Flood — South Slopes of the Central Brooks Range, Alaska

2025-08-26 to 2025-08-27 · near Wiseman, South Slopes of the Central Brooks Range, Alaska

Event narrative

Public reports and photos delivered to the NWS River Forecast Center in Alaska indicated that the road to Wiseman was completely covered, thus preventing any travel into or out of Wiseman by automobile. It was estimated that the Middle Fork of the Koyukuk rose high enough to cover the road with water 18 inches deep.

Wider weather episode

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.

View location on OpenStreetMap → (67.4132, -150.1223)

Source: NOAA Storm Events Database, event_id 1293173. Narrative written by the NWS forecast office that issued the report.