Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 710 PM EDT Sun Aug 22 2021 Valid 12Z Thu Aug 26 2021 - 12Z Mon Aug 30 2021 ...An Active Weather Regime for Alaska.. ...Guidance/Predictability Evaluation... The WPC Alaskan medium range product suite was primarily derived from a composite blend of reasonably well clustered solutions from the 12 UTC GFS/ECMWF/UKMET/Canadian days 4/5 (Thu-Fri). This solution is also supported by the National Blend of Models and GEFS/NAEFS/ECMWF ensemble means whose guidance seems more run to run stable into the days 6-8 period amid growing model forecast spread. This Alaskan WFO collaborated forecast strategy maintains good WPC continuity. ...Pattern Overview and Weather/Threats Highlights... An amplified flow pattern next week should maintain wet and unsettled conditions across much of Alaska. Upper energies interacting with an Arctic frontal boundary will support organized precipitation across northern and Interior Alaska. In particular, an organized low pressure system reaching northwest/western Alaska Thursday will bring increased chances for enhanced precipitation into the region and inland across the North Slope/Brooks Range and the Interior Thursday into Friday. Additionally, Arctic Ocean system development also favors organized precipitation underneath into the North Slope next weekend. This pattern supports below normal maximum temperatures down across much of Alaska. Meanwhile to the south, onshore fetch ahead of a series of energetic systems set to work across the Gulf of Alaska this week will direct significant moisture to fuel moderate to heavy rainfall from the southern coast to the Panhandle. Higher elevations will also see measurable snowfall. An exiting lead system over the eastern Gulf into Thu will give way to a more complex and amplified system to track from just south of the Aleutians and AKpen Thu into Fri that is expected to solidify across the northern Gulf later week into next weekend. Upstream, there is more uncertainty with system development and progression into days 7/8 from the west Pacific/East Asia of a deepened storm system to approach the western Aleutians/Bering Sea that may offer enhanced rainfall potential given some extratropical connection to current tropical system OMAIS. Schichtel 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