Alaska Extended Forecast Discussion National Weather Service College Park MD 443 PM EST Thu Nov 27 2025 Valid 12Z Mon 01 Dec 2025 - 12Z Fri 05 Dec 2025 ...Heavy Precipitation along Gulf Coast next week... ...Overview... A closed low will amplify over the Aleutians early next week before phasing with a northern stream trough over the western mainland and propagating eastward by mid-week. Upper ridging persists over the Panhandle. An eastern Siberian ridge will gradually build into the Bering Sea before halting due to the phasing systems to its east. ...Guidance Evaluation and Preferences... There's reasonable agreement on the overall synoptic evolution of the mid-level pattern throughout the period. A general model blend consisting of the Euro suite, GFS and Canadian suites were used for the days 4, 5 and 6 blends. The GEFS mean was introduced to the blend on day 7 and continued through the rest of the period. The determinstic GFS and Canadian have a more amplified trough over the North Pacific/Aleutians through next Wednesday compared to the Euro suites because the Euro is more progressive with the phasing of the two streams over the western mainland. There's an unusual amount of spread in the guidance beyond day 6 due to the aforementioned phasing of streams. ...Weather/Hazards Highlights... A deep low pressure system will bring heavy rain, heavy mountain snow and strong winds from Bristol Bay/AKPen to eastern portions of the mainland coast next week. Warm Gulf air will surge north through the Gulf Coast and into Southcentral AK beginning late this weekend and continuing through early next week. There's a notable EFI signal for extreme temperatures with maximum temperatures being 15-30 degrees above average across much of the mainland early next week. The most significant precipitation will occur Sunday night, when an atmospheric river arrives along the Central Gulf Coast. This will be followed by another impactful round arriving Tuesday over Bristol Bay, down to the Aleutians/AKPen and spreading across the Central Gulf Coast. Kebede 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