Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 553 PM EDT Sun Aug 02 2020 Valid 12Z Thu Aug 06 2020 - 12Z Mon Aug 10 2020 ...A Stormy Pattern for Alaska... ...Guidance Evaluation... The WPC Alaskan medium range product suite was primarily derived from a composite blend of well clustered guidance from the 12 UTC GFS/ECMWF/UKMET and Canadian models and the 19 UTC National Blend of Models on day 4/Thursday. The models offer a reasonably similar larger scale pattern days 5-8, but now offer more system variance than yesterday. Prefer to instead use a composite blend of the more compatible 12 UTC GEFS/NAEFS/ECMWF ensemble means and 19 UTC National Blend of Models, then apply manual adjustments to better define systems consistent with upper support and predictability. This solution maintains good WPC continuity. ...Weather Highlights/Threats and Predictability... A lead surface low will fill over the eastern Gulf into Thursday with modest lingering rains into southeast Alaska. Upstream, guidance highlights a powerful low and frontal system for Bristol Bay, Southwest/Western Alaska and the Alaskan Peninsula into Thursday, The system will weaken into the Interior into the weekend, but may remain a rain focus. Ample storm energy will meanwhile transfer downstream into unsettled northern Gulf of Alaska waters next Friday through next weekend and offers potential for enhanced rains, especially over favored southern tier Alaskan terrain. A potential third low near the Aleutians late week may transfer energies downstream into the northern Gulf of Alaska for the weekend. Substantial uncertainty remains with this low, but recent flow history favors another round of enhanced winds/waves and rain. 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 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