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FXAK02 KWNH 282228

PMDAK 



Alaska Extended Forecast Discussion

NWS Weather Prediction Center College Park MD

628 PM EDT Sun Apr 28 2024



Valid 12Z Thu May 02 2024 - 12Z Mon May 06 2024



...Guidance Evaluation and Preferences...



The 12 UTC GFS/ECMWF/UKMET/Canadian model solutions now seem well

clustered and supported by multi-model ensemble means Thursday

into Saturday, bolstering forecast confidence to above normal

levels. A composite solution lends a solid forecast basis and

representative detail. Later, prefer the ECMWF ensemble mean that

shows a more vibrant main low transition from the Bering Sea to

the Gulf of Alaska onward into Day 7/8. WPC product continuity is

decently maintained in this fashion, albeit with a continued

recent trend toward a more progressive and deeper main low.

Current satellite imagery of the origin system now exiting China

shows quite the dynamic supporting upper system.



...Weather/Hazards Highlights...



An organized low pressure system with supporting/amplified upper

trough support in a recent series will progress southeastward

across the Gulf of Alaska through later this week and favor areas

of enhanced maritime winds/waves and rainfall that should also

work inland across mainly coastal areas of the southern to

southeast tier of the state to produce some terrain focusing

modertate rainfall, albeit in an overall benign weather pattern

farther inland. A vast portion of the state will experience above

seasonal average temperatures for the start of the month

particularly portions of the Interior where anomalies will be the

highest. Additional upper troughing over the Arctic Ocean is

expected to also settle down into the northern tier of the state.

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 the northern Interior. Guidance shows

spotty light precipitation.



Meanwhile, guidance continues to highlight development of a much

deeper low pressure system to mainly affect the Aleutians and

Bering Sea into mid-later week. This deepened low offers a

potentially hazardous multi-day period with enhanced wind

flow/waves and rainfall. Steady progression of this well

organized/deep storm within the amplified pattern will lead to

enhanced lead inflow to fuel precipitation into west/southwest

Alaska into Saturday. Ample Gulf of Alaska redevelopment should

offer renewed maritime hazards along with moderate to potentially

heavier multi-day precipitation inland for the Alaska

Peninsula/Kodiak Island and then SouthCentral to Southeast Alaska

next weekend into early the following week to monitor given some

sensitve terrain.



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



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