695
FXAK02 KWNH 062321
PMDAK

Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
621 PM EST Thu Mar 06 2025

Valid 12Z Mon Mar 10 2025 - 12Z Fri Mar 14 2025

...Deep Bering Sea Storm to bring high winds to the Western and
Central Aleutians this weekend...

...Overview...

A strong western Bering Sea storm will send a leading front
through the Bering Sea/Aleutians, with a downstream low forming
over the western to northern Gulf of Alaska Sunday-Tuesday.
Guidance is split for the North Pacific/Aleutians/Bering Sea
pattern into mid-later next week, but with a majority suggesting
another fairly vigorous system may track toward/south of the
Aleutians and AKpen. Overall these systems will tend to focus
precipitation and potential for enhanced winds across the
Aleutians and surrounding waters.

...Guidance Evaluation and Preferences...

Model and ensemble guidance is reasonably well clustered valid for
this weekend/Monday and a composite of the 12 UTC
GFS/ECMWF/Canadian models and WPC product continuity seems to
offer a solid forecast base with good detail consistent with a
pattern with above normal predictability and continuity. Forecast
spread and uncertainty grow rapidly by Wednesday of next week.
Accordingly, quickly transitioned WP product guidance preference
at these longer time frames to the still compatible
GEFS/ECMWF/Canadian ensemble means.

...Weather/Hazards Highlights...

A strong western Bering Sea storm and its leading frontal system
will spread brisk to high winds (southerly ahead of the front and
westerly behind) and organized precipitation across the Aleutians
and surrounding waters this weekend. Guidance has come into better
agreement on high wind impacts hitting at least the Western
Aleutians starting Saturday afternoon and especially Saturday
night. Strong winds are likely to continue into Sunday into the
Central Aleutians. Some moisture and gusty winds may reach the
southwestern mainland as well, though they should not be nearly as
strong by the time they reach Southwest Alaska. Due to the well
agreed upon weakening of the low as it approaches Southwest
Alaska, agreement is not nearly as great about the location of the
center of the storm as it approaches the coast, as weaker lows are
less defined in the guidance.

An embedded developing frontal wave appears likely to develop into
a triple point low between Kodiak Island and the Kenai Peninsula
by early Monday, which may focus some heavier precipitation in its
vicinity around Sunday-Monday. There is a minority scenario that
could lead to a farther east track of this wave, resulting in more
light to moderate rainfall across the Panhandle. Another storm
potentially reaching the Aleutians around the middle of next week
may produce enhanced precipitation and strong winds, but there
remain significant differences in details among guidance temper
confidence in specifics at this time.

Moderately below normal temperatures, more likely for daytime
highs, should move across the state from west to east during the
weekend and into early next week.  These cool anomalies will
displace warmer temperatures forecast from this week into early
Saturday.   Some degree of upper ridging or southerly flow aloft
should favor a rebound in temperatures over the western mainland
during the first half of next week while a weak upper trough/low
just west of the Panhandle may keep highs below normal over that
region and eastern Southcentral during the early-middle part of
next week.

Wegman


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

$$