21 2009 


Discussion...the cold upper trough that has been locked in 
place across northern Alaska will finally get nudged out this weekend 
as an upper ridge develops across the northeast Pacific. Another 
upper low off the northern coast of Greenland will also be on the 
move and is expected to drop into the northern Chukchi Sea early 
next week. 


The models diverge by the middle of next week. Both the GFS and 
European model (ecmwf) then lift the incoming low back out to the north. The European model (ecmwf) 
however drops a portion of this upper trough into northwest Alaska late 
in the week and is colder than the GFS across the northwest half 
of the forecast area. The main jet will remain well south of the 
area...and the models all indicate that a series of lows will move 
across the northeast Pacific next week. The largest spread is 
noted with a system towards the end of the week. The GFS takes 
this low as far north as Saint Paul Island. The European model (ecmwf) is much 
further south across the Aleutians. For now will side with a more 
European model (ecmwf) outcome as the main jet is pretty far to the south. Overall 
this pattern should feature above average temperatures and below 
average precipitation for northern Alaska. The NCEP rmop by late next 
week has high measures of predictability to the west of the state 
and relatively low measures of predictability across the Mainland. 


Interior...near record cold expected again today and tonight. A 
milder airmass is expected to move in but it will take a while to 
scour out the cold air trapped in the deeper basins...which will 
cause dispersion problems this weekend. A tiny weak trough south 
of the Alaska Range is expected to move east today...there appears 
to be very little consequence with this trough...but it will 
bring a remote chance of a flurry or two for locations south and 
east of Fairbanks through tonight...which could moderate 
temperatures in some places. On Sunday...an inverted trough will 
poke up from the south and bring another chance of flurries for 
locations west of a line from Arctic Village to Lake Minchumina. 


South winds through Alaska Range passes will increase tonight 
and sun...though as winds increase temperatures will also 
rise...so wind chill advisories are not expected...but wind shear 
could become a problem for aviators as many valleys and basins 
north of the Alaska Range will remain cold and calm as the middle 
level winds skip off the top of well formed inversions. 


West Coast...a low near Point Hope will move south today and 
dissipate over the Seward Peninsula. A cold trough will linger 
over the West Coast after this low dissipates...moderate northerly 
flow over open water will keep snow showers around for coastal 
locations through the weekend. Temperatures will moderate early 
next week as a building ridge over the eastern part of the state 
pushes low pressure and a more moderate airmass west into the 
Bering Sea...along with a chance of snow for much of the area. 


North Slope...low stratus fog and flurries will hang around 
through the weekend. No major snow fall or strong winds expected. 


Coastal hazard potential days 3 and 4...none 


Hydrology...the Tanana river is out of its banks near ruger trail 
in Salcha. No major flooding is expected but water remains high in 
many areas in and around Salcha. 


&& 


Afg watches/warnings/advisories... 
heavy freezing spray warning for pkz210-pkz220-pkz225. 


Small Craft Advisory for pkz210. 
&& 


$$ 


Ka/cumulonimbus Nov 09 

National Weather Service Glossary of Abbreviations

Non-Expanded Version (with abbreviations)