Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 647 PM EST Tue Feb 21 2023 Valid 12Z Sat Feb 25 2023 - 12Z Wed Mar 1 2023 ...Model Guidance/Predictability Assessment... The 12Z model guidance agrees on most of the synoptic scale features and the ridge/trough evolution across the domain, with the normal level of mesoscale differences. In terms of model differences, the GFS continues to have a more southern track with the storm system entering the Bering Sea early next week and depicts two separate lows, with the second low the stronger event. The CMC and ECMWF are suggesting a more northwesterly track near the Siberian coast before entering the vicinity of the Bering Strait by late Tuesday. The 12Z ECENS is near the overall model consensus and represents a good starting point in regard to this event. The fronts/pressures forecast was primarily derived from the GFS/ECMWF along with some CMC/UKMET for the first half of the forecast period, and then increasing the percentage of the ensemble means to about 50% by next Monday, with more weighting to the ECENS. ...Pattern Overview and Weather/Hazard Highlights... An upper level trough is expected to be in place across the Gulf of Alaska this weekend after the ridge axis breaks down, along with a surface low that develops near the southeast Panhandle. A second surface low develops just north of the Aleutians by Saturday morning and steadily tracks eastward before weakening south of the Kenai Peninsula on Sunday. Looking ahead to early next week, the ridge axis rebuilds across the eastern Aleutians and over the western mainland. A well organized low pressure system is forecast to track across the Bering Sea on Monday, with a potential track similar to the event late this week. There may even be a separate trailing surface low behind this one by next Wednesday, although it will probably be weaker. Periods of moderate to heavy snow are expected across much of the southeast Panhandle on Friday night and into Saturday as Pacific moisture advects inland ahead of the Gulf low, with 1 to 2 feet of accumulation possible for the higher elevations. Much of the state should be dry going into the weekend. High winds are a good possibility for portions of the Aleutians Saturday into early Sunday as a low pressure system passes by to the north. The mild temperatures late in the week are forecast to drop substantially from the 20s/30s down to the 0s/10s across much of the mainland for highs going into the weekend as the upper ridge breaks down. The coldest readings are expected north of the Brooks Range, where the greatest coverage of subzero temperatures is likely. Depending on the track and magnitude of warm air advection with the large Bering Sea storm, temperatures are likely to moderate some across the southwestern mainland early next week, along with a return to increasing snowfall chances. Strong winds will also be possible near the western coast early next week. Hamrick Hazards: - Heavy snow across portions of the Alaska Panhandle, Fri-Sat, Feb 24-Feb 25. - High winds across portions of southern coastal mainland Alaska and the Aleutians, Sat, Feb 25. 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