Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 656 PM EDT Sat Mar 14 2020 Valid 12Z Wed Mar 18 2020 - 12Z Sun Mar 22 2020 ...Overview and Guidance/Predictability Assessment... A series of potentially powerful Pacific systems will lift through a highly unsettled Aleutians and Bering Sea and tend to work along with precipitation/weather inland into the Interior/North Slope then Arctic Ocean, with lead snows midweek. This will then include development of a particularly deep Bering Sea storm Wednesday/Thursday with well organized frontal structures that will focus winds and widespread and enhanced/widespread precipitation. This low will gradually fill and lift poleward later week in the wake of the lead system, but will remain a significant focus for weather. Temperatures will overall moderate across the Interior/North Slope next week, but remain cold enough to support periods of heavy snow, with a particular risk for northwest Alaska. Meanwhile underneath, additional but weaker system trough/jet energies will break eastward through the Gulf of Alaska in a pattern with more modest precipitation potential for southwest/southern/southeast Alaska. ...Weather Highlights/Threats... The WPC Alaskan medium range product suite valid Wednesday-Friday was mainly derived from a composite blend of reasonably well clustered guidance from the 12 UTC ECMWF/Canadian and GEFS/NAEFS/ECMWF ensemble means. The 12 UTC GFS and to a lesser extent the 12 UTC UKMET seem outlier solutions that are less supported by ensembles and WPC continuity. Forecast continuity and predictability seem above normal during this period. Forecast spread increases with embedded systems next weekend, so it seems prudent to rely much upon more consistent and seemingly reasonable GEFS/NAEFS/ECMWF ensemble mean guidance at these longer time frames. 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 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