Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 525 PM EST Thu Jan 23 2020 Valid 12Z Mon Jan 27 2020 - 12Z Fri Jan 31 2020 ...Well below average temperatures for most of mainland Alaska... Latest models and ensembles still offer good consensus that an upper level ridge will build to the west of Alaska and only slowly weaken/shift westward next week. Arctic energies digging over the ridge will act to anchor an upper level trough from the Mainland to the Gulf of Alaska. Forecast confidence is high that there will be a cold surface airmass settling underneath for much of Alaska to linger well into next week. An active North Pacific jet will send various shortwaves/surface lows across the North Pacific into the Gulf of Alaska, which should act to reinforce a closed upper low and deep surface low lingering over the northern Gulf. This setup would keep Southeast Alaska with relatively high precipitation chances through much of the period. Lingering deep layered cold low development just offshore over the northern Gulf will support some locally heavy snows thru lower elevations of southern Alaska and the northern Panhandle. While models agree on the overall larger scale pattern, they continue to struggle with the evolution and progression of the series of surface lows entering the Gulf and how they interact with the larger scale trough over Alaska. Accordingly, the specifics of this aspect of the forecast remains more chaotic with below average predictability. As a result, the WPC progs utilized the more agreeable 12 UTC GFS/ECMWF with the GEFS/ECMWF ensemble means day 4 into 5, then quickly switch to just these ensemble means to day 8 in a period with rapidly increasing forecast spread. This maintains decent continuity. Schichtel Additional 3-7 Day Hazard information can be found on the WPC medium range hazards chart at: https://www.wpc.ncep.noaa.gov/threats/threats.php Hazards: - Much below normal temperatures for much of mainland Alaska, Sun-Wed, Jan 26-Jan 29. 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