Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 540 PM EDT Mon Mar 16 2020 Valid 12Z Fri Mar 20 2020 - 12Z Tue Mar 24 2020 ...Overview and Guidance/Predictability Assessment... A threat of organized wintry weather/enhanced winds associated with a series of progressive/dynamic lows will lift through an unsettled Bering Sea/Strait and for periods work inland into the Interior/North Slope/Arctic Ocean. This will include development of a particularly deep Bering Sea storm Thursday into Friday that offers well organized frontal structures that will in particular focus winds and precipitation. This low will gradually fill and lift poleward later week in the wake of an exiting lead Arctic Ocean system. Several more systems will then train across the region in this recurring pattern, but predictability is lower for these more modest low/precipitation threats. Expect moderate temperatures over the Interior/North Slope this 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 dig through the Gulf of Alaska in a pattern with modest precipitation potential for southern/southeast Alaska. ...Weather Highlights/Threats... The WPC Alaskan medium range product suite valid Friday into Sunday was mainly derived from a composite blend of the 12 UTC GFS/ECMWF/UKMET/Canadian. Embedded system forecast spread is a bit messy during this period at smaller scales, but overall these models offer a similar system pattern. Transitioned to the more compatable 12 UTC GEFS/NAEFS/ECMWF ensemble means into early next week amid growing model spread. This methodology tends to mitigate less predictable small scale variance days 4-8 and maintains good WPC forecast 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: - Heavy snow across portions of western Alaska, Thu-Fri, Mar 19-Mar 20 and Sun, Mar 22. - Heavy snow across portions of southwestern mainland Alaska, Fri-Sat, Mar 20-Mar 21. - High winds across portions of mainland Alaska, Thu-Fri, Mar 19-Mar 20 and Sun, Mar 22. - Much above normal temperatures across much of northwestern to northern Alaska, Thu-Mon, Mar 19-Mar 23. 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