Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 721 PM EDT Thu Nov 04 2021 Valid 12Z Mon Nov 08 2021 - 12Z Fri Nov 12 2021 ...Overview and Model Guidance... Mean upper level low pressure will be maintained over the Gulf of Alaska region as an upper low rotates aloft and several shortwaves reinforces troughing from over Alaska to the Eastern Pacific. This sends various surface low pressure systems well south of the Aleutians and into the Gulf as surface high pressure builds in over the Mainland and western Aleutians. The 12z deterministic guidance from today remains in relatively good agreement on the overall, synoptic scale, pattern. Particularly the second half of the period, models begin to show increasing uncertainty regarding the details, placement, and strength of individual systems. WPC favored a blend of the deterministic guidance (12z GFS, ECMWF, CMC, and UKMET) through day 5/Tuesday, with increasing contributions from the ensemble means thereafter to account for and help mitigate the differences. This also maintains fairly good continuity with yesterdays WPC forecast. ...Weather/Hazard Highlights... Overall, the Alaska region should be relatively quiet in terms of impactful precipitation and hazards with much of the mainland remaining dry, with the exception of a few interior mountain snow showers. Showers remain likely through much of next week from the eastern Aleutians to the Panhandle as storms track well to the south. Periods of moderate to locally heavy rainfall are possible across southern portions of the Panhandle as a couple of surface lows deepen in the Gulf sending their cold fronts into western Canada. For temperatures, the North Slope region of Alaska may begin the period Monday above normal, but (with the exception of the far northern coast) should trend cooler by the end of the week. The rest of Alaska will also see a cooling trend through the week as surface high pressure builds in across the region. Portions of western and southwest Alaska could see daytime highs as much as 10 to 20+ degrees below normal. Santorelli No significant hazards are expected over Alaska during this forecast period. 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