A low that settled into the west coast the first few days of May brought showers and an increased chance (20-30%) of thunderstorms that also lowered rain-snow lines to 5500-7000 feet by early morning 3 May. Stronger showers and storms produced a mix of rain, snow, and ice pellets which lead to runoff issues in the lower elevations.
Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. 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 low that settled into the west coast the first few days of May brought showers and an increased chance (20-30%) of thunderstorms that also lowered rain-snow lines to 5500-7000 feet by early morning 3 May. Stronger showers and storms produced a mix of rain, snow, and ice pellets which lead to runoff issues in the lower elevations. High end chances (10-20%) of rainfall totals were expected to reach 0.50-1.00 inch. Although snow was projected to fall in the Sierra, the combination of warm road temperatures and the early May sun angle limited accumulations on paved surfaces. But bursts of convective heavy snow showers and/or snow occurring during the overnight hours were expected to bring overnight travel impacts to mountain passes. Tightening thermal and pressure gradients with the incoming low produced gusty south-southeast winds and travel impacts for portions of Churchill, Mineral, Lyon, and Mono Counties along US-395 and US-95.
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 2, 2:50 AM PST, 4 hours 10 minutes earlier.
Area Forecast Discussion National Weather Service Reno NV 350 AM PDT Tue May 2 2023 .SYNOPSIS... A much cooler late season weather system will stall over the California central coast this week. This lingering system will bring periods of rain, snow, and pellet showers; as well as a few thunderstorms. The cooler temps will also slow the snowmelt leading to a slight reduction in flows on creeks, stream, and rivers. .DISCUSSION… Today and Wednesday: Currently a wide band of rain and snow showers pivots northwest and west around a closed low that has settled over the California central coast. Little progress is foreseen by both blended and Hi-Res CAM guidance as this low pressure system brings anomalous lower temperatures and periods of precipitation that is more synonymous with transitional late winter (late Feb/early Mar) period. Well, I hope this brings up those May flowers with more splendor than normally seen any other year. Bands of rain/snow showers will continue to rotate north and northeast this afternoon and evening. Ensemble and blended guidance show no real change in snow levels which will hover between 5000-7000 across the Sierra and western NV, with brief lower periods in heavier showers. Therefore, look out for more Sierra snow showers to compliment lower elevation rain/pellet showers along with increased chances (15-25%) for occasional thunder. Thunderstorm activity will concentrate mostly over far western NV, the Sierra Front north-northwest into northeast California. This afternoon going into the evening, bands of heavier convective snow showers will bring quick bursts of localized heavy snowfall. Therefore, along the Sierra Crest above 7000' there's a good chance (50-70%) of 2-4" and a lower chance (20- 30%) of anything more than 6-8” of accumulated snow. Western NV valleys below 5500” will stay mostly rain today and Wednesday with projected precip ranging form a few hundredths of an inch up to of up to 0.30". Another supplemental shortwave will pivot south to north across western Nevada Wednesday morning and brings widespread light precipitation across the region. The best chance (40-60%) for precipitation remains mostly over the Sierra Crest to include the Lake Tahoe Basin that extends into NE CA. Snow levels will hover around 6000 to 7000 feet range with the potential for snow showers developing across much of the Sierra. More convective bands of snow showers could drop quick bursts of heavier snowfall over more localized areas. Blended guidance is trending lower for snowfall amounts with only a 50-70% chance for at least 4-6 inches of snow just south of the Tahoe Basin extending into Alpine and northern Mono counties from late Wednesday into early Saturday morning. Travel impacts are still not out of the question, so be sure to check with CalTrans and/or NDOT for the latest on road conditions. To add to the collective “UGHHH" feeling, blended guidance still projects that higher elevation areas across the Sierra crest could see up to a foot of snow through Wednesday morning. Breezy afternoon and evening south-southwest winds with gusts 15-30 mph for most areas across the Sierra into western NV will return today. More enhanced breezes with gusts as high as 30-35 mph will follow-up across eastern areas of the Basin and Range (Mineral-Churchill-Pershing counties) Wednesday afternoon and evening with gusts in wind prone areas reaching 40 mph that could make travel difficult over portions of US-395, US-50 east of Fallon, and US-95 in and around Walker