Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 654 PM EST Fri Mar 03 2023 Valid 12Z Tue Mar 07 2023 - 12Z Sat Mar 11 2023 ...Heavy precipitation is forecast to continue next Monday across the eastern Aleutians as heavy snow and gusty winds impact portions of western mainland... ...Pattern Overview with Model Guidance/Predictability Assessment and Weather Highlights... A plume of moisture is forecast to remain direct toward the state and will continue to impact a relatively narrow zone from the eastern Aleutians northward through western Alaska. This is in response to an anomalous ridge of high pressure forecast to extend further northward through mainland Alaska and into the Arctic Ocean as low pressure waves track from south to north along a quasi-stationary front across the Bering Sea and into the Arctic Ocean. Although there have been some ongoing wavering west/east of the general track, the run to run consistency of where the narrow swath of precipitation will setup has been fairly good for the extended period. The latest guidance has it forecast to fall in the form of mainly rain at the lower elevation of the eastern Aleutians while heavy snow is expected to impact the higher elevations. Meanwhile, snow is expected to be the main precipitation type across western Alaska. Models have trended the heavier precipitation a bit offshore for this period however if the models continue to wobble further east than heavy snow may return to portions of the over the southern half of the Seward Peninsula as well as the western extension of the Brooks Range across the Lisburne Peninsula toward Point Hope. Winds are forecast to gradually moderate by Monday as the highly amplified upper-level pattern begins to show signs of breaking down. A slow drying trend is forecast for the precipitation-affected areas through the middle of and into late next week as ensemble means continue to indicate further break down of the highly amplified pattern. Periods of light snow can be expected to move across the North Slope from mid- to late week as a piece of the anomalous ridge breaks off into an upper-level high over southern Alaska, then shifts slowly westward into the Bering Sea by late week. With the amplified ridging over much of the Mainland, several locations will have well above normal temperatures early next week with the warmest anomalies expected over the North Slope. The warmth will be not as anomalous across southwestern Alaska but above freezing high temperatures are forecast to change the snow to a wintry mix or all rain near the coast. Meanwhile, eastern Alaska/Panhandle will have temperatures much colder than normal thanks to the arctic high pressure system centered over Yukon. This pattern is forecast to persist but with a gradual moderating trend by the end of the extended period. The WPC forecast package was derived the 12Z ECWMF/EC ensemble mean, 12Z GFS/GEFS mean and the 12Z CMC. Campbell/Kong - Heavy precipitation across portions of mainland Alaska and the far eastern Aleutians, Mon, Mar 6. - Much above normal temperatures across portions of mainland Alaska, Mon-Tue, Mar 6-Mar 7. - Much below normal temperatures across portions of the Alaska Panhandle, Mon-Wed, Mar 6-Mar 8. 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