Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 748 PM EDT Sun May 22 2022 Valid 12Z Thu May 26 2022 - 12Z Mon May 30 2022 ...Overview... An upper high centered over the Bering Sea late this week is forecast to slowly shift eastward over the mainland by early next week. This blocky high will separate an upper low well northwest of Alaska that may send rounds of troughing into the northern mainland as well as a train of lows and upper-level energy in the North Pacific. Generally light precipitation is forecast with this pattern, with the western mainland likely staying dry underneath the ridge influence. ...Guidance/Predictability Assessment... Model guidance remains in generally good agreement with the fairly slowly evolving pattern described above, especially with the blocky ridge across the Bering Sea to the mainland. Some differences persist with the movement/reorientation of the upper low in the northern latitudes. The 12Z ECMWF seems farther east than consensus with the centroid of the high latitude upper low. Meanwhile the 12Z GFS is quite aggressive with the energy/southern and western extent of the troughing Fri-Sat over the mainland, taking troughing all the way to Southcentral Alaska Friday-Saturday and suppressing the ridge more west than other guidance. Thus today's WPC forecast blend incorporated some of the 06Z GFS and 00Z ECMWF to minimize the less desirable aspects of the 12Z models, with a fairly typical blend favoring the deterministic models early and increasing the proportion of the GEFS and EC means as the period progressed. This approach also worked reasonably well for the still uncertain details of the North Pacific energetic flow. ...Weather and Hazard Highlights... Generally light precipitation is forecast for Alaska through next week, with one area of focus over the North Slope and Brooks Range as frontal systems linger there. The eastern mainland and southern part to the Panhandle could also see rounds of light showers. Western Alaska could remain dry given the ridge pattern. River flooding may continue to be an issue over some locations in the middle latitudes of the mainland through parts of next week, due to snow melt and ice jams. Periods of slightly warmer than normal temperatures are expected for the western mainland into the central part of the state under the upper ridge influence. Parts of the Panhandle and the far southeastern mainland will likely be cooler than normal, while the North Slope could see a mix of above and below normal temperatures. Tate 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