EF3 tornado, Swayzee to Arcana, Indiana, March 31, 2023

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 mphthis tornado

   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

EF3

Date

March 31, 2023

Touchdown

11:42 PM EDT (03:42 UTC)

Lifted

11:47 PM EDT (03:47 UTC)

On the ground

5 minutes

Path length

6.3 miles (10.2 km)

Path width

200 yards (183 m)

Deaths

0

Injuries

0

County

Grant County

Touchdown point

40.481, -85.593

Lift-off point

40.537, -85.499

Record number

2303312142-01

57 damage points were recorded along this path by NWS IWX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF3. The highest wind the damage implies is 140 mph.

• Tree uprooted. Property and other trees ok.
• Building failed as 6x6 posts for wall supports snapped at the base. South facing garage door failed on sw side of building with subsequent roof failure. Wall bottom plate was not fastened to concrete pad. Likely inflow winds into developing tornado at this point north.
• Wall and roof debris scattered into field to the east anout 100 plus yards.
• Large out building with 2 of 4 walls collapsed. Debris spread to the south and east. Home to the NW 20 yards untouched. Garage to w of outbuilding lost some siding and roof covering.

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

Thunderstorms developing in the evening of March 31 resulted in multiple weather hazards. Hail nearly 2 inches in diameter was observed, trees were downed from thunderstorm wind, and flooding occurred from heavy rain rates. In the days that followed, storm damage surveys teams confirmed multiple tornadoes has moved through.

This tornado developed just south of 300 S west of Swayzee and tracked rapidly|east through downtown Swayzee, ending just east of 600 W east of town. Numerous|homes and building sustained minor to moderate damage including roof damage to |several businesses and the high school. Numerous trees and power poles in and|around town were snapped or uprooted.

This intense tornado developed just southeast of Gas City and tracked rapidly|northeast before dissipating just east of 900 E and just south of 100 S. Numerous|homes sustained minor to major damage along this track with extensive tree damage|noted in many areas. The hardest hit area was just east off Blackthorn Drive where|several homes were destroyed. Tornado weakened as it crossed I-69 yet continued to|produce varying degrees of damage to barns, trees and homes before it dissipated.

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

22 minutes of warning. NWS IWX issued a tornado warning for this county at 03:20 UTC, 22 minutes before the tornado touched down, in force until 03:45 UTC.

The county was under a tornado watch, issued at 00:00 UTC and running to 04:36 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 Moderate Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 01:04 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.

Marion (MZZ), 12 km from the path, in the two hours either side.

From the Iowa Environmental Mesonet's archive of airport observations.

The Northern Indiana radar (KIWX), 95 km away, was scanning. The volume nearest the touchdown began at 03:39 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 2023 tornado in IndianaEvery tornado in Indiana since 1950Warnings in force in Indiana nowThe forecast where you are

126 more were confirmed in the United States that day.

All 127 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.