Troughing over the western CONUS brought southwesterly flow aloft over the central and northern Plains for the duration of this event. In the couple of days leading up to May 21st, the upper-level flow pattern amplified as a trough deepened over the northern Rockies.
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.
Troughing over the western CONUS brought southwesterly flow aloft over the central and northern Plains for the duration of this event. In the couple of days leading up to May 21st, the upper-level flow pattern amplified as a trough deepened over the northern Rockies. This trough then ejected out into the central Plains on the 21st. At the surface, a stationary front developed and stretched across central Nebraska and southern Iowa by the evening of the 19th. Elevated convection that morning north of the developing surface boundary resulted in isolated instances of severe hail and wind across southeast Nebraska. Additional scattered strong to severe thunderstorms developed along this frontal boundary as it slowly lifted north, with a 64 miles per hour wind gust measured in Lancaster County and golf ball sized hail falling in Clarinda Iowa.
A weak low-pressure system developed the morning of the 20th in response to a shortwave rounding the base of the main trough out west, resulting in a cold front that pushed southeast across South Dakota and central Nebraska that afternoon. This front, however, stalled out across eastern Nebraska and western Iowa that evening, remaining draped across the region that night and into the morning of the 21st. Numerous rounds of strong and severe thunderstorms that night brought widespread severe weather and flash flooding, primarily across east-central Nebraska and southwest Iowa, though some elevated supercells in northeast Nebraska brought small hail to the area. After 10 UTC, an intense line of severe thunderstorms moved across eastern Nebraska and western Iowa bringing wind gusts ranging from 60 to 95 miles per hour, in addition to several spin-up tornadoes.
As the primary upper-level disturbance ejected out over the Great Plains, intense surface cyclogenesis was noted over eastern Nebraska. This resulted in the frontal boundary that had been draped across eastern Nebraska and western Iowa that night prior to be forced northward. By 18 UTC, a strong cold front pushed through southeast Nebraska and into Iowa that afternoon. Scattered supercell thunderstorms developed along this cold front and moved across southeast Nebraska and western Iowa. These supercells became tornadic after crossing the Missouri River into Iowa, with several long-track significant tornadoes being confirmed across the state. In the OAX CWA, the strongest tornado damage confirmed was that consistent of an EF-2 in Montgomery County. This tornado continued into the DMX CWA where it caused EF-3 damage. Another tornado developed in Page County shortly before 3 PM that afternoon. This tornado went on to produce EF-4 damage in the DMX CWA. All in all, over this three-day event, 10 tornadoes were confirmed across the OAX CWA.
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 19, 5:02 AM CST, 7 minutes earlier. Its key messages:
Area Forecast Discussion National Weather Service Omaha/Valley NE 602 AM CDT Sun May 19 2024 .KEY MESSAGES... - Several rounds of strong to severe thunderstorms will be possible across our region today through Tuesday afternoon. All modes of severe weather including flash flooding will be possible. - There will be another chance for thunderstorms Thursday night or Friday. && .DISCUSSION... Issued at 320 AM CDT Sun May 19 2024 Today and Tonight: A MCS has taken shape across western Kansas up through central Nebraska this morning associated with an upper-level shortwave that will continue northeast into eastern Nebraska by 7 AM this morning, brining this complex of storms through our area. With surface dew points in the 40s out ahead of this system and a stable boundary layer in place, these storms will remain elevated as they move across our area, which should limit any severe potential. While we could see a few wind gusts up to 40 to 50 mph, the bigger threat will likely be locally heavy rainfall which could cause flash flooding. CAMs show this storm complex exiting our area around noon, but we see additional showers and storms develop behind this complex, acting to delay environmental recovery this afternoon across most of our area. What we will be watching closely is the northward advancement of the warm front out of Kansas. Models differ on how far north the warm front gets, and it will likely depend on how much shower and storm activity we see across our area. There is a greater chance of sufficient surface-based instability for severe storms developing along and south of this warm front during the afternoon, and higher confidence this warm front gets at least