EF4 Dayton tornado, Ohio, May 27, 2019

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 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 mphthis tornado

   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

EF4

Date

May 27, 2019

Touchdown

10:41 PM EDT (02:41 UTC)

Lifted

11:13 PM EDT (03:13 UTC)

On the ground

32 minutes

Path length

18.2 miles (29.2 km)

Path width

1,050 yards (960 m)

Deaths

0

Injuries

166

Property damage

$500 million

County

Montgomery County

Touchdown point

39.824, -84.463

Lift-off point

39.758, -84.112

Record number

1905272041-01

102 damage points were recorded along this path by NWS ILN, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF3. The highest wind the damage implies is 138 mph.

• Likely Rear flank downdraft

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

Thunderstorms developed during the evening hours along a warm front lifting slowly north across the region. Many of the thunderstorms produced tornadoes, including a few strong to violent tornadoes.

The tornado initially touched down just west of Brookville and areas on the south side of Brookville sustained heavy damage, consistent with high-end EF2 wind speeds. Numerous homes suffered significant roof damage and removal, including exterior wall collapse and complete garage destruction. ||The tornado then carved a path east through Trotwood where damage consistent with EF2 wind speeds was widespread and some homes sustained damage consistent with EF3 wind speeds. Structures here again featured roof removal and exterior wall collapse. This was particularly true on the south side of Westbrook Road. A large number of homes and apartment complexes were impacted further east in Trotwood, with most of this damage consistent with high-end EF2 wind speeds.||The highest winds were estimated to have occurred in a corridor from eastern Trotwood (between Shiloh Springs Road and Westbrook Road), then southeast between Shiloh Springs Road and Turner Road, into areas along the Stillwater River/Riverside Drive area. Embedded within this zone was higher-end EF3 damage. Areas near Riverside Drive and the Stillwater River exhibited damage consistent with wind speeds of 170 mph, or lower-end EF4 damage. This damage included well-built apartment buildings that sustained complete roof and exterior wall removal. In addition, significant tree devastation was found along the Stillwater River, east of Riverside Drive, that included numerous trees that were debarked and nubbed down to the trunk.||The tornado continued southeast through Dayton and Northridge, and crossed I-75 into the Old North Dayton Area, where heavy damage continued to homes and businesses. As the tornado entered Riverside, damage began to lessen in intensity, but plenty of damage consistent with EF1 wind speeds was noted. The tornado continued further to the southeast, causing damage in a subdivision north of Burkhardt Road. The roof of an apartment building on Dodge Court was removed. This is the final known damage caused by this tornado.||An 86 year old woman died (indirect) on September 1st, 2019, in part due to injuries suffered when she was trapped in her home during the tornado.

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

10 minutes of warning. NWS ILN issued a tornado warning for this county at 02:31 UTC, 10 minutes before the tornado touched down, in force until 03:15 UTC.

The county was under a tornado watch, issued at 00:21 UTC and running to 04:34 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 Slight Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 01:18 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 Cincinnati radar (KILN), 57 km away, was scanning. The volume nearest the touchdown began at 02:40 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 2019 tornado in OhioEvery tornado in Ohio since 1950Warnings in force in Ohio nowThe forecast where you are

62 more were confirmed in the United States that day.

All 63 of them

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.