421 
fxak68 pafc 180030 
afdafc 


Area forecast discussion 
southcentral and southwest Alaska 
500 PM akdt Wednesday Mar 17 2010 


Analysis and upper levels... 
upper levels...the upper high over northwest Alaska continues to move 
east across northern Alaska. An strong upper low near northern 
Kamchatka peninsula is vertically stacked above the surface low. 


At the surface...a high over northwest Canada extends a ridge across 
the northern interior. A weak low south of Kodiak Island continues to 
weaken and will dissipate this evening. A strong low near northern 
Kamchatka peninsula continues to drift north toward Siberia. The 
associated weather front over the western Bering Sea continues to 
move east. 


Model discussion.. 
models are in good agreement over the Bering Sea and Mainland Alaska 
through Friday afternoon but have divergent solutions for the low 
pressure system entering the Gulf Thursday. The ec and NAM models 
tend to weaken the low over the northern Gulf Friday while the GFS moves 
it inland before dissipating. We have more confidence in the ec 
solution because it has been a more consistent model. 


Short term forecast... 
Gulf of Alaska and south-central Mainland... 
another low pressure system 500 miles south of Kodiak Island will 
move into the western Gulf Thursday night then will dissipate over 
the northern Gulf Friday. A south to southeast flow will develop over 
the Gulf ahead of the low tonight will persist through Friday 
morning. Isolated snow showers will develop over western Prince 
William Sound, eastern Kenai Peninsula and Kodiak Island tonight and 
will become scattered showers Thursday morning. A weather front 
associated with the low center will move into the Gulf Thursday 
morning and move inshore along the central Gulf Coast Thursday night. 
Rain associated with the next low will move into Kodiak Island 
Thursday morning. Rain and snow will move into Prince William Sound 
Thursday and become showers late Thursday night. Locally strong east 
to southeast winds will develop near the entrance to Prince William 
Sound Thursday afternoon and will persist through Friday. 


Southwest Mainland...middle to high level clouds will be moving into 
the area tonight. Areas of snow will develop along the Aleutian Range 
Thursday night but should change to snow showers Friday. Areas of 
light snow associated with the Bering weather front will move onto 
the Kuskokwim Delta coast Friday. 


Bering Sea...the weather front over the western Bering Sea will 
slowly weaken as it moves into the eastern Gulf late Thursday then 
will most likely dissipate along the Delta coast Friday. 


Long term forecast... 
scattered showers over south-central Alaska will diminish over the 
weekend as a weak upper high develops over the central Gulf Coast 
Saturday night and Sunday. Scattered showers will remain over 
southwest Alaska as an upper low develops over Bristol Bay Saturday 
and Sunday. A moderate low south of the western Aleutians late Friday 
will move north through the western Bering Sea through the weekend. 




Aer/alu...watch/warning summary 
public...none. 
Marine...gale 120 125 130 132 138 140 141 172 176 185 
fire weather...none. 


Nm Mar 10 

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