Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
621 PM EDT Sun Apr 10 2022
Valid 12Z Thu Apr 14 2022 - 12Z Mon Apr 18 2022
...Pattern and Weather/Hazard Highlights...
An upper level ridge axis is forecast to be in place across
mainland Alaska for the end of the week and into next weekend,
with an anomalous surface high becoming entrenched north of the
Arctic Coast. Meanwhile, a strong low pressure system should
cross the central Aleutians and then slowly weaken over the Bering
through the end of the week. An even more impressive storm may
approach this same region for the beginning of next week, along
with another low entering the Gulf of Alaska.
Most of the state should behind the extended period with
temperatures generally near to above average, and then colder
weather arrives in time for the weekend for the eastern half of
the state as a cold front moves in from western Canada. Milder
conditions should continue for the southwestern mainland going
into the beginning of next week. In terms of precipitation, most
of the Interior region should remain dry, and periods of rain and
mountain snow are likely for coastal regions of southern Alaska as
storm systems pass south of the coast. Windy conditions are also
possible for portions of the Aleutians by the end of the forecast
period.
...Guidance/Predictability Assessment...
The 12Z model guidance suite is initially in good synoptic scale
agreement and captures the omega block pattern well. By Saturday
and beyond, there is better model agreement among the ECMWF/CMC
regarding the evolution and track of both the Gulf and Aleutians
low pressure systems, with the GFS nearly non-existent with the
Aleutians low early next week which increases uncertainty in this
event. The GFS and UKMET are also faster with the trough entering
the Gulf region by early Saturday compared to the ensemble means.
Farther north, model consensus is good with the Arctic surface
high holding strong for the northern third of the state. For the
fronts/pressures forecast, a nearly deterministic model blend
suffices for Thursday, and then transitioning to more weighting on
the ECMWF/CMC solutions going into Friday and Saturday, with more
ensemble means by Sunday and Monday.
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