Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 648 PM EDT Wed Jun 10 2020 Valid 12Z Sun Jun 14 2020 - 12Z Thu Jun 18 2020 ...Overview and Weather Highlights/Threats... During the forecast period /Sun-Thur/, a relatively progressive flow pattern with a pair of storm systems will generally track south of the mainland and more across the North Pacific and Gulf of Alaska. For the start of the period /d4 Sun/, an area of low pressure will be moving out of the region. This is followed by another system mid-week that passes near the Aleutians. Aloft, troughing and a couple of closed lows will remains south to southwest of the mainland, while building heights and ridging hangs on for the eastern mainland. A relatively weak area in between will lead to more mesoscale driven sensible weather due to daytime heating, resulting in scattered showers and thunderstorms. Temperatures will also be on the increase, particularly for the eastern mainland as upper ridging remains in place. ...Guidance/Predictability Assessment... The 12Z ECMWF and 12Z GFS were heavily weighted for day 4/5 given the above average agreement to start the period. The 12Z CMC was again not incorporated with its too deep closed low lingering over the Gulf of Alaska Typical model biases develop by day 5/6, where the GFS appears to be too progressive with the next system that approaches the Aleutians. Forecast confidence however remains average to slightly above average given the good agreement through much of the period, but given the spread by day 6-8, the ECENS/GEFS were increasingly utilized. Taylor 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: - Much above normal temperatures across portions of mainland Alaska, Sat-Sun, Jun 13-Jun 14. 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