Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 639 PM EST Mon Jan 24 2022 Valid 12Z Fri Jan 28 2022 - 12Z Tue Feb 01 2022 ...Overview... The latest guidance continues to support the development of an Omega block pattern setting up over the Alaska region with little change through at least the weekend and into early next week. Storm tracks remain confined to the Gulf where a couple of systems may bring unsettled weather to Southeast Alaska this weekend. To the west, a couple of modestly deep cyclones get forced northward across the central/western Aleutians as surface high pressure holds strong over the Mainland. Models indicate the ridge/block may strengthen and slowly shift east with time as the upper low in the Gulf slides farther south. ...Guidance/Uncertainty Assessment... Good synoptic agreement amongst the latest 12z model guidance lends to modest confidence that an Omega block will maintain itself through the entire period. The greatest uncertainties lie in the strength of the ridge and block, especially as you go later in the period. This results in a rather chaotic array of surface lows near the western Aleutians and also in the Gulf. The 12z CMC is much stronger/farther west with the upper high by early next week generally resulting in a more westward track of lows south/west of the Aleutians. The GFS and UKMET are weaker with the ridge, tending to bring systems farther east across the Aleutians into the Bering. At this time, the 12z ECMWF seems to represent a good middle ground between the weaker GFS and stronger CMC, and is best in line with the ensemble means. In the Gulf, the GFS and ECMWF have good agreement with each other on consolidating low pressure until the very end of the period when the GFS pulls the low quicker to the south towards the Northwest U.S.. The WPC progs for today used a majority deterministic blend with more weighting towards the ECMWF days 4-6. After this, the CMC was dropped (due to its exceptionally strong ridge/block) in favor of more ensemble means to help mitigate the detail differences which are hard to resolve at these longer time scales. Despite the uncertainty, the overall forecast maintains good continuity with yesterdays WPC progs as well. ...Weather/Hazard Highlights... Arctic High pressure holding strong during the medium range period will keep most of Mainland Alaska cold and dry. Meanwhile, storm systems in the Gulf will translate to unsettled conditions along the Southeast coast and Panhandle regions. Moderate to heavy precipitation will shift slowly southward this weekend with conditions tending to dry out by early next week as the upper low moves farther south and some upper ridging tries to build in. A decent pressure gradient along the coast may bring a period of gusty winds as well to these areas. The eastern Aleutians/Peninsula should stay quiet through much of the period although a couple of storm systems to the west likely brings renewed wet weather to the western and central Aleutians. Temperatures across most of the state should start out below to much below normal on Friday (except the Panhandle), though ease with time as the upper ridge axis shifts slowly inland. By Sunday-Monday, parts of the Western Alaska and North Slope regions may see temperatures back to above normal, with the Panhandle transitioning to much below normal. Santorelli Additional 3-7 Day Hazard Information can be found on the WPC medium range hazards outlook chart at: https://www.wpc.ncep.noaa.gov/threats/threats.php Hazards: - Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Thu-Fri, Jan 27-Jan 28. - High winds across portions of the Alaska Panhandle and mainland Alaska, Thu-Fri, Jan 27-Jan 28. 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