Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 753 PM EDT Sun Aug 29 2021 Valid 12Z Thu Sep 02 2021 - 12Z Mon Sep 06 2021 ...Heavy rainfall possible for portions of the southern Coast region during the middle part of next week... ...Pattern Overview and Model Guidance... The models have been persistent with the evolution of the upper-level trough and the surface low pressure systems that track across the Gulf of Alaska. The ridging in place over the Interior and the Southeast is expected to drift to the east as the trough progresses eastward from the Bering Sea. In general, the latest guidance remains fairly clustered given the typical spread on specific details. Again, the approach of utilizing a blend of the 12Z ECWMF/CMC/GFS and 06Z GFS and their associated ensemble means helped smooth out the spread. The models are in agreement where the higher QPF will set up along the coast and adjacent locations through day 6 and begins to differ a little for the remainder of the extended period, especially across the Panhandle. ...Sensible Weather... Moderate to heavy rain will spread from the Aleutians to the southern coast of the Mainland by midweek and to the Panhandle by Friday. Rain will decrease over the western portion of the southern Coast while persisting over the Southeast this weekend and into early next week. Portions of western and eastern Interior may have a few showers this weekend as well as the frontal boundary will be draped across the northern Gulf of Alaska. These areas may also experience gusty winds. Initially, temperatures across parts of the Interior and Southeast may be above seasonal normal but will return to normal as the cloud cover and rain increases. Campbell Additional 3-7 Day Hazard Information can be found on the WPC medium range hazards outlook 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