Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 715 PM EDT Thu Jul 13 2023 Valid 12Z Mon Jul 17 2023 - 12Z Fri Jul 21 2023 ...Guidance Evaluation/Preferences and Predictability Assessment... Recent model and ensemble forecast clustering and run to run continuity problems may have stabilized, bolstering forecast confidence. Given recent issues though, prefer a broader blend of the 12 UTC GFS/ECMWF/UKMET/Canadian and GEFS/NAEFS/ECMWF ensemble means to limit precision given lingering uncertainties. Favorable trends include the stronger and more rapid digging of closed upper troughing southward into the Gulf of Alaska, development of an easterly wave pattern overtop from Southeast Alaska to Southcentral/Alaska Range/southern Interior along with a stronger signal for a lingering/renewed North Slope upper trough. ...Weather/Hazards Highlights... Closed upper low energy digging into the northern Gulf of Alaska and surface system response should allow weekend heavy rain and unsettled conditions linger into Monday for the Kenai Peninsula and into Southcentral Alaska as fueled by wrapping moisture. The carving out of an amplified and slow moving closed upper trough and surface based low over the Gulf of Alaska to the east of a highly anomalous upper ridge will increasingly present a protracted maritime concern for remainder of next week. However, easterly waves rotating overtop from Southeast Alaska back to Southcentral/Alaska Range and the southern Interior will support uncertainly timed daily bouts of mainly light to moderate rains across the broad region next week, but perhaps especially into favored terrain of the Southeast and the eastern Alaska Range. Meanwhile further north, lingering and renewed upper troughing settling from the Arctic Ocean into the North Slope and Brooks Range may act to produce some chances for locally unsettled weather and rain, with best potential possibly working into Northeast Alaska with system approach. Schichtel Hazards:- Heavy rain for the Kenai Peninsula and into Southcentral Alaska, Sun, Jul 16. 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