Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 637 PM EDT Sun Jun 07 2020 Valid 12Z Thu Jun 11 2020 - 12Z Mon Jun 15 2020 ...Overview and Weather Highlights/Threats... A relatively progressive flow pattern is expected to persist across the North Pacific and into the Gulf of Alaska through the extended forecast period, while weak and broad upper ridging persists from the Arctic Ocean into western Canada. Meanwhile, the Interior of Alaska will lie within a region of chaotic and relatively weak easterly upper-level flow. Onshore flow across southern mainland Alaska as low pressure weakens in the Gulf of Alaska will keep the potential for precipitation up through midweek (especially across the higher terrain), while weak easterly flow and occasional upper shortwave energy will also keep isolated to occasionally scattered convective activity in the picture across the Interior. A low pressure system expected to pass near the Aleutians as it moves into the Gulf of Alaska later this week and into the weekend will bring an increase in shower and perhaps some gusty winds to the Aleutians, with precipitation eventually increasing across the Alaska Peninsula as well. Temperatures in this pattern are expected to be above average through the forecast period, with highs ranging from 5 to 10 deg F above average for many areas, especially across western mainland Alaska. Meanwhile, more clouds and occasional precipitation will keep temperatures several degrees below average closer to the coast. ...Guidance/Predictability Assessment... A blend of the 12Z ECMWF/GFS was used during days 4-5 (Thu-Fri), with majority weight placed on ECENS/GEFS ensemble means from day 6 (Sat) onward. Despite some significant differences starting by the weekend among the deterministic guidance across the North Pacific, ensemble means showed relatively good agreement - indicating that forecast confidence is likely near average through the extended forecast period. Ryan 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