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…
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.
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, 2 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
The national radar mosaic for the moment the first event began.
6 heavy rain, 3 debris flow. Local standard time, as filed.
Mesonet station (MKEC1) located in Markleeville, CA, reported heavy rain total of 1.82 inches. Utility Mesonet sensor also located in Markleeville, CA, reported 2.49 inches in 90 minutes and 2.22 inches in 60 minutes.
Grover Hot Springs state park staff reported debris flow over Hot Springs RD due to intense, heavy rainfall. Depth and damage were unknown at this time. Also, Caltrans and CHP reported boulders and rocks in the area with one part of Hot Springs RD starting to wash out. Another road was reported impassible.
Severe flooding was reported along State Route 89 in and out of Markleeville, CA with numerous debris flows. Roadway damage was also reported, along with reports of vehicles starting to get swept away.
Mesonet station EW3821 located in Bridgeport, CA reported 0.81 inches total rainfall between 5:45 and 8:15 pm.
Mesonet station (LVTC1) located 1.1 mi S of Leavitt Meadows (SNOTEL) reported 0.60 inches total rainfall.
Heavy rain in the vicinity of the Tamarack Fire Burn Scar caused a slide over State Route 4 that was reported by CHP to be 3-4 feet deep and closed the highway in both directions. No rainfall reports in the exact location, but estimates of 0.5-1 were reported to the south and 2-3 to the north, which occurred in a few hours. This is in addition to the heavy rainfall the day before.
AWOS station (KBAN) located at the Marine Corp Mountain Warfare Training Center (MCMWTC) reported heavy rainfall total of 1.49 inches.
Mesonet station (CRVC1) located near Crestview, CA., and Mesonet station (DEXC1) located 13 mi ENE of Crestview, CA, (near 2021 Dexter fire scar) reported rainfall totals of 0.92 and 3.33 inches respectively.
Mesonet station DW5868 located at Mammoth lakes, CA., reported a rainfall total of 1.01 inches.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2022Every state in 2022This day in weather historyWarnings in California, 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: 1050966, 1050961, 1050965, 1050970, 1050969, 1050967, 1050971, 1050973, 1050974.