Heavy Rain — Lyon, Nevada

2022-08-03 · near Dayton, Lyon, Nevada

Event narrative

Trained spotter located 2.0 mi ESE of Six Mile Canyon reported a one hour total rainfall amount of 1.56 inches between 5:00 PM and 6:00 PM LST.

Wider weather episode

A deep layer of monsoonal moisture pushed northwest and north into California, Sierra, and western Nevada in a southerly upper flow that marked the western margins of an area of strong high-pressure ridging into the Great Basin region. Thickening mid-level moisture coupled with steep afternoon lapse rates and warmer surface heating initiated deep columns of slow-moving moisture-laden showers and thunderstorms with torrential rains over the 2021 Tamarack burn scar. This resulted in widespread flash flooding and debris flows in Alpine County CA that created a number of impacts. Rainfall rates of 2.22 inches per hour were observed during the peak of the storm in Markleeville, CA which corresponds to at least a 500 year recurrence interval and possibly 1000 year, per NOAA 14 atlas.

View location on OpenStreetMap → (39.3000, -119.5300)

Source: NOAA Storm Events Database, event_id 1051018. Narrative written by the NWS forecast office that issued the report.