The National Weather Service in Pendleton has issued a flood watch through Tuesday afternoon for the John Day Basin and Ochoco-John Day Highlands in Central Oregon.
In Northeastern Oregon, Grande Ronde Valley, the Northern Blue Mountains of Oregon, Southern Blue Mountains of Oregon and Wallowa County are also under flood watch.
NWS says 1-2 inches of rain is expected, with locally higher amounts, especially in Wallowa County.
The excessive runoff may result in flooding of creeks, streams, and other low-lying and flood-prone locations such as burn scars and areas of steep terrain. Flooding may occur in poor drainage and urban areas.
Mainstem river flooding is not expected.
Tropical Storm Hilary drenched Southern California from the coast to the desert resort city of Palm Springs, forcing rescuers to pull several people from swollen rivers, before heading east and flooding a county about 40 miles outside of Las Vegas.
The National Hurricane Center in Miami downgraded Hilary to a post-tropical storm Monday morning, but warned that “continued life-threatening and locally catastrophic flooding” was expected over portions of the southwestern U.S., along with “record breaking” rainfall and potential flooding in states as far north as Oregon and Idaho.
The Associated Press contributed to this report.