Tornadoes · United States · Illinois · 2015
EF0 tornado, Sterling Arpt, Illinois, July 16, 2015
This EF0 tornado ran 0.6 miles across Whiteside County on July 16, 2015, touching down at 8:48 PM CDT and reaching 10 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
- July 16, 2015
- Touchdown
- 8:48 PM CDT (01:48 UTC)
- Lifted
- 8:49 PM CDT (01:49 UTC)
- On the ground
- 1 minutes
- Path length
- 0.6 miles (0.9 km)
- Path width
- 10 yards (9 m)
- Deaths
- 0
- Injuries
- 0
- County
- Whiteside County
- Touchdown point
- 41.720, -89.700
- Lift-off point
- 41.728, -89.691
- Record number
- 1507161948-01
What the Weather Service recorded
A wave on a northward moving warm front produced scattered thunderstorms along the boundary. Low level shear was favorable for severe weather and tornadoes.
An EF0 tornado with peak winds estimated at 80 mph touched down 4 miles south of Rock Falls. It traveled about 0.55 miles in open country. According to spotter account and video, it was on the ground for about 1 minute 20 seconds. No damage was reported.
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 |
|---|---|---|---|
| 09:00 UTC | 15:33 UTC | Flash Flood Watch | DVN |
| 23:57 UTC | 00:33 UTC | Tornado Warning | DVN |
| 01:05 UTC | 04:30 UTC | Flash Flood Warning | DVN |
| 18:00 UTC | 17:03 UTC | Heat Advisory | 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, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 00:49 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), 00:00Z
1.8 hours before the tornado, 68 km from the path. July 17, 2015.
- Mixed-layer CAPE
- 883 J/kg
- Mixed-layer CIN
- -30 J/kg
- Surface CAPE
- 1247 J/kg
- Mixed-layer LCL
- 796 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km bulk shear
- 22 kt
- 0-1 km storm-relative helicity
- 141 m²/s²
- 0-3 km storm-relative helicity
- 181 m²/s²
- Significant tornado parameter
- 0.5
- Supercell composite
- 3.0
- 0-3 km lapse rate
- 5.4 K/km
Davenport, (KDVN), 12:00Z
10.2 hours after it, 68 km from the path. July 17, 2015.
- Mixed-layer CAPE
- 1964 J/kg
- Mixed-layer CIN
- -63 J/kg
- Surface CAPE
- 531 J/kg
- Mixed-layer LCL
- 968 m above ground
- 0-6 km bulk shear
- 36 kt
- 0-1 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- 72 m²/s²
- 0-3 km storm-relative helicity
- 83 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 3.0
- 0-3 km lapse rate
- 4.1 K/km
The radar
The Quad Cities radar (KDVN), 75 km away, was scanning. The volume nearest the touchdown began at 01:49 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 |
|---|---|---|---|---|
| 00:05 UTC | FUNNEL CLOUD | Fulton | Whiteside, IL | |
| 00:10 UTC | TSTM WND DMG | Port Byron | Rock Island, IL | PROPERTY AND TREE DAMAGE NEAR 94TH AVE IN PORT BYRON - REPORT VIA SOCIAL MEDIA |
| 00:10 UTC | TORNADO 1 | 1 E Port Byron | Rock Island, IL | PROPERTY AND TREE DAMAGE ALONG 94TH AVE. RATING EF-1. ESTIMATED PEAK WIND 105 MPH. PATH LENGTH 1.2 MILES. MAX WIDTH 200 YARDS. START TIME 700 PM CDT. START LOCATION 0.8 NE PORT BYRON IL. END TIME 710 PM CDT. END LOCATION |
| 00:10 UTC | TORNADO | 1 E Port Byron | Rock Island, IL | PROPERTY AND TREE DAMAGE ALONG 94TH AVE. |
| 00:10 UTC | TORNADO | 1 E Port Byron | Rock Island, IL | PROPERTY AND TREE DAMAGE ON 94TH AVE...TIME ESTIMATED FROM RADAR. |
| 01:00 UTC | HEAVY RAIN 1.95 | Nw Erie | Whiteside, IL | 1.95 RAIN TOTAL IN LESS THAN 3 HOURS. |
| 01:40 UTC | FLASH FLOOD | Prophetstown | Whiteside, IL | MANY STREETS REPORTED TO BE FLOODED WITH SEVERAL INCHES OF WATER IN PROPHETSTOWN. |
| 01:49 UTC | TORNADO 0 | 4 S Rock Falls | Whiteside, IL | RATING EF-0. ESTIMATED PEAK WIND OF 80 MPH. MAX WIDTH IS 10 YARDS AND IT WAS ON THE GROUND FOR 0.55 MILES. THE START TIME WAS 848 PM CDT AND THE END TIME WAS 849 PM CDT. THE TORNADO WAS ON GROUND 4 MILES SOUTH OF ROCKFAL |
From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.
This ground now
The live radar over the trackEvery 2015 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are
The other tornadoes of July 16, 2015
8 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| July 16 | 5:14 PM CDT | EF0 | Henry, IA | 1.5 | 10 | |||
| July 16 | 6:09 PM CDT | EF1 | Henderson, IL | 0.8 | 100 | $25,000 | ||
| July 16 | 6:49 PM CDT | EF1 | Warren, IL | 1.4 | 50 | $2,000 | ||
| July 16 | 7:00 PM CDT | EF1 | Rock Island, IL | 1.1 | 200 | $2,000 | ||
| July 16 | 7:09 PM CDT | EF2 | Warren, IL | 1.7 | 300 | $150,000 | ||
| July 16 | 7:13 PM CDT | EF2 | Warren, IL | 6.0 | 700 | 1 | $1.5 million | |
| July 16 | 8:34 PM CDT | EF0 | Mitchell, IA | 2.1 | 40 | $40,000 | ||
| July 16 | 11:39 PM CDT | EF2 | Tazewell, IL | 2.4 | 250 | 1 | $1.2 million |
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.