On the afternoon of May 18, severe thunderstorms produced tornadoes, damaging winds gusts, hail and flash flooding across southeast Nebraska. a strong shortwave trough ejected eastward across the region, providing robust forcing for large-scale ascent.
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 OAX wrote it up.
On the afternoon of May 18, severe thunderstorms produced tornadoes, damaging winds gusts, hail and flash flooding across southeast Nebraska. a strong shortwave trough ejected eastward across the region, providing robust forcing for large-scale ascent. Despite lingering morning cloud cover, very steep mid-level lapse rates combined with the daytime heating of a moist low-level airmass to generate strong instability south of an advancing cold front. Mesoanalysis revealed strong theta-e advection extending from central Kansas through southeast Nebraska and southwest Iowa, highlighting the rapid return of a highly volatile environment. Thunderstorms initially initiated on the warm side of the boundary over northwest Kansas before additional development began over far southeast Nebraska by 2:00 PM CST. This convection initially exhibited discrete supercell characteristics before eventually transitioning into a broader multicell cluster. Additional cells developed north of the cold front across eastern Nebraska, bringing primarily an isolated hail threat.
The system dropped large hail up to golf ball size (1.75 inches) and generated destructive straight-line winds, including a measured peak gust of 90 mph. The initial supercell storm mode was particularly prolific for tornadogenesis, resulting in 8 tornado across southeast Nebraska. While several of these tornadoes were brief, others caused concentrated damage to trees, farm outbuildings, and irrigation pivots most notably in Johnson, Nemaha, and Richardson counties. In several instances, these tornadoes were embedded within even broader swaths of intense 80 to 95 mph downburst winds. As the storms transitioned into a messy multicell cluster, torrential downpours also triggered isolated reports of flash flooding.
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 Omaha, NE wrote its last area forecast discussion before the first event at May 18, 11:47 AM CST, 1 hour 59 minutes earlier. Its key messages:
Area Forecast Discussion
National Weather Service Omaha/Valley NE
1247 PM CDT Mon May 18 2026
.KEY MESSAGES...
- Potential for more severe weather today, mainly across
southeast Nebraska and southwest Iowa. Large hail, damaging
winds, strong tornadoes, and flash flooding will all be
possible.
- Cooler weather moves in on Tuesday with potential for morning
frost for northeast Nebraska on Wednesday.
- Another active pattern may set up going into next weekend with
chances for more storms, and possibly severe weather.
&&
.DISCUSSION...
Issued at 1155 PM CDT Sun May 17 2026
Today and Tonight...
We had a deceivingly cool, cloudy start to the day. Temperatures
this morning started off in the 50s at 9 AM, and dipped into the
upper 40s over northeast Nebraska. Farther south, however, Falls
City had already warmed to 70 degrees, on the warm side of a cold
front draped from Beatrice, to Offutt AFB, towards Shelby, IA.
Spotty showers and a few rumbles of thunder developed behind the
boundary this morning. A strong shortwave trough will continue to
eject eastward this afternoon, bringing forcing for large-scale
ascent. Despite the lingering cloud cover, very steep lapse rates
aloft and daytime heating of a moist low-level airmass will likely
support strong instability south of the cold front. Mesoanalysis
depicting strong thetaE advection from central Kansas through
southeast Nebraska and southwest Iowa depicted the abrupt resurgence
of a volatile airmass. Storms have already begun to fire on the warm
side of the boundary over northwest Kansas, and are expected to
develop over far southeast Nebraska by 2 PM this afternoon. Initial
isolated supercells will have the greatest potential for producing
strong, potentially violent tornadoes, very large hail, and damaging
winds, with the greatest risk in far southeast Nebraska. By 4 or 5
PM, CAMS depict more widespread clusters of storms developing, with
the potential for supercell structures. While not as extreme as the
possible intensity over far southeast Nebraska, these storms,
primarily along and southeast of a line from Lincoln to Omaha will
still be capable of producing large hail, damaging winds, and
perhaps a tornado or two.
