A landslide briefly blocked part of the Nooksack River around midnight Friday morning, causing water flow to take an impressive plunge for a moment before the river broke through the muck and returned to normal flow, according to geologist Dan McShane.
McShane is an engineering geologist in Bellingham (and a former Whatcom County Council member) and keeps the blog "Observations of Washington State Landscapes, Geology, Geography, Ecology, History and Land use." His Friday night, Feb. 21 post about the slide can be found here.
The river flow plunged from 2,330 cubic feet per second at midnight Friday to 410 cfs at 1 a.m., before bouncing back to 2,020 cfs by 1:45 a.m., according to provisional data collected by the U.S. Geological Survey near Nugents Corner.
Here's a graph of the provisional data showing the dip in water flow.