Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 636 PM EDT Mon Oct 31 2022 Valid 12Z Fri Nov 04 2022 - 12Z Tue Nov 08 2022 ...Gusty winds likely across southern and southeast portions of Alaska... ...Overview... The start of the period will remain unsettled and active, particularly across portions of southern and southeast Alaska. By this weekend, a strong and anomalous upper ridge axis will begin to move eastward over the Mainland, eventually closing off off over northern Alaska. At the surface, very strong high pressure will bring potentially below normal temperatures. Storminess along the coastal areas will bring potential for high winds at times through the period. By early to mid next week, another storm system is possible for the western Aleutians. ...Guidance/Predictability Assessment and Preferences... Overall, the model guidance shows fairly good agreement at the start of the period. Aloft, a strong shortwave trough will move through the Mainland into the Gulf of Alaska while at the surface, low pressure off southeast Alaska and its associated frontal boundary will interact with the mid-upper level feature. Some minor timing and strength differences were found with this feature, but in general a blend of available deterministic guidance sufficed. By late this weekend into next week, the upper ridge axis will shift eastward and pinch off a closed high across northern Alaska. While individual runs of the ECMWF and GFS differ on this scenario, the ensemble means showed decent agreement, giving confidence in the forecast scenario. At the surface, very strong high pressure (1048mb+) will settle over eastern AK into northwest Canada. By day 7-8, the largest differences lie southwest of Alaska with the approach of a possible storm system affecting portions of the Aleutians. The models show potential for a pretty deep low to cross through mid-week, but there is considerable model spread that a ensemble mean approach was preferred. This helped to maintain good continuity days 4-7 compared to yesterdays forecast as well. ...Weather/Hazards Highlights... The strong atmospheric river will be subsiding later this week but lingering precipitation will continue to affect portions of the Alaska Panhandle Friday with valley rain and mountain snow. On the north side of the surface low that settles in the Gulf of Alaska, gusty northerly winds may end up creating a Gap Wind event across southern and southeast Alaska and result in high winds. This may affect a lot of the coastal region. By this weekend into next week, strong high pressure settling over eastern Alaska will bring a period of drier weather, but an extended period of below normal temperatures. Readings as low as 20 to near 30 degrees below normal are possible, particularly for daytime highs and especially for the southern half of the Mainland. Northern Alaska may end up being near or slightly above normal for temperatures. Taylor - High winds across portions of mainland Alaska, Thu-Sat, Nov 3-Nov 5. - High winds across portions of the Alaska Panhandle, Fri-Mon, Nov 4-Nov 7. 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