to the Missouri state line but could get as far north as I-80. Severe storm potential will start to increase around 4 PM with the northward advancement of the warm front as we'll start to see stronger discrete storms develop in the warm-sector south of the warm front. I think our best chance for severe weather will be with the QLCS feature that starts to develop over Central Kansas during the late afternoon and moves into southeast Nebraska this evening. This will be around a 4-hr window from around 6 PM to 12 AM. During this time period, we see a broad region with 60 to 80% chance of greater than 1500 J/kg of SBCAPE and 200 m2/s2 of 0-3 km SRH. This indicates a primed environment with ample instability and shear for strong to severe storms. QLCS storm mode indicates the greatest threat will likely be damaging winds with hail also possible. We'll want to watch closely along the warm front, though, as LCL heights get lower near the warm front and we see higher 0-1 km SRH as well. The warm front could provide an anchor for low-level vorticity which could increase the tornado threat locally. Monday - Monday Night: Once these storms exit the area tonight, CAMs show a break in the shower activity while the NAM and GFS show the potential for a few lingering showers into Monday morning. In any case, the severe weather threat will be over and our attention turns to the next shortwave that will eject out ahead of the trough over the Southwest region. We see a stationary boundary set up bisecting our area near I-80. Another MCS appears likely to develop and ride north of this stationary boundary producing heavy rainfall Monday night into early Tuesday with a risk for flash flooding across northeast Nebraska. South of the stationary boundary we'll have more destabilized environment but low-level shear will be lacking during the day on Monday. Tuesday night we'll see the shortwave arrive associated with the MCS to the north which will provide stronger forcing for ascent and additional low-level shear which will increase the potential for severe storms. The only question will be how well the boundary layer can decouple ahead of storm development which could limit tornado potential. Hail and damaging winds seem like the biggest threats at this time. Best timing for severe weather will probably be 7 PM to midnight. Tuesday - Tuesday Night: Tuesday we see the first upper-level trough move through, bringing the surface low northeast along that stationary frontal boundary bisecting our area. By Tuesday morning we'll see the surface low already over our area bringing the cold front through with the air mass ahead of the cold front destabilizing quickly. Storms will initialize along the cold front in eastern Nebraska by 10 AM and crossing into Iowa and out of our area by noon. The Storm Prediction Center has us under an Enhanced (level 3 out of 5) risk for severe storms during this window with a 30% chance for severe storms for our southwestern Iowa counties. It will be a short window as storms will initiate in our area but move quickly off to the east. Once the cold front moves through, we may have a few showers linger behind the front, but winds will shift to northerly and it will feel cooler during the afternoon into the evening. Wednesday - Saturday: Going into the latter half of the week, we find ourselves north of the storm track as the broad upper-level trough expands eastward into the Central US. Wednesday we get a bit of a break in the storms as a surface high moves in behind the cold front. Temperatures will be a bit on the cooler side with highs in the low 70s. Meanwhile, we watch out to the west as additional trough activity reloads, getting ready to move in to our area Thursday night or Friday. There is still quite a bit of model spread on timing of the late-week system with precip chances Thursday through Saturday to encompass this uncertainty. Can't rule out another chance for severe weather at this time as CIPS and CSU Machine Learning does show some signals for potential for far southeast Nebraska, though the greater potential does appear to stay to our south over Kansas. We'll want to monitor this time frame just in case. && .AVIATION /12Z TAFS THROUGH 12Z MONDAY/... Issued at 554 AM CDT Sun May 19 2024 A round of showers and thunderstorms is moving across the area from west to east this morning. This is expected to impact the terminals in the 11-16Z timeframe with a few lingering rain showers possible into the early afternoon. Another round of thunderstorms is possible later Sunday afternoon and evening. Confidence is low in the storm coverage and timing and it has therefore been left out of the TAFs until confidences is gained. VFR conditions will likely prevail through the forecast period, unless a stronger storm resides over the terminal. Winds will remain out of the southeast with a gradual shift to southwesterly late this afternoon. Winds will increase to speeds greater than 12 kts early this morning with gusts up to 20-25 kts possible through the majority of the forecast period. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && DISCUSSION...McCoy AVIATION...Wood
