Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 755 PM EDT Thu Aug 27 2020 Valid 12Z Mon Aug 31 2020 - 12Z Fri Sep 04 2020 ...A dynamic storm to bring enhanced winds/seas/rainfall to the Gulf of Alaska and southern/southeast Alaska early next week... ...Guidance Assessment/Predictability and Weather Highlights/Threats... Two main flow streams will maintain an active weather pattern for Alaska for at least the next week. Northern stream energy transfer and adverse weather focus into a cooled Interior seems on tap into Monday. However, details and focus with an unsettling later series of individual systems to work into a larger scale Bering Sea and Interior mean upper trough position remain less certain. Underneath, a potent upper jet will race across the northern Pacific to the Gulf of Alaska. Early week energy transfer and deep tropical moisture plume advection with precipitable water values of 1.5-2" will be associated with the remnants of former west Pacific Typhoon Bevi. This sets the stage for dynamic storm development. Decided to use the 12 UTC GFS as the base model next week whose early trends to hold the main storm track southward seem to best fit the upper jet flow punch and stream separation. This was collaborated with the local Alaskan offices. Accordingly, expect enhanced winds/seas/rainfall for the Gulf of Alaska and southern/southeast Alaska by early next week. Heaviest rainfall will focus over favored southern Alaska to southeast Panhandle terrain into early next week. However, models and ensembles continue to offer run to run issues later period with embedded system timings and intermittent stream interactions, so continuity is less than stellar in this complex and progressive pattern. 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-Mon, Aug 30-Aug 31. - Heavy rain across portions of the Alaska Panhandle and mainland Alaska, Mon-Wed, Aug 31-Sep 2. - High winds across portions of mainland Alaska and the Aleutians, Sun-Mon, Aug 30-Aug 31. 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