In addition to hail, winds, and a chance for tornadoes, heavy rain
will also become an issue overnight. Last night's round of
convection brought around 0.5" to 1" of rain across the forecast
area. The potential for a few training storms with 3"+ per hour
rates on top of the already saturated soils will create the
potential for flash flooding across parts of far southeast Nebraska
and southwest Iowa tonight. Therefore, a Flood Watch remains in
effect until 7 AM Tuesday for southeast Nebraska and parts of
southwest Iowa.
Tuesday and Beyond...
We'll see the cold front clear well to the south and east of our
area by Tuesday, putting a cooler Canadian air mass in place
across the region. Tuesday will start out cloudy once again, but
really clear by the afternoon as high pressure builds over our
area. High temperatures on Tuesday will only reach into the
upper 50s to mid 60s. With clear skies and nearly calm winds,
this lends to potential for frost early Wednesday. Overnight
lows will drop into the mid 30s for northeast Nebraska to low
40s across southeast Nebraska and southwest Iowa. Cooler weather
holds into Wednesday though we do see a reversal to southerly
winds and start to advect moisture back into the region. An
upper-level shortwave could potentially bring a few showers to
the area Wednesday afternoon and evening, but the ensembles
haven't picked up on this latest change in the deterministic
guidance. In any case, this wouldn't be anything impactful.
A better chance for showers and storms moves in Thursday as the
longwave trough that's been nearly stationary over the western
US shifts eastward toward our area. With temperatures still in
the sixties for highs, I wouldn't anticipate much of a severe
weather threat with this system for our area.
Temperatures start to rebound on Friday though as we see
enhanced warm air advection ahead of a deepening surface low
which develops on the lee side of the Rockies over eastern
Colorado and western Nebraska. Depending on the track of this
system, we could potentially see more active weather next
weekend with several chances for storms.
&&
.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1244 PM CDT Mon May 18 2026
Widespread IFR/MVFR ceilings are observed across terminals this
afternoon. Will see an area of scattered showers and storms
overspread KLNK and KOMA after 21z. Have refined timing a bit with
this issuance, but expect further refinements and adjustments.
Storms that affect terminals will likely become severe with strong
winds, very large hail, and the potential for a tornado. Have added
a transition to -SHRA at KOMA and KLNK after 01/02z. Ceilings will
bounce between MVFR/IFR overnight, before largely becoming MVFR late
in the TAF period. Winds from the north northeast will turn to the
north northwest this evening, with gusts gradually increasing to 25
to 30 kts, persisting for the rest of the TAF cycle.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...Flood Watch through Tuesday morning for NEZ065-066-068-078-
088>093.
IA...Flood Watch through Tuesday morning for IAZ090-091.
&&
DISCUSSION...KG/McCoy
AVIATION...CastilloHazardous Weather Outlook National Weather Service Omaha/Valley NE 1256 PM CDT Mon May 18 2026 IAZ043-055-056-069-079-080-090-091-NEZ011-012-015>018-030>034- 042>045-050>053-065>068-078-088>093-191800- Monona-Harrison-Shelby-Pottawattamie-Mills-Montgomery-Fremont-Page- Knox-Cedar-Thurston-Antelope-Pierce-Wayne-Boone-Madison-Stanton- Cuming-Burt-Platte-Colfax-Dodge-Washington-Butler-Saunders-Douglas- Sarpy-Seward-Lancaster-Cass-Otoe-Saline-Jefferson-Gage-Johnson- Nemaha-Pawnee-Richardson- 1256 PM CDT Mon May 18 2026 This Hazardous Weather Outlook is for southwest Iowa, west central Iowa, east central Nebraska, northeast Nebraska and southeast Nebraska. .DAY ONE...This afternoon and tonight. Additional strong to severe storms are forecast this afternoon, with an increased threat for large hail (2-4+ inches) and strong tornadoes. Additional chances for heavy rainfall on top of what has already fallen since Friday night will result in a potential for flash flooding, particularly for portions of southeastern Nebraska. Chances to see severe storm activity is maximized over southeast Nebraska. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday. The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Spotter activation will likely be needed this afternoon and evening.
Preliminary Local Storm Report
National Weather Service Omaha/Valley NE
918 AM CDT Mon May 18 2026
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1130 PM Hail Ashland 41.04N 96.37W
05/16/2026 E2.50 Inch Saunders NE Public
Delayed social media report of 2.5 inch
hail.
