An unsettled pattern established by a broad area of troughing over the western states that continued through the end of May. Upper level shortwaves provided sufficient forcing for generation on a near-daily basis of afternoon convection in the prevailing moist and unstable air-mass.
Every event with a place to put it; 2 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.
An unsettled pattern established by a broad area of troughing over the western states that continued through the end of May. Upper level shortwaves provided sufficient forcing for generation on a near-daily basis of afternoon convection in the prevailing moist and unstable air-mass. A nearly zonal steering flow aloft led to faster moving and stronger storm cells that held the potential for outflow gusts to 50 mph, brief heavy rainfall, and small hail.
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 27, 11:06 AM PST, 1 hour 44 minutes earlier.
Area Forecast Discussion National Weather Service Reno NV 1206 PM PDT Sat May 27 2023 .SYNOPSIS... Daily showers and thunderstorms (30-60% chances) are forecast through the holiday weekend and into next week. Stronger storms may produce locally heavy rainfall, small hail, gusty outflow winds, and frequent lightning. Snowmelt will keep streams running cold and fast, with main flood concerns for the Walker River. && .DISCUSSION... No significant changes to the ongoing forecast. Plan on daily afternoon thunderstorms (30-60% chances) through the holiday and into early next week as well as ongoing snow melt impacts. Thunderstorm impacts each day will include: locally heavy rainfall, small hail, gusty and erratic outflow winds, and frequent lightning. TODAY: A cut off low across the Pacific Northwest is punting a shortwave across northern CA/NV this afternoon and evening and triggering convective activity for areas along and north of Interstate 80 today. Visible satellite imagery shows an expansive area of cumulus buildups well underway with thunderstorm initiation occurring across northern Lassen and northern Washoe counties. Areas of showers and thunderstorms are already ongoing across Lassen and Washoe counties with a west to east track. Outdoor enthusiasts be aware of the rapidly changing conditions and be prepared to shelter in a sturdy building or vehicle if you hear thunder. Even small pea-sized hail is quite painful if you get stuck outside in a storm! REST OF THE HOLIDAY WEEKEND: The cut off low drops south along the CA coast and meanders about CA from this weekend into midweek next week. East surface winds combined with southerly steering will result in directional shear across the Sierra and western Nevada on Sunday. The combination of low to mid level shear, surface instability, and upper level divergence may produce stronger, longer-duration storms midday Sunday into the evening, especially for storms that form along and south of Interstate 80. As the low lingers offshore, thunderstorm potential will shift slightly with the best potential (30-40% chances) along the Sierra, northeast CA, and far western NV. Generally with thunderstorms this weekend into early next week, we could see localized heavy rainfall rates that may aggravate flooding impacts in sensitive areas such as recent burn scars, steep canyons, and along rivers and creeks already running fast and high from spring snowmelt. Plan on the unsettled pattern with above normal precipitation chances (due to showers and thunderstorms) appears to linger on with the West as we head into early June. No signals for building high pressure ridge for the CA/NV region. -Edan && .AVIATION... A steady pattern of scattered afternoon showers and thunderstorms will be possible through the weekend. There will be a 30-40% chance for storms impacting KTRK-KTVL as well as KRNO-CXP-KMEV through 03z this evening. Storms may produce brief heavy rainfall, with terrain obscuration, gusty and erratic outflow winds in excess of 40 kts, and small hail. More widespread shower and storms chances will be possible Sunday afternoon (40-50% chance). Outside of storms, conditions will be VFR with scattered to broken cumulus decks. Periods of fog will be possible overnight at KTRK from 10-15z. Fuentes && .HYDROLOGY... No significant updates or changes in ongoing flood concerns. Headwater flows have diminished a bit with cooler temperatures, and crests are slowly migrating down mainstem rivers. * WALKER: Prolonged minor to moderate flooding will continue along the East Fork and main-stem of the Walker River. The Walker River in the Mason Valley continues to trend slightly downward. Very minimal decreases in flow are expected this weekend, but it will depend on reservoir management adjustments which are intended to maintain storage and to mitigate future, and potentially, higher peaks. * CARSON: Minor flood impacts may be a concern along the East and West Forks of the Carson, but trends are down from earlier in the week. * MONO COUNTY: Keep a close eye on Mono county small streams which have been running very high. * THUNDERSTORMS: Thunderstorms will continue to be a wild card. Unsettled, storm pattern continues for the weekend and into next week. With saturated soils and elevated streamflows, additional rain will result in rapid rises and enhanced flooding potential. These storms will be most impactful along smaller creeks and streams, but could also exacerbate problems along mainstem rivers which are already flooding or are very close to flood impact levels. Note: River forecasts are incapable of incorporating these short duration high intensity rain events. -Bardsley/Edan && .REV Watches/Warnings/Advisories... NV...None. CA...None. &&
Special Weather Statement
National Weather Service Reno NV
100 PM PDT Sat May 27 2023
NVZ003>005-272100-
Western Nevada Basin and Range including Pyramid Lake NV-
Northern Washoe County NV-Greater Reno-Carson City-Minden Area NV-
100 PM PDT Sat May 27 2023
...Strong thunderstorms will impact Pyramid Lake through 200 PM
PDT...
At 1259 PM PDT, Doppler radar was tracking a cluster of strong
thunderstorms over Pyramid Lake, moving east at 30 mph.
HAZARD...Winds in excess of 40 mph and half inch hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could capsize small vessels on the lake. Minor
damage to outdoor objects is possible.
Locations impacted include...
Pyramid Lake, Sutcliffe, Nixon, The Needle Rocks and Tohakum Peak.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
&&
LAT...LON 3995 11968 4022 11981 4029 11948 3984 11936
3981 11949
TIME...MOT...LOC 1959Z 263DEG 25KT 4008 11958
MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH
TFThe national radar mosaic for the moment the first event began.
2 high wind. Local standard time, as filed.
A mesonet station (UP793) located 3.9 mi SW of Gerlach, NV, reported a thunderstorm peak wind gust of 58 mph.
A mesonet station (MJBN2-MAJUBA) located 21.0 mi WNW of Imlay, NV, reported a thunderstorm peak wind gust of 71 mph.
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: 1102028, 1102027.