Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 615 PM EST Thu Feb 16 2023 Valid 12Z Mon Feb 20 2023 - 12Z Fri Feb 24 2023 ...Major storm track up through the Bering Sea/Strait next week will bring heavy wind threats from the Aleutians through a wintry western to northern Alaska... ...Model Guidance/Predictability Assessment... The 12 UTC GFS/ECMWF/Canadian offer a similar and reasonable larger scale pattern evolution that signifcantly amplifies next week. The WPC Alaskan medium range product suite was primarilty derived from composite model blend to hold system and sensible weather grids intensities in a pattern with good ensemble support and above average overall predictability. WPC product continuity is less than stellar with a repeating storm track up through the Bering Sea/Strait lifting on the western periphery of a building mainland upper ridge that now shows deeper lows with frontal systems pushing farther eastward to bring threatening winds and wintry precipitation more robustly into western and northern Alaska, especially later next week as height falls work earnestly into the northern portion of the upper ridge. ...Pattern Overview and Weather/Hazard Highlights... The seemingly last of a series of uncertain lead systems may track to South-central Alaska into Monday, with the bulk of supporting energy transfering downstream into northern and eastern Gulf of Alaska system genesis in progressive flow. Expect a light to moderate swath of wintry weather across the southern Interior and South-central. Enhanced precipitation will meanwhile develop and linger early next week into Southeast Alaska before departure. This will lead into a cold and windy post-frontal pattern with enhanced gap winds for the rest of next week as upper trough energies dig earnestly through the region. Upstream, upper-level systems from the northwest Pacific will include a series of closed lows/deepened surface lows/frontal systems that are slated to lift over the western Bering Sea and provide a protracted maritime threat with a subsequent storm track up through the Bering Strait in the Arctic Ocean next week. In this pattern, a downstream upper ridge will build significantly up over the mainland by early next week. With these deepened low pressure systems, wrapped enhanced winds and moderate to heavier precipitation will periodically intensify through the period up through the western periphery of the upper ridge. This activity will spread and focus across the Aleutians and Bering Sea/maritime interests, then eventually into western/southwestern Alaska and to a lesser extent the Alaskan Peninsula and vicinity into mid-later next week. Latest model trends for more robust height falls working into the northern portion of the upper ridge mid-later next week suggests more enhanced weather in store to include high winds with a mixed wintry precipitation focus over the Southwest Alaska and bursts of snow farther north from western to northern Alaska. Schichtel Hazards: - High winds across the Aleutians, Mon-Tue, Feb 20-Feb 21. - High winds and heavy precipitation across western Mainland Alaska, Wed-Thu, Feb 22-Feb 23. 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