Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 630 PM EDT Wed Apr 27 2022 Valid 12Z Sun May 01 2022 - 12Z Thu May 05 2022 ...Guidance/Predictability Assessment... An active, fast/progressive flow pattern is expected to evolve over the region through the medium range period with several storm systems likely to bring unsettled weather to portions of Alaska. The 12Z model guidance showed very good agreement and clustering through at least day 6 and this led to average to above average forecast confidence heading into the middle of next week. Low pressure Sunday in the Gulf will weaken through Monday as the next stronger closed low tracks across the Aleutians Monday into Tuesday. That system then occludes and stalls over the Gulf through the remainder of the period, keeping the unsettled weather in place along the southern mainland and Panhandle. Toward the end of the period, fast moving shortwave energy closes off and is likely to become absorbed into the existing closed low over the Gulf, reinforcing the pattern in place through day 8. For the WPC forecast blend, the ECMWF/GFS were favored along with the UKMET through day 6 then increasing weights of the ECENS/GEFS means were included for day 7 and day 8 to account for some increasing forecast model spread and uncertainty and also to maintain WPC continuity. ...Overview Weather/Hazard Highlights... A series of storm systems and frontal passages will keep southern Alaska and southeast areas unsettled with periods of moderate to perhaps heavy precipitation. The best periods of heavier rain look to be Sunday into early Monday and again Monday evening into Tuesday, particularly across southeast Alaska, as a stronger low settles into the Gulf. Toward the end of the period, Wednesday/Thursday another storm system may bring active weather to Panhandle but details that far out are too uncertain. For the remainder of the state, the interior regions will be under the influence of high pressure and this should lead to a prolonged period of near to above normal temperatures, especially for parts of northern and western Alaska. The combination of above normal temperatures and remaining snow-pack could lead to flooding across Yukon River in the western mainland. Taylor Hazards: Flooding possible across portions of mainland Alaska, Sat-Wed, Apr 30-May 4. 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