Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 627 PM EDT Sat May 14 2022 Valid 12Z Wed May 18 2022 - 12Z Sun May 22 2022 ...Overview and Guidance/Predictability Assessment... A rather amplified upper level pattern is expected across the Alaska domain for the middle to end of next week, with a closed upper high over the Bering remaining nearly anchored in place, with a potential rex block developing by the end of the week as an upper low develops to its south. Some upper level troughing will likely be in place across the Arctic Coast region at the beginning of the forecast period. At the surface, a low pressure system over the eastern Gulf will gradually weaken and move inland by Wednesday, while a broader, elongated low develops over the North Pacific. The 12Z model guidance suite is in good synoptic scale agreement across much Alaska and vicinity through the end of the week. Both the UKMET/GFS have trended stronger regarding the extent of the upper ridge across the Aleutians/Bering compared to yesterday's runs. The CMC/GFS are stronger with a trough crossing northern Alaska by Friday and into Saturday compared to the ECMWF, and there is still good consensus for a southeast-northwest oriented ridge axis across the southwestern mainland through next weekend. The WPC forecast was primarily derived from a multi-deterministic model blend through early Friday, with slightly greater weighting towards the ECMWF/CMC solutions, and then a gradual increase in the GEFS/ECENS for next weekend whilst still maintaining some of the deterministic guidance. ...Weather and Hazard Highlights... Most of the state is expected to remain dry, with the best potential for some passing showers across the Aleutians later in the week. However, the main threat should continue to be river flooding associated with snow melt and ice jams. Temperatures across much of the mainland for the middle of next week are likely to start off a bit below normal, with the greatest anomalies for eastern Alaska as a deeper shortwave exits the region. Temperatures are forecast to moderate going into the end of the week, with parts of western Alaska and the Peninsula likely having above normal highs as the Bering Sea ridge slowly works inland next week. 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