Alaska Extended Forecast Discussion National Weather Service College Park MD 650 PM EST Sat Dec 6 2025 Valid 12Z Wed 10 Dec 2025 - 12Z Sun 14 Dec 2025 ...Overview... The synoptic-scale upper pattern across Alaska from midweek next week to next weekend will likely feature an amplifying omega block with an increasingly pronounced warm core high anchoring over the Bering Sea. Meanwhile, an arctic surface high will remain lodged against the Alaska Range under the eastern branch of the omega block sustained by upper-level convergence. This pattern will effectively prevent strong Pacific cyclones from reaching the Alaska domain. Only a relatively weak system manages to approach the southern portion of the Alaska Panhandle by next weekend. ...Guidance Evaluation and Preferences... The ensemble means from major global models are in favor of the above-mentioned synoptic scale pattern through next weekend. The high amplitude and strength of the omega blocking pattern will effectively keep strong cyclones from reaching the Alaska domain. Nevertheless, the Canadian model has been allowing a fairly strong low pressure/frontal system to sneak across the northern periphery of the omega block by next Friday or so over the Arctic Ocean. This scenario was only weakly supported by other models as well as the 00Z EC ensemble mean. However, the 12Z EC ensemble mean appears much more supportive of this scenario. The WPC medium-range forecasts for Alaska was based on the consensus blend of 40% from the 12Z GFS/GEFS, 40% from the 12Z ECMWF/00Z EC mean, and 20% from the 12Z CMC/CMC mean. This blend yielded a solution fairly compatible with yesterday's forecasts with notable differences across the Arctic Ocean and the northeastern Pacific. ...Weather/Hazards Highlights... With the omega block over the Bering Sea forecast to amplify further through the medium-range period, there is not a substantial low pressure system to speak of that will get close to the Alaska domain. Nevertheless, there remains the possibility of northerly gap winds across eastern Aleutians to the Alaska Peninsula and into the waters near Kodiak Island and the western tip of the Kenai Peninsula on Tuesday between the building high over the Bering Sea and a surface low that is forecast to track well to the south. Farther north, light snow ahead of a frontal system and the possibility of a low pressure system passing north of Alaska is forecast to reach at least the western portion of the Brooks Range and the North Slope late next week into the weekend. Other than that, an arctic surface high is forecast to remain anchored across mainland Alaska to keep it frigid and dry south of the Brooks Range. Temperatures down into the -30s will be common across interior Alaska, with the coldest readings into 40 below zero early to midweek next week for the Yukon Flats and near the Canadian border in eastern interior section. A Hazardous Cold area has been introduced for the eastern interior section for Dec 9-10. In contrast, temperatures will remain as much as 20 degrees milder than normal for the North Slope and western portion of Seward Peninsula. The Aleutians will also be somewhat milder than normal through the medium-range period. Across the Alaska Panhandle, light precipitation associated with a dissipating cyclone near the start of the medium-range period should taper off further. But precipitation chances will likely increase gradually through late next week and into the weekend, especially for the southern half of the Panhandle, as a relatively weak low/wave approaches slowly from the Pacific. Kong 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