Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 405 PM EDT Sun Oct 06 2019 Valid 12Z Thu Oct 10 2019 - 12Z Mon Oct 14 2019 Models and ensembles show an amplified but progressive pattern in place across Alaska and vicinity for the extended period. Guidance consensus was good into day 5/Fri, though the larger scale flow evolution even seems fairly well depicted by most guidance through day 8. Smaller scale systems after day 5 continue to offer plenty of timing variance, but there was fairly good agreement with the ensemble means (ECENS/GEFS) days 6-8. Accordingly, WPCs Alaska medium range suite for today was primarily derived from a blend of the ECMWF/GFS and respective ensemble means, with majority deterministic weighting in the early days (4-5) and increasing mean blend through the end of the period. This brings a shortwave/possible closed low into the Gulf of Alaska on Thursday, eventually weakening as it moves into western Canada next weekend. This system includes some remnant tropical moisture from what was Typhoon Mitag, so enhanced precipitation (locally heavy) can be expected along with a continued maritime risk. Behind this, there remains decent model signal for the development of another organized shortwave trough to track across the Aleutians Fri, into the Gulf by Saturday. This should also feed additional precipitation chances across southern and southeast Alaska. By early next week, most guidance suggests a deep low pressure system drops into the northern Bering Sea, though plenty of timing/placement/amplitude differences remain at this time scale. Regardless though, this could present a maritime risk (high winds, heavy seas) across the Bering Sea and potentially along parts of the Aleutians and western coast of mainland Alaska. This system may also spread increased precipitation into parts of mainland Alaska, though impact/amounts remains highly uncertain. Santorelli 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 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