lake into Hawthorne, NV. Latter half of the week into the weekend: Thursday starts with another subsequent wave of mid-high level convergent forcing and Pacific moisture swinging northeast and north round the main upper level low centered over the central CA coast. This wave will bring another round of showers and an increased chance (15-20%) for isolated thunderstorms to the Sierra and western NV. GEFS and European ensemble guidance project that the best chance for stronger storm cell development looks to cover mostly northeast CA, that extends east across northern NV both Thursday and Friday afternoon. These areas also better align will ECMWF extreme forecast index for normalized CAPE, shear, and QPF projections. Winds will remain mostly breezy from the west- southwest in the afternoon, except in and around storms where outflow gusts could exceed 40 mph. Temperatures will remain mostly below normal with daytime highs 5-10 degrees below seasonal averages. The key point at this time is model simulations show the area of low pressure spinning down and becoming less organized. Therefore, precipitation timing and trajectory projections remain an open question through the second half of this week into the weekend. Nonetheless, unsettled weather conditions and cooler temperatures will persist across the region into the weekend with as pockets of energy continue to rotate around the base of broader area of upper toughing that stays more or less fixed over the western US. -Amanda && .AVIATION... * Hi-Res CAMS simulations show the current band of rain/snow showers will continuing to rotate northwest into NE-CA through 18Z. Another band of showers and isolated thunderstorms are projected to develop over western NV and the Sierra this afternoon that rotates northwest into NE CA through this evening. Terminals nearest thunderstorms will see brief MVFR conditions, lightning, brief heavy rainfall, mountain obscurations, strong outflow winds greater than 40 mph, and small hail/snow pellets. * With snow levels hovering around 5500-6500 today into this evening, there remains a moderate chance (30-40%) for snow showers bringing brief periods of IFR-MVFR conditions for Sierra terminals. These convective bands of snow showers will continue this afternoon into the evening, and bring more slushy light snow, IFR conditions, lowered CIGs/VIS, and mountain obscurations to Sierra and NE CA terminals. High sun angles and warm tarmac temperatures should limit the potential for any accumulations greater than an inch. * Southerly upper flow will increase winds to 30-40 kts at FL100 along with periods of mountain wave turbulence and LLWS across the Sierra and east into western Nevada today through Wednesday. Breezy afternoon and evening winds will gust to 15-25 kts today across Sierra and western NV terminals. There is an increased potential today and Wednesday for gusts 25-40 kts for terminals in the Basin and Range/west-central Nevada. -Amanda && .AVALANCHE... * Another round of snow showers will push into the Sierra through the evening. Some heavier snow snowfall is possible will more convection bands snow showers that moves through the area. Winds will stay breezy out of the south-southwest this afternoon, with ridges above 8000' gusting 40+ mph. * Around the Lake Tahoe Basin, snow amounts are ranging from 2-5" below 7000', 6-11" above 7000', and 2-5" above 6000' in NE CA. Liquid totals of 0.3-0.7" above 7000' in the Sierra to 0.4-0.6" in NE CA. Snow ratios will mainly hover between 13:1-17:1 throughout the duration. Snowfall rates will be generally around 0.5"/hr but could reach as high as 1"/hr during the heaviest convective snowfall this afternoon between 1PM-6PM PDT. * Intermittent snow showers look to continue through the second half of this week with periods of heavier convective bands of showers in the afternoon into the evening. -Amanda && .REV Watches/Warnings/Advisories... NV...Winter Weather Advisory until 11 PM PDT this evening NVZ002. CA...Winter Weather Advisory until 11 PM PDT this evening CAZ072. &&
The national radar mosaic for the moment the first event began.
2 heavy rain, 1 heavy snow. Local standard time, as filed.
A COCORAHS station (CA-NV-79 Reno), located 9.0 NNE of Cold Springs, NV, and the public located at Dagget Pass, NV, reported 24 hour snowfall totals of 12.0 inches and 3.0 inches respectively.
An ASOS located at the Reno-Tahoe International Airport, a COCORAHS (NV-WH-2 Reno) located 1.4 mi NNE of Reno, NV, and a COCORAHS (NV-WH-133 Reno) located 1.7 mi WSW of Reno, NV, reported 24 hour rainfall totals of 0.84 inches, 0.91 inches, and 0.93 inches respectively.
A trained spotter located 4.0 mi SSW of Reno, NV, reported a 24 hour rainfall total of 1.04 inches, as well as one inch storm total snowfall.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Nevada in 2023Every state in 2023This day in weather historyWarnings in Nevada, May 2023
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: 1102021, 1102022, 1102023.