Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 603 PM EDT Sun Mar 24 2024 Valid 12Z Thu Mar 28 2024 - 12Z Mon Apr 01 2024 ...Major North Pacific to Bering Sea Storm to threaten Alaska late week... ...Guidance Evaluation and Preferences... Guidance continuity remains quite reasonable overall for later this week, holding forecast confidence to above normal levels for both the pattern evolution and the main weather systems in increasingly active and dynamic flow. This still includes the development and approach of a potentially major North Pacific to Bering Sea Storm as powered by a strong East Asian jet. A composite of best clustered 12 UTC GFS/ECMWF/UKMET guidance provides reasonable detail for Thursday into Saturday. A transition over next weekend to reliance upon the still compatible 12 UTC GEFS/ECMWF ensemble means then provides a solid and consistent depiction of the flow/main systems at these longer time frames, especially when aligned with applied manual adjustments to ensure significant surface system depth consistent with favorable upper support. ...Pattern Overview and Weather/Hazards Highlights... A compact closed low currently digging southward from the Arctic should meander and may prove slow to weaken over the Bering Sea through late week, but will slowly losing influence as blocked by an ambient downstream upper ridge lingering into the eastern Mainland. This pattern may favor enhanced winds around the Bering Sea circulation along with light to moderate western/southwestern mainland snow potential as locally aided by uncertain interaction/lifting moisture from the Pacific stream. Meanwhile, there remains a good 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 week that would offer turbulent maritime conditions and swirling winds and rains. This potentially deep/major storm is now likely to track northeastward into the southern Bering Sea and become increasingly impactful for coastal/wind/heavy precipitation threats for western/Southwest Alaska and into the Interior as well as downstream/underneath with energy transference into the Gulf of Alaska and inland with lead moisture influx for the Alaska Peninsula/Kodiak Island and then SouthCentral to Southeast Alaska through next 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