Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 345 PM EDT Wed Sep 04 2019 Valid 12Z Sun Sep 08 2019 - 12Z Thu Sep 12 2019 ...Weather/Hazards Highlights... An active weather pattern for Alaska and adjoining waters next week. The lifting of a weekend northern Bering Sea low through the Bering Strait into the Arctic Monday will produce modest precipitation and unsettled weather. A lead southern stream upper closed low/trough will meanwhile exit through the southeast panhandle to produce lingering weekend unsettled weather and precipitation. Dynamic upstream system energy and deepened surface low/system will track across the Aleutians/Southern Bering Sea and Alaskan Peninsula Sunday-Tuesday to then emerge over the Gulf of Alaska along with a heightening threat of wrapping heavy weather and seas. A deep low is then expected to track eastward from coastal Asia into the Bering Sea with roots from typhoons Lingling and Fourteen-W. This pedigree suggests a likely significant maritime hazard that would be slated to effect the Aleutians then mainland Alaska near the end of this forecast period that needs to be closely monitored. ...Guidance and Predictabililty Assessment... Recent models and ensembles show ample smaller scale/embedded system variance but overall reasonable compatability with the larger scale flow evolution. Accordingly, the WPC Alaskan medium range product suite was primarily derived from a composite blend of the 12 UTC GFS/GEFS and ECMWF/ECMWF ensemble mean. 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 No significant hazards are expected over Alaska during this forecast period. 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