Tornadoes · United States · Indiana · 2017

EF1 tornado, Chili to Stockdale, Indiana, July 10, 2017

From Chili to Stockdale, this EF1 tornado ran 3.0 miles across Miami County on July 10, 2017, touching down at 7:58 PM EDT and reaching 100 yards wide. It killed nobody.

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.

  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.

The record

Rating
EF1
Date
July 10, 2017
Touchdown
7:58 PM EDT (23:58 UTC)
Lifted
8:06 PM EDT (00:06 UTC)
On the ground
8 minutes
Path length
3.0 miles (4.7 km)
Path width
100 yards (91 m)
Deaths
0
Injuries
0
County
Miami County
Touchdown point
40.882, -86.008
Lift-off point
40.898, -85.956
Record number
1707101758-01

The damage survey

3 damage points were recorded along this path by NWS IWX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 90 mph.

  • Large treee limbs in yard. Also some damage in corn field.
  • Rough start point of tornado. Damage noted in trees but too dense to get in to look.
  • No further damage noted. Debris from pole barn was deposited in the field, so circulation either lifted or dissipated.

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

Synoptic quasi-stationary boundary was located across the forecast area, initially across northern parts during the morning and then sagging south as an upper level wave moved into the region during the late afternoon and evening hours. A morning complex of storms caused sporadic wind damage as well as some areal flooding. Subsidence behind the system kept any further development of storms limited until the approach of the wave. This wave, combined with the front and instability advected in from central Illinois all set the stage for increasing thunderstorm development. Several supercells developed, producing long lived wall clouds and two confirmed tornadoes. IN addition, training of convection caused flash flooding in some parts of Indiana and Ohio.

A NWS survey of damage indicated a tornado touched down northeast of Denver, near the intersection of N Warsaw Trail and E County Road 800 N. The tornado remained over open fields for part of its time, doing crop damage along its path. Some trees were either snapped or uprooted. A poorly anchored, older barn was destroyed near the intersection of N County Road 600 East and E County Road 900 N. The tornado lifted shortly after crossing 900 N. Maximum winds were estimated at around 90 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 Northern Indiana wrote its last area forecast discussion before the tornado touched down at Jul 10, 7:37 PM EDT, 21 minutes earlier.

Area forecast discussion, Jul 10, 7:37 PM EDT, 21 minutes before
Area Forecast Discussion
National Weather Service Northern Indiana
737 PM EDT Mon Jul 10 2017

.SYNOPSIS...
Issued at 415 PM EDT Mon Jul 10 2017

Showers and thunderstorms will become likely tonight, especially
south of Route 30. A few of the storms may be strong to severe
with locally damaging wind gusts and large hail. In addition,
locally heavy rainfall is possible that may lead to flooding,
especially across areas which have received heavy rainfall over
the past several days. A frontal boundary will settle across
central Indiana for Tuesday with a continued chance of showers and
thunderstorms for southern portions of the area. This front will
return northward as a warm front Tuesday night into Wednesday with
a continued chance of showers and thunderstorms. Low temperatures
tonight will range from 65 to 70. High temperatures on Tuesday
will reach into the lower to mid 80s.

&&

.SHORT TERM...(This Evening through Tuesday)
Issued at 415 PM EDT Mon Jul 10 2017

Potentially active weather this evening/early overnight in terms of
severe/heavy rain potential will continue to be the primary focus for
the short term. MCV which tracked across the area earlier today
bringing heavy rain to some locations has temporarily stabilized
conditions across the area, with stable bubble now centered across
northwest Ohio/south central Lower Michigan. Moderate instability
axis resides back across the Mid Ms Rvr Valley and strong
west/southwest low level flow should allow max instability axis to
nose across central IL into portions of NE IL early this evening.
Very strong moisture convergence with this low level theta-e
surge should aid in convective initiation across northeast or
east central Illinois after 21Z or 22Z this afternoon. Given
strong westerly low level jet tonight and orientation of
instability axis to the west-southwest of the area, would expect
that storms that develop would exhibit some upwind propagation,
with Corfidi vectors showing strong northerly and even northeast
component at times. PWAT axis along this zone of strongest
moisture transport/convergence should increase into the 1.75-2.00
inch range. Warm cloud depths also increase into the 13-14k ft
range this evening which will also support very efficient rainfall
rates with any storms that form tonight. Mornings storms did lay
out an axis of 1 to 3 inch totals across portions of the Maumee
basin. Portions of northern Indiana from Marshall county to
Huntington county also were affected by very heavy rainfall of 2
to 5 inches last Friday, with saturated conditions along this
axis. With the potential of high rain rates tonight across
especially southern half of the CWA, and very wet antecedent
conditions for much of this same area, did go ahead and issue a
flash flood watch through 06Z tonight for southern portions of the
forecast area. Far southwest portions of the area did miss out on
much of the heavier rainfall this morning, but these locations
may experience max precip totals tonight which argues for
inclusion in the watch given rainrate potential.