&&The Topeka radar (KTWX), 131 km away, was scanning. The volume nearest the first event began at 19:43 UTC.
24 hail, 9 tornado, 9 thunderstorm wind, 2 flash flood. Local standard time, as filed.
Storm chaser video showed a brief tornado that began just south of State Highway 8, approximately 4.5 miles south-southeast of Diller. It continued northeast, crossing the highway before quickly dissipating. No damage was noted.
Wymore Fire Department and a storm spotter reported a tornado approximately 3 miles northwest of Odell. NWS survey was inconclusive. Tree damage across western Gage County was primarily due to straight line winds from thunderstorms that occurred two days before this event.
Emergency management report of hail measured up to 1.00 inch in diameter.
Personal weather station measured wind gust of 70 mph.
Public report of hail measured up to 0.75 inches in diameter. Report received via mPING.
Trained spotter report of hail estimated up to 1.75 inches in diameter. Spotter was driving on US Highway 77 southbound towards Beatrice, NE.
Personal weather station measured wind gust of 58 mph.
Public report of hail estimated up to 0.75 inches in diameter. Report received via mPING.
Personal weather station measured wind gust of 81 mph along with tree branches (6 to 8 inches in diameter) down.
Emergency management report of hail estimated up to 1.75 inches in diameter.
Personal weather station measured wind gust of 66 mph.
Storm chaser report of several tree limbs down, some large. Time estimated with radar. Winds were estimated at 70-80 mph.
A tornado developed in open fields near the intersection of 625 Avenue and 725 Road, and moved quickly east. The tornado damaged many trees, flipped pivots, and destroyed at least two large farm sheds. The damage along the track was somewhat sporadic at times, and this concentrated area of tornado damage was embedded within a much broader area of 60 to 80 mph winds in the downdraft regions of the parent thunderstorm. The peak width of the tornado was determined where it traveled through a long line of trees and gave evidence to the most intense focused zone of winds being approximately 200 yards wide. Maximum wind speeds were estimated at 97 mph. The tornado continued into Nemaha county before dissipating at 3:11 PM CST.
A tornado developed in open fields near the intersection of 625 Avenue and 725 Road in Johnson county at 3:05 PM CST, and moved quickly east before entering Nemaha county. The tornado damaged many trees, flipped pivots, and destroyed at least two large farm sheds. The damage along the track was somewhat sporadic at times, and this concentrated area of tornado damage was embedded within a much broader area of 60 to 80 mph winds in the downdraft regions of the parent thunderstorm. The peak width of the tornado was determined where it traveled through a long line of trees and gave evidence to the most intense focused zone of winds being approximately 200 yards wide. Maximum wind speeds were estimated at 97 mph. The tornado continued into Nemaha county before dissipating at 15:11 PM CST.
Public report of hail measured up to 1.00 inch in diameter. Report received via mPING.
Personal weather station measured wind gust of 90 mph.
In the late afternoon and early evening of May 18, 2026, severe thunderstorms and heavy rain triggered flash flooding across central Gage County. Because the area was already saturated from several consecutive days of rain, the ground could not absorb the sudden deluge. Driven by intense downpours of 1 to 2 inches per hour, total accumulations rapidly reached 3.00 to 4.50 inches. Law enforcement in Beatrice, Nebraska, reported multiple flooded intersections with water depths of one to two feet, leaving several vehicles stranded.
A tornado developed just south of Highway 136 and west of 636 Avenue, and moved east northeast to the area near Highway 136 and just east of 637 Avenue. This tornado caused sporadic tree damage and uprooting, and impacted two farms. At one farm, a large trailer was rolled approximately 50 yards and debris distributed downstream across a field. Several trees were snapped or uprooted and landed on a home. Another farm had a large shed destroyed with the debris field extending more than a half mile downstream. Maximum wind speeds were estimated at 100 mph. This tornado was embedded in a broad area of straight line downburst winds estimated at up to 95 mph, especially near and just south of the tornado track.
Public report of hail estimated up to 1.50 inch in diameter. Report received via Social Media.
