PROJECT ALERT NOTICE (MT WY) Flooding in Wyoming and Montana continues

Date: Wed, 30 May 2018 08:53:18 EDT

Summary: Flooding from rainfall and snowmelt runoff is occurring in northwestern Wyoming and western and south-central Montana.

Flooding from rainfall and snowmelt runoff is occurring in the Wind and upper Snake River basins in Wyoming and the Yellowstone and upper Missouri River basins in Montana. Flooding from rainfall and snowmelt in the Clark Fork River basin in western Montana continues.

National Weather Service flood stage recently has been exceeded / is being exceeded at 12 USGS streamgages. Estimated annual exceedance probabilities in some basins ranged from greater than 0.10 to less than 0.02. Annual peak streamflows to date in the Clark Fork basin ranked as high as 2nd for periods of record up to 98 years.

Six crews of 2 currently are deployed. Two streamgages have sustained damage and have been repaired. Several ratings have been extended. Additional rating extensions will be required at streamgages in the Tongue River basin. Coordination with the State of Montana for possible floodplain studies on the Yellowstone River and Clarks Fork Yellowstone River in south-central Montana is occurring.

USGS continues to provide current measurement and rating information to National Weather Service offices via email and "NWSChat." USGS also continues to participate in weekly State of Montana flood readiness calls. The public is engaged via the Center Twitter and Instagram accounts (@USGS_WY and @USGS_MT).