Other concern tonight will be severe weather potential. Shear
environment remains quite favorable with effective shear values in
the 35 to 45 knot range. As mentioned, instability profiles
should improve late this afternoon, particularly across far
southwest portions of the forecast area. Storms may tend to
congeal rather quickly with an initial hail/wind threat followed
by mainly a marginal wind threat late evening. Tornadic threat now
looking very minimal due to more elevated nature of instability,
with possible exception across the far southwest where narrow
window of sfc based instability is more probably late
afternoon/early evening. As mentioned in previous discussion,
impressive 0-1 km shear values of 20-25 do lend some concern
though, but wind/hail/heavy rain appear to be greatest threats at
this time. Storms should sag southward across southern portions of
the forecast area late evening/early overnight taking effective
frontal boundary southward.

Focus for additional showers and thunderstorms on Tuesday should
shift across far southern portions of the forecast area with
southward displacement of low level boundary. Guidance does
suggest a weak short wave approaching from the Central Plains
Tuesday afternoon with some strong/severe potential across the far
south/southwest Tuesday afternoon where moderate to strong
instability axis is possible.

&&

.LONG TERM...(Tuesday Night through Monday)
Issued at 415 PM EDT Mon Jul 10 2017

Better chances of showers and thunderstorms should return
northward late Tuesday night-Wednesday as boundary returns
northward as a warm front. Have kept PoPs in low to mid chance
range until late Wed afternoon/Wed night when better pool of low
level moisture drops south in advance of next mid level wave/sfc
trough from Upper MS Valley to the Great Lakes region. Far
northern portions of the area will be on the southern periphery of
stronger mid/upper flow but given increasing moisture
depth/instability concur with Day 3 Slight Risk for late
Wednesday. Maintained low PoPs into Thursday with boundary
lagging in the area, but conditions should dry out by the end of
the work week.

&&

.AVIATION...(For the 00Z TAFS through 00Z Tuesday Evening)
Issued at 726 PM EDT Mon Jul 10 2017

Main focus for thunderstorms this evening will be near or just
south of KFWA next few hours. Satellite and radar mosaics indicate
best forcing slowly sagging south of terminals. A few stray shra
and tsra noted upstream but chances of hitting terminals low and
have kept just a VCSH at KSBN and TSRA at KFWA for just a few
hours. Light winds and moist boundary layer may lead to some fog
development overnight along with stratus. This will be slow to
dissipate Tuesday morning but trend will be toward VFR layer in
the morning or early afternoon. Could see additional tsra chances
Tuesday afternoon but best chances will be after this valid
period.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Flash Flood Watch until 2 AM EDT /1 AM CDT/ Tuesday for
     INZ012>018-020-022>027-032>034.

MI...NONE.
OH...Flash Flood Watch until 2 AM EDT Tuesday for OHZ015-016-024-025.

LM...NONE.
&&

SYNOPSIS...Marsili
SHORT TERM...Marsili
LONG TERM...Marsili
AVIATION...Lashley

Visit us at www.weather.gov/iwx

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Hazardous weather outlook, Jul 10, 5:25 PM EDT, 2 hours 33 minutes before
Hazardous Weather Outlook
National Weather Service Northern Indiana
525 PM EDT Mon Jul 10 2017

INZ004>009-MIZ077>081-OHZ001-002-004-005-112130-
St. Joseph IN-Elkhart-Lagrange-Steuben-Noble-De Kalb-Berrien-Cass MI-
St. Joseph MI-Branch-Hillsdale-Williams-Fulton OH-Defiance-Henry-
525 PM EDT Mon Jul 10 2017

This hazardous weather outlook is for portions of southwest
Michigan...northern Indiana and northwest Ohio.

.DAY ONE...Tonight

Scattered to numerous showers and thunderstorms can be expected this
evening. Widespread severe weather is not expected but an isolated
severe storm with large hail is possible.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

There is a chance of thunderstorms Tuesday night. Severe weather is
not expected.

Additional thunderstorms are expected on Wednesday and Thursday.
Severe weather may be possible but confidence is low at this time.

.SPOTTER INFORMATION STATEMENT...

Severe weather is expected to remain isolated tonight, but any
reports of isolated severe weather will be appreciated.

&&

Stay tuned to NOAA Weather Radio for further details or updates...or
check our web site at weather.gov/iwx

INZ003-012>018-020-022>027-032>034-OHZ015-016-024-025-112130-
La Porte-Starke-Pulaski-Marshall-Fulton IN-Kosciusko-Whitley-
Allen IN-White-Cass IN-Miami-Wabash-Huntington-Wells-Adams-Grant-
Blackford-Jay-Paulding-Putnam-Van Wert-Allen OH-
525 PM EDT Mon Jul 10 2017 /425 PM CDT Mon Jul 10 2017/

This hazardous weather outlook is for portions of northern Indiana
and northwest Ohio.

