PROJECT ALERT NOTICE (MT) Flooding in Montana, day 4

Date: Wed, 15 Jun 2022 23:53:13 EDT

Summary: Flooding persists in the Yellowstone River basin, day 4

Flooding persists in the Yellowstone River basin in Montana and Wyoming as a result of several inches of rain (2.5-4) on top of snowmelt runoff over the weekend (June 11-12). Many of the tributaries have peaked. Gages in the upper portion the Yellowstone River basin have already peaked. The gages on the lower portion of the Yellowstone River continue to rise and are expected to peak by the end of the week and over the weekend.

Rock Cr nr Red Lodge remains the only gage not operating, and will be reinstalled as soon as time allows. MT expects to have 2 sites exceed the stage-discharge rating and numerous provisional peaks of record have been recorded. Notably, a crew was able to install an RDG on HWY 87 upstream of the gage Yellowstone River at Billings as the gage and cableway were damaged by floodwaters, and the crew was able to obtain 2 of the highest measurements on record.

Currently WY-MT has 10 crews in the field making measurements and field observations around Wyoming and Montana. Crews are downloading measurements, applying shifts and/or extending ratings from the field. The USGS is communicating with the NWS and other cooperators as needed.

WY-MT crews will continue to make measurements through Friday June 17 and will reassess as the weekend approaches.

Is has been communicated that there is still 12 inches of snow-water-equivalent (SWE) coupled with high temperatures forecasted to be in the 90's by the end of the week that will result in additional flooding over the weekend and into early next week.

Please contact Scott Whiteman or Cheryl Miller for questions regarding WY-MT gages.