Hazardous Weather Outlook National Weather Service Omaha/Valley NE 402 AM CDT Sun May 19 2024 IAZ043-055-056-069-079-080-090-091-NEZ011-012-015>018-030>034- 042>045-050>053-065>068-078-088>093-192315- 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- 402 AM CDT Sun May 19 2024 This Hazardous Weather Outlook is for portions of southwest Iowa...west central Iowa...east central Nebraska...northeast Nebraska and southeast Nebraska. .DAY ONE...Today and Tonight Scattered thunderstorms are expected to move through portions of eastern Nebraska and western Iowa this morning. These storms will pose a low-end wind risk. This afternoon, isolated strong to severe thunderstorms may develop across southeast Nebraska with a threat for large hail and damaging winds, particularly after 4 PM. .DAYS TWO THROUGH SEVEN...Monday through Saturday Several rounds of strong to severe thunderstorms will be possible through Tuesday afternoon. The greatest threat at this time appears to be large hail, some of which could be greater than 2 inches in diameter. Severe wind gusts, tornadoes and flash flooding will all be possible as well. We'll have additional chances for thunderstorms beginning Thursday afternoon and heading into next weekend. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed through Saturday.
The Omaha radar (KOAX), 64 km away, was scanning. The volume nearest the first event began at 11:09 UTC.
20 hail, 17 thunderstorm wind, 7 flash flood, 5 tornado, 2 funnel cloud. Local standard time, as filed.
The office received a public report of large tree branches down in Lincoln.
The office received a public report of quarter sized hail from mPING.
The office received a public report of quarter sized hail from mPING.
The office received a public report of quarter sized hail from mPING.
A 64 mph wind gust was measured by a personal weather station.
A swath of severe hail started in Bloomfield, Nebraska with half dollar sized hail being reported by the public on the north side of town. As the storm moved northeast, severe hail fell in mainly rural areas before entering the town of Crofton where golf ball sized hail was reported.
A report of half dollar sized hail was relayed to the office by the 911 Call Center.
The office received a report of golfball sized hail from the public 2 miles northwest of Weston, Nebraska.
The office received a report from the 911 Call Center for golfball sized hail 2 miles to the northwest of Hartington, NE.
The office received a report from the public of quarter sized hail 1 mile south of Malmo, Nebraska.
The office received a report from social media of golfball sized hail that fell in far eastern Cedar County, Nebraska.
The Burt County Emergency Manager reported a 65 miles per hour wind gust on the north side of Decatur, Nebraska.
The office received an mPING report of half dollar sized hail in Valparaiso, Nebraska.
There was a 69 miles per hour wind gust measured at an ASOS station 4 miles northeast of Bennington, Nebraska.
The intersection of 180th and Maple was completely covered in water, with some vehicles having difficulty driving. Low-lying roads to the north of Dodge and 204th are covered with water but not all the way up to the gutters. Some cars were having trouble driving through the street. Ponding was also reported on the eastbound side of Dodge Street in Boy's Town. Further east just after 1 in the morning, two cars were reported stuck in the water in northeast Douglas County.
Several rounds of thunderstorms training over Fremont resulted in flash flooding across the city during the early morning hours of the 21st. The first report of flooding in the city came into the office at 3:47 in the morning. Just before 5 in the morning, fast-flowing water was observed over East 11th Street. Flooded roadways continued to be reported through the morning hours between Fremont and south into Saunders and northwest Douglas Counties.
A 69 mph wind gust was measured from a personal weather station.
A 58 mph wind gust was recorded on a personal weather station.
A swath of high-end straight-line wind damage began on the northwest side of Columbus, Nebraska around 5 a.m. Initial measured wing gusts in this part of town ranged from 60 to 70 miles per hour until a 90 miles per hour wind gust was reported by the Platte County Emergency Manager on the northeast side of town at 5:05 in the morning. Severe straight-line winds ranging from 75 to 90 miles per hour continued to the east of Columbus snapping power poles and tree trunks, overturning center pivots, and damaging farm outbuildings by taking over panels and roofing material.
