Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
724 PM EDT Mon May 5 2025
Valid 12Z Fri 9 May 2025 - 12Z Tue 13 May 2025
...General Overview...
The strong low pressure system over the Gulf early this week should
be weakening and sinking to the south by the beginning of the
forecast period Friday, with a stationary frontal boundary draped
across the Interior. Meanwhile, an organizing storm system
approaches from the west and is in the vicinity of the Aleutians
and southern Bering by next weekend. The strong Arctic surface
high across northern Alaska weakens through time with a gradual
warm up expected over the upcoming week.
...Guidance/Predictability Assessment...
The 12Z deterministic model guidance is in good overall agreement
across the domain to close out the work week. Similar to
yesterday, the GFS and GEFS are a little faster with the low
situated over the Bering Sea region, but close enough to be a part
of the preferred model blend. Looking ahead to Sunday, the ECMWF
and GFS both feature a developing surface low south of the
Aleutians that appears distinct from the low over the Bering. Upon
examination of the AIFS guidance, a solution closer to the
CMC/UKMET is also possible with more of a surface trough, so the
frontal boundary was depicted with a wave of low pressure along it
south of the Aleutians. Towards the end of the period next
Tuesday, the model consensus generally favors the idea of a
surface low in the vicinity of the Alaska Peninsula, and a trough
of low pressure extending west across the central Bering. The
ensemble means were increased to about half by this time.
...Weather/Hazards Highlights...
Scattered to numerous showers are likely to be ongoing across the
southeast Panhandle region for the end of the week and perhaps
into Saturday with onshore flow continuing east of the weakening
Gulf low, but does not appear to be excessive. There could be an
abatement in the precipitation by Sunday across much of south-
central Alaska as the region will be between storm systems. With
the next low pressure system from the Aleutians/Bering moving in
by Monday/Tuesday, rain and mountain snowfall chances increase
once again, mainly for the windward facing terrain. Temperatures
are expected to be slightly above average across most of the
mainland, with highs gradually warming each day with readings
approaching 70 degrees for some Interior valley locations by early
next week. The Arctic Coast has the coldest anomalies, but these
too should moderate going forward.
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