Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 621 PM EDT Sun May 15 2022 Valid 12Z Thu May 19 2022 - 12Z Mon May 23 2022 ...Overview and Guidance/Predictability Assessment... An upper level rex block pattern will likely be in place across western Alaska and the Aleutians for the end of the week, and this will be slow to change going into next weekend and beyond. By Saturday, the upper high slowly retrogrades west across the Bering and an upper trough from the Arctic tries to build in across eastern Alaska by Sunday and into Monday. Meanwhile, and organized low pressure system develops over the North Pacific, but it is currently not expected to make much progress towards the southern Alaska coast through the weekend. The 12Z model guidance suite is in good synoptic scale agreement across much Alaska and vicinity through the end of the work week. By Saturday, the GFS develops a triple point low over the Gulf that extends farther north than the other guidance, whilst the ECMWF is stronger with a surface low over the northern Gulf by next Monday. The CMC keeps the axis of low pressure farthest south across the southern Gulf with less in the way of impacts to the coast. There has been improving model agreement on an amplifying upper trough over the North Slope and Arctic Coast region by the weekend. The WPC forecast was primarily derived from a multi-deterministic model blend through Friday night, 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 rain across the Aleutians on Friday as moisture from the offshore low edges north. Some showers are also likely for the southeast Panhandle for next weekend with onshore flow ahead of the next storm system. However, the main threat should continue to be river flooding associated with snow melt and ice jams. Temperatures across much of the mainland are forecast to moderate going into the end of the week, with parts of western and central Alaska and the Peninsula likely having above normal highs as the Bering Sea ridge slowly works inland. However, a cold front sinking southward across the northeastern part of the state by next weekend will likely bring a return to colder weather for that region. 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