Tornadoes · United States · Iowa · 2014
EF0 tornado, Lisbon Mohn Arpt, Iowa, April 27, 2014
This EF0 tornado ran 0.5 miles across Linn County on April 27, 2014, touching down at 4:40 PM CDT and reaching 50 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.
EF065 to 85 mphthis tornado
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mph
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
- EF0
- Date
- April 27, 2014
- Touchdown
- 4:40 PM CDT (21:40 UTC)
- Path length
- 0.5 miles (0.8 km)
- Path width
- 50 yards (46 m)
- Deaths
- 0
- Injuries
- 0
- County
- Linn County
- Touchdown point
- 41.962, -91.382
- Lift-off point
- 41.962, -91.382
- Record number
- 1404271540-02
What the Weather Service recorded
A powerful storm system lifted into the central Plains on the afternoon of April 27, 2014 and brought several rounds of showers and thunderstorms to eastern Iowa. Some of these thunderstorms were severe and produced damaging winds and an isolated hail report. There was one confirmed tornado during the event that moved across Keokuk, Iowa and Johnson Counties with two fatalities. In addition to the damaging winds rainfall totals ranged from a half an inch to around 1 inch in a little under an hour.
Several spotters reported a tornado between Mt. Vernon and Springville. Traffic lights were knocked out by the tornado. Radar signatures show that this tornado shares the same parent storm circulation that can be traced back to the Keokuk County tornado.
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
The warnings
No tornado warning for this county appears in the archive as in force at the moment the tornado touched down. One was issued for the county at another hour that day.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 21:13 UTC | 22:00 UTC | Severe Thunderstorm Warning | DVN |
| 21:23 UTC | 21:31 UTC | Tornado Warning | DVN |
| 21:43 UTC | 21:53 UTC | Tornado Warning | DVN |
| 21:52 UTC | 22:05 UTC | Severe Thunderstorm Warning | DVN |
| 00:00 UTC | 23:03 UTC | Flood Watch | DVN |
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 Slight Risk. The outlook in force was issued at 20:00 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
9.7 hours before the tornado, 82 km from the path. April 27, 2014.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- -105870 J/kg
- Surface CAPE
- 0 J/kg
- Mixed-layer LCL
- 1230 m above ground
- 0-6 km bulk shear
- 43 kt
- 0-1 km bulk shear
- 34 kt
- 0-1 km storm-relative helicity
- 467 m²/s²
- 0-3 km storm-relative helicity
- 555 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 1.7 K/km
The surface observations
Cedar Rapids (CID), 30 km from the path, in the two hours either side.
| Time (UTC) | Temp (°F) | Dew point (°F) | Wind | Gust (kt) | Pressure (mb) | Weather |
|---|---|---|---|---|---|---|
| 19:52 UTC | 67 | 46 | 100° 25 kt | 35 | 1001.7 | |
| 20:52 UTC | 66 | 45 | 100° 21 kt | 30 | 1000 | |
| 21:08 UTC | 67 | 45 | 100° 28 kt | 37 | 999.7 | VCTS |
| 21:24 UTC | 60 | 51 | 210° 26 kt | 46 | 1004.7 | VCTS -RA SQ |
| 21:31 UTC | 57 | 53 | 210° 15 kt | 46 | 1004.4 | +TSRA BR |
| 21:33 UTC | 60 | 53 | 270° 19 kt | 32 | 1004.1 | +TSRA |
| 21:38 UTC | 59 | 54 | 290° 7 kt | 32 | 1004.1 | TSRA |
| 21:52 UTC | 58 | 55 | 360° 4 kt | 1004.1 | VCTS -RA BR | |
| 22:10 UTC | 56 | 55 | 90° 9 kt | 1003.7 | RA BR | |
| 22:17 UTC | 55 | 55 | 90° 13 kt | 1003.7 | VCTS -RA | |
| 22:52 UTC | 55 | 55 | 100° 15 kt | 22 | 1004.1 | VCTS -RA |
From the Iowa Environmental Mesonet's archive of airport observations.
