Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 746 PM EDT Thu Apr 28 2022 Valid 12Z Mon May 2 2022 - 12Z Fri May 6 2022 ...Guidance/Predictability Assessment... An active flow pattern is expected to evolve over the region through the extended 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 early next week, so a deterministic model blend sufficed as a starting point through next Tuesday. The low pressure initially over the Gulf of Alaska late Sunday/early Monday weakens as the next stronger closed low tracks across the Aleutians Monday into Tuesday. That system then occludes and stalls over the Gulf through the middle to end of the week, keeping the unsettled weather in place along the southern mainland and southeast Panhandle. Toward the end of the period, a second shortwave approaches the Gulf and is likely to become absorbed into the existing closed low over the Gulf, reinforcing the pattern in place through next Friday. There was increased use of the ensemble means for days 7 and 8, whilst still keeping some of the operational GFS and ECMWF. ...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, especially across coastal terrain that is orthogonal to the onshore flow. 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. By Wednesday and into Thursday, another storm system may bring active weather to the southeast Panhandle, but details that far out remain uncertain. The potential exists for several inches of total rainfall for portions of the Kenai Peninsula, and also the southeast Panhandle. 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 the Interior. The combination of above normal temperatures and remaining snow-pack could lead to flooding across portions of the Yukon River basin in the western mainland. Hamrick Hazards: Flooding possible across portions of mainland Alaska, Sun-Thu, May 1-5. 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