Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
305 PM EST Wed Jan 31 2018

Valid 12Z Sun Feb 04 2018 - 12Z Thu Feb 08 2018

The medium range forecast period starts off rather straight
forward for AK with a high amplitude bubble ridge of high
pressure, extending from Chukchi Sea southeastward into the state.
This sturdy 500mb feature will stay stationary or drift south and
east toward the state into early next week. However, by next
Tuesday or Wednesday, the upper ridge center perhaps weakens of
pinched off by low pressure systems to the north and south. For
the most, a constant deep cyclone will be present near the
southern extent of the Aleutians with cold arctic high pressure
over most of the state. However, within conjunction with the
weakening ridge, a powerful low pressure system may emerge into
the gulf of AK with onshore southerly component next Wednesday or
Thursday. The model guidance spread is actually somewhat minimal,
which may allow operational guidance out through the middle of
next week. WPC generally followed a blend of the 00z/31 ecmwf/ec
mean with 06z/31 gfs/gefs mean throughout, with a bit more weight
toward the ecmwf.

In terms of sensible weather, this pattern will be a dry one for
much of mainland Alaska, with surface high pressure dominant
through much of the period. Meanwhile, a relatively wet pattern
appears possible from the Aleutians to the Panhandle within this
large scale regime.

Musher