NWS forecasts up to 1.5 inches of rain in the Chena River basin

Up to an inch and a half of rain is expected across the Chena River basin over the next two days, and the Chena and Little Chena will rise with it. Forecasters in Fairbanks do not expect flooding, but said that could change "should the focus for heaviest rainfall shift further east."

An atmospheric river is bringing 1 to 2.5 inches across the Interior, heavy enough that most places see rain like this only once every two to five years, and a few pockets far less often than that. Rates should ease by Sunday afternoon.

The Little Chena near Fairbanks sat at 13.5 feet Thursday evening, well under the 21 feet at which the river starts to warrant attention and the 25 feet that counts as minor flooding.

Fairbanks watches this closely for a reason. August rain in 1967 put roughly 95 percent of the city underwater for about five days, damaging nearly 6,000 homes and causing more than $170 million in damage. The Chena River Lakes Flood Control Project came out of it, and the Army Corps of Engineers has run Moose Creek Dam since 1979, holding flows through downtown to no more than 12,000 cubic feet per second.

The dam does not cover everything. The borough's own hazard profile notes the project controls Chena River flows only, and that many developed residential areas sit in flood-prone ground the dam does not protect, in zones mapped without a calculated flood height.