Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 734 PM EDT Tue Nov 1 2022 Valid 12Z Sat Nov 5 2022 - 12Z Wed Nov 9 2022 ...Synoptic Scale Overview... The strong low pressure system that'll initially be over the eastern Gulf region for the end of the week is forecast to move towards the southeast and away from the region for the weekend, with precipitation abating in intensity for most of the coastal areas. An impressive upper level ridge and corresponding surface high will evolve across the mainland with an omega block type pattern likely developing going into early next week, with surface pressures perhaps reaching 1050mb across portions of the Interior! There will be some shortwave/frontal passages across the Aleutians and the Bering, although the eastward progress of these will be limited by the big high to the east. ...Guidance/Predictability Assessment and Preferences... Overall, the model guidance shows fairly good agreement at the start of the forecast period this weekend, and there is also strong agreement in the ensemble guidance for the high latitude ridge axis that develops. The greatest degree of forecast uncertainty resides west of this ridge across the Bering and the Aleutians where a few shortwave perturbations will track northwestward, although none of these appear to be strong in the guidance at this juncture. It appears the 18Z run of the GFS tries to break down the ridge axis sooner than the CMC/ECMWF, but the ensemble means suggest the ridge axis will remain robust through about Wednesday. In terms of model preferences, a multi-deterministic blend sufficed through Sunday, followed by gradually increasing portions of the GEFS/EC means early next week. ...Sensible Weather and Potential Hazards... The strong atmospheric river will be subsiding by the end of the week, but some lingering precipitation will continue to affect portions of the southeast Panhandle region early Saturday with valley rain and mountain snow. On the northwest side of the Gulf surface low, gusty northerly winds may end up creating a gap wind event across southeast Alaska and result in high winds, affecting portions of the coastal region. By this weekend into early next week, high pressure will be large and in charge across much of the mainland with little in the way of snow or wind. This will also produce a very strong low level temperature inversion for the Interior valleys, with readings well below typical early November levels and very little mixing with the warmer air aloft. Some locations will likely remain subzero for a few days across the Yukon Flats of the eastern Interior, mainly Saturday through Monday. Northern Alaska may end up being near or slightly above normal for temperatures where there will be less of an inversion to deal with north of the Brooks Range. Hamrick - High winds across portions of the Alaska Peninsula and Kodiak Island, Fri-Sat, Nov 4-Nov 5. - High winds across portions of the Alaska Southeast Panhandle, Sat-Sun, Nov 5-Nov 6. 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