A high amount of atmospheric moisture in the region interacted with a short-wave trough, allowing for widespread heavy precipitation. This was day four of an extended push of monsoon moisture that produced heavy rain, localized flooding, strong outflow winds.
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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 high amount of atmospheric moisture in the region interacted with a short-wave trough, allowing for widespread heavy precipitation. This was day four of an extended push of monsoon moisture that produced heavy rain, localized flooding, strong outflow winds.
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 26, 10:33 AM PST, 3 hours 24 minutes earlier. Its key messages:
Area Forecast Discussion National Weather Service Reno NV 1133 AM PDT Tue Aug 26 2025 .KEY MESSAGES... * Slow-moving, wet thunderstorms continue to bring an elevated risk of flash flooding through this evening, especially over urban areas and burn scars. * Additional showers and storms are expected Wednesday, but a drying trend will reduce thunderstorm activity Thursday onward. * Cooler temperatures persist until warming settles in later this week. && .DISCUSSION... Deep monsoonal moisture combined with sufficient afternoon heating will provide another round of thunderstorms today. A handful of showers and thunderstorms are already kicking up along the western periphery of an expansive cloud deck that covers much of the Basin and Range. Primary risk with storms today will be flash flooding, but we can't rule out small hail, strong gusty winds, and of course lightning concerns remain as well. Flash Flood Concerns: A flash flood watch has been issued for much of the Sierra and northeastern California today and will be in effect from noon to 9pm. Heavy rain this week may have saturated the ground for many mountain locations in the Sierra with rain amounts 1 to 3 inches. Any additional rainfall will be quick to run off due to the already saturated soils, especially for burn areas. Timing: With the widespread cloud deck across the Basin and Range areas, mostly east of Highway 395, thunderstorm development will be delayed until more clearing occurs. West of that periphery, a handful of storms are already firing with showers near Hawthorne and over/near Mt Rose Summit. The most widespread activity will kick off between 1p-3p for western Nevada and spread eastward into the Basin and Range between 2p-8p. Outflows may propagate and kick off storms well past 8p tonight, especially across western NV, with some simulations holding onto showers for along and south of I80 through early Wednesday morning. Wednesday Weather: Plan on another active day of storms and showers with similar concerns for flash flooding, hail, lightning, and winds. Simulations have been leaning toward less widespread activity, but with the deep monsoon moisture in place, we will still have quite a few storms out and about to monitor. Thursday offers the first day of 'relief' as moisture is projected to become more limited across the Sierra and western Nevada. Even still with precipitable water values around 0.5-0.7", we are still well within a thunderstorm-producing air mass. The risk may shift from heavy rain and flash flooding to strong, dry outflow winds but we will have to see just how much moisture scours out and how much lingers on through the end of the week. -Edan && .AVIATION... Scattered thunderstorms are the primary concern today, especially between 19Z and 03Z. Heavy rain and IFR conditions, strong outflow winds, small hail, and frequent lightning are the main threats with any thunderstorms near regional terminals. The best chance (40-50%) of thunderstorm impacts exists at KMMH with lesser odds of 30-40% at other terminals. Periods of fog and IFR conditions will return overnight and persist at KTRK through 15-16Z before dissipating. Otherwise, VFR conditions and areas of mid-upper clouds will prevail for tomorrow morning. Light rain showers may persist overnight through 12z Wednesday for KRNO, KMEV, and KCXP. -Salas/Edan && .REV Watches/Warnings/Advisories... NV...Flood Watch until 9 PM PDT this evening NVZ001>003. CA...Flood Watch until 9 PM PDT this evening CAZ071>073. &&
Preliminary Local Storm Report
National Weather Service Reno NV
101 PM PDT Tue Aug 26 2025
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1245 PM Hail 5 WNW Susanville 40.43N 120.75W
08/26/2025 E0.50 Inch Lassen CA Public
Spotter estimated marble-sized hail. Heavy
rain and near zero visibility with strong
winds.
&&
ELPreliminary Local Storm Report
National Weather Service Reno NV
140 PM PDT Tue Aug 26 2025
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0107 PM Debris Flow Markleeville 38.69N 119.78W
08/26/2025 Alpine CA Dept of Highways
CHP reported 2 large rocks in northbound
lane on Highway 89 near Markleeville.
&&
ELPreliminary Local Storm Report
National Weather Service Reno NV
150 PM PDT Tue Aug 26 2025
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0123 PM Debris Flow 4 SE Markleeville 38.66N 119.73W
08/26/2025 Alpine CA Law Enforcement
CHP reporting mud, dirt, rocks at SR 4 and
SR 89 junction south of Markleeville.
&&
ELPreliminary Local Storm Report
National Weather Service Reno NV
236 PM PDT Tue Aug 26 2025
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0235 PM Debris Flow 8 WNW Frenchman Lake 39.95N 120.35W
08/26/2025 Plumas CA Park/Forest Srvc
Plumas Dispatch reported marble size hail
and heavy rain at the Corral wildfire.
&&
ELThe Reno radar (KRGX), 36 km away, was scanning. The volume nearest the first event began at 21:59 UTC.
6 flash flood. Local standard time, as filed.
Minor debris and roadway flooding on South Rock Blvd along both directions near Hymer Ave in Sparks. Additional flooding was reported throughout the city of Sparks, with rainfall estimations up to 1.15 inches.
SR-439 in both directions closed near Portofino Drive due to flooding. All lanes are blocked.
Nevada Department of Transportation reported flash flooding with mud and debris on US-50 near Bryce Road. Additionally, minor debris and flooding was reported on US-50 near US-95 ALT near Silver Springs.
Minor debris and roadway flooding along SR-359 in both directions near Spanish Springs road.
Flooding was reported throughout Incline Village, with multiple reports of closed roads. Upwards of 2.22 inches of rain had fallen over the area.
SR-447 closed from Church Street in Nixon to the Pershing Washoe County line.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Nevada in 2025Every state in 2025This day in weather historyWarnings in Nevada, August 2025
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: 1280332, 1280333, 1280331, 1280330, 1280335, 1280334.