Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 637 PM EDT Wed Apr 08 2020 Valid 12Z Sun Apr 12 2020 - 12Z Thu Apr 16 2020 ...Overview and model guidance... Strong upper ridging over northeastern Russia (+4 sigma 500mb height anomaly later this week into the weekend) will meander southward between 110-130E as a second area of ridging builds into the eastern Gulf/Panhandle. This will favor troughing in between, mostly over the Bering, as several lead shortwaves pave the way for a more defined system south of the Aleutians around the middle of next week. Strong jet off central Asia will set up a split flow east of the Dateline which has led to some run-to-run changes in the guidance, but the recent 12Z suite offered some more stability. The 12Z GFS/ECMWF were squarely within the ensemble spread and a nearly even blend of the deterministic plus ensemble counterparts formed a good starting point. Trend in the past 24 hrs was 1) toward a more defined system skirting south of the Aleutians next Mon/Tue before lifting into the central Bering and dissipating and 2) toward holding a system in the mid-latitudes south of 50N to slip under the Gulf ridge. End result is somewhat the same -- storminess over the southwestern and southern coastal areas blocked from moving eastward by the upper ridge. ...Weather/Threats Highlights... Lead system lifting across into Bristol Bay Sunday will bring modest to perhaps locally heavier rain and wind to the AKPEN and favored upslope regions of Kodiak Island eastward across the southern Kenai into Prince William Sound. Otherwise, rain/snowfall will be on the lighter side over the rest of the state as high pressure very slowly retreats into Canada early in the week. Next system Wed/Thu will bring another round of rain and some snow to the same areas as Sun/Mon (Kodiak --> Kenai --> PWS). Along the North Slope, a warm front will bring in milder air (temperatures perhaps 10-25 degrees above normal but still below freezing around Utqiagvik) with some snow before the boundary dissipates and then perhaps reforms. Over southeastern areas, temperatures will be below normal as high pressure remains to the northeast and east. Fracasso Hazards: - Heavy precipitation across portions of mainland Alaska, Mon-Wed, Apr 13-Apr 15. - High winds across portions of mainland Alaska, Tue-Wed, Apr 14-Apr 15. - High winds across portions of the Aleutians, Sun-Mon, Apr 12-Apr 13. - Much above normal temperatures across portions of mainland Alaska, Sun-Wed, Apr 12-Apr 15. 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