Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 658 PM EST Sat Feb 24 2024 Valid 12Z Wed Feb 28 2024 - 12Z Sun Mar 03 2024 ...Guidance Evaluation and Preferences... Model solutions today agree quite well that the cyclone centered over the Gulf of Alaska at the beginning of the medium-range period will slide southeastward gradually away from the southern coastline of Alaska and weaken late next week, with the ECMWF solution being slightly faster on the forward speed of the system. The next system of concern will likely be later next week into the weekend when a larger occluded cyclone from the Pacific edges into the Bering Sea. The 12Z ECMWF solutions were quite a bit slower than the 06Z and 12Z GFS with the 12Z CMC being in the middle. Their ensemble means also exhibited similar discrepancies though not as spread out as their deterministic counterparts. In fact, similar trends persist for the rest of the medium-range period as the system heads gradually toward southwestern Alaska before a triple-point low possibly splitting off into the Gulf of Alaska later next weekend. It appears that the deterministic GFS ejects too much energy northeastward into southwestern Alaska too fast late next week, whereas the ECMWF is perhaps too slow given the increased amplitude of the system as well as a sharper and more vigorous front ahead of the cyclone. Therefore, today's WPC Alaskan products were derived based on a consensus of the 12Z ECMWF/EC mean, 12Z GFS/GEFS, and the 12Z CMC/CMC mean. This blend yielded solutions quite compatible with yesterday's products for most areas, with a faster progression of the QPF reaching the Aleutians given a faster preference to the late week Pacific cyclone. ...Pattern Overview and Weather/Hazards Highlights... Unsettled weather that starts out the medium-range period along the southern coastline midweek will give way to more active weather moving into the Aleutians late week, and then toward southwestern Alaska next weekend. A cyclone in the Gulf of Alaska broadens in scale while moving south to southeastward within an amplifying flow regime across the Pacific. A larger cyclone moves northward offshore Asia and impacts the western and central Aleutians mid to late next week. The southern tier of the state, including the Aleutians, will be wetter/snowier than locations farther north due to the expected storm track, though with a faster northeastward trend in the QPF as noted above. Gale to storm force winds are anticipated at times across the Aleutians, Alaska Peninsula, and near Kodiak Island, particularly in areas of gap flow/areas that usually deal with accelerated winds in northwesterly low-level flow. Colder conditions are expected to spread through southwest mainland Alaska into the middle of next week, spreading farther east through the eastern mainland, before milder marine air ahead of the Pacific cyclone heads toward southwestern Alaska next weekend. Normally colder eastern interior and northern locations could flirt with -40F readings for overnight lows. For wetter southern areas, rain in the Aleutians and snow in southern mainland Alaska, including the Alaska Panhandle is expected within the cold air mass. Kong/Roth 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