Alaska Extended Forecast Discussion National Weather Service College Park MD 658 PM EST Fri Dec 5 2025 Valid 12Z Tue 09 Dec 2025 - 12Z Sat 13 Dec 2025 ...Overview... Albeit with some shortwaves, the large scale pattern across Alaska next week will consist of positively tilted upper troughing across the eastern part of the state into the Gulf, with strong upper ridging behind. The mean northerly flow and arctic surface high pressure over the Mainland will lead to cold conditions through much of the week especially over central and eastern Alaska. Rounds of relatively weak low pressure systems in the Gulf/Pacific could produce some light to moderate precipitation (mainly snow) over Southeast Alaska, while northerly gap winds could be somewhat strong across the Alaska Peninsula toward the western Kenai Peninsula midweek. ...Guidance Evaluation and Preferences... Models show reasonably good agreement on the overall pattern early in the period. Troughing stretching across Southeast Alaska into the Pacific on Tuesday is forecast to shift east into midweek, while another shortwave digs through the western and central Mainland for a brief bout of troughing there. Deterministic guidance was similar enough to blend with the positions of these trough features, so used a multi-model blend favoring the ECMWF and GFS in the early period. Then into later next week, there are some uncertainties with where the upper high over the Pacific/Aleutians/Bering Sea sets up, and with shortwaves that may round its northern side (with a possibly resulting surface frontal system). Recent CMC runs have been oriented farther north and west with the ridge's most anomalous heights into the Bering compared to most other guidance. It does have some support from its ensemble mean and somewhat from the ICON, but this seems like a lower probability solution. The ECMWF was stronger with its shortwave reaching the northwestern Mainland compared to other guidance, and suspect the upper ridge may be too strong to see the shortwave erode it that much. Overall, increased the proportion of ensemble means in the model blend to half Day 7 and more Day 8 amid the increasing spread. ...Weather/Hazards Highlights... Most precipitation across Alaska at least early to midweek will be across Southeast Alaska given Gulf of Alaska low pressure systems. Just light to moderate totals (mostly snow) are expected as heavier precipitation phases into the short range. On the backside of the mean surface low, northerly gap winds are possible across the Alaska Peninsula into the waters near Kodiak Island and the western side of the Kenai Peninsula, with the highest winds expected on Wednesday. Additional northerly gap winds could be a threat later next week too, depending on the evolution of the pattern. Light snow is possible across the Brooks Range and North Slope. Other than that, surface high pressure dominating will lead to dry conditions. By Thursday, a round of snow may push into the northwestern Mainland and spread across the Interior late week, but this is dependent on an uncertain potential shortwave and its surface front reflection. High pressure will dominate much of the Mainland into the Panhandle next week, causing temperatures to be colder than (already cold) averages. Temperatures well into the -30s will be common in the central to eastern Interior, which is 20-40 degrees below average. As the upper ridging sneaks into western areas as the week progresses, the Aleutians into western areas of the Mainland should moderate somewhat closer to normal. Tate 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