Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 708 PM EDT Mon Jun 14 2021 Valid 12Z Fri Jun 18 2021 - 12Z Tue Jun 22 2021 ...Guidance/Predictability Evaluation... The WPC Alaskan medium range product suite was primarily derived from a composite blend of well clustered guidance of the 12 UTC GFS/ECMWF, 12 UTC GEFS/NAEFS/ECMWF ensemble means and the 19 UTC National Blend of Models Day 4-8 (Friday-next Tuesday). Improved guidance forecast spread and continuity over the past two days now portends above normal predictability for this forecast period. ...Weather/Threats Highlights... A lead system track from south of the Aleutians to the Gulf of Alaska will continue to produce a complex series of lows and frontal systems this week that are expected to produce unsettled maritime conditions along with a periodic rain focus into the Alaskan Peninsula and southern to southeast Alaska. Meanwhile, a warming mean upper ridge is expected to linger over much of the Interior and North Slope into the weekend, but embedded small scale impulses may support spotty local activity. The upper ridge transitions from the weekend into early next week as the pattern modifies to allow potentially vigorous ocean storms lift toward the Aleutians, the Alaska Peninsula, and Southwest/Southern Alaska. This is slated to occur as ample upper trough/system energies approach from eastern Asia and the Pacific mid-latitudes to interact with lingering northern stream energies and entrain deeper moisture. This offers an emerging maritime and regional threat to monitor for a much wetter pattern. Schichtel Hazards: 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