Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 646 PM EDT Thu Jun 11 2020 Valid 12Z Mon Jun 15 2020 - 12Z Fri Jun 19 2020 ...Overview and Weather Highlights/Threats... For the forecast period /Mon-Fri/, a couple of storm systems will brush south of the Alaska mainland and move across the North Pacific and Gulf of Alaska. The first will be weakening as it approaches the far southeast Alaska area while further west over the Aleutians, low pressure again organizes with a deepening trough. That system is forecast to deepen and move northeast over the North Pacific by the mid/late portions of the week. Further north over the mainland, generally upper ridging is expected, anchored over eastern Alaska and western Canada. This should support a continuation of slightly above average temperatures and mesoscale driven sensible weather characterized by showers and thunderstorms in the afternoon. ...Guidance/Predictability Assessment... After starting out with above average agreement, the latest forecast guidance shifted to below average from the mid to late periods as a stronger storm system develops along and south of the Aleutians. The 12Z ECMWF, GFS, and CMC were incorporated with near equal weight for day 4 /Mon/. However, the GFS quickly becomes out of favor as it is too deep and slow with low moving out of the Gulf of Alaska mid-week, and also is way too fast with the area of low pressure developing by day 7/8. Therefore, the blend incorporated more of the ECMWF, ECENS, and GEFS means which should fairly good agreement and continuity. 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: No significant hazards are expected over Alaska during this forecast period. 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