Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 542 PM EST Mon Jan 13 2020 Valid 12Z Fri Jan 17 2020 - 12Z Tue Jan 21 2020 ...Overview... Upper pattern will feature increased troughing across the Bering, AKPEN, and into the Gulf as an upper high rotates eastward across the North Slope and into NW Canada before weakening. Well below normal temperatures in eastern/southeastern portions will slowly moderate starting this coming weekend as the upper low over the Panhandle moves westward beneath the upper high. Precipitation will be confined to the Aleutians Thu-Sat and then focus over the Panhandle and Southcentral as weak systems rotate into the Gulf. ...Guidance/Predictability Assessment... The 12Z GFS/ECMWF/Canadian/UKMET offered reasonable clustering with the 00Z ECMWF ensemble mean and 12Z GEFS mean to start the period, Fri-Sun, with the couple systems along 50N. Consensus approach served well with the latest guidance on the track of the upper high as well. Thereafter, uncertainty increases with the smaller-scale systems rotating northward then northwestward into the Gulf as the mean upper trough pulls westward. Trended toward an ensemble blend (mostly 12Z GEFS mean and 00Z ECMWF ensemble mean) to mitigate daily changes in the forecast. Canadian mean was quite fast with the system just south of the Aleutians next Tuesday by more than a day. Near the Gulf, weak systems will maintain a stormy but milder pattern for the Panhandle. ...Weather/Hazards Highlights... Much of eastern/southeastern Alaska, especially the Panhandle, will slowly moderate back toward normal temperatures after this weekend. Above normal temperatures may be limited to the North Slope. Precipitation will be light overall until later in the week through the weekend, focused over the Aleutians then to the Panhandle/Southcentral. Highest amounts may lie over the southern Panhandle closer to higher moisture values off the Pacific and a better fetch. Fracasso 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 - Much below normal temperatures across portions of the Alaska Panhandle and mainland Alaska, Thu-Sat, Jan 16-Jan 18. 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