Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 755 PM EDT Wed Mar 15 2023 Valid 12Z Sun Mar 19 2023 - 12Z Thu Mar 23 2023 ...Overview/Guidance Evaluation/Predictability Assessment... A compact but strong surface low over the northern Gulf this weekend is forecast to rapidly weaken going into Monday. However, a strong low pressure system approaching the western Bering and eastern Siberia will be the next weather feature to potentially make headlines, although the worst of the weather is currently expected to remain offshore and thus no hazards are currently indicated for land areas at this time. By midweek, a new low pressure system is appearing likely to develop south of Kodiak Island and this should slowly drift east 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 early Tuesday. The CMC is likely displaced too far east with the low across the Bering Sea when compared to the ensembles and the other guidance, so it was not favored for this forecast cycle. A gradual increase of the ensemble means, along with some previous WPC continuity, was warranted for the second half of the forecast period owing to increasing mesoscale uncertainties. ...Weather/Hazard Highlights... The weakening storm system over the northern Gulf on Sunday is still expected to produce rounds of inland snow and coastal rain for the southern portion of the state. 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 portions of the western mainland Alaska coast, so this will continue to be monitored. 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 middle 30s are likely next week, and 10s north of the Brooks Range. Some subzero overnight lows are likely Sunday and Monday for the northern half of the state, but these readings should also moderate going into Tuesday and beyond. Hamrick 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