Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 745 PM EDT Thu Oct 21 2021 Valid 12Z Mon Oct 25 2021 - 12Z Fri Oct 29 2021 ...Overview and Guidance/Predictability Assessment... The medium-range period will likely begin with a cyclone center passing quickly eastward to the south of the Alaska Peninsula early next Monday. Model solutions have converged quite a bit since yesterday but there is still a sizable east-west/timing spread regarding the cyclone track. A general model compromise yielded a track slightly to the south of yesterday's forecast. In addition, it appears that the 06Z GFS rather than the 12Z run is more compatible with the overall ensemble means for next Monday. Beyond this time-frame, the ensemble means generally agree that a broad cyclonic circulation will meander over the Gulf of Alaska through the middle of next week. An even blend of the ensemble means yielded solutions that are fairly close to continuity from yesterday. Therefore, the WPC forecast grids for Alaska were based on a blend of the 06Z GFS/12Z GFS & GEFS, the 12Z ECMWF/12Z EC mean, together with smaller contributions from the 12Z CMC/CMC mean. The blend is then progressively weighed toward an even blend of the ensemble means toward the end of the forecast period. ...Weather/Hazard Highlights... Winds should be subsiding across the Aleutians later next Monday as a cyclone center is forecast to pass south of the islands. Thereafter, flow around a Bering Sea frontal wave should increase precipitation somewhat from the eastern Aleutians to southwestern mainland Tuesday to Wednesday along with gusty winds. Meanwhile, generally quiet conditions are expected for much of mainland Alaska, with occasional snow showers along the North Slope and the Arctic Coastal Plain. The southern coast and Panhandle should see a modest increase of rain/snow toward midweek as a broad cyclonic circulation is forecast to meander over or south of the Gulf of Alaska. Expect above normal temperatures to dominate much of interior Alaska to start the new week. A slow cooling trend is then anticipated for the entire area as heights aloft are forecast to slowly decline, leading to progressively colder readings along the southern periphery of Mainland and into the Alaska Panhandle toward midweek as the broad cyclonic circulation over the Gulf edges closer toward the coast. 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 Hazards: - No significant hazards are expected over Alaska during this forecast period. 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