Alaska Extended Forecast Discussion National Weather Service College Park MD 721 PM EDT Tue May 20 2025 Valid 12Z Sat 24 May 2025 - 12Z Wed 28 May 2025 ...Overview... The upper level pattern over the Alaska domain will feature weaker troughing over mainland Alaska and a rather persistent upper low in the Gulf. Stronger upper ridging south of the central Aleutians will eventually relax and stretch westward, further allowing troughing in the Bering to reload into the Gulf. The end result will be a progressive pattern with temperatures generally within 10 degrees of climatology, and multiple chances of rain for the southern/coastal portions of the state, with the greatest coverage across the Panhandle. ...Guidance Evaluation and Preferences... The 12Z model guidance suite features decent overall agreement across the Alaska domain for the upcoming weekend across the Gulf and the mainland, but more uncertainty than usual for the Bering with the next storm system moving in. The ensembles show greater spread with timing and intensity of the low as it crosses the Bering, and things actually get better defined by late Sunday into Monday as the low eventually re-forms over the Gulf. There are also noteworthy model differences across the Arctic with a closed low north of the Arctic Coast. However, there appeared to be no major outliers and a general model blend worked through Monday, followed by gradually increasing percentages of the ensemble means through the middle of next week. ...Weather/Hazards Highlights... Periods of rain and high mountain snow are expected from the Alaska Peninsula to the southeast Panhandle region, with the greatest coverage and intensity expected from Juneau and points south. A heavy rain area is delineated in the WPC medium range hazards graphic for the 24th to the 27th given how late in the season this is, and the duration of the rainfall expected, even though it will not be as heavy as many early season events. Farther inland across the Interior, scattered afternoon and evening thunderstorms are likely to develop in the presence of an unstable airmass, and lightning strikes from these storms may increase the threat of wildfires in the region. Temperatures overall are expected to be near to slightly above average by late May standards across the central and southern mainland, and slightly below north of the Brooks Range. Cooler conditions are also likely for the coastal areas and the near shore islands owing to increased cloud cover and rainfall. 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