EF0 tornado, Oak to Angus, Nebraska, May 24, 2020

1. EF065 to 85 mphthis tornado

   Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

2. EF186 to 110 mph

   Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

3. EF2111 to 135 mph

   Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.

4. EF3136 to 165 mph

   Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

5. EF4166 to 200 mph

   Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

6. EF5over 200 mph

   Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.

7. Unrated

   The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.

Rating

EF0

Date

May 24, 2020

Touchdown

6:26 PM CDT (23:26 UTC)

Lifted

6:36 PM CDT (23:36 UTC)

On the ground

10 minutes

Path length

3.3 miles (5.3 km)

Path width

40 yards (37 m)

Deaths

0

Injuries

0

Property damage

$15,000

County

Nuckolls County

Touchdown point

40.341, -97.855

Lift-off point

40.318, -97.910

Record number

2005241726-01

5 damage points were recorded along this path by NWS GID, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 85 mph.

• Image from @NEgrainguy. Looking north from Highway 4 down 4500 road.
• Potential start. WSW movement. Resident just NW of Rd 4900 & Rd Z said it did not get into Clay Cty, touched down ~2 E of Sedan.
• Possible end point. Resident on Rd 4500 between HWY 4 and Rd Y & said it did not get to HWY 4. Said there was a "mark in the field" to her west.

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

Thunderstorms brought heavy rain and a landspout to portions of south central Nebraska the evening of Sunday, May 24 into the early morning hours of Memorial Day, Monday, May 25.||Just after 6 PM CDT Sunday evening, weak thundershowers began developing along a frontal boundary that was located from near Stockton, KS to Red Cloud, NE to Shelby, NE. One of these weak thundershowers managed to spawn a landspout tornado a few miles west of Davenport, NE, in extreme northeastern portions of Nuckolls County. This landspout, unlike most, did cause some damage as nearly a dozen empty coal railroad cars were overturned. The aforementioned line of thunderstorms strengthened slightly during the evening, per radar reflectivity, before weakening with loss of daytime heating around sunset. The landspout was the only known severe weather caused by this line of thunderstorms as the main focus for severe convection remained further south across Kansas near the Interstate 70 corridor.||Showers and thunderstorms blossomed over south central Nebraska and north central Kansas after 10 PM Sunday and continued through the entire overnight. This activity remained non-severe, but very slow storm motions and abundant deep layer moisture allowed for heavy rain rates and, subsequently, pockets of very heavy rainfall. The heaviest rainfall amounts of 4 to 8 inches (per radar and ground truth observations) appeared to focus across northwest Adams County and southwest Hall County. Numerous county roads became submerged in water and impassable late Sunday night into early Monday morning. The most severe impact, however, was to a residence northwest of Kenesaw as flood water filled the basement and even encroached on the main floor, prompting their rescue early Monday morning. The rescue had to be done via air boat because so many roads in the area were under water and impassable. ||The heavy rain from Sunday night into Monday morning occurred over areas that were already saturated from recent heavy rains from May 21-23, and this likely contributed to the flooding impacts from this event. Very slow storm motions and seasonably high precipitable water values near 1.5��� were also meteorological factors to this heavy rain event. The tornado occurred in conditions fairly typical of landspouts as it was along a surface front with abundant ambient vorticity that was stretched into the vertical axis by steep low level lapse rates and sufficient 0-3 km CAPE near 100 J/kg.

A landspout tornado was confirmed via several eyewitness reports and a damage survey in northern Nuckolls County. This tornado formed along a weak frontal boundary and exhibited the classic landspout characteristics of a long, translucent condensation/dust funnel. The landspout moved southwest along the boundary for over 3 miles. The main damage along its path was the overturning of 11 empty coal railroad cars. Otherwise, damage was minimal. The maximum wind speed was estimated to be 80 MPH.

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down. One was issued for the county at another hour that day.

The county was under a severe thunderstorm watch, issued at 22:36 UTC and running to 05:00 UTC.

Every warning and watch covering the touchdown point that day, from the Iowa Environmental Mesonet's archive of National Weather Service products. Lead time is measured from the issue of the warning in force to the touchdown time in the database, both of which were recorded to the minute by different people.

The Storm Prediction Center had this point in a Marginal Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 19:55 UTC.

SPC's Day 1 convective outlook as it stood when the tornado began, read at the touchdown point. The same archive is on the radar archive.

The radiosonde launches on either side of the tornado, from the nearest station that was launching then, drawn and analyzed the way Storm Lab does: the same diagram, the same parcel and shear definitions SPC's mesoanalysis uses.

The Grand Island radar (KUEX), 47 km away, was scanning. The volume nearest the touchdown began at 23:26 UTC.

Open the radar archive at this moment, over the track

Reflectivity and velocity, decoded from the Level II archive in the browser. Volumes take a few seconds to open the first time.

Local storm reports within 60 km of the path, in the three hours either side.

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

The live radar over the trackEvery 2020 tornado in NebraskaEvery tornado in Nebraska since 1950Warnings in force in Nebraska nowThe forecast where you are

2 more were confirmed in the United States that day.

Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.