Two rounds of rain this week could flood Susitna Valley gravel bars

Gravel bars and low riverside camps in the Susitna Valley may go underwater this week. Two rounds of rain will push rivers and streams in the Yentna and Skwentna basins toward bankfull, the National Weather Service in Anchorage said in a hydrologic outlook issued Sunday afternoon.

The first round arrives late Monday night and lasts through Wednesday morning. Forecasters put the odds of widespread rainfall of 0.5 to 1.5 inches at 70 to 80 percent. The highest totals are very likely from Petersville east to Talkeetna and along the Talkeetna Mountains to Hatcher Pass. Forecasters put those odds at 80 to 90 percent.

The second round runs from late Thursday night through Saturday evening, with another 0.5 to 1.5 inches likely. Forecasters are less confident in that one, putting it at 60 to 70 percent. Far northern and western parts of the valley have a 20 to 30 percent chance of seeing more than 1.5 inches.

The outlook covers the Yentna and Skwentna basins along with creeks and streams heading in the western Talkeetna Mountains. "Expect sharp rises on many small streams and rivers, including the Yentna at Lake Creek," the outlook said. Gravel bars and other spots popular for camping may flood as rivers reach bankfull. Heavy rain may also pond in low-lying areas with poor drainage.

Residents and river users should expect higher than normal water and should monitor weather and river forecasts, the outlook said.

• Weather or flooding reports: 1-907-266-5127 or inws.ncep.noaa.gov/report/

• River condition reports: the river forecast center at 1-907-266-5160

The outlook expires Monday afternoon. That is before the first round of rain is due to begin.