Flood in Bonner County, Idaho

The emergency manager of Bonner County relayed numerous road damage reports from across the county due to flooding from March 31st. The roads included in this report were Fish Creek, Sandborn Creek, West Shingle Mill, Bottle Bay, Dufort, Peninsula, Eastriver, Blacktail, Beare, Eureka, Helen Thompson, Moore Loop, South First Street, Spring Haven Drive, Wells, North Riley Creek, Mountain Creek, Snow Valley, Forest Siding, Comeback Lane, Cocolalla Loop, and LeClerc Road. Several other private roads were also damaged from flooding.

A stationary trough of low pressure off the Pacific Northwest Coast steered a deep fetch of subtropical moisture into the Idaho Panhandle which persisted from March 29th through early April. This resulted in several rounds of moderate to heavy precipitation, which primarily fell as rain below 6000 feet. Mild temperatures and breezy winds accompanying the subtropical moisture feed resulted in excessive mid-elevation snowmelt. The combination of heavy rainfall and excessive snow melt resulted in sharp rises in most basins within the Central Idaho Panhandle and Idaho Palouse. In addition, saturated soils became unstable in some locations resulting in debris flows.