Flood Watch expands to Anchorage and Kenai Peninsula as atmospheric river intensifies

Flood watches and advisories are in effect across Southcentral Alaska, covering some of the state's most populated areas and remote river corridors, as an atmospheric river drives heavy rain and strong winds through early this week.

Anchorage and Kenai Peninsula

NWS Anchorage expanded its Flood Watch Sunday to include Anchorage, Anchorage Hillside/Eagle River, the northwest and southwest Kenai Peninsula, and Skilak Lake, adding those areas to the Southern Kenai Mountains already under the watch.

An atmospheric river is driving the event, delivering 3 to 5 inches of rain to Whittier and 2 to 4 inches to Portage, with gusts to 55 mph at Portage. The National Weather Service warned that heavy rain and strong winds may cause ponding on roadways and make driving difficult, especially for high-profile vehicles, along the Seward and Sterling Highways through Monday evening.

Western Susitna Valley

A separate Flood Advisory is in effect for the Western Susitna Valley through noon Wednesday. The Yentna River at Lake Creek measured 18.6 feet at 9:50 a.m. Sunday and is forecast to crest at 21.6 feet by Tuesday afternoon, well above the 20.5-foot flood stage. NWS Anchorage identified Anglers Inn and King Point Lodges as facing water in several cabins once the river reaches flood stage.

The Susitna Valley hydrologic outlook projects 1.5 to 2.5 inches of additional rainfall through Monday night across the Yentna, Skwentna, and Susitna River basins. Sharp rises are expected on small streams and rivers, with crests arriving late Monday night into Tuesday. Gravel bars and low-lying camping areas are likely to be inundated as rivers reach bankfull conditions. The outlook also warns of localized ponding in low-lying areas and locations with poor drainage.

Atmospheric rivers can stall over the eastern Gulf of Alaska and extend heavy rainfall for one to three days, according to NWS guidance. The National Weather Service advises river users and recreators along Susitna Valley waterways to anticipate higher than normal water levels and monitor weather and river forecasts closely.

Flooding or weather reports can be called in to NWS Anchorage at 907-266-5127. River condition reports go to the river forecast center at 907-266-5160.