Tornadoes · United States · Indiana · 2018

EF1 tornado, Moonsville, Indiana, July 20, 2018

Name: EF1 tornado, Moonsville, Indiana, July 20, 2018
Start: 2018-07-20T19:50:00.000Z
End: 2018-07-20T19:52:00.000Z
Location: Moonsville, Indiana

This EF1 tornado ran 0.6 miles across Madison County on July 20, 2018, touching down at 3:50 PM EDT and reaching 30 yards wide. It killed nobody, and did $30,000 of property damage.

The rating scale

Tracks are drawn in the color of the rating. The Enhanced Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

EF065 to 85 mph
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mphthis tornado
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
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.
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.
EF4166 to 200 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
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.
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.

The record

Rating: EF1
Date: July 20, 2018
Touchdown: 3:50 PM EDT (19:50 UTC)
Lifted: 3:52 PM EDT (19:52 UTC)
On the ground: 2 minutes
Path length: 0.6 miles (1.0 km)
Path width: 30 yards (27 m)
Deaths: 0
Injuries: 0
Property damage: $30,000
Crop damage: $500
County: Madison County
Touchdown point: 40.195, -85.612
Lift-off point: 40.199, -85.601
Record number: 1807201350-01

The damage survey

3 damage points were recorded along this path by NWS IND, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 100 mph.

A small ranch home sustained the loss of a portion of its roof on the east side of County Road 350E. A small shed was blown over, and a couple trees were damaged as well. Debris from the adjacent farmhouse was blown onto the property.
Damage to crop field, noted path began at this point and continued E/NE towards the farm house off of Co Road 350E.

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

What the Weather Service recorded

A frontal system moved through central Indiana during the afternoon of July 20th, producing thunderstorms. Some of the storms were severe with damaging winds, large hail, and one EF-1 tornado in Madison County.

An EF-1 tornado was observed and recorded via video on Friday afternoon in Moonville in Madison County. Madison County Emergency Management, in coordination with the National Weather Service in Indianapolis, conducted a storm survey and determined a tornado touched down and destroyed a barn, caused roof damage to an adjacent home, produced tree damage, and flipped a storage shed onto its side. The track of the tornado began in a soybean field to the west-southwest of the barn. The maximum winds were estimated at 100 mph.

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

What forecasters said that day

The local office's own words before the tornado touched down, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Indianapolis, IN wrote its last area forecast discussion before the tornado touched down at Jul 20, 3:03 PM EDT, 47 minutes earlier.

Area forecast discussion, Jul 20, 3:03 PM EDT, 47 minutes before

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Hazardous weather outlook, Jul 20, 9:12 AM EDT, 6 hours 38 minutes before

Hazardous Weather Outlook
National Weather Service Indianapolis IN
912 AM EDT Fri Jul 20 2018

INZ021-028>031-035>049-051>057-060>065-067>072-211315-
Carroll-Warren-Tippecanoe-Clinton-Howard-Fountain-Montgomery-Boone-
Tipton-Hamilton-Madison-Delaware-Randolph-Vermillion-Parke-Putnam-
Hendricks-Marion-Hancock-Henry-Vigo-Clay-Owen-Morgan-Johnson-Shelby-
Rush-Sullivan-Greene-Monroe-Brown-Bartholomew-Decatur-Knox-Daviess-
Martin-Lawrence-Jackson-Jennings-
Including the cities of Lafayette, Frankfort, Kokomo,
Crawfordsville, Anderson, Muncie, Indianapolis, Terre Haute,
Shelbyville, Bloomington, Columbus, Vincennes, Bedford, and Seymour
912 AM EDT Fri Jul 20 2018

This hazardous weather outlook is for central Indiana.

.DAY ONE...Today and Tonight.

Outlook: Severe storms are expected today.

Hazards: Large hail, damaging winds, tornadoes, localized flash
flooding and frequent lightning.

Timing: Thunderstorms are possible throughout the day, but the most
likely window for severe storms is from 1 to 10 pm.

Discussion: An unseasonably strong low pressure system will bring
thunderstorms, some severe, to central Indiana today and early
tonight. Hail larger than golf ball size is likely in some of these
storms, along with damaging winds and isolated tornadoes.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

Outlook: Thunderstorms will be possible most times from Saturday
through Monday, but severe storms are not expected. There are also
small chances for storms off and on from Tuesday through Thursday,
but again none of these appear to have severe potential.

Discussion: A strong low pressure system moving through the Great
Lakes and Ohio Valley will keep chances for thunderstorms in the
forecast through Monday. After that surface fronts will bring small
off and on chances for thunderstorms through Thursday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will likely be needed this afternoon and evening.

&&

More information, along with other weather, hydrological and climate
information can be found at http://weather.gov/ind

DRT

In the hours before

Local storm report, Jul 20, 2:04 PM EDT, 1 hour 46 minutes before

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Local storm report, Jul 20, 2:23 PM EDT, 1 hour 27 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
223 PM EDT FRI JUL 20 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0202 PM     HAIL             2 E SEYMOUR             38.96N 85.84W
07/20/2018  M1.00 INCH       JACKSON            IN   PUBLIC

            TIME ESTIMATED BY RADAR.

&&

KEH

Local storm report, Jul 20, 2:43 PM EDT, 1 hour 7 minutes before

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Local storm report, Jul 20, 3:37 PM EDT, 13 minutes before

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Local storm report, Jul 20, 3:41 PM EDT, 9 minutes before

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Local storm report, Jul 20, 3:43 PM EDT, 7 minutes before

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The air that afternoon

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.

Cncnati-Daytn, OH (KILN), 00:00Z

4.2 hours after it, 176 km from the path. July 21, 2018.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.

Mixed-layer CAPE: 0 J/kg
Mixed-layer CIN: -38651 J/kg
Surface CAPE: 1 J/kg
Mixed-layer LCL: 1684 m above ground
0-6 km bulk shear: 31 kt
0-1 km bulk shear: 23 kt
0-1 km storm-relative helicity: 181 m²/s²
0-3 km storm-relative helicity: 235 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0
0-3 km lapse rate: 5.1 K/km

Open this sounding in Storm Lab

The surface observations

Anderson Municip (AID), 10 km from the path, in the two hours either side.

Time (UTC)	Temp (°F)	Dew point (°F)	Wind	Gust (kt)	Pressure (mb)	Weather
00:00 UTC

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

The radar

The Indianapolis radar (KIND), 79 km away, was scanning. The volume nearest the touchdown began at 19:50 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.

This ground now

The live radar over the track Every 2018 tornado in Indiana Every tornado in Indiana since 1950 Warnings in force in Indiana now The forecast where you are

The other tornadoes of July 20, 2018

9 more were confirmed in the United States that day.

Date	Time	Rating	Where	Path (mi)	Width (yd)	Damage
July 20	4:32 AM CDT	EF0	Camden, MO	0.1	75
July 20	1:53 PM EDT	EF0	Marshall, IN	0.5	50
July 20	12:55 PM CDT	EF0	Waushara, WI	0.1	10
July 20	2:03 PM EDT	EF0	Washington, IN	1.1	75	$50,000
July 20	2:04 PM EDT	EF1	Harrison, IN	6.0	250	$600,000
July 20	3:14 PM EDT	EF0	Wabash, IN	0.8	25
July 20	4:22 PM EDT	EF0	Miami-Dade, FL	0.2	20	$5,000
July 20	6:03 PM CDT	EF0	Metcalfe, KY	2.1	60	$125,000
July 20	9:56 PM CDT	EF1	Hart, KY	1.2	60	$200,000

What this means

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.

Sources

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