Aug 26, 2025
A prolonged period of deep moist southwesterly flow from the North Pacific ocean, otherwise known as an Atmospheric River, produced several days of heavy rainfall along the south slopes of the Brooks Range. Over about a 5 day period total rainfall of three to six inches resulted in considerable flooding for the Koyukuk and it's tributaries. In addition this southwest flow also resulted in very strong winds through the Alaska Range passes.
Source: NOAA National Weather Service Storm Events Database (event 1293373). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Dalton Highway Summits County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.