Alaska Extended Forecast Discussion National Weather Service College Park MD 630 PM EDT Sat Aug 2 2025 Valid 12Z Wed 06 Aug 2025 - 12Z Sun 10 Aug 2025 ...Synoptic Overview... An upper level low over the Aleutians Wednesday will gradually shift eastward and deepen into a trough as it approaches the AKpen and Kodiak Island by Friday. An upper level low over the Panhandle Wednesday will quickly move to the east by Thursday, to be replaced by ridging and high pressure until the weekend. An upper level trough over the Arctic Ocean will gradually sink south as multiple east-moving shortwaves race along the North Slope. An upper level low is likely to form north of the Chukotsk Peninsula by the weekend, reinforcing the upper level trough over Southwest Alaska, though the details of that evolution are highly uncertain. The surface low over the Aleutians will pick up additional energy from a North Pacific low Wednesday and Thursday, allowing the whole conglomeration of lows to merge into one near the AKpen and Kodiak Island. This will keep the weather unsettled throughout the period for much of southern Alaska. For the Panhandle, high pressure moving in will allow for a period of dry weather Thursday and Friday. However, by the weekend, the approach of the warm front with the western Gulf low and any other potential North Pacific lows will usher in a very rainy period by the weekend. Despite a very active pattern aloft across Northern Alaska, relatively little will reach the surface in the form of heavy precipitation. However, a series of disturbances combined with potential upslope along the Brooks Range will increase the chances for mixed precipitation and snow at the higher elevations, as marginally but increasingly cold air settle into the North Slope. ...Guidance Evaluation and Preferences... Unlike yesterday, the 12Z suite offered a lot of uncertainty as to the evolution of the pattern across Alaska. The best agreement was with the Aleutians low Wednesday through Friday, slowly drifting from the Aleutians to the AkPen and Kodiak Island. High pressure providing a pair of dry days across the Panhandle also is of higher confidence. Elsewhere, confidence is much lower due to considerable discrepancy among the guidance. The 12Z CMC was the middle ground model among the various outlier features between the GFS and the EC. Thus, the forecast used a greater amount of CMC compared with the other two, moving towards ensemble outputs by the weekend. ...Weather/Hazards Highlights... No hazardous weather is expected across Alaska through the period. A few areas to note will be the gaps through the Eastern Aleutians where winds approaching gale force may increase local wave action. Another area will be the Panhandle, where the potential for heavy rain this weekend could cause worsened flooding from the Mendenhall Glacier. Finally, the potential for snow at the higher elevations of the Brooks Range could cause travel hazards along the Dalton Highway this weekend. && Wegman 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