Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 618 PM EDT Wed Apr 01 2020 Valid 12Z Sun Apr 05 2020 - 12Z Thu Apr 09 2020 ...A Stormy Pattern for Alaska... ...Guidance/Predictability Assessment and Weather/Threats Highlights... The WPC Alaskan medium range product suite was primarily derived from a composite blend of reasonably well clustered guidance from the 12 UTC GFS/ECMWF/UKMET Sunday-Monday along with the 19 UTC National Blend of Models. Opted to switch to a blend of the 12 UTC GEFS/NAEFS/ECMWF ensemble means Tuesday-next Thursday amid growing forecast spread along with the 19 UTC National Blend of Models to maintain max continuity. This forecast strategy has been collaborated with Alaskan offices for this active and stormy weather pattern. Mid-upper level trough and jet progression northeastward over the Bering Sea will support a well developed surface low/frontal system this weekend. This storm presents a maritime threat with hazardous coastal conditions including high winds into western Alaska. Heavy snows will translate inland over the Interior as precursor much warmer than normal temperatures cool. Energy transference downstream will then support low/system formations over the Gulf of Alaska next week, but guidance has trended weaker aloft in this flow with more northern stream energy working eastward over an unsettled Interior/North Slope. This pattern still offers a maritime threat over the Gulf of Alaska along with precipitation potential for the southern/southeastern Alaskan tier. Upstream, there remains a decent signal for the gradual approach of amplified mid-upper level closed low/trough and deepened low over the north Pacific to the Aleutians by next midweek. 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, Sat-Sun, Apr 4-Apr 5. - High winds across portions of mainland Alaska, Sat-Sun, Apr 4-Apr 5. - Much above normal temperatures across portions of mainland Alaska, Sat, Apr 4. 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