Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 656 PM EST Thu Jan 16 2025 Valid 12Z Mon Jan 20 2025 - 12Z Fri Jan 24 2025 ...Stormy weather continues from western Alaska through the Alaskan southern tier... ...General Overview with Model Guidance Assessment... The upper-level pattern over the Alaskan domain will continue to favor back-to-back cyclones to track across the Alaskan southern tier during much of the medium-range period ahead of an upper-level ridge that tends to re-establish itself over mainland Alaska. Models show good agreement that there will be at least three significant cyclones to impact the Aleutians and through the southern coastal sections during the medium-range period. The first cyclone is expected to extend impacts well into western Alaska this weekend. The second system is forecast to track right along the Aleutian island chain early next week, as deterministic solutions begin to show more divergence next Tuesday when the cyclone center approaches the Alaska Peninsula. The ECMWF/EC mean solutions are preferred over the much slower GFS solutions, and to a lesser degree the GEFS, and the slightly faster CMC/CMC mean solutions. This general model preference is maintained through the rest of the medium-range period as the ensemble means show decent agreement for the next cyclone to track into the vicinity of western Bering Sea during the latter part of next week. There is increasing model agreement for the first cyclone to track north from the Bering Sea and be reinvigorated early next week as the cyclone moves farther north into the Arctic Ocean. The WPC medium-range package was based on 50% from the 00Z EC and EC mean, 30% from the 12Z GFS and GEFS, and 20% from the 12Z CMC and CMC mean. This blend maintains reasonably good WPC product continuity. ...Weather/Hazards Highlights... Heavy precipitation/winds will be near peak intensity from the eastern portion of the Alaska Peninsula to along the southern coastlines and into parts of Southeast Alaska as the medium-range period begins this holiday weekend. Above normal temperatures will make rain the main precipitation type in southwest Alaska and for coastal locations, but wintry mixed precipitation and snow is likely farther north and at elevation. Rain falling on top of snow could enhance snowmelt and lead to localized flooding concerns in some areas. Meanwhile, moderate to locally heavy snow/blowing snow farther north over western Alaska will gradually subside as the new work week begins but snow can be expected to linger into midweek over the south-facing portion of the Seward Peninsula. The second cyclone tracking through the Aleutians early next week could bring a period of higher winds and enhanced precipitation toward/into the Alaska Peninsula per the latest guidance trend. Only a modest increase in precipitation chances is expected for the southern coastline to the Panhandle midweek next week as the second cyclone is forecast to weaken over the Gulf of Alaska. The third cyclone should begin to make its presence known across the western Aleutians later next week as precipitation chances and southerly flow increase. Above freezing high temperatures are forecast across western Alaska on Sunday as the first cyclone center tracks northward just off the coast. Slightly colder air will move in thereafter but temperatures will remain well above normal for much of Alaska other than the southern portion of the Panhandle through the medium-range period. A lingering front with strong pressure gradient may make the Northern Slope breezy as well. Kong 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