S. on the 16th and persisted through the 17th.
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 broad area of upper level low pressure moved into the western part of the U.S. on the 16th and persisted through the 17th. Bands of moderate to heavy rain developed north of the main center of the low stretching across the northern Sierra and into far western Nevada on the 16th.
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 May 16, 4:40 AM PST, 20 minutes earlier.
Area Forecast Discussion...UPDATED National Weather Service Reno NV 540 AM PDT Wed May 16 2018 .UPDATE... Quick update to add thunderstorms to all areas this morning. A lot of buildups seen this morning, and we have already seen a thunderstorm develop over Galena Ridge west of Reno. The overall forecast remains on track. While cloud cover may be an issue for some areas this morning, there are many breaks currently. Some strong storms will occur, and it still looks most likely from Mineral County north into Pershing County where the most breaks are this morning. There is also a noticeable break north of Reno from Eastern Plumas and Lassen Counties into the Black Rock Desert. If this lasts, strong storms are possible here as well. Main threats will be gusty winds, and pea to marble hail. With more breaks this morning, heavy rain could be more of an issue this afternoon with stronger storms. Something to watch for...X && .PREVIOUS DISCUSSION... /Issued 335 AM PDT Wed May 16 2018/ SHORT TERM... Widespread rain with embedded thunderstorms are expected throughout the region today. The main weather threats today will be periods of heavy rain, possibility of accumulating small hail (snow above ~8-8500'), and lightning. Ponding on roads, and low visibility will likely be the biggest hazards for transportation with the potential for isolated minor to moderate flash flooding depending on just how much storms are able to develop. Precipitation is expected to start in the late morning in the Sierra and central western Nevada with a few hours of heavy rain and high elevation snow, especially around the Tahoe Basin and in the Reno/Carson City area. The area with the most persistent signal for significant heavy rain potential and runoff concerns is around Churchill and Pershing Counties during the late afternoon and into the early evening. It's also possible the northern Sierra and Lassen counties could be a heavy rain threat later in the afternoon, but clouds will have a better chance of inhibiting convection in that area. The cut-off low pressure that has been spinning over the region this last week is finally being pushed north of the Nevada border this morning as another area of low pressure is currently moving into the central California coast. This will create a wide area of divergence aloft over the region and bring a new round of upper level forcing. Clouds are expected to inhibit some storm development today, but it currently looks like there will be enough clearing and instability to get stronger storms to form, especially around Mono/Mineral counties where the best chance for clear skies will be this morning. Model simulations are pointing towards the possibility of a mesoscale complex of storms developing around Mineral county this afternoon and moving into Churchill and Pershing counties later in the day. This type of convective development is very difficult to predict but most models are simulating a similar scenario with the potential for 1-2 inches of precipitation if this feature develops. One question that persists today is how much cloud cover inhibits surface heating that could add to the instability. The band of light showers in the region overnight moved north faster than models had forecast with current IR satellite observations showing good clearing in the southern part of the CWA. It is really difficult to say how much increasing cloud cover could hamper storm development, but the latest guidance is pointing towards some strong thunderstorm development today. Lighter showers are expected on Thursday with only a slight chance of thunderstorm development. By Friday it looks like the main area of concern will be in the central and southern Sierra where thunderstorms could develop with potential for heavy rain and high elevation snow. -Zach LONG TERM...Saturday into next week... It is slowly becoming a bit clearer on the timing of the upper low, with the models and ensembles in better agreement for the weekend. They are also in better agreement with timing of the next low for Monday into Tuesday, although the track is still hazy. For the weekend, the GFS/EC have a weak wave moving through in light west flow aloft between the upper lows. Instability is not overly impressive, but will keep the slight chance to low chance for the Sierra and adjacent eastern slopes. Sunday the low approaches, but the southwest flow ahead of it will increase. For now, the track appears to be toward the SF bay area which would put the best forcing north of a KSVE-KLOL line, but this could change. With the stronger SW flow, Sierra convection will be hard pressed to form unless it's early in the afternoon. Have the best chances east of there and then where the best forcing is for Sunday. SW winds will make a decent appearance, with peak gusts of 25-30 mph. Keep in mind, this is the best idea for now, but with the way the models have been changing, this forecast may be way off. Monday into Tuesday, the area will be affected by the upper low. Where it tracks will determine best chances. It could end up being similar to what we see tomorrow, or just generic thunderstorms. Will keep the chance pops going both days area-wide with a decrease Wednesday as the low pulls away. Temperatures will be near average through the period, although Monday could be cooler depending on track of the low. X AVIATION... FG will continue around the Tahoe terminals and Sierra Valleys this morning with LIFR conditions. Expect it to burn off between 15=16Z. The upper low will move in today with High chances of SHRA and embedded TSRA for Reno-Tahoe area 17-23Z, about 80-90% for each terminal. Some small hail is also likely to occur with MVFR to local IFR conditions and mtn obscuration in the showers/storms. These showers and storms will move north and east during the evening. 70-90% chances for periods of MVFR CIGS/VIS at KSVE/KLOL/KNFL 23-06Z this evening. KMMH/KHTH will still see storms around, but chances of those terminals being affected are less, 40- 50% and 18-23Z. Winds will be light outside of thunderstorms, where peak gusts could approach 35-40 kts. More thunderstorms Thursday, but not as widespread with chances 40- 50% for any terminal. Wind gusts to 40kts and small hail primary threats. Thunderstorm threat a little less Friday into Saturday before possibly increasing again early next week with another upper low. X && .REV Watches/Warnings/Advisories... NV...None. CA...None. && For more information from the National Weather Service visit... http://weather.gov/reno
The national radar mosaic for the moment the first event began.
7 heavy rain. Local standard time, as filed.
Ravendale RAWS, 5 miles south-southeast of Ravendale (elevation 5450 feet) reported 0.62 inches of rainfall in a 24-hour period from 16 May 0500PST to 17 May 0500PST.
Mesonet station FARC1, 2 miles northwest of Floriston (elevation 5188 feet) reported 0.67 inches of rainfall from 16 May 0600PST to 17 May 1930PST.
Mesonet station WRDC1, 2 miles south of Alpine Meadows (elevation 6764 feet) reported 0.60 inches of rainfall from 16 May 0600PST to 1400PST.
Mesonet station TT142, 6 miles north-northwest of Stampede Reservoir (elevation 6260 feet) reported 1.14 inches of rainfall from 16 May 0635PST to 17 May 0435PST.
COOP observer station SERC1, Sierraville Ranger Station reported 0.53 inches of rainfall in a 24-hour period from 16 May 0700PST to 17 May 0700PST.
Mesonet station BDOC1, 6 miles east of Madeline (elevation 5927 feet) reported 0.93 inches of rainfall from 16 May 1159PST to 17 May 0659PST.
Mesonet station GORC1, 9 miles northwest of Spaulding (elevation 6215 feet) reported 0.66 inches of rainfall from 16 May 1204PST to 17 May 0504PST.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2018Every state in 2018This day in weather historyWarnings in California, May 2018
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: 762276, 762271, 762273, 762122, 762274, 762123, 762272.