Daytime heating and ample moisture along the periphery of a ridge caused scattered convection over western Nevada and the eastern Sierra July 19th through the 25th. Several storms produced heavy rainfall which led to flash flooding and debris flows.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS REV wrote it up.
Daytime heating and ample moisture along the periphery of a ridge caused scattered convection over western Nevada and the eastern Sierra July 19th through the 25th. Several storms produced heavy rainfall which led to flash flooding and debris flows. Hail was also reported with some storms.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Reno, NV wrote its last area forecast discussion before the first event at Jul 19, 1:23 PM PST, 2 hours 22 minutes earlier.
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</html>The San Joaquin Valley radar (KHNX), 175 km away, was scanning. The volume nearest the first event began at 23:43 UTC.
7 heavy rain, 4 debris flow, 2 hail, 1 flood. Local standard time, as filed.
California Highway Patrol reported minor roadway flooding along Valley Road and Hunter Avenue in Chalfant Valley at 19 July 1550PST. No damage estimates were available.
SNOTEL MNPC1 at Monitor Pass (elevation 8304 feet) reported 1.10 inches of rainfall in a 5-hour period from 20 July 1200PST to 1700PST.
NRAWS 13, located within the Slinkard Fire burn scar (elevation 7451 feet) reported 1.09 inches of rainfall in just over a 5-hour period from 20 July 1207PST to 1722PST.
California Highway Patrol indicated a two-lane road closure of Lundy Lake Road, about 5 miles northwest of Mono Lake, due to a rock slide/debris flow across the roadway. The Lundy Raws sensor recorded 0.75 inches of rain in a 3 hour time period before the slide occurred. No damage estimates were available.
California Highway Patrol reported a debris flow containing trees and boulders crossing California Highway 89 below Monitor Pass. A series of thunderstorms moved over the Slinkard Fire burn scar and produced 0.26 inches of rainfall in just over a 2-hour period from 21 July 1337PST to 1552PST at the RAWS located within the burn scar. Over an inch of rain fell on the burn scar the two days prior to the debris flow, which saturated the soil. No damage/cleanup estimates were available.
California Department of Transportation (Caltrans) reported a debris flow just east of Tioga Pass on State Route 120 in Mono County, closing a three mile stretch of the road from US Highway 395 to the debris flow site. According to The Mercury News, a car was hit by a rock at 1600PST. Within 20 minutes, an active debris flow was declared. The road remained closed until 21 July 1930PST. No nearby gauges were available to estimate the rainfall amounts near the debris flow path. No damage/cleanup estimates were available.
California Highway Patrol reported a rock slide/debris flow closing California Highway 120/US Highway 395 just south of Lee Vining due to heavy rainfall from thunderstorms. No damage/cleanup estimates were available.
A trained weather spotter reported hail 0.75 inches in diameter and heavy rain 4 miles west-northwest of Frenchman Lake.
Mesonet station TKEC1, Truckee reported 1.22 inches of rainfall in a 6-hour period from 23 July 1033PST to 1633PST.
CO-OP Observer station SERC1, Sierraville Ranger Station, reported 0.64 inches of rainfall in a 6-hour period from 23 July 1100PST to 1700PST.
Mesonet station D9436, 1 mile southwest of Sierraville (elevation 5100 feet) reported 1.13 inches of rainfall in a 1 hour and 45 minute period from 23 July 1314PST to 1459PST.
Mesonet station MKEC1, Markleeville (elevation 5501 feet) reported 0.64 inches of rainfall in a 5-hour time period from 23 July 1348PST to 1848PST.
Mesonet station PSRC1, 1 mile east of Prosser Creek Reservoir (elevation 5776 feet) reported 1.02 inches of rainfall from 23 July 1445PST to 1615PST.
Public 1-mile west-northwest of Truckee reported quarter size hail via social media.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2018Every state in 2018This day in weather historyWarnings in California, July 2018
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-10-01. Each event’s entry at NCEI: 778217, 778231, 778230, 778218, 778229, 778302, 778232, 778254, 778287, 778285, 778289, 778288, 778286, 778257.