Alaska Extended Forecast Discussion National Weather Service College Park MD 748 PM EDT Mon Sep 1 2025 Valid 12Z Fri 05 Sep 2025 - 12Z Tue 09 Sep 2025 ...Windy with locally heavy rain across the Aleutians Friday into Saturday followed by a round of widespread moderate rainfall across the Southwest and western Mainland Sunday into Monday... ...Guidance Evaluation/Preferences... For late this week (Thu-Fri), the ECMWF has been indicating a deeper cyclone to track northward from the eastern Aleutians through western Alaska in contrast to the GFS and CMC which show a more elongated and weaker wave to track farther east and dissipate over central mainland Alaska. Regarding the next cyclone in its wake, model agreement appears quite good regarding its predicted depth and track for a Day 4-6 forecast--the GFS is on the slower side, CMC on the faster side, and the ECMWF near the middle by early on Sunday when the cyclone center is forecast to make landfall on the west coast of mainland Alaska. The track of this cyclone across western Alaska is rather similar to its predecessor as forecast by the ECMWF. As the cyclone weakens over mainland Alaska Days 7 and 8 (Mon-Tue), there is good model signal for the next cyclone to approach the western Aleutians. There is considerable model spread regarding the track and intensity of this system. The operational GFS favors a much stronger system while its ensemble mean as well as both the ECMWF and CMC and their ensemble means favor a weaker low center skirting just south of the Aleutians early next week. ...Weather/Hazards Highlights... A predominant storm track from the Aleutians toward western Alaska will continue to bring active weather with frequent rounds of wind and rain across these areas through the forecast period. As the ECMWF indicates a stronger cyclone with a track farther to the west regarding the first cyclone, there appears to be a good chance for moderate to heavy rain to spread farther west across the Brooks Range compared with the weaker and farther east solution from the GFS. Portions of the Alaska Range could receive heavier amounts from this system as well. The next cyclone in line appears to be stronger than its predecessor, and will bring a higher threat of gale force winds with moderate to possibly heavy rain Thu-Fri through the Aleutian Islands before bringing widespread moderate rainfall and windy conditions into western Alaska Sunday into Monday. As the system pushes farther inland, it appears to present another opportunity for the threat of heavy precipitation to affect the western portion of the Brooks Range early next week. Meanwhile, there is a good model signal for the next cyclone to reach the western Aleutians early next week, with the ensemble means favoring a weaker system than its predecessor, and with more modest precipitation amounts spreading into the Aleutians. The southern periphery of the first two systems is forecast to bring a couple rounds of moderate to locally heavy rain for the southern coastal sections such as Kodiak Island. There appears to be little to no rain to speak of farther east across all of the Alaska Panhandle until perhaps by late Monday next week. With the prevalence of clouds and rain, cool daytime temperatures are expected across southwestern Alaska. Otherwise, somewhat warmer than normal conditions are expected for the eastern part of the state especially the Panhandle, the North Slope, and portions of the Alaskan Peninsula through early next week. Kong 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