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…
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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.
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.
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 Aug 3, 12:24 PM PST, 4 hours 36 minutes earlier.
Area Forecast Discussion National Weather Service Reno NV 124 PM PDT Wed Aug 3 2022 .SYNOPSIS... Persistent monsoonal flow will continue to generate showers and thunderstorms each afternoon and evening through at least Saturday. Storms will be capable of producing heavy rain, flash flooding, frequent lightning, small hail, and gusty outflow winds with blowing dust. Temperatures will cool to around average this weekend. Cloud cover could help to dampen daytime highs across western Nevada. && .SHORT TERM...Through Thursday night... This forecaster had a few rumbles of thunder and a wetting rain at his house last night, which was a welcome smell of petrichor. After quite a humid and clear morning, showers and thunderstorms are beginning to build along the higher terrain across northeast California, the Sierra Front, and the Eastern Sierra. Thunderstorms Today and Thursday: * Thunderstorms will be possible this afternoon and evening across northeast California, northwest Nevada, along the Interstate 80 corridor, as well as the eastern Sierra from the Tahoe Basin south into Mono County. As mentioned previously, the stronger storms will be most likely south of US Highway 50. The main hazards will be frequent lightning, localized heavy rainfall, small hail, and gusty outflow winds to 45 mph. Blowing dust may also be possible ahead of outflow boundaries in areas that have not received rainfall recently. * A Flash Flood Watch is in effect from noon this afternoon through 9 PM PDT Thursday for areas mainly south of US Highway 50. You might be asking yourself: why the Flash Flood Watch issuance? Well, this morning's 12z sounding from our office showed a very deep and moist vertical profile, coupled with CAPE near 1000 J/kg, a low LCL for this area's standards, a record high PWAT of 1.07" (the previous record for 8/3 was 1.01"), and slow storm-relative wind speeds, which should promote the training of thunderstorms over burn scars and steep terrain. Nearly all CAMs are indicating heavy convective rainfall possible across much of Douglas, Alpine, southern Lyon, Mono, and Mineral counties between 3:00 PM and 9:00 PM PDT today and Thursday. This excessive rainfall could trigger flash flooding of low-lying areas and debris flows in and near recent burn scars. Residents and those recreating in and immediately next to recent burn scars should prepare for potential flooding impacts. Be ready to act and move to higher ground should a Flash Flood Warning be issued for your location. * Thursday will nearly be a repeat of this afternoon and evening, with most of the action located south of Interstate 80. Once again, we'll see chances for heavy rainfall south of US 50, with recent burn scars and steep terrain being the most dangerous areas to be near. In addition to heavy rainfall, frequent lightning, small hail, and gusty outflow winds to 50 mph can be expected. Winds and Temperatures: * Winds outside of thunderstorms will be pretty tame this afternoon and Thursday afternoon, with gusts to 25 mph expected from the west. Near thunderstorms, erratic wind gusts as high as 50 mph can be expected. * High temperatures this afternoon look to be a little warmer compared to tomorrow, due to the chance for more cloud cover from convective debris. Highs are expected to climb into the mid-to- upper 90s this afternoon across western Nevada and northeast California, and in the 80s across Sierra valleys. Thursday, highs will struggle to reach the low-90s across the lower valleys and low-80s in Sierra valleys. Smoke/Air Quality: * Haze and degraded air quality are also expected across northeast California today and tomorrow due to ongoing fire activity in northern California. -Johnston .LONG TERM...Friday onward... Shower and thunderstorm chances will continue for most of the region on Friday as high pressure remains settled over the Four Corners region. Moisture will continue to flow around the western periphery of the high, keeping PWATs in the 0.8-1.1" range Friday. These values indicate potential for storms to produce heavy rains that could lead to flash flooding in sensitive terrain such as burn areas or steep slopes. However, given that we are on a stretch of monsoonal flow, it is possible skies may not clear out Friday morning and consequently limit surface heating. Under this scenario, the lack of surface heating will inhibit destabilization of the atmosphere, and in turn eliminate significant thunderstorm activity. A shortwave trough is expected to brush by to our north on Saturday, subsequently flattening the ridge and directing dry southwest flow over our region. Southwest flow will close the door to any additional monsoonal moisture pushes, but thunderstorm chances continue through Saturday. Greatest thunderstorm activity will likely remain confined to areas farther south, especially in Mono/Mineral counties. Any storms that develop may likely produce gusty and erratic winds as model soundings suggest dry lower-levels and high DCAPE. Ensemble guidance currently suggests that as the trough exits the region on Saturday, a closed low currently sitting off the NorCal coast will begin to lift to the northeast into the Pacific NW on Sunday, allowing dry southwest flow to continue through the end of the forecast period. This pattern will likely keep thunderstorm chances slight through mid-week. -Whitlam && .AVIATION... * Showers and thunderstorms are beginning to form this afternoon across much of the area. These showers and storms will mainly affect terminal sites south of Interstate 80 and last through approximately 06z Thursday. Tomorrow we'll see nearly the same situation. * Near and within thunderstorms, expect localized heavy rainfall, wet microbursts with erratic and gusty outflow winds to 40 kts, low-level wind shear, small hail, frequent lightning, and terrain obscurations. Stronger outflow winds tracking over dry desert ground may also loft dust, which may reduce ground and slantwise visibility also. * Thunderstorm chances remain through the weekend, although coverage looks to lessen each day past Friday. -Johnston && .REV Watches/Warnings/Advisories... NV...Flood Watch through Thursday evening NVZ001>003. CA...Flood Watch through Thursday evening CAZ072-073. && For more information from the National Weather Service visit... http://weather.gov/reno
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RENO NV
416 PM PDT WED AUG 3 2022
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0407 PM DEBRIS FLOW GROVER HOT SPRINGS 38.70N 119.84W
08/03/2022 ALPINE CA PARK/FOREST SRVC
GROVER HOT SPRINGS STATE PARK STAFF REPORTED
DEBRIS FLOW OVER HOT SPRINGS RD DUE TO
INTENSE, HEAVY RAINFALL. DEPTH AND DAMAGE
UNKNOWN AT THIS TIME.
