Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 646 PM EST Fri Jan 10 2025 Valid 12Z Tue Jan 14 2025 - 12Z Sat Jan 18 2025 ...General Overview... Active weather is forecast to continue through early next week as a series of quick but weak lows move across the Aleutians into the Gulf. This will continue a threat for heavy precipitation in Southeast Alaska and elevated winds and temperatures for much of the Mainland. High pressure will stretch across the state mid-week, bringing calmer weather and cooler temperatures, but a couple strong low pressure systems will likely approach from the west-southwest late next week or early next weekend. These systems will bring the next chance for heavy precipitation and high winds to western portions of Alaska. ...Model Guidance Assessment... Model guidance remains in good agreement through the first couple days of the forecast period. The GFS/ECMWF/CMC show good clustering with the weaker lows that will track into the Gulf next week. Model spread increases later in the period as the two Pacific lows approach the state. The leading low looks to get blocked by high pressure in the Gulf, and models are starting to pick up on the upper level energy splitting around the high, with a portion going north towards the Alaska peninsula and a portion going south towards the Canadian west coast. The CMC/CMCE seems to be the slowest to resolve this trend, keeping the majority of the upper level energy to the south while the GFS and ECMWF have shifted to favor more energy splitting to the north. Any energy splitting north will move quickly ahead of the second low approaching from the West late next week. For WPC's forecast, a near even blend of the deterministic GFS/ECMWF/CMC was used for Tuesday and Wednesday, after which ensemble means from the GEFS and ECENS were added in increasing amounts while the CMC was phased out. This resulted in a good starting point for the forecast, favoring a northward split of energy from the leading Pacific low. ...Weather/Hazards Highlights... The focus for heavy precipitation will be in Southeast Alaska as weaker lows track through the Gulf Tuesday into Wednesday. Above normal temperatures will result in most precipitation falling as rain, but wintry mixed precipitation and snow could be possible in some areas. Precipitation chances will gradually decrease for Southeast Alaska Thursday and Friday as high pressure builds in the Gulf. High pressure will dominate the weather pattern for much of the interior and northern Alaska later next week as well, which will result in mostly dry conditions and will allow for temperatures to cool back to near normal values. By Friday and Saturday, two strong Pacific lows will likely approach the state and bring the next chance for impactful weather. The leading low pressure system will be blocked by strong high pressure in the Gulf, forcing the energy to split around the high. Energy splitting north is forecast to track towards the Aleutians and Alaska Peninsula, and could focus anomalous moisture and heavy precipitation over this region. The second Pacific low is forecast to slowly push into the Bering Sea and push a frontal boundary across the Aleutians on Saturday. Moisture streaming ahead of the second system could prolong heavy precipitation and expand it into portions of western Alaska. High winds will also be a concern for western portions of the state due to the tight pressure gradient expected with these deep surface lows. There is still significant uncertainty in how these lows will interact with each other, which would impact sensible weather and hazards late next week. Dolan 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 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