Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
752 PM EDT Wed May 01 2024

Valid 12Z Sun May 05 2024 - 12Z Thu May 09 2024

...Aleutians to Gulf of Alaska Storm Threat through Sunday...


...Guidance Evaluation and Preferences...

The latest suite of guidance had an increase in model spread
compared to yesterday; however, consensus maintains a deeper than
average low near the Bering/Aleutian/western Gulf of Alaska that
has multiple lobes of energy pinwheeling through the flow toward
the Panhandle and across the Interior. Differing from yesterday's
preferred blend, less emphasis was placed on the CMC since it and
the UKMET were on the periphery of the cluster for a majority of
the extended period. The WPC blend began with a multi-model
approach that quickly transitioned to ECWMF/GFS and their ensemble
means.


...Weather/Hazards Highlights...

An amplified trough on the order of 2 standard deviations deeper
than average will track southeast across the Gulf of Alaska.
Multiple lobes of energy will pinwheel through this trough which
will send multiple fronts across the Aleutians and into the Gulf.
The low pressure system expected for later in the period is
shaping up to be stronger which offers a potentially hazardous
multi-day period with enhanced wind flow/waves and precipitation
set to work downstream. Steady progression of this well
organized/deep storm within the amplified pattern will lead to
enhanced lead inflow to fuel precipitation into West and Southwest
Alaska into Saturday. Ample Gulf of Alaska redevelopment should
offer renewed maritime hazards along with moderate to heavy
multi-day precipitation inland for the Alaska Peninsula/Kodiak
Island and then South-Central to Southeast Alaska this weekend
into early next week. Strong, gusty winds along with precipitation
will accompany each feature keeping much of the southern/eastern
part of the state unsettled.

Portions of the state will have above seasonal average
temperatures for early May, particularly parts of the southern
Interior where anomalies will be the highest. There is some risk
there for enhanced downslope winds off the Alaska Range into
drying soils to monitor for wildfire hazards. Additional upper
troughing over the Arctic Ocean is expected to also settle down
into the northern tier of the state then dig into the Bering Sea
into next week. In this pattern, areas to the north of a surface
front settling over the northern and central mainland in cold high
pressure should keep temperatures below normal, especially across
the unsettled North Slope and northern Interior.

Campbell


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