Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 612 PM EST Fri Dec 31 2021 Valid 12Z Tue Jan 04 2022 - 12Z Sat Jan 08 2022 ...Record cold possible for some areas of the Panhandle next week... ...Overview... A blocky pattern will continue through much of the medium range period over the high latitudes as an upper high over northeastern Russia meanders in place while changing shape. This favors very cold high pressure over most of the region south of the Brooks Range with generally light precipitation confined to immediate coastal areas of the Aleutians and brisk winds off the continent. ...Guidance Evaluation and Preferences... Ensembles were in good agreement overall with the lead surge of vorticity moving westward underneath the expanding upper high from Southcentral on Monday into the Bering and then northern Pacific around the start of the period. Upper high is forecast to change shape from an extended N-S orientation Monday to E-W Tue-Wed before again elongating N-S Thu-Fri. By then, spread increases and a general blend/trend toward ensembles was preferred. A deterministic blend to start sufficed with the good agreement. Favored the 12Z ECMWF/Canadian a bit more than the GFS as the former held more high pressure over the Bering while the latter allowed leftover low pressure to drift across the Aleutians. While the GFS scenario is plausible, ensembles suggested keeping lower pressures south of the Aleutians. By the end of the period, a retraction of the influence of the upper high would allow systems to approach the southwestern Gulf by next weekend. Transition toward a more open pattern is usually bumpy regarding model/ensemble timing/track, so a blend of the ensembles with only a minority weighting of the deterministic models was used for next Fri/Sat. ...Weather/Hazard Highlights... Most of the mainland will see dry weather next week as strong high pressure over the northeastern mainland on Tuesday settles into northwestern Canada while a weaker surface ridge likely persists over the northern half of the mainland into late week. Far northern/northeastern locations could see a little light snow toward Thursday or Friday as a weak surface boundary slips through northwestern Canada. Much below normal temperatures over the southeastern half or so of the mainland will slowly trend less extreme with time while readings should stay well below normal over the Panhandle the entire week with offshore flow. Temperatures could approach record cold for overnight lows and/or daytime highs. The North Slope will see a warming trend with temperatures reaching well above normal by mid-late week before easing back a bit. Generally light rain/snow is favored over parts of the Aleutians into Kodiak Island on easterly flow. A system emerging from the western Pacific could eventually spread some rain/snow into Southcentral next weekend as a warm front may push toward or into the Gulf. Fracasso Hazards: - High winds across portions of the Alaska Panhandle and mainland Alaska, Mon-Tue, Jan 3-Jan 4. - High winds across portions of mainland Alaska and the Aleutians, Sun-Wed, Jan 3-Jan 6. - Much below normal temperatures across portions of the Alaska Panhandle and mainland Alaska, Mon-Fri, Jan 3-Jan 7. 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