Slow-moving thunderstorms caused heavy rainfall in the Pine Nut Range southeast of Gardnerville. The heavy rain fell on the Ray May wildfire burn scar which produced a large debris flow over highway 395.
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.
Slow-moving thunderstorms caused heavy rainfall in the Pine Nut Range southeast of Gardnerville. The heavy rain fell on the Ray May wildfire burn scar which produced a large debris flow over highway 395.
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 17, 12:08 PM PST, 1 hour 52 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RENO NV 108 PM PDT FRI AUG 17 2012 .SHORT TERM... MADE ONLY MINOR CHANGES TO THE SHORT TERM FORECAST AS THE MODELS HAVE A GOOD HANDLE ON THE OVERALL PATTERN THROUGH EARLY NEXT WEEK. THE RENO CWA REMAINS IN BETWEEN A CUTOFF AREA OF LOW PRESSURE OFF THE CALIFORNIA COAST AND HIGH PRESSURE OVER THE FOUR CORNERS. THIS HAS ALLOWED ANOTHER SURGE OF MONSOON MOISTURE TO PUSH NORTH OVERNIGHT WITH PWATS INCREASING TO 0.59 INCHES NEAR RENO AND 1.24 INCHES NEAR LAS VEGAS. ALONG THE LEADING EDGE OF THE SURGE, A DISTURBANCE MOVED NORTH ACROSS THE SOUTHERN HALF OF THE RENO CWA THIS MORNING. INCREASED CLOUDINESS FROM THIS DISTURBANCE WILL SLOW CONVECTIVE INITIATION BETWEEN INTERSTATE 80 AND US 50 BY A FEW HOURS THIS AFTERNOON. SOUTH OF HWY 50, CONVECTIVE BUILDUPS ARE EVIDENT ON VISIBLE SATELLITE IMAGERY. THERE IS ALSO ANOTHER WEAK DISTURBANCE EVIDENT ON WV IMAGERY OVER THE SOUTHERN SIERRA. AS THIS FEATURE MOVES NORTH THIS AFTERNOON, EXPECT COVERAGE TO EXPAND NORTH ALONG THE SIERRA AND EVENTUALLY INTO THE 395 CORRIDOR BY LATE THIS AFTERNOON. STORM MOTIONS WILL BE SLOW, SO THE MAIN CONCERNS REMAIN LOCALLY HEAVY RAINFALL AND GUSTY OUTFLOW WINDS. MID-LEVEL MOISTURE FROM THE REMNANTS OF HECTOR WILL DRAWN NORTH ACROSS NORTHEAST CALIFORNIA AND WESTERN NEVADA LATE TONIGHT AND SATURDAY. THE BEST INSTABILITY OVERNIGHT IS ACROSS LASSEN, PERSHING, NORTHERN WASHOE AND THE SURPRISE VALLEY WHERE ISOLATED THUNDERSTORMS ARE FORECAST. ELSEWHERE, EXPECT ISOLATED SHOWERS TO GRADUALLY WEAKEN OVERNIGHT. WITH CLOUD COVER MOST OF THE NIGHT, OVERNIGHT LOWS WILL STRUGGLE TO REACH THE UPPER 60S ACROSS WESTERN NEVADA VALLEYS. ON SATURDAY, THE BEST INSTABILITY AND JET SUPPORT REMAIN NORTH OF THE RENO CWA. UPPER LEVEL LAPSE RATES ALSO LOOK LESS FAVORABLE (BETWEEN 6-6.5 C/KM) AS THE HECTOR REMNANTS MOVE OVER THE REGION. FROM RECENT EXPERIENCE, WE HAVE HAD A TENDENCY OF OVERDOING THE CONVECTIVE THREAT ON DAYS WHEN THE REMNANTS OF A TROPICAL SYSTEM MOVE ACROSS THE CWA. WITH THIS PACKAGE, ADJUSTED THE FORECAST TO REDUCE COVERAGE TO ISOLATED SHOWERS AND THUNDERSTORMS FOR ALL AREAS ON SATURDAY. THE PERSISTENT PATTERN WE HAVE BEEN UNDER FOR MOST OF THIS WEEK WILL FINALLY BEGIN TO BREAK DOWN ON SUNDAY AS THE RIDGE AXIS BEGINS TO SLIDE EAST. THIS WILL ALLOW THE FLOW TO SHIFT TO THE SOUTHWEST, USHERING IN A DRIER, MORE STABLE AIRMASS. MAINTAINED THE CURRENT FORECAST FOR SUNDAY, WITH ISOLATED THUNDERSTORMS MAINLY EAST OF US HWY 95. MONDAY WILL BE A TYPICAL SUMMER DAY ACROSS WESTERN NEVADA, WITH SLIGHTLY ABOVE NORMAL TEMPERATURES AND AFTERNOON ZEPHYR WINDS. MYRICK .LONG