Alaska Extended Forecast Discussion National Weather Service College Park MD 654 PM EST Wed Nov 19 2025 Valid 12Z Sun 23 Nov 2025 - 12Z Thu 27 Nov 2025 ...Overview... A blocky pattern will be in place across Alaska for the weekend into much of next week. At the start of the period Sunday, a weak low across the Gulf, a stronger and longer lasting upper/surface low over the Aleutians, and an upper high near the Bering Strait anchoring a ridge over parts of the Mainland will create an omega block aloft. The Aleutians low could lead to some high winds over the weekend. As the high moves northeast into the Arctic Ocean, energy over the Aleutians should undercut it and slowly move east, spreading modest precipitation over the Alaska Peninsula and across the southern coast. Colder temperatures are forecast next week after an above average period in the short range. ...Guidance Evaluation and Preferences... Model guidance is reasonably agreeable with the initial omega block pattern described above. There are some minor model differences with the placement of the surface low near or over the Aleutians, with most 12Z guidance south of the islands whereas the 06Z GFS and the ensembles still have hints that the low could be over or north, affecting potential strong wind directions and timing. There is a general trend for the low to weaken as it moves east with some uncertainty in a dual low structure into Monday- Tuesday. Farther east, after the Gulf low weakens and pulls eastward, there is good agreement for surface ridging to build in western Canada and into the eastern Mainland. Aloft, there are some model differences with the upper high as it tracks northeast. Most models have trended slower with its movement compared to a day ago, with a more southwestern position early next week compared to the previous WPC forecast. Then variations arise with how far north or south the high is by the middle of next week. GFS and GFS Graphcast are generally on the southern side atop the North Slope, as energy from the Arctic Circle pushes the high southward, which other models do not show. The ECMWF is farther north into the Arctic with the upper high, with the EC-AIFS and the CMC in between. A middle ground position seems reasonable and model differences are not too large for the Day 7-8 period. The WPC forecast was based on a multi-model blend of the deterministic guidance early in the period, and blended in ensemble means in increasing proportions to half by the end of the period. ...Weather/Hazards Highlights... The reasonably strong low pressure system (960s mb) near the Aleutians over the weekend could lead to high winds across western and central portions of the Aleutians, first as southerlies and then wraparound winds on the backside of the low, along with some precipitation. Meanwhile the weaker low in the Gulf could promote some light to moderate precipitation from Prince William Sound into Southeast Alaska, while some light snow is possible across the Interior. Into the workweek, precipitation will spread across the Alaska Peninsula with the primary low, while light precipitation is possible across the southern coast. As the low gets stalled by the upper ridge, QPF amounts of a few inches could eventually pile up next week over favored areas of the Alaska Peninsula into favored areas of Kodiak Island and the Kenai Peninsula, but likely to stay below hazardous levels since the precipitation falls over several days. Meanwhile, Interior Alaska should generally see clearer skies and little to no precipitation into next week as high pressure at the surface develops. This surface high will contrast with lower pressures over the Gulf, creating a pressure gradient pattern for possible gap winds across parts of Southcentral and Southeast that will continue to be monitored. The surface ridge over at least eastern portions of the Interior will lead to cold continental flow, cooling temperatures compared to the relatively warm short range period. Highs in the single digits will be common with lows in the negatives. Slightly below average highs are possible in Southeast as well. Meanwhile above average temperatures could spread across the Alaska Peninsula into the Lower Kuskokwim and Kodiak Island given relatively warmer oceanic flow. 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