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FXAK02 KWNH 222320
PMDAK

Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
618 PM EST Sat Feb 22 2025

Valid 12Z Wed Feb 26 2025 - 12Z Sun Mar 2 2025

...General Overview...

A moderately strong surface low is expected to track in a general
northward direction across the eastern Gulf for the middle of the
week, and weaken by the time it reaches the southern mainland
coast.  A much stronger storm system develops over the north
Pacific, potentially near 960 mb, and tracks in a general
northeasterly direction to the south of the Aleutians through the
end of the week, and likely reaching a location a few hundred
miles to the south of Kodiak Island by Friday morning.  This will
also increase chances for moderate to heavy precipitation near the
southern coastal areas along with windy conditions.  Meanwhile, an
upper ridge axis is expected to extend from western Canada into
the Interior through most of the forecast period, with relatively
mild conditions for central and southern Alaska, and continued
cold north of the Brooks Range where an arctic surface high will
govern the overall weather pattern.


...Guidance Evaluation and Preferences...

For the beginning of the forecast period Wednesday, there remain
noteworthy model spread with respect to the eastern Gulf low.
There is decent agreement among the CMC/ECMWF/UKMET solutions with
this low, but the GFS is still considerably slower in bringing
this low to the north, with the ensemble means generally between
these.  The AIFS guidance is much closer to the non-GFS cluster,
so the blend for Wednesday into Thursday used less GFS to account
for this.

The big low pressure system south of the Aleutians has better
overall model agreement, even though the CMC/UKMET are slightly
faster with it.  Going into Friday, the ECMWF/ECENS serve as a
good middle ground solution between the faster CMC/UKMET and
slower GFS/GEFS with that low, but all bring impacts with enhanced
onshore flow and heavy precipitation/wind.

Heading into next weekend, the models generally agree that a broad
upper ridge will extend across the eastern mainland and western
Canada, but vary more across the North Pacific with the next
potential storm system to develop south of the Aleutians and a
separate arctic upper low near eastern Siberia.  The ensemble
means were gradually increased to about half of the forecast blend
by next Sunday.


...Weather/Hazards Highlights...

In terms of precipitation, multiple rounds of coastal rain and
mountain snow can be expected for the southeast Panhandle region,
and another surge of moisture in association with the big Pacific
low late in the week will likely result in 1-3 inches of rainfall
for parts of the Kenai Peninsula, Kodiak Island, and near the
Prince William Sound, and heavy snow for the higher elevations.
Widespread gale to strong force winds are likely across the open
waters of the Gulf and potentially reaching some of the coastal
zones, so this would create hazardous boating conditions.

Temperatures are generally expected to be near to slightly above
average across most of central mainland Alaska through the
forecast period south of the Brooks Range, and potentially greater
positive anomalies across inland portions of southern mainland
Alaska.  It should remain the case that the coldest conditions
will continue to be across the North Slope and northward to the
Arctic Coast where readings should remain slightly below seasonal
averages with the Arctic high in place.

Hamrick


Additional 3-7 Day Hazard Information can be found on the WPC
medium range hazards outlook chart at:
https://www.wpc.ncep.noaa.gov/threats/threats.php

WPC medium range Alaskan products including 500mb, surface
fronts/pressures progs and sensible weather grids can also be
found at:
https://www.wpc.ncep.noaa.gov/alaska/ak_5dayfcst500_wbg.gif
https://www.wpc.ncep.noaa.gov/alaska/akmedr.shtml
https://www.wpc.ncep.noaa.gov/alaska/ak_5km_gridsbody.html

$$