Tornadoes · United States · Iowa · 2019

EF0 tornado, Spring Grove, Iowa, May 27, 2019

This EF0 tornado ran 0.1 miles across Des Moines County on May 27, 2019, touching down at 2:03 PM CDT and reaching 20 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 mphthis tornado

    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 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
EF0
Date
May 27, 2019
Touchdown
2:03 PM CDT (19:03 UTC)
Lifted
2:05 PM CDT (19:05 UTC)
On the ground
2 minutes
Path length
0.1 miles (0.2 km)
Path width
20 yards (18 m)
Deaths
0
Injuries
0
County
Des Moines County
Touchdown point
40.757, -91.195
Lift-off point
40.757, -91.193
Record number
1905271303-01

The damage survey

1 damage points were recorded along this path by NWS DVN, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 70 mph.

  • Video and picture evidence of tornado near this location. No known damage.

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

Showers and thunderstorms tracked eastward across parts of eastern Iowa and northern Illinois on Memorial Day 2019 as a low pressure system lifted a warm front through the region. | |Some of the storms produced tornadoes during the early to mid afternoon hours. Very heavy rain also fell in a short amount of time in areas. Flash flooding occurred in the Quad Cities metro, with several feet of water on many streets.

Video and picture evidence of a tornado occurring at this location. However, there have been no reports of damage near the touchdown.

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

The warnings

28 minutes of warning. NWS DVN issued a tornado warning for this county at 18:35 UTC, 28 minutes before the tornado touched down, in force until 19:15 UTC.

The county was under a tornado watch, issued at 18:25 UTC and running to 20:51 UTC.

Issued (UTC)ExpiredProductOffice
18:25 UTC20:51 UTCTornado WatchDVN
18:35 UTC19:15 UTCTornado WarningDVN
19:04 UTC19:32 UTCTornado WarningDVN
19:05 UTC22:46 UTCFlash Flood WarningDVN

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 forecast that day

The Storm Prediction Center had this point in a Enhanced Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 16:22 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 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.

Davenport, (KDVN), 12:00Z

7.1 hours before the tornado, 112 km from the path. May 27, 2019.

Skew-T log-pSkew-T log-p diagram, Davenport, at 12:00Z on 2019-05-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 54 joules per kilogram, CIN -209, lifted condensation level 828 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°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, Davenport, at 12:00Z on 2019-05-27The 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 95 square meters per square second, 0 to 6 km bulk shear 48 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
54 J/kg
Mixed-layer CIN
-209 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
828 m above ground
0-6 km bulk shear
48 kt
0-1 km bulk shear
15 kt
0-1 km storm-relative helicity
95 m²/s²
0-3 km storm-relative helicity
115 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1
0-3 km lapse rate
3.8 K/km

Open this sounding in Storm Lab

Davenport, (KDVN), 00:00Z

4.9 hours after it, 112 km from the path. May 28, 2019.

Skew-T log-pSkew-T log-p diagram, Davenport, at 00:00Z on 2019-05-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 713 joules per kilogram, CIN -1, lifted condensation level 911 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°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, Davenport, at 00:00Z on 2019-05-28The 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 174 square meters per square second, 0 to 6 km bulk shear 42 knots.19395878Sfc1 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
713 J/kg
Mixed-layer CIN
-1 J/kg
Surface CAPE
2392 J/kg
Mixed-layer LCL
911 m above ground
0-6 km bulk shear
42 kt
0-1 km bulk shear
26 kt
0-1 km storm-relative helicity
174 m²/s²
0-3 km storm-relative helicity
275 m²/s²
Significant tornado parameter
0.7
Supercell composite
9.3
0-3 km lapse rate
7.0 K/km

