Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
111 PM EST Wed Jan 30 2019

Valid 12Z Sun Feb 03 2019 - 12Z Thu Feb 07 2019

...Guidance and Predictability Assessment...

Latest models and ensembles offer better than normal solution
clustering, bolstering forecast confidence.
Accordingly, the WPC medium range product suite was primarily
derived from a composite blend of the 12 UTC GFS/GEFS mean and 00
UTC ECMWF/ECMWF ensemble mean along with guidance from the 12 UTC
National Blend of Models. Applied manual adjustments to this blend
to insure surface low pressure depths consistent with ample
support aloft. This solution maintained excellent WPC continuity
from yesterday.

...Pattern Overview and Weather/Hazards Highlights...

Guidance is fairly agreeable in showing a mean pattern that
features a mean ridge over the east-central Pacific into Mainland
Alaska and an area of troughing with multiple closed lows across
the northwestern Pacific and into the Bering Sea. The mean ridge
will be somewhat porous, allowing periodic passage into the
western periphery of energy contained within Bering Sea/North
Pacific flow. This pattern will tend to keep the strongest low
pressure systems over the Bering Sea while leading frontal systems
weaken in their approach to the mainland. Associated triple point
waves may track across the Alaska Peninsula and Gulf of Alaska.
These systems offer maritime wind/waves threats and inland
advecting moisture with system approaches will support widespread
periodic precipitation from the Bering Sea/Aleutians into
western/southwestern Alaksa out through the southern/southeastern
Alaskan tier.

Schichtel

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