Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 531 PM EST Fri Feb 12 2021 Valid 12Z Tue Feb 16 2021 - 12Z Sat Feb 20 2021 ...Guidance/Uncertainty and Weather/Hazards Assessments... The latest model guidance is fairly clustered and in general agreement with the evolution of multiple storm systems passing through the Bering and Gulf of Alaska within the upper-level trough. This will keep much of the islands, peninsulas, southwest/southern Mainland along with parts of the Panhandle stormy through the next week. Each storm system will usher in stronger wind gusts and precipitation mainly near the coasts nearby inland areas. Meanwhile, the North Slope and areas into the Interior will mainly be cold and dry as impulses traverse through the upper ridge. Below normal temperatures across the Panhandle initially with moderate by early next week. Due to model spread increasing by mid/late periods over the eastern Gulf of Alaska, there is uncertainty as to whether organized precipitation will affect southern Mainland and the Southeast. A combination of the 12Z GFS/ECMWF/CMC and the respective ensemble means provided a decent forecast for the extended periods. The weighting of the ensemble means were increased gradually to the end of extended, where the spread over the eastern Gulf was more pronounced. Campbell Hazards: - Heavy precipitation across portions of mainland Alaska, Wed-Thu, Feb 17-Feb 18. 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 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