Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 649 PM EST Wed Jan 8 2020 Valid 12Z Sun Jan 12 2020 - 12Z Thu Jan 16 2020 ...Guidance/Predictability Assessment... The latest runs of the 12z deterministic guidance show fairly good agreement on a weakening surface low crossing the northern Bering Sea on Sunday, with the GFS and GEFS indicating a more northward track. Farther south, a frontal wave will likely develop into the next well defined surface low as it enters the southern Gulf of Alaska by Tuesday and into Wednesday. Both the 12z GEFS and EC means are indicating a more northern solution with the Gulf low, whereas the deterministic GFS, ECMWF, and CMC suggest a track farther south near 45 degrees north. Given the strength of the upper level high over the Aleutians and western Alaska, the more southern track appears the most realistic. With the upper level ridge axis beginning to break down some over the central Aleutians by mid-week, the next potentially significant surface low may begin affecting the western Aleutians and the Bering Sea by late Wednesday or early Thursday, with the 12z GFS and ECMWF among the fastest solutions. In terms of the WPC forecast over this domain, a more deterministic blend of the 12z ECMWF, 6z/12z GFS, and CMC was incorporated through Monday night, and then gradually increased use of the ensemble means towards the end of the forecast period. ...Weather/Hazards Highlights... A building upper ridge over the North Slope and much of the Interior will partially abate the current spell of frigid weather, with lingering much below normal temperatures expected early in the forecast period over the eastern Interior/Southeast and Panhandle region as post-frontal arctic high pressure continues to build in from Canada. Temperatures across some of the more sheltered valleys in the eastern Interior may approach 50 below! Snow showers and gusty winds are likely for western Alaska on Sunday as the Bering Sea surface low lifts northeastward. The shortwave moving into an already unsettled Gulf of Alaska early next week should bring more modest effects for maritime interests and perhaps for coastal areas of southern Alaska. The next surface low for the Aleutians may bring a period of gusty winds and heavy precipitation by the middle of next week, with noteworthy differences in timing remaining. Hamrick 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: - Much below normal temperatures across portions of mainland Alaska, Sat-Sun, Jan 11-Jan 12. - Much below normal temperatures across portions of the Alaska Panhandle, Sat-Tue, Jan 11-Jan 14. 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