This is a continuation of the swath of straight-line damaging winds from southern Platte County. Across much of Colfax County, widespread tree damage and overturned center pivots were observed. The most intense damage was focused along a corridor along and just north of US Highway 30. 1 miles east-northeast of Richland, Nebraska, the Colfax County Emergency Manager reported numerous outbuildings with their roofs blown off including a machine shed and 2 hog units. Peak wind gusts in the county were estimated at 95 miles per hour. This was determined from significant damage to large trees on Road G between Road 4 and Road 5. A trained spotter also recorded a wind gust of 79 miles per hour in Howells, Nebraska.
The Butler County Emergency Manager reported several center pivots overturned and multiple power poles snapped from the intersection of U.S. Highway 80 and State Highway 64 East towards Bellwood. A damage survey also found an empty grain bin that had been blown off its foundation and smashed against the side of a farm building.
This tornado touched down on a farmstead 200 yards west of Road 6 about a quarter-mile south of Road H. Here, the roof was blown off of a farm outbuilding. As it moved northeast and crossed Road 6, the wind caused a wooden power pole to lean about 45 degrees from the ground. The tornado then continued to another farmstead on the south side of Road H, a quarter-mile east of Road 6. Here, an empty grain silo was pushed over. The tornado then dissipated just short of crossing Road H. Peak winds in this tornado were estimated at 82 miles per hour, with a max width of 50 yards and an estimated mean width at 40 yards.
This brief tornado touched down a quarter mile north of 28 Road and a quarter mile west of Q Road, and tracked east for approximately two-thirds of a mile before dissipating. On the west side of Q road, a center pivot was overturned. Several hardwood trees were blown down on the east side of Q road. This tornado had peak estimated winds of 84 miles per hour, with a max width of 50 yards and an estimated mean width of 40 yards.
This is a continuation of the straight-line wind damage swath from Platte and Colfax Counties. When the storm moved into the northwest side of the county, winds were still estimated to have been anywhere from 80 to 93 mph. The Emergency Manager reported a segment of snapped power poles 1 to 2 miles south of Snyder along Highway 79. The most intense damage was at a farm building 1 mile southwest of Snyder where the roof was blown off the structure. The estimated wind speeds here were at 93 mph and the time of occurrence was at approximately 5:36 in the morning. Winds up to 60 mph were estimated to have continued to Highway 275 where surveyed damage and storm reports stopped.
Numerous hail reports were received to the office between Elkhorn and Bennington, Nebraska, extending northeast towards the Douglas-Washington County Line a few miles east of Bennington. Hail sizes were predominantly quarters, with golf ball sized hail reported 3 miles southwest of Bennington at 5:30 AM.
This tornado touched down approximately half a mile east of T Road on 28 Road where tree branches were snapped off trees and littered across the road. This tornado then continued east along 28 Road to V Road snapping branches of trees along its way. Just after it crossed V Road, trees along 28 Road were sheared off at their tops. The tornado then continued east where it dissipated a quarter mile east of W Road. At the time of dissipation, a farm outbuilding had pieces of its roof paneling blown off. The peak estimated winds in this tornado were 80 miles per hour, with a max width at 50 yards and an estimated average width of 40 yards.
The office received a report of a roof blown off a shed. Several large trees were also blown down in the area.
The emergency manager relayed reports of numerous outbuildings that were damaged. Trees were uprooted and powerlines were blown down in the area as well.
This brief tornado tracked just under half a mile, starting in the Valley View Golf Course and dissipating just west of US Highway 77. Branches were broken off of trees along its path through the golf course and at homes near the intersection of Iron Couty and Eagle Drive. Peak winds in this tornado were estimated to be 83 miles per hour, with a peak width measured at 50 yards and an average width of 50 yards.
