Alaska Extended Forecast Discussion National Weather Service College Park MD 636 PM EDT Mon Oct 20 2025 Valid 12Z Fri 24 Oct 2025 - 12Z Tue 28 Oct 2025 ...Heavy rain and gusty winds likely for the Southeast this week... ...Overview... An upper low will drift slowly south across the Bering while multiple waves rotate around it. The low is forecast to elongate early next week as it shifts from over the Bering to the Gulf of Alaska. Another upper low is expected to linger over the Gulf through the weekend. This upper level pattern will produce several surface low pressure systems that will track across the Aleutians and into the Gulf, resulting in generally unsettled weather for southern Alaska, especially the Aleutians and Southeast Alaska. Southeast Alaska may see heavy rain and gusty winds as a relatively stronger low pressure systems approaches mid-to-late this week. ...Guidance Evaluation/Preferences... Model guidance continues to show relatively good agreement on the overall large scale pattern, with some expected uncertainty in the details. The highest uncertainty will surround the evolution of low pressure moving from the Bering to the Gulf early next week. Previous model runs were showing some interaction with an Arctic low, but the 12Z model suite has backed off from that idea, resulting in a cleaner consolidation of low pressure in the Bering this weekend. As the low gradually shifts south towards the Gulf early next week, the evolution becomes a bit messier with several shortwave interactions that are harder for models to resolve. For now, a blend of the best clustered deterministic models (12Z GFS and ECMWF) and ensemble means from the GEFS and ECENS produced a decent forecast that represents the pattern well. WPC's forecast used a blend of the latest runs of the available deterministic models (GFS/ECMWF/CMC/UKMET) for Friday and Saturday, added ensemble means from the GEFS and ECENS (20% of blend) on Sunday, and used a mix of the deterministic GFS and ECMWF (60% of blend) and ensemble means from the GEFS and ECENS (40% of blend) for Monday and Tuesday. This maintained good consistency with yesterday's forecast and represents the pattern well, smoothing out model differences while maintaining some detail through the end of the period. ...Weather/Hazards Highlights... Another round of heavy precipitation (with mountain snow) is forecast for Southeast Alaska mid-to-late this week as a low pressure system approaches from the Gulf. This system should be pretty quick, producing a period of heavy precipitation Wednesday into Thursday, then moving swiftly into Canada. Strong, gusty winds will likely accompany this system on Thursday. The heaviest winds (and consequently waves) will be offshore though, but this will create a significant maritime threat. Some moderate gap winds may be present in favorable locations on the backside of this low as well. Precipitation chances may linger over southern and Southeast Alaska through the weekend and into Monday as low pressure lingers over the northern Gulf with troughing extending along the coast. Generally unsettled weather can be expected, but nothing particularly hazardous is forecast. Precipitation chances should decrease on Tuesday as high pressure nudges towards the region from the northwest, steering an approaching Pacific low to the south of the state. Meanwhile, low pressure in the Bering is forecast to slowly move south late this week into the weekend. Winds and precipitation associated with this low should remain over the open waters of the Bering, then move over the Aleutians late this weekend. Little to no impacts are expected for western Alaska from this system. This low will spawn several fronts that will pivot around it while it is over the Bering, then one dominant frontal system will emerge across the Aleutians into the Gulf early next week. Quiet weather is expected for northern and interior Alaska with relatively higher pressure forecast to develop over these regions this weekend into early next week. High pressure combined with generally southerly flow will result in above normal temperatures through the period. Dolan 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