TERM...TUESDAY THROUGH FRIDAY... COOLED HIGHS SLIGHTLY TUESDAY AND WEDNESDAY, OTHERWISE LITTLE CHANGE TO THE LONG TERM FORECAST. THE UPPER RIDGE THAT HAS RESIDED NEAR NORTHEAST CALIFORNIA AND WESTERN NEVADA LATELY WILL BREAK DOWN NEXT WEEK FOR COOLER TEMPERATURES (NEAR AVERAGE) AND DRY CONDITIONS, ESPECIALLY WEDNESDAY THROUGH FRIDAY. THE MAIN MODEL DISCREPANCIES TODAY BETWEEN THE 12Z GFS/GEM AND 00Z ECMWF REVOLVE AROUND THE PASSAGE OF THE EASTERN PACIFIC TROUGH ON TUESDAY. THE EC WAS THE SLOWEST/MOST NEGATIVELY TILTED WITH THE TROUGH WHILE THE GEM/GFS WERE MORE PROGRESSIVE/MORE NEUTRALLY TILTED WITH LESS CLOSING OFF OF THE LOW AT THE BASE OF THE TROUGH. THE 00Z EC WOULD BRING A BETTER CHANCE FOR CONVECTION TUESDAY AND ESPECIALLY TUESDAY NIGHT AS THE NEGATIVE TILT SOLUTION WOULD BRING BETTER LIFT OVER NORTHWEST NEVADA AND NORTHEAST CALIFORNIA WITH EVEN A SHOT AT NOCTURNAL CONVECTION. THE GFS/GEM WOULD USHER IN DRIER/MORE STABLE SOUTHWEST FLOW ALOFT BY TUESDAY AFTERNOON FOR MAINLY CLEAR SKIES AND NO CONVECTION. WITH ALL THIS IN MIND, I HEDGED TO THE POSSIBILITY OF THE ECMWF BY PUTTING PARTLY CLOUDY SKIES THROUGH TUESDAY NIGHT WITH A BROAD 10% POP (NO WEATHER MENTIONED) NORTH OF HIGHWAY 50. HOWEVER, THE 12Z ECMWF HAS COME IN COMPLETELY DIFFERENT WITH MUCH DRIER CONDITIONS FOR TUESDAY SO THE CLOUDS AND POP MAY NEED TO BE REDUCED IN FUTURE PACKAGES. WEDNESDAY THROUGH FRIDAY LOOKS DRY AND STABLE IN MOST MODELS SO I HAVE REDUCED CLOUD COVER FOR THAT TIME PERIOD. HOWEVER, THE 12Z ECMWF FLOPPED FROM ITS 00Z SOLUTION BY LEAVING ENERGY BEHIND OVER THE PACIFIC TUESDAY AND THEN BRINGING IT THROUGH WEDNESDAY NIGHT. I HAVE DISREGARDED THIS SOLUTION FOR NOW WITH LITTLE SUPPORT ELSEWHERE. SNYDER && .AVIATION... LIGHT S-SSW FLOW ALOFT IS FAVORING THUNDERSTORM DEVELOPMENT OVER THE HIGH TERRAIN OF THE SIERRA SOUTH OF LAKE TAHOE AND ALONG THE BORDER OF MONO AND MINERAL COUNTIES. THIS WILL CONTINUE TO BUILD TO THE N-NNE IN THE UPPER FLOW THROUGH THE AFTERNOON AND DIE OFF BY AROUND 8-9 PM. STORMS WILL BE CAPABLE OF OUTFLOW TO 35 KTS (OR SLIGHTLY GREATER OVER BASIN VALLEYS) AND BRIEF HEAVY RAIN TO LOWER VIS DIRECTLY UNDER STORM CORES. SATURDAY, THE CHANCE FOR THUNDERSTORMS IS REDUCED AS COMPARED WITH EARLIER FORECASTS. COPIOUS MID-HIGH CLOUD COVER WITH THE REMNANTS OF A TROPICAL SYSTEM SHOULD KEEP INSTABILITY FOR THUNDERSTORMS REDUCED (DUE TO LESS SURFACE HEATING). STILL, ISOLATED STORMS COULD BRING BRIEF HEAVY RAIN AND WIND GUSTS TO 30 KTS. SNYDER && .FIRE WEATHER... MOISTURE WILL CONTINUE TO PUSH INTO THE SIERRA AND WESTERN NEVADA ALONG THE WESTERN EDGE OF THE GREAT BASIN HIGH PRESSURE. INCREASED MOISTURE AND SLOW SHOWERS/THUNDERSTORM MOVEMENT WILL PRODUCE WETTING RAINS THROUGH SATURDAY. GUSTY AND ERRATIC OUTFLOWS ARE THE PRIMARY CONCERN WHERE SPEEDS COULD EXCEED 40 MPH. LOW WELL OFF THE CALIFORNIA COAST WILL TRACK TOWARD THE PACIFIC NORTHWEST COAST TONIGHT AND MAY PROVIDE A BOOST FOR ISOLATED THUNDERSTORMS OVERNIGHT NORTH OF LASSEN PEAK, RAVENDALE/RUSH FIRE, INTO FAR NORTHERN WASHOE COUNTY AND THE SURPRISE VALLEY. IN THIS AREA TONIGHT AND EARLY SATURDAY MORNING, CONFIDENCE IS GOOD IN STORMS PRODUCING WETTING RAINS DESPITE