An area of low pressure that moved through the area produced some travel impacts over Sierra passes as a quick burst of snow above 6500 feet added a few more inches to area ski resorts. Shower and thunderstorm chances (15-25%), and chilly winds, continued through May 6.
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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.
An area of low pressure that moved through the area produced some travel impacts over Sierra passes as a quick burst of snow above 6500 feet added a few more inches to area ski resorts. Shower and thunderstorm chances (15-25%), and chilly winds, continued through May 6.
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 5, 2:02 AM PST, 5 hours 58 minutes earlier.
Area Forecast Discussion National Weather Service Reno NV 302 AM PDT Fri May 5 2023 .SYNOPSIS... A broad area of low pressure over the western US continues to bring showers to northeast California, the Sierra Crest, and western Nevada. Additional weather systems will maintain cooler and unsettled conditions across the region through this weekend into the first half of next week. && .DISCUSSION... The low pressure disturbance that had stalled then meandered over central CA looks to be finally on the move with a projected trajectory showing the low and mid-level circulation lifting northeast into southern Idaho. Its attendant upper trough will continue to swing over western NV this morning before lifting northeast across the Great Basin region this afternoon and evening. * Fewer Showers Today... Hi-Res CAM simulations project that showers will be more concentrated north of I-80, nearer to the better forcing and instability offered by the now exiting low pressure disturbance and its attendant upper trough. But blended guidance does offer up a chance (30-50%) for a few higher elevation showers across the Sierra crest and the Basin and Range through early afternoon where modest low and mid-level moisture, and weak surface convergence provided by upslope enhancement in and around terrain favored areas. Liquid precipitation totals will vary between 0.10” to 0.35” across the Sierra and Basin and Range. Higher mountain passes may even see a chance (20-30%) up to an inch of slushy light snow. But early May sun angles may limit accumulations due to warmer road surfaces. Hi-Res model guidance does show a weak progressive upper shortwave ridge axis following up quickly east across northern California into western Nevada today. The weak higher pressure that does build into the region will also pull in drier, and more stable conditions that looks to stymie any further shower activity across the Sierra and western NV later this afternoon into the evening. * Sierra Snow Showers and Basin and Range Storms Saturday... Just when things seem to be looking up, a negative tilted upper shortwave trough swings into the western US. This next spring system will bring in another round of higher elevation snow that starts later tonight that continues into Saturday with valley rain showers that may be accompanied with isolated thunder as well. Higher mountain passes may see some travel impacts overnight through Saturday as there remains a decent chance (30-40%) of 3-5” of accumulating snow during the cooler early morning hours. The highest Sierra ridges could see snowfall totals close to a foot before tapering off overnight Saturday. Of course, the higher liquid precipitation totals will be along the Sierra Crest, and range between 0.30-0.90” with the Basin and Range seeing a few hundredths to at least an quarter of an inch. Winds will take the back seat this time around with afternoon and evening breezes gusting to 30 mph before gradually diminishing going into the evening hours. The negative orientation of the lifting upper short will also bring a slight chance for isolated thunderstorms across western NV. Any storms that do form will have brief periods of heavy rain, lightning, and gusty outflow winds in and around their cores. * Sunday and Beyond... Sunday looks to be the better day weather-wise for this upcoming weekend although temperatures still remain 10-15 degrees below seasonal average that will complemented with afternoon west- southwest breezes gusting 20-30 mph. A few showers will still linger far to the north near the Oregon border, otherwise a dry day is expected. But winds across higher Sierra ridgetops will start to gust to 50 mph that heralds the entrance of the next upstream upper wave and attendant cold front that swings into the West Coast Monday. The best chances (30-40%) for any showers will be confined to northeast CA and far northwest NV with a low chance (< 15%) for a few light showers reaching south and east to I-80. Blended guidance holds liquid precipitation totals to just a few hundredths of an inch for much of the area north of I-80. The tightening thermal and pressure gradients with the incoming cold will bring breezy winds gusting to 25-35 mph with a few wind prone areas along US-395 and the I-80 corridor in the Basin and Range gusting 40 mph. Ensemble cluster guidance doesn’t show the broader long wave trough pattern breaking down until after mid week as another low pressure disturbance looks to drive east into the western US around the Tuesday time frame. But wait! As we get to the latter half of next week, blended guidance projects a warming trend with dry conditions prevailing. This coincides with ensemble cluster guidance projecting a hint of higher pressure emerging on the more extended forecast horizon. -Amanda && .AVIATION... * For today, widespread cloud cover with some mountain obscurations is expected with an area of steady light rain in northwest NV diminishing by late morning. For the main terminals, isolated showers are possible into mid-afternoon with about a 15% probability of occurring within 5 miles of the western NV sites, and 20-30% probability for the Sierra/Tahoe sites, producing brief MVFR conditions mainly from 18-23Z. * For late tonight and Saturday morning, shower chances increase especially for the Sierra terminals, with periods of IFR conditions and up to 1" of snow accumulation possible prior to daybreak. By Saturday afternoon, shower and thunderstorm chances expand to western NV, bringing short periods of heavier rain or pellets to lower elevations and a rain-snow mix to the Sierra terminals. * SW-W breezes are expected each afternoon/evening through the weekend, with gusts 15-25 kts at terminal sites. Ridge level wind gusts of 35-45 kt through the weekend will bring periods of mountain wave activity. Surface and ridge level wind gusts could increase by 5-10 kt Monday afternoon-evening. * Unsettled conditions are likely to continue for early next week with more shower chances, before a drier pattern finally returns later in the week. MJD && .REV Watches/Warnings/Advisories... NV...None. CA...None. &&
Special Weather Statement National Weather Service RENO NV 317 AM PDT Fri May 5 2023 CAZ071>073-NVZ002-061600- Lassen-Eastern Plumas-Eastern Sierra Counties- Greater Lake Tahoe Area-Mono County- Including the cities of Portola, Susanville, Westwood, Sierraville, Loyalton, South Lake Tahoe, Tahoe City, Truckee, Markleeville, Bridgeport, Coleville, Lee Vining, Mammoth Lakes, Stateline, Glenbrook, and Incline Village 317 AM PDT Fri May 5 2023 ...SNOW COULD PRODUCE WINTER TRAVEL CONDITIONS OVER THE SIERRA LATE TONIGHT INTO SATURDAY MORNING... * A cold weather system will bring areas of snow to northeast California above 5000 feet and the Sierra late tonight into Saturday morning. * Snowfall accumulations of 4-8 inches are possible near the Sierra crest above 6500 feet, with up to 2 inches possible in the Lake Tahoe basin and above 5000 feet in northeast California west of US-395. * Anyone planning travel over the main Sierra passes from late tonight through Saturday morning should prepare for slushy or snow covered roads. Road conditions will improve during the day Saturday, although scattered snow showers could still produce reduced visibility at times. http://weather.gov/reno
The national radar mosaic for the moment the first event began.
2 heavy snow. Local standard time, as filed.
The public located 6.0 mi W of Truckee, CA, at the Central Sierra Snow Lab reported 72-hour storm total snowfall of 10.4 inches.
The public located at the Palisades Tahoe Alpine Lodge, CA, reported a 24 hour snowfall total of 14 inches.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2023Every state in 2023This day in weather historyWarnings in California, 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: 1103564, 1102011.