Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 642 PM EDT Mon Aug 24 2020 Valid 12Z Fri Aug 28 2020 - 12Z Tue Sep 01 2020 ...Overview and Guidance Evaluation/Preferences... Behind a late-week system tracking from the Alaska Peninsula/Kodiak Island across the Gulf of Alaska and Panhandle, guidance continues to advertise a significant large-scale pattern change toward a mean upper low over the Bering Sea and downstream ridge aloft building over the Northeast Pacific and eastern mainland/western Canada. There is good agreement that a strong North Pacific into Bering Sea storm will usher in this change, with a broad area of wet/windy conditions. The latest model guidance showed average to slightly above average agreement and this allowed for a heavy component of the available deterministic guidance to be used (12Z ECMWF/GFS/UKMET/CMC) for the day 4-6 forecast with higher components of the 00Z ECENS and 06Z GEFS means for the latter portions of the forecast period. ...Weather Highlights/Threats... Continue to expect a broad area of precipitation and stronger winds to accompany the storm forecast to track from the North Pacific into the Bering Sea during the period. Recent trends have held back the northward progression of impacts a bit but there is still reasonable consensus that enhanced precip/winds should reach the Alaska Peninsula and then extend into the southwestern third to half of the mainland over the course of the weekend. Some moisture could reach as far east as the Panhandle by Sun or Mon. Significant precip totals will be possible along the southern coast and over some areas of favored terrain in the southwestern mainland. The system tracking from near Kodiak Island to the Panhandle Thu-Fri will bring some focused precipitation to areas along the southern coast and Panhandle. There will also be a broader area of scattered precip over portions of the mainland late this week. A drier trend will progress west to east behind this system and before the approach of moisture ahead of the Aleutians/Bering Sea storm. Below normal highs will prevail most of the period from the North Slope through the eastern and southern-southeastern mainland and Panhandle. Western areas will see the best potential for above normal highs. There will be greater coverage of above normal readings for low temperatures. Expect highest anomalies for lows late this week to be over the northeastern mainland. Flow ahead of the Aleutians/Bering Sea storm should spread warmer min temperatures across much of the state during the weekend and early next week. Rausch/Taylor No significant hazards are expected over Alaska during this forecast period. 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