SLIGHTLY FASTER STORM MOTIONS. FOR TOMORROW, AN EXTENSIVE AREA OF CLOUD COVER WILL LIMIT SURFACE HEATING. INSTABILITY IS WEAK AND WITH NO WELL DEFINED TRIGGER, DO NOT EXPECT MUCH IN THE WAY OF DEEP CONVECTION FOR THUNDERSTORMS. HOWEVER WITH ABUNDANT MOISTURE, EVEN WEAK LIFT WILL PRODUCE ISOLATED SHOWERS AND THUNDERSTORMS WITH WETTING RAINS. THE TROUGH IS FORECAST TO REMAIN OFF THE PACIFIC NORTHWEST COAST AND PUSH GREAT BASIN RIDGE INTO THE ROCKIES SUNDAY. THIS WILL PRODUCE A DRIER AND STABLE SOUTHWEST FLOW NORTH OF INTERSTATE 80. THUNDERSTORMS ARE POSSIBLE ALONG AND EAST OF A LINE FROM LOVELOCK TO BRIDGEPORT SUNDAY, WITH DRYING CONDITIONS FOR RENO-TAHOE NORTH TO LASSEN COUNTY AND THE RUSH FIRE. EARLY NEXT WEEK THE TYPICAL AFTERNOON AND EVENING BREEZES SHOULD RETURN WITH PEAK GUSTS 25-30 MPH AND POOR OVERNIGHT HUMIDITY RECOVERIES. BRONG && .REV WATCHES/WARNINGS/ADVISORIES... NV...NONE. CA...NONE. && FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT... HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RENO NV 708 AM PDT FRI AUG 17 2012 CAZ070>073-NVZ001>005-181200- SURPRISE VALLEY CALIFORNIA-LASSEN-EASTERN PLUMAS- EASTERN SIERRA COUNTIES-GREATER LAKE TAHOE AREA-MONO- MINERAL AND SOUTHERN LYON COUNTIES-GREATER RENO-CARSON CITY- MINDEN AREA-WESTERN NEVADA BASIN AND RANGE INCLUDING PYRAMID LAKE- NORTHERN WASHOE COUNTY- 708 AM PDT FRI AUG 17 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE EASTERN SIERRA... NORTHEAST CALIFORNIA AND WESTERN NEVADA. .DAY ONE...TODAY AND TONIGHT MOISTURE WILL SURGE NORTH TODAY AND COMBINE WITH VERY WARM TEMPERATURES TO PRODUCE THUNDERSTORMS ACROSS EASTERN CALIFORNIA AND WESTERN NEVADA. THE STORMS WILL BE SLOW MOVING AND COULD PRODUCE BRIEF PERIODS OF MODERATE TO HEAVY RAIN AND SOME LOCALIZED FLOODING. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY AN UPPER LEVEL DISTURBANCE WILL LIFT NORTHEAST ACROSS FAR NORTHEAST CALIFORNIA SATURDAY MORNING. THIS DISTURBANCE WILL AID IN PRODUCING MORE THUNDERSTORMS ACROSS THE REGION SATURDAY. THESE STORMS WILL BE MOVING FASTER AND MAY PRODUCE DRY LIGHTNING STRIKES ALONG WITH GUSTY OUTFLOW WINDS. ISOLATED THUNDERSTORMS ARE LIKELY OVER WESTERN NEVADA SUNDAY. DRY AIR WILL PUSH INTO THE REGION BY MONDAY ENDING THE CHANCE FOR THUNDERSTORMS. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED AT THIS TIME. HOWEVER... SPOTTERS SHOULD REMAIN ALERT TO THE POSSIBILITY OF HEAVY RAIN THIS AFTERNOON AND EVENING AND PASS REPORTS TO THE NATIONAL WEATHER SERVICE IN RENO. FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT... HTTP://FORECAST.WEATHER.GOV/HAZARDS/REV (ALL LOWER CASE)
The national radar mosaic for the moment the first event began.
1 debris flow. Local standard time, as filed.
Large rocks and mud covered highway 395 near the Ray May burn scar as heavy rain caused the hillside to give way. The debris flow/rock slide caused highway 395 to be closed as heavy equipment was required to remove the rocks from the road.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Nevada in 2012Every state in 2012This day in weather historyWarnings in Nevada, August 2012
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: 406992.