Alaska Extended Forecast Discussion National Weather Service College Park MD 640 PM EDT Sat Oct 18 2025 Valid 12Z Wed 22 Oct 2025 - 12Z Sun 26 Oct 2025 ...Very wet pattern for the Southeast next week... ...Overview... An elongated upper low (with multiple vortices) will be stationed over the region for much of the period with an axis from eastern Russia, over the Mainland, and the Gulf. The weather across Alaska during the extended range period (Tuesday-Saturday) will be driven by a couple of shortwaves/upper lows rounding the base of the trough from the Aleutians/AK Peninsula into the Gulf. This will support surface low pressure in the Gulf and a generally wet period for the Southeast with heavy rainfall potential early to mid week. ...Guidance Evaluation/Preferences... The guidance is in relatively good agreement with the overall large scale upper pattern, but there remains plenty of uncertainty in the details. By Wednesday, a surface low will be lifting from the Gulf towards the southern Coast while a second low drifts east south of the Aleutians towards the Gulf. The first low will weaken in favor of this second low, which looks to be fairly deep with guidance suggesting central low pressure possibly down into the 960s. There is some variability with exact low placement still in the Gulf, but very consistent agreement on its presence and track. With a blocky ridge over Canada, this low should meander in the Gulf through the rest of the period. There is more uncertainty further west with another weaker surface low in the western Bering Sea. The WPC progs today used a majority blend of the deterministic guidance through Day 6, with increasing weighting of the ensemble means to 60 percent of the blend by Days 7 and 8 to account for some greater uncertainty. This maintained good agreement with yesterdays forecast as well. ...Weather/Hazards Highlights... The initial cyclone moving into the Gulf and weakening Tuesday- Wednesday will allow for a round of heavy rain (mountain snows) across much of the Panhandle region. As this low weakens, there may be a brief break in the precipitation, but another round of heavy precip will move into the region around Thursday. The heaviest rainfall may come to an end around Friday, but the entire period will be wet for especially the Southeast as low pressure meanders in the Gulf. Guidance is suggesting multi-day rainfall totals of 5+ inches in some locations across the Panhandle. Gusty winds may also accompany this system mid to later next week. Elsewhere, the southern coast, Aleutians, and parts of the Mainland may remain generally unsettled and showery underneath the upper low. Temperatures across Alaska should trend colder and below normal for most places next week. The North Slope and parts of eastern Alaska may be above normal with influence from some upper ridging. Santorelli 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