Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 639 PM EST Sat Jan 28 2023 Valid 12Z Wed Feb 01 2023 - 12Z Sun Feb 05 2023 ...Pattern overview and Weather/Hazard Highlights with Model Guidance/Predictability Assessment... A highly anomalous upper ridge currently over Alaska will continue to be eroded during the medium-range period as additional troughing associated with outbreaks of frigid air from Siberia work their way across the North Pacific. Model ensemble means show very good agreement that a piece of the anomalous ridge will retreat into the Arctic Ocean and then evolve into an upper closed High while the main center of a polar vortex meanders over eastern Siberia. In this pattern, light snow early next week across the north-central interior section near a break in the upper ridge is forecast to gradually taper off through midweek. A lingering low pressure system centered over the Gulf of Alaska will bring unsettled weather slowly eastward from the Alaska Peninsula to the southern coastline followed by the Panhandle through next week. Precipitation is not expected to be excessive, though the southern Panhandle should see moderate to heavy amounts of mountain snow Thursday/Friday. Meanwhile, unsettled weather will continue across the Aleutians as relatively small scale cyclones/disturbances attempt to consolidate near the Aleutians during the middle of next week and then pass by to the southeast. Models continue to indicate uncertainty in handling the interaction of these disturbances but the associated weather impacts are not expected to be hazardous. Toward next weekend though, model ensembles show decent agreement that moisture ahead of a larger scale cyclone will gradually advance across the Aleutians from west to east ahead of the lead front. This system will be monitored for the potential of high winds and heavy precipitation to impact the Aleutians next weekend. Temperature-wise, a slow cooling trend is forecast to continue across the entire mainland Alaska through the medium-range period, bringing temperatures down to near normal by the end of next week when sub-zero readings are forecast to expand across the northern half of the state. The WPC Alaskan medium range product suite was derived from a 40% blend of the 12Z GFS/GEFS, 40% from the 12Z ECMWF/00Z EC mean, and 20% from the 12Z CMC/CMC mean, with increasing usage of the ensemble means for Days 6-8 in a pattern with overall near average predictability. The blend results appear quite compatible with yesterday's forecast package. Kong 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