Alaska Extended Forecast Discussion National Weather Service College Park MD 640 PM EST Thu Nov 20 2025 Valid 12Z Mon 24 Nov 2025 - 12Z Fri 28 Nov 2025 ...Overview... A blocky pattern will be in place across Alaska next week. An upper high will track from near the Bering Strait into the Chukchi and Beaufort Sea with ridging influence over the North Slope and into the Mainland. Meanwhile combining upper energies west and south of the high should create a broad mean upper low with a surface low reflection moving slowly across the Aleutians to Alaska Peninsula. The Aleutians low could lead to some high winds there into Sunday, and then as it tracks eastward and weakens, spread 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 larger scale pattern described above, with the most impactful differences primarily regarding the details of vort maxes and resulting surface lows undercutting the upper high/ridge. Even at the start of the period Monday, model differences are seen with energy spilling south from Russia reaching toward preexisting troughing in the Aleutians. The 12Z ECMWF was particularly strong with this energy and yields a double barreled 500mb and surface low Monday into Tuesday, whereas other guidance favors energies combining into one low. This results in the ECMWF being farther east with its primary upper low into Tuesday compared to other dynamical models and the EC-based AIFS. The 00Z EC ensemble mean did provide some support for this eastern position, and the 12Z EC ensemble mean (available after forecast generation) slowed down a touch, but is still faster than other guidance. The WPC forecast instead favored a GFS/GEFS/CMC/UKMET blend as the better clustered guidance that was also supported by the EC-AIFS. For the latter half of the week, the Aleutians/AKPen low spins near Bristol Bay and weakens while some of its energy spills well south into the Pacific. The Arctic upper high is generally forecast to move slowly eastward with ridging atop the central to eastern Mainland. Meanwhile, additional upper troughing is forecast to eject from Japan and move through the northern Pacific with a potentially large surface low. This looks to stay south of the Aleutians initially, but this trough may combine with the lingering energy to yield troughing and surface low pressure influencing the Aleutians/AKPen once again. All this has fair agreement for a Day 6-8 forecast, so a blend of the deterministic models with the ensemble means was used for the latter part of the period, favoring the means to smooth out individual model differences. ...Weather/Hazards Highlights... The reasonably strong low pressure system (960s mb) near the Aleutians into Sunday could lead to high winds across western and central portions of the Aleutians, along with some precipitation. 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, 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 and nearby waters. Any high winds are currently forecast to be localized and dependent on exact wind directions channeling through favored areas, so likely not widespread for any Day 3-7 hazard area. The surface ridge over at least eastern portions of the Interior will lead to cold continental flow. While temperature anomalies will not be too much below normal, it will be a marked change from the relative warmth in the 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