Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
328 PM EST Wed Dec 12 2018

Valid 12Z Sun Dec 16 2018 - 12Z Thu Dec 20 2018

The latest runs of model and ensemble guidance is reducing the
spread of error for the pattern evolution in the extended periods.
Two closed lows are progged to pass south of the Aleutian chain
and continues eastward through the Gulf of Alaska. The leading
system will weaken as it approaches the south/southeast coast
while ushering in scattered to widespread precipitation to these
areas. The second cyclone is expected to follow a similar track
through the Gulf of Alaska by the middle of this coming week. The
preferred blend comprised of the 00Z ECMWF and its ensemble mean,
the 12Z GFS, and the 12Z GEFS/NAEFS means.

Campbell

WPC medium range Alaskan products including 500mb, surface
fronts/pressures progs and sensible weather grids can be found at:

http://www.wpc.ncep.noaa.gov/alaska/ak_5dayfcst500_wbg.gif
http://www.wpc.ncep.noaa.gov/alaska/akmedr.shtml
http://www.wpc.ncep.noaa.gov/alaska/ak_5km_gridsbody.html