Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
748 PM EDT Sat Mar 29 2025
Valid 12Z Wed 2 Apr 2025 - 12Z Sun 6 Apr 2025
...General Overview...
A generally mild pattern is expected to be in place across the
Alaska domain for the middle to end of the week, with an upper
level ridge axis building north into the central and eastern
mainland. Surface low pressure and accompanying upper level
shortwave is progged to clip the northwestern portion of the state
mid-week, bringing some light rain and snow to much of the
Interior through early Thursday. A larger low pressure system
organizes over the Gulf and brings a return to coastal rain and
mountain snow to southern Alaska late Friday and into the weekend.
...Guidance/Predictability Assessment...
The 12Z model guidance suite features decent overall agreement
across the Alaska domain for the middle of the week with some
mesoscale differences noted with the low reaching northern Alaska,
so a multi-deterministic model blend suffices as a starting point
in the forecast process. Looking ahead to the end of the week and
beyond, the 12Z GEFS mean diverges from the overall consensus in
suppressing the upper level ridge axis across the state, and has
the Gulf low over the weekend to the east of the better clustered
CMC/ECMWF/GFS/ECENS guidance. Therefore, the ECENS was favored
much more than the GEFS for the Friday through Sunday time period.
Overall model differences increase quite a bit going into Sunday,
so the ECENS was increased to about 40% by this time.
...Weather/Hazards Highlights...
Widespread light snow is expected across the northern half of the
state on Wednesday in association with the polar low and the
trailing cold front, and light rain for the lower elevations of
the central/southern Interior. Some gusty winds may also accompany
this front as it passes. Heavier precipitation becomes
increasingly likely for the southern coastal areas from the Alaska
Peninsula to the Prince William Sound and then western portions
of the southeast panhandle going into next weekend. An expansive
area of low pressure develops over the central/southern Gulf and
slowly lifts north, bringing a return to moist onshore flow with
coastal rain and mountain snow, which could be heavy at times.
Gale force winds are likely over the open waters of the Gulf and
gap wind events are also likely.
Temperatures are generally expected to be above average across the
majority of the state Wednesday, followed by a return to more
seasonal readings by the end of the week behind the front. The
mild conditions are likely to continue going into next weekend
across the southeast portion of the mainland as the upper ridge is
expected to persist and delay the arrival of any cold fronts.
However, it does not appear likely that it will be warm enough yet
for river ice break-up concerns for most areas.
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