Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 444 PM EDT Fri Nov 04 2022 Valid 12Z Tue Nov 08 2022 - 12Z Sat Nov 12 2022 ...Synoptic Scale Overview... Cold offshore flow continues across the AK Panhandle this period. Overall, ridging across southeast AK and western Canada should waver in intensity this period while storminess impacts the southern and western extremities of AK. ...Guidance/Predictability Assessment and Preferences... Overall, the model guidance shows fairly good agreement through the period, with some spread lingering early to mid next week across the Aleutians with a cyclone moving nearby, likely south of the archipelago early to mid next week and the general persistence of the mid to upper level ridging over AK. The 12z Canadian and to some degree the ECMWF struggle run-to-run and day-to-day in determining whether or not this cyclone/its upper low phases with a trough to its north, which continues to alter the latitude of its trajectory/whether or not it crosses the Aleutians into the Bering Sea. Normally, unphased/separated flow is best, so weighted the 12z Canadian and 12z ECMWF minimally across Siberia and western mainland AK. A compromise of the 12z GFS, 12z ECMWF, 12z Canadian, and 12z UKMET sufficed Monday night before early on before minimizing the 12z Canadian. Split the blend half deterministic and half ensemble mean late in the period, as usual, for the pressures, 500 hPa heights, and winds. For QPF, used a compromise of the 19z NBM 12z GFS, and 12z ECMWF ensemble mean guidance to account for uncertainty. The remainder of the grids relied heavily on the 19z NBM. ...Sensible Weather and Potential Hazards..., Much of Alaska will be cold and dry as an Arctic high pressure migrates south and east across western Canada. Strong gap flows across the AK Panhandle continue to be a concern through early next week. Over the Southeast Alaska Panhandle, much below Normal temperatures are expected through midweek as the frigid Arctic air infiltrates from the east with anomalously cold high temperatures into the 20s Fahrenheit and subzero Fahrenheit lows lasting for multiple days in a row. Otherwise, expect the bulk of the heavy precipitation chances to be confined to the Northernmost Aleutians, Alaska Panhandle, southwest Alaska, and the Kenai Peninsula through Tuesday as a cyclone migrates through the Gulf of Alaska. Additional high wind concerns remain to the north over Bristol Bay and into the Bering Sea Monday as a pair of occluding surface lows support strong periods of strong winds upwards of 60 mph, sometimes favorably oriented toward the coast to lead to coastal flooding concerns. High winds are also expected to lead to blizzard conditions and coastal flooding across western Alaska northward to the Bering Strait on Monday. Roth/Snell - Heavy precipitation across portions of mainland Alaska, Mon-Tue, Nov 7-Nov 8. - High winds across portions of the Alaska Panhandle and western mainland Alaska, Mon, Nov 7. - Much below normal temperatures across portions of the Alaska Panhandle, Mon-Wed, Nov 7-Nov 9. 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