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.

Debris Flow in MONO, CALIFORNIA
From 21-JUL-18 14:40:00 to 21-JUL-18 17:40:00 (PST-8)
Location: MONO LAKE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

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.

Flood in MONO, CALIFORNIA
From 19-JUL-18 15:45:00 to 19-JUL-18 16:30:00 (PST-8)
Location: CHALFANT
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

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.

Debris Flow in MONO, CALIFORNIA
From 20-JUL-18 16:00:00 to 20-JUL-18 18:00:00 (PST-8)
Location: MONO LAKE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

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.

Heavy Rain in MONO, CALIFORNIA
From 20-JUL-18 12:07:00 to 20-JUL-18 17:22:00 (PST-8)
Location: WALKER
Reported by: RAWS

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.

Heavy Rain in ALPINE, CALIFORNIA
From 20-JUL-18 12:00:00 to 20-JUL-18 17:00:00 (PST-8)
Location: LOOPE
Reported by: SNOTEL

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.

Debris Flow in MONO, CALIFORNIA
From 21-JUL-18 15:47:00 to 21-JUL-18 16:47:00 (PST-8)
Location: LEE VINING ARPT
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

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.

Hail in PLUMAS, CALIFORNIA
From 21-JUL-18 17:40:00 to 21-JUL-18 18:20:00 (PST-8)
Location: HINDOO
Magnitude: 0.75 
Reported by: Trained Spotter

A trained weather spotter reported hail 0.75 inches in diameter and heavy rain 4 miles west-northwest of Frenchman Lake.

Heavy Rain in NEVADA, CALIFORNIA
From 23-JUL-18 10:33:00 to 23-JUL-18 16:33:00 (PST-8)
Location: TRUCKEE
Reported by: Mesonet

Mesonet station TKEC1, Truckee reported 1.22 inches of rainfall in a 6-hour period from 23 July 1033PST to 1633PST.

Heavy Rain in ALPINE, CALIFORNIA
From 23-JUL-18 13:48:00 to 23-JUL-18 18:48:00 (PST-8)
Location: MARKLEEVILLE
Reported by: Mesonet

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.

Heavy Rain in SIERRA, CALIFORNIA
From 23-JUL-18 13:14:00 to 23-JUL-18 14:59:00 (PST-8)
Location: SIERRAVILLE
Reported by: Mesonet

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.

Hail in NEVADA, CALIFORNIA
From 23-JUL-18 15:28:00 to 23-JUL-18 15:50:00 (PST-8)
Location: TRUCKEE
Magnitude: 1.00 
Reported by: Public

Public 1-mile west-northwest of Truckee reported quarter size hail via social media.

Heavy Rain in SIERRA, CALIFORNIA
From 23-JUL-18 11:00:00 to 23-JUL-18 17:00:00 (PST-8)
Location: SIERRAVILLE DRWTR AR
Reported by: COOP Observer

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.

Heavy Rain in NEVADA, CALIFORNIA
From 23-JUL-18 14:45:00 to 23-JUL-18 16:15:00 (PST-8)
Location: HOBART MILLS
Reported by: Mesonet

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.

Debris Flow in MONO, CALIFORNIA
From 21-JUL-18 13:37:00 to 21-JUL-18 15:52:00 (PST-8)
Location: WALKER
Flood cause: Heavy Rain / Burn Area
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

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.