Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 339 PM EDT Wed Aug 14 2019 Valid 12Z Sun Aug 18 2019 - 12Z Thu Aug 22 2019 Amplified flow will transition back to a more typical high latitude pattern with a deep upper low headed into the Bering Sea next week. Models/ensembles were mostly in sync on the longwave pattern change with expected detail differences. The ECMWF ensemble mean has been a best guide in recent cycles (after a fairly unusual deviation several days ago) with the GEFS mean next best. This would transition troughing away from eastern/southeastern areas toward the eastern Beaufort Sea in response to a polar upper low. That low, per the ensembles, should stay north of northern areas but the 00Z ECMWF did bring it toward far northeastern Alaska (well south of the consensus). Farther south, system approaching/passing over the Aleutians next week has shown the best continuity and a consensus blend approach served well. South of the Gulf, guidance has split on where to track a surface system next Tue/Wed--yesterday the thought was much closer to the southern Panhandle. ECMWF-led consensus (with about half the GEFS/Canadian members) either show it meandering near 50N or moving slowly northeast or east-northeastward toward Haida Gwaii/southwestern British Columbia and a remnant trough to its north-northwest. 12Z GFS was a northerly exception into the Panhandle. Wind/rain will accompany the Aleutians storm next week with the heaviest amounts generally west of Adak. Southern portion of the Panhandle may be at the confluence of Pacific moisture plume and surface lift as a front on the south side of the upper low pushes through the area. Several inches of rain are possible but this will taper off farther north toward Juneau. Below normal temperatures are expected there until heights start to rise later next week. Fracasso 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