Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 709 PM EDT Sat Oct 16 2021 Valid 12Z Wed Oct 20 2021 - 12Z Sun Oct 24 2021 ...Stormy Pattern Continues from the Aleutians through Southern and Southeast Alaska... ... Guidance and Predictability Assessment... A rather stormy pattern over parts of Alaska will continue through at least the next week as a parade of low pressure systems moves from the Bering Sea/Aleutians into the Gulf. This should help to maintain mean low pressure across the Gulf through the entire extended range period. The models show good agreement on this overall pattern through the first half of the period, so a general model compromise provides a good starting point. After this, some bigger differences begin to arise regarding details of both a low in the Gulf and another low moving across the Aleutians, and how the two may interact. There's also plenty of uncertainty regarding exact track and location of low pressure systems as they move through the region. To help mitigate some of these differences, the WPC forecast trends quickly towards the more agreeable ensemble means. This approach allowed for good continuity from yesterdays forecast, as well as with downstream across the CONUS. ...Pattern Overview and Weather/Hazard Highlights... The period starts Wednesday with one system weakening in the Gulf of Alaska as another one deepens to its south and lifts towards the southern Panhandle by the end of next week. This should keep unsettled wet weather in the forecast from the southern coast to the Panhandle. Most places should see just scattered light to moderate precipitation, though locally heavy precipitation is likely in some spots, with snow in the higher elevations. The next system moves across the Aleutians on Thursday-Friday with widespread precipitation and gusty winds likely to accompany. As the low moves into the Gulf next weekend, precipitation intensity and coverage may increase again across the southern coast/southeast AK/Panhandle region as southerly flow gets pulled north ahead of the cold front. Temperatures from the Aleutians to the Panhandle should remain near or below normal through the period as surface low pressure and upper level troughing becomes established over the region. Into interior and northern Alaska, a warming trend is expected by the early to middle part of next week as upper level ridging tries to work over the state. Daytime highs, especially across the northern half of the state could be 10 to 20 degrees above normal through the second half of next week and next weekend. 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 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