Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 650 PM EDT Fri Jun 12 2020 Valid 12Z Tue Jun 16 2020 - 12Z Sat Jun 20 2020 ...Overview and Weather Highlights/Threats... For the forecast period /Tue-Sat/, the main feature will be the developing area of low pressure and associated closed upper low that stalls/slows over portions of the North Pacific, south of the mainland. An area of low pressure is expected to track from south of the Aleutians to the North Pacific by mid-week then slow/stall with a large upper low setting up in the region. This will be competed by an area of upper ridging over the eastern mainland and northwest Canada which should persist the above normal temperatures. Some periods of wet weather could be possible early in the week with the aforementioned low but widespread hazardous precipitation is not expected. Across the mainland, the mostly ridging in place should result in slightly above average temperatures and mesoscale driven sensible weather characterized by showers and thunderstorms in the afternoon. ...Guidance/Predictability Assessment... Forecast confidence ranges from average to slightly above average for the beginning of the period but quickly drops to below average by mid to late week as the evolution of a slow moving to retrograding low pressure south of the Aleutians remains uncertain the latest forecast guidance. The CMC is the most progressive with this feature, with a secondary area of low pressure quickly undercutting it and deepening over the North Pacific. Meanwhile, the GFS and ECMWF offer somewhat similar solutions, though the GFS retrogrades the low more than ECMWF. Both models however have similar timing and depth to the area of low pressure skirting south of the main low mid week. Finally, toward the end of the period, another area of low pressure forms well west of the Aleutians but model agreement is below normal. The ECMWF was most favored but some components of the GFS were incorporated early on. From day 6-8, increasing amounts of the ECENS/GEFS were utilized given the less than favorable model agreement. 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