Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 526 PM EST Tue Jan 12 2021 Valid 12Z Sat Jan 16 2021 - 12Z Wed Jan 20 2021 ...Active Gulf of Alaska this weekend into early next week... ...Overview and Guidance/Uncertainty Assessment... Deep troughing will move out of eastern Asia later this week and across the northern Pacific this weekend, promoting split flow across the Dateline. This will drive a couple systems into the Gulf of Alaska first on Saturday then again on Monday before a Bering system from the west becomes the focus. The models and ensembles generally showed this evolution, but differed on timing of the systems. For the Gulf, the ensemble means were generally quicker than the 12Z deterministic models, with a slight slower trend overall. Lead-in pattern into the Gulf will be downstream of split flow and with ridging over western North America it opens the door to more meridional flow and generally a slower progression. However, upstream flow over the western to central North Pacific will, simultaneously, transition toward increasingly zonal with a fast 200kt jet off Japan Sunday. Given the slower deterministic models, opted to put more weight in their cluster of solutions than the quicker ensemble means. By next week, transitioned toward increased ensemble weighting for the Bering system as the models quickly lost any agreement due to the quickening flow. ...Weather/Hazards Highlights... The pair of systems in the Gulf will bring several inches of precipitation to the Kenai Peninsula/southeastern Alaska/Panhandle with a northeastward push of the fronts. Winds to gale or perhaps storm force will accompany the areas of low pressure--see the Ocean Prediction Center for more information. Bering system will bring in light to moderate precipitation along the Aleutians next week. Temperatures will be well above average for most areas during the period owing to ridging nosing into the area from the southeast. Fracasso Hazards: - High winds across portions of mainland Alaska, Fri, Jan 15. - Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Fri-Tue, Jan 15-Jan 19. 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