The radar
The Quad Cities radar (KDVN), 77 km away, was scanning. The volume nearest the touchdown began at 21:41 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) | Report | Where | County | Remark |
|---|---|---|---|---|
| 21:05 UTC | HAIL 0.25 | Marengo | Iowa, IA | PEA SIZE HAIL. |
| 21:09 UTC | TSTM WND GST 70 | 4 N Marengo | Iowa, IA | WIND GUSTS ESTIMATED TO BE 60 TO 70 MPH. SMALL BRANCHES COMING DOWN. |
| 21:11 UTC | TSTM WND GST 65 | Tiffin | Johnson, IA | ON INTERSTATE 80 WEST OF CORALVILLE NEAR TIFFIN. |
| 21:20 UTC | TSTM WND DMG | Norway | Benton, IA | TWO BUILDINGS DAMAGED. WIND MEASURED AT 89 MPH FROM A DAVIS INSTRUMENT SYSTEM. |
| 21:22 UTC | TSTM WND DMG | 2 Ne Fairfax | Linn, IA | SEVERAL TREES SNAPPED OR UPROOTED. TEN INCH DIAMETER TREE SNAPPED. SEVERAL MEDIUM SIZE BRANCHES DOWN. WINDS ESTIMATED AT 60 MPH. |
| 21:25 UTC | TSTM WND DMG | Blairstown | Benton, IA | BUILDING BLOWN DOWN. POWER LINES DOWN. SEMI JACKNIFED ON HIGHWAY 30. |
| 21:29 UTC | HAIL 0.75 | Hills | Johnson, IA | PENNY SIZED HAIL AND SMALLER. FORMER SPOTTER JH286. |
| 21:32 UTC | HEAVY RAIN 0.91 | Iowa City | Johnson, IA | 40 MINUTE RAINFALL. |
| 21:33 UTC | TSTM WND DMG | Iowa City | Johnson, IA | POWER POLE BLOWN DOWN NEAR THE EMERGENCY DISPATCH CENTER. |
| 21:33 UTC | TSTM WND GST 65 | Iowa City | Johnson, IA | |
| 21:33 UTC | HAIL 0.75 | Iowa City | Johnson, IA | PENNY SIZE HAIL. |
| 21:34 UTC | HAIL 0.25 | Iowa City | Johnson, IA | SIX REPORTS OF PEA SIZED HAIL IN IOWA CITY OVER THE PAST 5 MINUTES. RELAYED BY SKYWARN SPOTTER. ALSO HEAVY RAIN OF 0.91 INCHES IN 40 MINUTES. |
| 21:41 UTC | TORNADO | 2 Ne Mount Vernon | Linn, IA | SPOTTERS REPORTED TORNADO ON GROUND NEAR LINN RIDGE ROAD AND HIGHWAY 1. IT WAS LIFTING BACK UP BY 442 PM. RELAYED BY EMERGENCY MANAGEMENT. |
| 21:42 UTC | TORNADO | Springville | Linn, IA | TORNADO TOUCHDOWN JUST SOUTH OF SPRINGVILLE. |
| 22:00 UTC | TSTM WND DMG | Atkins | Benton, IA | SHINGLES OFF A HOUSE. POWER LINES DOWN BLOCKING HIGHWAY 30 BETWEEN 218 AND 21ST AVENUE. TRAFFIC BEING RE-ROUTED.REPORT RELAYED BY KWWL-TV. |
| 22:00 UTC | HEAVY RAIN 1.19 | Iowa City Municipal Air | Johnson, IA | 1 HOUR RAINFALL. |
| 22:24 UTC | TSTM WND DMG | Baldwin | Jackson, IA | TREE DOWN IN BALDWIN. TIME ESTIMATED. |
From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.
This ground now
The live radar over the trackEvery 2014 tornado in IowaEvery tornado in Iowa since 1950Warnings in force in Iowa nowThe forecast where you are
The other tornadoes of April 27, 2014
16 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| April 27 | 12:51 PM CDT | EF0 | Lafayette, MO | 2.4 | 50 | |||
| April 27 | 2:26 PM CDT | EF0 | Franklin, NE | 0.1 | 35 | |||
| April 27 | 3:20 PM CDT | EF1 | Wapello, IA | 45.7 | 1,600 | 2 | $25,000 | |
| April 27 | 4:40 PM CDT | EF0 | York, NE | 0.1 | 45 | |||
| April 27 | 5:17 PM CDT | EF0 | Polk, NE | 0.4 | 45 | |||
| April 27 | 5:29 PM CDT | EF2 | Ottawa, OK to KS | 11.4 | 325 | 1 | 37 | $13 million |
| April 27 | 5:31 PM CDT | EF1 | LeFlore, OK | 1.5 | 250 | |||
| April 27 | 5:40 PM CDT | EF2 | Bourbon, KS | 16.1 | 400 | $500,000 | ||
| April 27 | 6:15 PM CDT | EF0 | Vernon, MO | 0.3 | 100 | |||
| April 27 | 7:06 PM CDT | EF4 | Mayflower–Vilonia tornado, AR | 41.1 | 1,320 | 16 | 193 | $223 million |
| April 27 | 5:30 PM PDT | EF0 | Pierce, WA | 0.2 | 25 | $5,000 | ||
| April 27 | 8:16 PM CDT | EF2 | White, AR | 7.3 | 880 | 1 | $1.4 million | |
| April 27 | 8:38 PM CDT | EF0 | White, AR | 1.6 | 250 | $100,000 | ||
| April 27 | 8:43 PM CDT | EF1 | White, AR | 5.3 | 100 | $110,000 | ||
| April 27 | 8:52 PM CDT | EF1 | Independence, AR | 0.8 | 50 | $20,000 | ||
| April 27 | 11:45 PM CDT | EF0 | Douglas, MO | 0.9 | 100 | $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.