Alaska Extended Forecast Discussion National Weather Service College Park MD 703 PM EDT Thu Jun 26 2025 Valid 12Z Mon 30 Jun 2025 - 12Z Fri 4 Jul 2025 ...General Overview... The main theme of the overall weather pattern expected next week will be a broad upper low/trough that will be situated over the northern Gulf, and an upper ridge axis that evolves into a closed upper high over the western mainland towards the end of the week. With an incoming upper low from the western Bering, this will tend to form an omega block pattern that will likely have some staying power from the middle of the week and beyond. Warm conditions continue across the mainland with scattered to numerous showers and storms for the eastern Interior, and periods of light rain for the southern coastal areas. ...Guidance Evaluation/Preferences... The 12Z model guidance suite is in reasonably good agreement for the start of the period Monday, and there has been a stronger trend in the guidance for the shortwave trough dropping southeast from the Bering to the western Gulf for early in the week. This will tend to reinforce the upper low that will already be in place across the northern Gulf. Looking ahead to Thursday, the CMC becomes farther west than the model consensus/AIFS guidance with the upper low south of the Alaska Peninsula, and also with the low approaching from eastern Siberia, so its contribution in the preferred model blend is reduced for the end of the week. The ensemble means were gradually increased to about half by next Friday. ...Weather/Hazards Highlights... A broad upper level low with reinforcing surface lows will be present across the northern Gulf through most of the forecast period. The upper ridge axis appears likely to build back in to the north across the central and northern mainland going into the middle of next week and potentially forming an omega block type pattern as a closed upper high likely develops. Meanwhile, a trough approaches from eastern Siberia for the middle to end of the week, but does not appear to be all that impactful for now. There will likely be an increase in shower and thunderstorm coverage going into Sunday and early next week across eastern portions of the Interior. Relatively moist northeasterly flow approaching the central and eastern portions of the Alaska Range will increase the potential for heavier rainfall, with the highest totals where there is an upslope flow component where 1 to locally 2 inches will be possible. A heavy rainfall area remains on the WPC hazards chart for the 29th and 30th for east-central portions of the Interior, although there has been a slight downward trend in QPF with the 12Z guidance compared to yesterday. This rainfall would help to mitigate any ongoing fire weather concerns. Showers are also expected for southeast Alaska as moist onshore flow continues courtesy of the loitering low over the northern Gulf. 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