Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 731 PM EDT Thu Mar 16 2023 Valid 12Z Mon Mar 20 2023 - 12Z Fri Mar 24 2023 ...Overview/Guidance Evaluation/Predictability Assessment... A strong low pressure system entering the western Bering and eastern Siberia will be the next weather feature to make headlines early next week. Even though the worst of the weather is currently expected to remain offshore over the Bering, some southerly high wind gusts over 40 mph are possible for coastal portions of the southwestern mainland on Sunday and Sunday night, and may also result in elevated tides. By midweek, a new low pressure system is forecast to develop south of Kodiak Island and this should slowly drift east and then southeast across the Gulf, while high pressure continues to govern the overall weather pattern across the Interior. In terms of the model guidance, there was enough agreement among the GFS/ECMWF/UKMET to merit a blend of those models through midweek. The CMC is closer with the placement of the Bering Sea low to the model consensus compared to yesterday, but it was more out of alignment across the Gulf for the midweek system, so it was not favored beyond Monday. Towards the end of the week, the GFS is depicting a stronger low south of the central Aleutians compared to the other guidance, and also more progressive with it. A gradual increase of the ensemble means was warranted for the second half of the forecast period owing to increasing mesoscale uncertainties. ...Weather/Hazard Highlights... The strong storm entering the western Bering is expected to produce widespread gusty winds for the central and western Aleutians and gale to storm force winds across the open waters. If the track of the low trends farther east in future updates, impactful winds and coastal flooding may affect greater portions of the western mainland Alaska coast, so this will continue to be monitored as the event begins to enter the short range forecast period. In any case, there should be enough deep layer southerly flow ahead of this low to advect a warmer maritime air mass northward across much of the mainland and even across the Brooks Range and the North Slope. Widespread highs in the upper 20s to upper 30s are likely next week, and 10s north of the Brooks Range. Some subzero overnight lows are likely Monday for the northern half of the state, but these readings should also moderate going into Tuesday and beyond with 0s and 10s being most common for inland areas. Hamrick Hazards: - High winds across portions of southern mainland Alaska, Sun, Mar 19. - High winds across western mainland Alaska, Mon, Mar 20. 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