EF1 tornado, Table Rock to Humboldt, Nebraska, August 8, 2015

1. EF065 to 85 mph

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

2. EF186 to 110 mphthis tornado

   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

EF1

Date

August 8, 2015

Touchdown

8:55 PM CDT (01:55 UTC)

Lifted

9:12 PM CDT (02:12 UTC)

On the ground

17 minutes

Path length

2.2 miles (3.5 km)

Path width

238 yards (218 m)

Deaths

0

Injuries

0

Counties

Pawnee and Richardson counties

Touchdown point

40.258, -96.013

Lift-off point

40.255, -95.973

Record number

1508081955-01

5 damage points were recorded along this path by NWS OAX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 94 mph.

• northern edge flattened con.
• southern edge flattened corn
• corn and brome grass flattened.
• larger branch down 1/4 mile east of the highway.

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

A seasonably strong jet stream was moving across the northern Plains during the day on the 8th of August. During the late afternoon and evening a warm front lifted north into southeast Nebraska as low pressure associated with the jet streak moved into eastern Nebraska. Thunderstorms developed by mid evening along the warm front producing an isolated tornado and locally heavy rainfall across southeast Nebraska and into southwest Iowa.

A tornado developed in the extreme northeast part of Pawnee County from a supercell moving southeast. The tornado only occurred for a short distance in Pawnee County before moving into Richardson County. Little damage occurred in in Pawnee County but the tornado was given an EF1 rating based on how extensive the crop damage was from the tornado.

The tornado continued into Richardson County from Pawnee County. The tornado continue to produce little damage in Richardson County as there were little structures for the tornado to impact. Some tree damage was noted along the path in Richardson County as well as continued crop damage. As the tornado dissipated it made a loop near 632nd Ave and move southwest for a short time before finally dissipating.

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.

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 Slight Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 00:50 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 Omaha radar (KOAX), 122 km away, was scanning. The volume nearest the touchdown began at 01:52 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 2015 tornado in NebraskaEvery tornado in Nebraska since 1950Warnings in force in Nebraska nowThe forecast where you are

4 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.