Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 248 PM EDT Thu Sep 26 2019 Valid 12Z Mon Sep 30 2019 - 12Z Fri Oct 04 2019 Guidance reasonably advertises an energetic and steadily progressive Alaskan flow evolution next week in a pattern with average to above average predictabillity. An amplified and warming/shielding upper-level ridge shifts eastward over the eastern interior and southeast Alaska early to mid next week. This occurs as an unsettling and amplified Arctic/Bering Sea/North Pacific Ocean upper trough shifts slowly eastward and splits, with the southern portion carving out a significant Gulf of Alaska closed upper low and surface cyclogenesis/frontogenesis. This will threaten maritime interests and also support heavier precipitation from southern to southeast Alaska. Expect more limited precipitation for the North Slope and Interior. Upstream, upper troughing should amplify from the Bering Sea to North Pacific mid-late next week and then reach western Alaska and dig more in ernest into the Gulf of Alaska late next week. This will offer a renewed heavy weather threat from the Aleutians into western/southwest to southern Alaska along with an offshore maritime threat. The WPC medium range product suite was primarily derived from a composite blend of best clustered solutions of the 12 UTC GFS/00 UTC ECMWF and 00 UTC ECMWF ensemble mean days 4-8, albeit with increased day 7/8 forecast spread. This solution maintains decent WPC 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 rain across portions of the Alaska Panhandle and mainland Alaska, Sun-Tue, Sep 29-Oct 1. 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