Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 655 PM EST Fri Nov 24 2023 Valid 12Z Tue Nov 28 2023 - 12Z Sat Dec 2 2023 ...Synoptic Overview... An upper ridge axis is expected to extend from western British Columbia to the eastern Alaska mainland for much of next week, and thus keeping temperatures generally above late November averages across most of the state. A broad upper level gyre is expected to reside across the Bering Sea region through early in the week, before gradually moving eastward towards the western coast and weakening, following by another broad upper low vortex across the Bering by next Thursday. Meanwhile, a storm system will likely develop in the general vicinity of the Alaska Peninsula sometime around midweek and bring a renewed round of organized precipitation, with perhaps another storm system to close out the work week over the central Gulf. ...Guidance Evaluation and Preferences... Model differences and spread have deteriorated compared to yesterday's 12Z guidance across the Alaska domain. Even though there is decent overall agreement on Tuesday, differences quickly become apparent across much of the North Pacific and into the Gulf by Wednesday. There has been poor run-to-run model continuity with recent ECMWF runs, and the 12Z run is closer to the CMC that was ruled out as part of the blend both yesterday and beyond day 4 today. Both the 12Z ECMWF and CMC are much faster than the 00Z ECMWF and 12Z GFS with the strong trough entering the Gulf region, with well below average confidence on the eventual evolution. To maintain WPC continuity without major changes, the fronts/pressures forecast was hedged more in the direction of the 00Z ECMWF/12Z GFS, which better matched the ensemble means that were available at the time. However, if more of the future guidance trends in the direction of the latest ECMWF/CMC, then more substantial changes in the forecast may become necessary with later issuances. The ensemble means were gradually increased throughout the period to reach about 50% by next Saturday, while still maintaining some previous WPC continuity in light of the recent model differences. ...Weather/Hazards Highlights... The weather pattern will continue to remain fairly active across southern coastal portions of the state for much of next week, although it appears the latest rain/snow and associated winds should not be considered hazardous at this time. Lighter precipitation is expected on Tuesday ahead of the next round of heavier precipitation from Kodiak Island to Prince William Sound for mid-week. In terms of temperatures, highs are generally expected to be in the 20s to lower 30s for most inland areas Tuesday-Wednesday, and 10s for the North Slope and lower-middle 40s for the southern coastal areas. There will likely be a return to colder weather by the end of the week and into next weekend, with some subzero lows expected for the normally colder locations in the Interior, and highs in the 0s and 10s for the northern half of the state. Hamrick 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