USGS Water Data recorded sharp overnight changes across four river monitoring stations, with readings taken 27 September 2026.

At Lees Ferry on the Colorado River in Arizona, streamflow fell to 6,350 ft³/s, down from 8,110 ft³/s recorded one day prior.

Water temperature on the Rio Grande at Embudo, New Mexico dropped to 16 C, down from 20.3 C on 26 September.

Streamflow at the Willamette River gauge in Portland, Oregon was measured at 13,400 ft³/s. The prior day reading was -27,700 ft³/s.

At the Duwamish River gauge in Tukwila, Washington, streamflow came in at 631 ft³/s, compared to -907 ft³/s logged 26 September.

No explanation for the magnitude of the observed shifts is included in the public gauge feeds.