0411 PM DEBRIS FLOW 1 ENE GROVER HOT SPRING 38.70N 119.83W
08/03/2022 ALPINE CA DEPT OF HIGHWAYS
CALTRANS AND CHP REPORTING BOULDERS AND
ROCKS IN THE AREA. ONE PART OF HOT SPRINGS
RD STARTING TO WASH OUT. ONE IS IMPASSIBLE.
0409 PM HAIL GROVER HOT SPRINGS 38.70N 119.84W
08/03/2022 E0.25 INCH ALPINE CA PARK/FOREST SRVC
GROVER HOT SPRINGS STAFF REPORTED 0.25 INCH
HAIL.
&&
WHITLAMPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RENO NV
459 PM PDT WED AUG 3 2022
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0457 PM HEAVY RAIN MARKLEEVILLE 38.69N 119.78W
08/03/2022 M2.49 INCH ALPINE CA UTILITY COMPANY
UTILITY MESONET SENSOR REPORTED 2.49 INCHES
IN 90 MINUTES AND 2.22 INCHES IN 60 MINUTES.
&&
WHITLAMPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RENO NV
502 PM PDT WED AUG 3 2022
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0430 PM DEBRIS FLOW 2 ESE MARKLEEVILLE 38.68N 119.75W
08/03/2022 ALPINE CA EMERGENCY MNGR
SEVERE FLOODING REPORTED ALONG WITH NUMEROUS
DEBRIS FLOWS. ROADWAY DAMAGE REPORTED, ALONG
WITH REPORTS OF VEHICLES STARTING TO GET
SWEPT AWAY.
&&
WHITLAMThe Reno radar (KRGX), 51 km away, was scanning. The volume nearest the first event began at 01:02 UTC.
6 heavy rain, 1 flood, 1 debris flow, 1 flash flood. Local standard time, as filed.
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.
ASOS station (KRNO) located at the Reno-Tahoe International airport recoded a one hour rainfall total of 1.22 inches between 6:45PM and 7:45 PM LST.
Trained weather spotter located 3.0 miles WSW of Gardnerville Ranch reported a total rainfall amount of 3.1 inches from 12:00 PM to 17:25 PM LST. Spotter also reported flooding issues along Foothill Road in the area.
Trained weather spotter located 1.0 miles W of Johnson Lane reported a total rainfall amount of 2.5 inches that fell during the period from 12:00 PM to 18:33 PM.
Trained spotter located 3.0 mi WSW of Garnerville Ranch, NV, reported some mud over foothill road, and also some minor flooding impacts. Rainfall total over a 1.5 hour period was reported as 1.98 inches.
NDOT and CHP reported mud, dirt, and rock in roadway making Jackson Ranch Road impassible.
Mesonet station WCTN2 located 5.1 mi N of Washoe City, and mesonet station GALN2 (Galena) located 4.0 mi NNW of Washoe City reported rainfall totals of 1.81 and 2.75 inches respectively.
It was reported on August 5 by a Washoe County official that flash flooding occurring on August 4 closed the lower Whites Creek trail in Galena Creek Park from Timberline Road to Thomas Creek Road due to extensive trail damage from recent flooding. It was also reported that rainfall amounts between 2.5 and 3 inches occurred in the area on Thursday 8/4.
Mesonet stations Fox Mountain (FOXN2) located 27 mi NNW of Gerlach, NV, and Juniper Springs (JSPN2) located 36 mi S of Vya, NV, both reported rainfall totals of 0.59 inches and 0.83 inches respectively.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Nevada in 2022Every state in 2022This day in weather historyWarnings in Nevada, August 2022
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 2026-09-24. Each event’s entry at NCEI: 1051018, 1051019, 1051022, 1051023, 1051020, 1051021, 1051172, 1051173, 1051198.