Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
526 PM EST Sat Feb 26 2022
Valid 12Z Wed Mar 2 2022 - 12Z Sun Mar 6 2022
...Pattern Overview...
Multiple storm systems are forecast to traverse the North Pacific
and impact the Aleutians and portions of the western mainland
through the end of the week, although nothing out of the ordinary
in terms of expected intensity. An upper level ridge is expected
to build over eastern Alaska and western Canada by Friday and into
next weekend, with a return to above normal temperatures across
much of the state.
...Guidance/Predictability Assessment...
There is reasonable synoptic scale agreement on the main weather
features of interest on Wednesday, including a weakening low
approaching the southeast Panhandle region. By Thursday, the
ECMWF is displaced to the southeast of the model consensus with
the next low lifting northward towards the Aleutians, and this
trend continues through Friday night as the main low settles over
the Bering. The GFS and CMC solutions are closer to the ensemble
means. More uncertainty exists with the last organized low
entering the Alaska domain from the North Pacific next weekend,
with the CMC well east of the ensemble means, and the GFS slower
in bringing the low north and the ECMWF well to the north.
Taking these factors into account, the WPC fronts/pressures
forecast was primarily based on a multi-deterministic blend for
Wednesday, and then weighting slightly more towards the GFS whilst
gradually increasing contributions from the ECENS/GEFS means
through the remainder of the forecast period.
...Weather/Hazard Highlights...
Southerly flow from the Gulf of Alaska will advect moisture
northward and thus keep rain and snow chances in the forecast from
the Aleutians to the Alaska Peninsula, as a low pressure system
lifts northward and then enters the Bering. Periods of moderate
to locally heavy rain/snow are possible, along with gusty winds,
and the locations of the heaviest QPF will be dependent on the low
track. Some light rain/mountain snow will likely reach across
western Alaska later next week, but central and eastern portions
of the Interior should remain dry underneath a building upper
ridge.
Above average temperatures will dominate much of Mainland Alaska
through next week, both for daytime highs and overnight lows. The
highest anomalies are forecast over the northern and western parts
of the mainland later in the week and into the weekend. The
exception to this will be across the Panhandle and southeastern
Mainland where near average temps are expected owing to more
onshore flow.
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