Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
749 PM EDT Thu Mar 13 2025
Valid 12Z Mon 17 Mar 2025 - 12Z Fri 21 Mar 2025
...General Overview...
The active storm track across the North Pacific continues through
next week as a series of low pressure system steady track from
east to west and enter the Gulf region. The first system of
interest during this forecast period is expected to pass just
south of the Alaska Peninsula Monday and then reach the northern
Gulf Tuesday into Wednesday while weakening. The second storm
system crosses the Aleutians mid-week and then enters the Gulf by
late Thursday/early Friday, and the final storm appears on the
distant horizon on Friday south of the central Aleutians. Most of
these low pressure systems should be on the order of 975-990 mb.
Across the mainland, a steady warming trend ensues as a warm front
lifts northward towards the Brooks Range, while the Arctic Coast
remains under the influence of a cold arctic surface high.
...Model guidance and predictability assessment...
The 12Z model guidance suite features good overall agreement
across the domain for the beginning of next week with mainly
mesoscale differences noted with the first low passing just south
of the Alaska Peninsula, so a multi-deterministic model blend
suffices as a starting point in the forecast process. For the
storm system approaching the Aleutians mid-week, the GFS and the
GEFS are generally a little faster compared to the ECMWF and the
ECENS, and the GFS depicts a stronger triple point low development
by Thursday night across the eastern Gulf. For the final low
crossing south of the Aleutians Friday, the GFS is slower and
stronger, whereas the CMC is weaker and farther to the southeast,
with the ECMWF between these two solutions. The ensemble means
were increased to about half by the end of next week to account
for gradually increasing model spread across the domain.
...Sensible weather and potential hazards...
The majority of the precipitation across the state will be next
Monday and Tuesday as the first storm system enters the Gulf and
produces an atmospheric river event at the southern mainland coast
and eventually southeast Alaska, with rain near the coast and
heavy snow for the coastal mountain ranges. This is now being
depicted on the WPC hazards chart with the event spanning two
days, with several inches of rainfall across the windward terrain.
Windy conditions and some blowing snow are likely for the North
Slope and points north owing to a strong pressure gradient from
the arctic high early in the week. After most of the state starts
off the week with slightly below average temperatures, a steady
warming trend results in most of the Interior being above average
to close out the work week.
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