Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 722 PM EDT Fri Mar 22 2024 Valid 12Z Tue Mar 26 2024 - 12Z Sat Mar 30 2024 ...Deep Pacific Storm may Threaten Alaska late next week... ...Guidance Evaluation and Preferences... Run to run guidance continuity from short range to medium range time periods for the Bering Sea and the Mainland have been quite less than stellar with digging Arctic stream systems, but seems better with more energetic/stormy Pacific flow to impact the state. Despite apparent initialization sensitivities, 12 UTC GFS/ECMWF and GEFS/ECMWF ensemble mean solutions seem surprisingly well clustered across the domain for much of next week and a composite was utilized to produce the WPC Alaskan medium range product suite. While forecast confidence at higher latitudes is tempered given recent issues, it is comforting that the â€correction†for this cycle is manifested in the short range when changes of this order can often be considered reliable. ...Pattern Overview and Weather/Hazards Highlights... Leading Pacific/Gulf of Alaska system energies and moisture will act to focus lingering wet conditions from the Alaska Peninsula and Kodiak Island through SouthCentral and more modestly into the Southeast Tuesday before losing influence. Coastal rains and inland/terrain snows seem generally light to moderate. Meanwhile, guidance has trending strongly toward the weekend digging of much more defined Arctic stream upper trough energy down into the Bering Sea to the lee of initially amplified upper high/ridging upstream. This closed low should meander and slower weaken over the Bering Sea into mid-later next week. This pattern may favor enhanced/high winds offshore from the Bering Strait to the Bering Sea and offer light to moderate western/southwestern mainland snow potential as aided by any uncertain interaction/lifting moisture from southern stream energies. Later, there is quite an emerging guidance signal to monitor for subsequent development and approach of amplified closed upper trough/low Pacific stream energy and associated deep surface low pressure system toward the Aleutians by later next week that would offer turbulent maritime conditions and swirling winds and rains. This potentially potent storm may work northeastward to mainland Alaska into next weekend with some punch. 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