Open this sounding in Storm Lab

The surface observations

Burlington (BRL), 6 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
17:10 UTC190° 11 kt1009.5
17:15 UTC180° 11 kt1009.8
17:20 UTC180° 9 kt1009.8
17:28 UTC7569190° 6 kt1009.8
17:30 UTC190° 5 kt1009.8
17:35 UTC190° 8 kt1009.8
17:40 UTC200° 7 kt1009.5
17:50 UTC200° 8 kt1009.5
17:53 UTC7669210° 10 kt1009.5
17:55 UTC200° 8 kt1009.5
18:05 UTC7770210° 7 kt1008.8-RA
18:10 UTC190° 5 kt1008.5-RA
18:15 UTC200° 5 kt1008.5-RA
18:25 UTC180° 2 kt1007.8-RA
18:30 UTC180° 4 kt1007.8-RA
18:35 UTC150° 4 kt1007.8-RA
18:41 UTC757090° 4 kt1007.1VCTS RA
18:45 UTC150° 4 kt1007.1+RA BR
18:50 UTC220° 4 kt1007.8+RA BR
18:53 UTC7370 4 kt1007.5VCTS +RA FG
19:00 UTC7367180° 8 kt271007.5+TSRA
19:03 UTC7467150° 8 kt271007.1-TSRA
19:05 UTC 8 kt1007.1-RA
19:07 UTC7268160° 11 kt181007.1-TSRA BR
19:10 UTC 14 kt1007.5-RA
19:20 UTC190° 5 kt1007.5-RA
19:25 UTC300° 8 kt1007.5RA BR
19:27 UTC7268330° 10 kt161007.5-RA BR
19:30 UTC350° 8 kt1007.1-RA BR
19:35 UTC300° 5 kt1007.1-RA
19:40 UTC300° 4 kt1007.1-RA
19:45 UTC280° 10 kt171007.8-RA BR
19:50 UTC280° 8 kt1007.5-RA
19:53 UTC7368280° 10 kt171007.5
20:00 UTC260° 8 kt1007.5
20:05 UTC260° 7 kt1007.5
20:10 UTC260° 8 kt1007.1
20:20 UTC260° 7 kt1007.1
20:25 UTC260° 5 kt1007.1
20:35 UTC270° 4 kt1006.8
20:40 UTC260° 5 kt1006.4
20:45 UTC240° 7 kt1006.4
20:53 UTC7870250° 6 kt1006.4
20:55 UTC250° 7 kt1006.4
21:00 UTC240° 7 kt1006.4

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

The radar

The Quad Cities radar (KDVN), 108 km away, was scanning. The volume nearest the touchdown began at 19:04 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.

What was reported nearby

Local storm reports within 60 km of the path, in the three hours either side.

Time (UTC)ReportWhereCountyRemark
18:36 UTCTORNADO1 S HoughtonLee, IAEF1 TORNADO TOUCHED DOWN SOUTH OF HOUGHTON STRIKING A METAL BUILDING. THE ROOF WAS REMOVED FROM THE BUILDING AND THE WINDS WERE ESTIMATED AT 100 MPH.
18:45 UTCTORNADO1 S HoughtonLee, IATWO BARNS DOWN.
19:03 UTCTORNADO1 Wsw Spring GroveDes Moines, IASPOTTER OBSERVED A TORNADO TOUCH DOWN LOOKING NORTH OF LOCATION HEADING TOWARD SPRING GROVE WHILE ON PHONE WITH NWS. TIME EXACT.
19:05 UTCTORNADO3 Sw BurlingtonDes Moines, IAVIDEO AND PICTURE EVIDENCE OF A TORNADO OCCURRING AT THIS LOCATION. HOWEVER, THERE HAVE BEEN NO REPORTS OF DAMAGE NEAR THE TOUCHDOWN.
19:05 UTCTORNADO3 Sw BurlingtonDes Moines, IASPOTTER OBSERVED A TORNADO TOUCH DOWN LOOKING NORTH OF LOCATION HEADING TOWARD SPRING GROVE WHILE ON PHONE WITH NWS. TIME EXACT. DO HAVE PICTURE AND VIDEO EVIDENCE OF THE TORNADO. HOWEVER, NO DAMAGE WAS REPORTED NEAR THE
19:15 UTCHEAVY RAIN 1.44 Se Mt HamillLee, IARAINFALL IN 1/2 HOUR.
19:30 UTCFLASH FLOOD1 Nw BurlingtonDes Moines, IAROOSEVELT AVE (HWY 61) CLOSED DUE TO HIGH WATER OVER ROAD FOR APPROX 45 MIN.