Emergency management report of extensive thunderstorm wind damage in Auburn, NE. Possible people trapped in homes. Time estimated with radar. Wind speeds estimated up to 90 mph.
Video from broadcast media showed a small, rain-wrapped tornado moving generally eastward just south of Road 733A and Highway 75. Damage consisted of a small cluster of large downed tree branches, with estimated maximum winds of 80 mph.
In the late afternoon and early evening of May 18, 2026, severe thunderstorms and heavy rain triggered flash flooding across central Johnson County. Because the area was already saturated from several consecutive days of rain, the ground could not absorb the sudden deluge. Driven by intense downpours of 1 to 2 inches per hour, total accumulations rapidly reached 3.00 to 4.50 inches. Emergency management reported localized flooding through Tecumseh, NE.
Personal weather station measured wind gust of 62 mph.
Estimated time and location of tornado based on reports received from emergency management and radar interpretation.
Public report of golf ball size hail north of Auburn. Location and time are estimated from radar.
Personal weather station measured wind gust of 59 mph.
At approximately 3:46 PM CST, a tornado developed 4 miles east of Bern, KS, and tracked northeast before crossing into Richardson county, Nebraska (see Storm Data for Kansas for more information on the beginning portion of this tornado in Kansas). The tornado continued west of 639 Boulevard, damaging some trees. It continued northeast, crossing 639 Boulevard and producing significant damage to the roof of a large metal outbuilding. The tornado then crossed US Highway 75 just northwest of the intersection with 641 Avenue, causing further tree damage and impacting a second metal outbuilding in the area. Additional tree damage occurred near Rock Creek and 642 Avenue. Maximum estimated wind speeds peaked at 100 mph.
Public report of hail estimated up to 1.50 inches in diameter. Report received via mPING.
Trained spotter report of hail measured up to 1.75 inches in diameter.
Delayed report received via social media of hail estimated up to 1.5 inches in diameter. Social media report displayed multiple pictures of the hail.
A tornado developed at approximately 4:07 PM CST near the intersection of 646 Avenue and 708 Road, about 1 mile northeast of Salem. Intermittent damage to trees and farm outbuildings was noted between 646 and 647 Avenues. The tornado continued northeast, damaging more trees and breaking power poles along 650 Avenue. Additional damage to trees and farm outbuildings was noted near the intersection of 651 Avenue and 710 Road. The tornado then crossed US Highway 73 and lifted the roof off another farm outbuilding east of 652 Avenue before dissipating shortly thereafter. Maximum wind speeds were estimated at 107 mph.
Law enforcement report of hail estimated up to 1.75 inches in diameter.
Trained spotter report of hail estimated up to 1 inch in diameter with a mix of pea and quarter sized hail.
Trained spotter report of hail measured up to 1 inch in diameter. Report relayed via NWS Chat.
Public report of hail measured up to 1 inch in diameter.
Public report of hail estimated up to 1 inch in diameter. Report received via mPING.
Public report of hail estimated up to 0.75 inches in diameter. Report received via mPING.
Public report of hail estimated up to 0.75 inches in diameter. Report received via mPING.
Trained spotter report of hail measured up to 1.25 inches in diameter.
Public report of hail measured up to 1.25 inches in diameter.
Trained spotter report of hail measured up to 1.00 inch in diameter.
Public report of hail measured up to 1.50 inches in diameter. Report received via mPING.
Trained spotter report of hail measured up to 1.00 inch in diameter.
Public report of hail estimated up to 1.00 inch in diameter. Report received via mPING.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Nebraska in 2026Every state in 2026This day in weather historyThe tornado archive for Nebraska, 2026Warnings in Nebraska, May 2026
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: 1339518, 1339519, 1339474, 1339480, 1339479, 1339475, 1339481, 1339477, 1339482, 1339476, 1339489, 1339495, 1339521, 1339523, 1339483, 1339490, 1339459, 1339524, 1339488, 1339494, 1339526, 1339460, 1339491, 1339528, 1339487, 1339492, 1339531, 1339499, 1339485, 1339515, 1339536, 1339500, 1339501, 1339503, 1339505, 1339506, 1339513, 1339514, 1339507, 1339509, and more.