Umatilla County Sheriff's Office issued the following announcement on May 6.
"Minor areas of flooding is possible but widespread flooding is NOT EXPECTED" is the message from this week's briefing given to the Umatilla County Sheirff's Office, Emergency Mangement Division and Community Partners by the National Weather Service, Pendleton.
According to the National Weather Service, periods of rain are expected with a slight chance of thunderstorms Friday and Saturday. Unseasonable cold temperatures will return starting Saturday night and continue through midweek. Scattered showers with mountain snow showers just about each day.
Already high streams and rivers will see higher flows through early Sunday, then slowly receding flows next week. A few locations will see the highest flows of the season. The fast high flows will cause bank erosion and may see minor areas of flooding. Widespread flooding is not expected.
Releases from McKay Reservoir will continue as needed based on rain amounts over the next several days. This has slightly increased flows on the Umatilla river below Pendleton.
Updated river conditions and forecasts can be found at 
https://water.weather.gov/ahps2/index.php?wfo=pdt
For information on flood preparation go to https://www.ready.gov/floods"
Original source can be found here.
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