Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 609 PM EDT Fri May 22 2020 Valid 12Z Tue May 26 2020 - 12Z Sat May 30 2020 ...Overview and Weather Hazards/Threats... It remains the case that a blocky large scale flow pattern over Alaska is expected to stay relatively unchanged next week. An amplified upper-level ridge is forecast to persist from the Arctic Ocean across eastern Alaska and into northwest Canada. This will result in above average temperatures with anomalies upwards of +15 deg F over northern Alaska. This will enhance snow/ice melt, so please refer to your local office for all seasonal river ice flow issues. An upper low and surface system will gradually weaken while lifting northward on the western periphery of the upper ridge from the Bering Sea Monday to the Arctic Ocean by Thursday. This system offers some lingering wind/rain threat and an open water maritime hazard. A second system will meanwhile organize well south of the state over the eastern Pacific early next week. Yesterday, this system was slated to lift slowly northward into the Gulf of Alaska mid-later next week. However, latest model and ensemble guidance has strongly trended to suppress system lift and development. WPC progs now depict a much weaker/uncertain Gulf of Alaska low in consideration of both continuity and guidance trends. This solution was collaborated with local Alaskan offices. ...Guidance/Predictability Assessment... Larger scale predictability across Alaska is above average due to a relatively stable and blocky flow regime. A composite guidance solution seems reasonable days 4/5 (Tuesday/Wednesday) and WPC continuity is well maintained during this period. However, day 6-8 forecast spread is still quite evident with ridge evolution specifics and especially with the development/track of the second system. Accordingly, the WPC Alaskan medium range product suite was primarily derived from a blend of the GEFS/ECMWF ensemble means along with the 19 UTC National Blend of Models for days 6-8. 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 precipitation across portions of mainland Alaska, Mon, May 25. - Much above normal temperatures across portions of mainland Alaska, Mon-Thu, May 25-May 28. 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