A 58 mph wind gust was recorded on a personal weather station.
Broadcast Media reported ping-pong ball sized hail shortly before 6 am just west of Omaha. There was another public report of quarter sized hail in the area at the same time. Severe hail lasted for approximately 3 minutes.
Several prolonged rounds of heavy rain during the early morning hours of the 21st led to flash flooding across central and northeast Saunders County. A National Weather Service employee reported water flowing over U.S. Highway 77 shortly after 7 AM, with traffic cameras showing widespread flooding across fields and roads in and around Wahoo. The Saunders County Emergency Manager also reported 6 homes flooded in Lashara, 4 of which had residents that needed to be evacuated.
The Tekamah ASOS recorded a 62 miles per hour wind gust.
Broadcast Media recorded a 60 mph wind gust.
Several rounds of thunderstorms during the early morning hours across the Omaha metro brought flash flooding to parts of the metro. The first reports of flash flooding came in just before 6:30 in the morning near Maple and 132nd Street. An additional report of flooded streets was received west of Carter Lake near the Sorensen and Fontenelle intersection. Water was also reported over a road in Boys Town.
Quarter sized hail was reported by media in west Omaha.
The Butler County Emergency Manager reported flooding in Bruno, and in rural areas just to the south and eat of the town. Many roads were under water, particularly in the Skull Creek area.
Following several rounds of thunderstorms and heavy rain which resulted in flash flooding across the Omaha metro, flood waters continued to linger through the morning of the 21st. Broadcast Media reported multiple stalled vehicles at Center and 67th Street.
The office received a public report of half-dollar sized hail.
The office received a public report of quarter sized hail from mPING.
An NWS Employee reported golf ball sized hail.
A swath of severe hail fell across the city of Fremont half an hour after noon on the 21st. Most hail reports were of golf ball sized hail, however, the office did receive a report from amateur radio that 2-inch hail fell just north of the Fremont airport.
A trained spotter recorded a 65 miles per hour wind gust in Fremont.
This brief tornado touched down on the Upper Clear Creek approximately 100 yards north of East Vine Street. Here, several branches were broken off of trees before the tornado moved towards the north-northeast. along its path towards County Road N, additional trees had branches broken off as it passed through the west side of a homestead. The tornado dissipated approximately 50 yards north of County Road N. The peak estimated wind speeds in this tornado were 80 miles per hour, with a max width at 50 yards. The average width of this tornado was also estimated to be at 50 yards.
Law Enforcement took a video of a funnel cloud a few miles east of Yutan.
Law Enforcement closed 276th Street north of Valley between Highway 275 and Highway 36 due to flowing water over the roadway.
A swath of severe hail fell in association with a supercell thunderstorm that tracked across Otoe County and into eastern Cass County. The first reports of hail came from Syracuse, Nebraska, where half-dollar sized hail fell. Severe hail continued to fall as the storm crossed the county line into Cass County. The Otoe County Emergency Manager reported golf ball sized hail just south of the County line. About a mile west of this, a 2 inch hailstone was reported by the public.
The office received a public report of trees down 5 miles east of Bennington.
The office received a report of quarter sized hail via mPING.
Cass County Emergency Management relayed a report from a trained spotter of tennis ball sized hail at 67th and A street.
A trained spotter reported a funnel cloud to the west of Thurman. Strong rotation persisted even after the funnel cloud dissipated.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Nebraska in 2024Every state in 2024This day in weather historyThe tornado archive for Nebraska, 2024Warnings in Nebraska, May 2024
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: 1180719, 1180721, 1180722, 1180724, 1180725, 1180726, 1180727, 1180728, 1180730, 1180732, 1180733, 1180734, 1180737, 1180739, 1180741, 1180742, 1180743, 1180746, 1180749, 1181009, 1180751, 1188200, 1181045, 1181010, 1181008, 1181051, 1181011, 1181015, 1181055, 1181017, 1181018, 1181023, 1181019, 1181020, 1181021, 1181022, 1180745, 1181024, 1181025, 1181026, and more.