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

This ground now

The live radar over the trackEvery 2019 tornado in IowaEvery tornado in Iowa since 1950Warnings in force in Iowa nowThe forecast where you are

The other tornadoes of May 27, 2019

62 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 271:10 AM CDTEF0Potter, TX1.650
May 271:13 AM CDTEF0Mitchell, KS0.025$25,000
May 2712:07 PM CDTEF0Freeborn, MN0.650
May 2712:23 PM CDTEF1Floyd, IA9.8105$625,000
May 271:10 PM CDTEF0Chickasaw, IA4.125$35,000
May 271:23 PM CDTEF0Fillmore, MN0.225$15,000
May 271:25 PM CDTEF1Howard, IA12.695$1.3 million
May 271:25 PM CDTEF3Van Buren, IA7.3100
May 271:29 PM CDTEF0Fillmore, MN0.215$5,000
May 271:36 PM CDTEF1Lee, IA0.520
May 271:40 PM CDTEF0Fillmore, MN0.225$20,000
May 271:47 PM CDTEF0Kendall, IL1.030
May 271:49 PM CDTEF0Howard, IA to MN6.230$202,000
May 272:04 PM CDTEF0Will, IL3.2300
May 273:15 PM CDTEF0Knox, IL0.110
May 273:02 PM MDTEF0Morgan, CO0.025
May 273:22 PM MDTEF0Logan, CO0.025
May 274:27 PM CDTEF0Lee, IL0.730
May 274:27 PM CDTEF0Cook, IL0.850
May 274:30 PM CDTEF0Lake, IN1.1100
May 274:38 PM CDTEF0Woodford, IL0.110
May 273:40 PM MDTEF0Elmore, ID0.510
May 274:35 PM MDTEF0Logan, CO0.025
May 274:44 PM MDTEF0Sedgwick, CO0.050
May 274:53 PM MDTEF0Adams, CO0.025
May 275:04 PM MDTEF0Weld, CO0.025
May 275:25 PM MDTUnratedYuma, CO0.010
May 277:34 PM EDTEF1Miami, IN0.650
May 277:51 PM EDTEF3Fulton, IN13.7800
May 275:51 PM MDTEF0Phillips, CO0.025
May 278:05 PM EDTEF2Madison, IN5.91001$150,000
May 278:10 PM EDTEF2Grant, IN4.1150
May 278:26 PM EDTEF1Wabash, IN1.950
May 278:29 PM EDTEF1Henry, IN0.250$20,000
May 276:31 PM MDTEF0Phillips, CO0.025
May 278:39 PM EDTEF1Henry, IN2.5200$40,000
May 276:43 PM MDTEF0Chase, NE0.225
May 278:59 PM EDTEF3Wells, IN12.81,2002
May 277:23 PM MDTEF1Chase, NE5.5250$200,000
May 277:37 PM MDTEF0Chase, NE0.150$15,000
May 279:48 PM EDTEF1Darke, OH1.4100$100,000
May 2710:02 PM EDTEF3Mercer, OH10.825018$15 million
May 2710:04 PM EDTEF1Darke, OH0.5200$500,000
May 278:05 PM MDTEF0Chase, NE0.225$15,000
May 2710:25 PM EDTEF3Darke, OH10.51,3201$10 million
May 2710:33 PM EDTEF1Auglaize, OH1.3150$500,000
May 2710:41 PM EDTEF4Dayton tornado, OH18.21,050166$500 million
May 2710:47 PM EDTEF0Auglaize, OH4.0150$50,000
May 2710:47 PM EDTEF0Miami, OH5.6200$50,000
May 2711:01 PM EDTEF0Auglaize, OH0.230$10,000
May 2711:08 PM EDTEF0Miami, OH1.150$10,000
May 2711:12 PM EDTEF3Montgomery, OH9.91,230$51 million
May 2711:19 PM EDTEF0Miami, OH3.050$70,000
May 2711:28 PM EDTEF0Hardin, OH2.050$25,000
May 2711:34 PM EDTEF2Montgomery, OH7.6440$1.0 million
May 2710:45 PM CDTEF0Nuckolls, NE0.075$75,000
May 2711:48 PM EDTEF1Greene, OH5.8250$53,000
May 2712:23 AM EDTEF0Greene, OH4.2250$200,000
May 2712:57 AM EDTEF1Pickaway, OH3.8150$1.0 million
May 271:09 AM EDTEF1Pickaway, OH1.675$1.5 million

All 63 of them

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.