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FXAK02 KWNH 272240

PMDAK 



Alaska Extended Forecast Discussion

NWS Weather Prediction Center College Park MD

639 PM EDT Sat Apr 27 2024



Valid 12Z Wed May 01 2024 - 12Z Sun May 05 2024



...Guidance Evaluation and Preferences...



12 UTC GFS/ECMWF/Canadian model solutions seem best clustered with

ensemble means through medium range time scales, albeit with less

than ideal forecast spread with embedded systems. Accordingly,

overall predictability seems close to average. A composite

solution lends a solid forecast basis, but shifted focus to the

more compatible NAEFS/ECMWF ensemble means next weekend amid

faster growing variances. WPC product continuity is decently

maintained in this fashion, albeit with a trend toward slightly

more progressive Pacific low/frontal system progressions.



...Weather/Hazards Highlights...



Multiple organized low pressure/frontal systems and

supporting/amplified upper lows/troughs will queue and progress

generally west to east across the Bering Sea/Aleutians and North

Pacific into the Gulf of Alaska through next weekend to focus

areas of modest maritime winds/waves/rainfall that could clip

western to southwestern through southern tier coastal areas,

albeit in an overall benign weather pattern inland. A vast portion

of the state will experience above seasonal average temperatures

for the start of the month particularly much of the Interior where

anomalies will be the highest. Additional upper troughing over the

Arctic Ocean may settle down into the northern tier of the state.

In this pattern, areas to the north of a surface front settling

over the north-central mainland in cold high pressure over the

Arctic should keep temperatures below normal, especially across

the North Slope and into the northern Interior. Guidance shows

some spotty light precipitation.



Meanwhile, guidance has been trending toward the development of

much deeper low pressure systems to mainly affect the Aleutians

and Bering Sea into mid-later next week. These offer potentially

hazardous multi-day periods with enhanced wind flow/waves and

rainfall to monitor. Slow eastward progressions of these organized

systems within the amplified pattern may lead to enhanced lead

frontal inflow and precipitation into west/southwest Alaska and

downstream with re-developments into the Alaska Peninsula/Kodiak

Island and then Southcentral Alaska late next week/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



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