Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 536 PM EST Wed Jan 13 2021 Valid 12Z Sun Jan 17 2021 - 12Z Thu Jan 21 2021 ...Active Gulf of Alaska early next week will shift focus to the Bering Sea... ...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 one system into the Gulf of Alaska on Monday before a lead then trailing Bering system from the west become the focus. The models and ensembles generally showed this evolution, but continued to differ on timing of the systems, especially in the Bering Sea. For the Gulf, guidance has mostly converged on a track/speed given the lead time (somewhat in between the quicker ensembles and slower deterministic guidance 24 hrs ago) and a blend of the 12Z models sufficed. Front will lift steadily northeastward into the southeastern mainland and the Panhandle late Monday but will pack a bit of a punch with strong winds and modest to heavy precipitation. For Tue-Thu, upstream pattern will transition from strongly zonal ahead of a deep trough in eastern Asia to increasingly amplified. This will favor building ridging into the mainland from the south even as shortwaves pass through and weaken. Good ensemble agreement exists even by next Wed-Thu with a second Bering system on the heels of the first, and used their consensus to form most of the frontal/low placement. ...Weather/Hazards Highlights... Gulf system on Monday will bring modest to locally heavy precipitation to the southeastern Kenai Peninsula/southeastern mainland Alaska/coastal Panhandle. Winds to gale or perhaps storm force will accompany the area of low pressure--see the Ocean Prediction Center for more information. Bering systems will bring in light to moderate precipitation along the Aleutians next week, perhaps enhanced with the second system as it may tap more subtropical moisture. Temperatures will be well above average for most areas of the mainland during the period owing to ridging nosing into the area from the southeast. The Panhandle and Aleutians may see near to even below normal temperatures at times as systems pass through. Fracasso Hazards: - High winds across portions of southern mainland Alaska, Sat, Jan 16. - High winds across portions of northern mainland Alaska, Sat-Sun, Jan 16-Jan 17. - Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Sat-Tue, Jan 16-Jan 19. - High winds across portions of the Alaska Panhandle and mainland Alaska, Mon, Jan 18. 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