Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
634 PM EDT Mon Mar 25 2024
Valid 12Z Fri Mar 29 2024 - 12Z Tue Apr 02 2024
...Late Week/Holiday Weekend One-Two Storm Punch to offer
Wind/Wave/Coastal Flooding and/or Snow/Rain Threats from the
Aleutians through Southwest and Southern Alaska...
...Guidance Evaluation and Preferences...
The 12 UTC GFS/ECMWF/UKMET/Canadian model solutions are broadly
clustered into Easter morning with decent ensemble support. A
favored model composite highlights the most predictable detail in
highly energetic flow, despite pesky but mostly smaller scale
differences. Prefer the still compatible GEFS/ECMWF ensemble means
onward into next week amid growing system and stream phasing
differences issues. This mainly includes conditions for a cooling
Mainland as Arctic stream upper trough energy works to dig
southward and potential/eventual phasing to some degree with
Pacific stream energies into the Gulf of Alaska and associated
cold low developments offshore to monitor.
...Pattern Overview and Weather/Hazards Highlights...
There remains a good guidance signal that an amplified upper
trough and an associated surface low pressure system will
track/develop from a position currently by Japan to across the
northwest Pacific to near the Aleutians Thursday to offer
turbulent maritime conditions and swirling winds and rains. This
storm and frontal system is likely to work northeastward into the
Bering Sea and support high winds/waves and potential associated
coastal flooding threats up the coast of western/Southwest Alaska
Friday into Saturday before losing this influence offshore.
Meanwhile, guidance has strongly jumped on robust development of a
trailing frontal wave back over the north Pacific that is now
slated to lift northward toward the Alaska Peninsula Saturday as a
potentially potent storm/high winds threats, with subsequent track
into Southwest Alaska and into an unsettled/snowy Interior while
slowly weakening. This energetic scenario would focus a heavy snow
threat over portions of Southwest Alaska and into the Alaska
Range. There would also be a heavy rainfall and more
inland/terrain heavy snow threats as fueled by a
channeled/deepened lead Pacific moisture feed up into the Alaska
Peninsula/Kodiak Island and SouthCentral Alaska, and to a much
lesser extent Southeast Alaska through the weekend.
Schichtel
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