.DAY ONE...Tonight

Showers and thunderstorms will continue to develop tonight. Scattered
severe storms are possible with the main threat being large hail and
damaging wind gusts. In addition, localized heavy rainfall is
possible. Some areas have received recent heavy rainfall, and
additional heavy rainfall tonight may lead to flooding and flash
flooding.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

There is a chance of thunderstorms Tuesday afternoon and night. There
is a low risk of an isolated strong storm Tuesday afternoon and
evening.

Additional thunderstorms are expected on Wednesday and Thursday.
Severe weather may be possible but confidence is low at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will be needed tonight. Reports of rainfall
amounts in excess of one inch or reports of flooding will be
appreciated.

&&

Stay tuned to NOAA Weather Radio for further details or updates...or
check our web site at weather.gov/iwx

LMZ043-046-112130-
New Buffalo MI to St Joseph MI-Michigan City IN to New Buffalo MI-
525 PM EDT Mon Jul 10 2017

This hazardous weather outlook is for portions of The Nearshore
Waters of Southeastern Lake Michigan.

.DAY ONE...Tonight

Scattered thunderstorms are possible early this evening. A few storms
may produce small hail and wind gusts to 30 knots.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

Additional thunderstorms are possible Wednesday and Thursday.

&&

Stay tuned to NOAA Weather Radio for further details or updates...or
check our web site at weather.gov/iwx

In the hours before

Local storm report, Jul 10, 2:06 PM EDT, 5 hours 52 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTHERN INDIANA
206 PM EDT MON JUL 10 2017

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

1240 PM     FLOOD            LIMA                    40.74N 84.11W
07/10/2017                   ALLEN              OH   BROADCAST MEDIA

            NUMEROUS STREETS FLOODED IN AND AROUND LIMA.
            SOME STREETS ARE BEING CLOSED OFF BY POLICE.

&&

SKIP
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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.

Lincoln, IL (KILX), 12:00Z

12.0 hours before the tornado, 236 km from the path. July 10, 2017.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 12:00Z on 2017-07-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1522 joules per kilogram, CIN -136, lifted condensation level 1184 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
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.
HodographHodograph, Lincoln, IL at 12:00Z on 2017-07-10The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 151 square meters per square second, 0 to 6 km bulk shear 33 knots.193958Sfc1 km3 km6 km9 kmRMLM
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
1522 J/kg
Mixed-layer CIN
-136 J/kg
Surface CAPE
1440 J/kg
Mixed-layer LCL
1184 m above ground
0-6 km bulk shear
33 kt
0-1 km bulk shear
30 kt
0-1 km storm-relative helicity
151 m²/s²
0-3 km storm-relative helicity
155 m²/s²
Significant tornado parameter
0.3
Supercell composite
2.6
0-3 km lapse rate
5.7 K/km

Open this sounding in Storm Lab

Lincoln, IL (KILX), 00:00Z

0.0 hours before the tornado, 236 km from the path. July 11, 2017.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 00:00Z on 2017-07-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 2755 joules per kilogram, CIN -15, lifted condensation level 1493 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
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.
HodographHodograph, Lincoln, IL at 00:00Z on 2017-07-11The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 135 square meters per square second, 0 to 6 km bulk shear 27 knots.193958Sfc1 km3 km6 km9 kmRMLM
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
2755 J/kg
Mixed-layer CIN
-15 J/kg
Surface CAPE
4228 J/kg
Mixed-layer LCL
1493 m above ground
0-6 km bulk shear
27 kt
0-1 km bulk shear
20 kt
0-1 km storm-relative helicity
135 m²/s²
0-3 km storm-relative helicity
236 m²/s²
Significant tornado parameter
1.0
Supercell composite
14.2
0-3 km lapse rate
6.3 K/km

Open this sounding in Storm Lab

The surface observations

Rochester (RCR), 26 km from the path, in the two hours either side.

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

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

The radar

The Northern Indiana radar (KIWX), 57 km away, was scanning. The volume nearest the touchdown began at 23:58 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 trackEvery 2017 tornado in IndianaEvery tornado in Indiana since 1950Warnings in force in Indiana nowThe forecast where you are

The other tornadoes of July 10, 2017

6 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
July 1012:00 PM MDTUnratedGarfield, UT0.11
July 103:57 PM EDTEF0Beaver, PA3.275$30,000
July 105:45 PM CDTEF0Peoria, IL1.650
July 107:35 PM EDTEF0Meigs, OH0.450$15,000
July 107:53 PM EDTEF1Cass, IN3.8200
July 108:14 PM EDTEF0Mercer, OH6.3150$10,000

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.