Tornadoes · United States · Tennessee · 2009
EF0 tornado, Forest Mill, Tennessee, April 13, 2009
This EF0 tornado ran 0.5 miles across Coffee County on April 13, 2009, touching down at 8:45 PM CDT and reaching 30 yards wide. It killed nobody, and did $12,000 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 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 13, 2009
- Touchdown
- 8:45 PM CDT (01:45 UTC)
- Lifted
- 8:54 PM CDT (01:54 UTC)
- On the ground
- 9 minutes
- Path length
- 0.5 miles (0.8 km)
- Path width
- 30 yards (27 m)
- Deaths
- 0
- Injuries
- 0
- Property damage
- $12,000
- County
- Coffee County
- Touchdown point
- 35.515, -86.084
- Lift-off point
- 35.517, -86.073
- Record number
- 0904131945-01
What the Weather Service recorded
A line of thunderstorms moved through eastern portions of Middle Tennessee, resulting in a tornado touchdown and severe hail in Coffee County.
The tornado touched down near the intersection of Highway 53 and Riddle|Road in Manchester. It then traveled northeast and ended just east of|Riddle Road. The tornado damage path was a half mile long and approximately 30 yards wide.||The start of the damage was found off Highway 53 near Riddle Road.|Numerous trees were found twisted and snapped with a couple of |shallow rooted large trees uprooted along the damage path. Also, a|home had some damage to the roof. Based on the damage found, |maximum estimated wind speeds were 70 mph which corresponds to an|EF-0 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 |
|---|---|---|---|
| 18:00 UTC | 21:44 UTC | Tornado Watch | OHX |
| 01:41 UTC | 02:15 UTC | Severe Thunderstorm Warning | OHX |
| 01:49 UTC | 02:15 UTC | Tornado Warning | OHX |
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 01:02 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.
Nashville Metro, TN (KBNA), 00:00Z
1.8 hours before the tornado, 83 km from the path. April 14, 2009.
- Mixed-layer CAPE
- 703 J/kg
- Mixed-layer CIN
- -5 J/kg
- Surface CAPE
- 484 J/kg
- Mixed-layer LCL
- 752 m above ground
- 0-6 km bulk shear
- 64 kt
- 0-1 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- 34 m²/s²
- 0-3 km storm-relative helicity
- 159 m²/s²
- Significant tornado parameter
- 0.5
- Supercell composite
- 2.0
- 0-3 km lapse rate
- 7.3 K/km
Nashville Metro, TN (KBNA), 12:00Z
10.2 hours after it, 83 km from the path. April 14, 2009.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- -80226 J/kg
- Surface CAPE
- 0 J/kg
- Mixed-layer LCL
- 727 m above ground
- 0-6 km bulk shear
- 37 kt
- 0-1 km bulk shear
- 17 kt
- 0-1 km storm-relative helicity
- -32 m²/s²
- 0-3 km storm-relative helicity
- 51 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 4.2 K/km
The surface observations
Smyrna (MQY), 68 km from the path, in the two hours either side.
| Time (UTC) | Temp (°F) | Dew point (°F) | Wind | Gust (kt) | Pressure (mb) | Weather |
|---|---|---|---|---|---|---|
| 23:56 UTC | 65 | 58 | 0° 0 kt | 1005.8 | ||
| 00:56 UTC | 61 | 56.84 | 130° 6 kt | 1006.4 | ||
| 01:56 UTC | 61 | 58 | 0° 0 kt | 1006.8 | VCTS | |
| 02:20 UTC | 62.6 | 59 | 250° 10 kt | 1007.8 | +TSRA BR | |
| 02:35 UTC | 60.8 | 55.4 | 250° 6 kt | 1007.8 | VCTS | |
| 02:56 UTC | 59 | 54 | 0° 0 kt | 1007.5 |
From the Iowa Environmental Mesonet's archive of airport observations.
The radar
The Northeast Alabama radar (KHTX), 65 km away, was scanning. The volume nearest the touchdown began at 01:45 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 |
|---|---|---|---|---|
| 01:40 UTC | HAIL 1 | Manchester | Coffee, TN | |
| 01:49 UTC | TORNADO | 10 Ene Manchester | Coffee, TN | SPOTTER REPORTED A BRIEF TORNADO TOUCHDOWN ABOUT 3 MILES SOUTH OF HIGHWAY 55 BETWEEN SUMMITVILLE AND VIOLA |
| 02:29 UTC | HAIL 1 | 5 S Estill Springs | Franklin, TN | QUARTER SIZED HAIL REPORTED IN WINCHESTER. |
From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.
This ground now
The live radar over the trackEvery 2009 tornado in TennesseeEvery tornado in Tennessee since 1950Warnings in force in Tennessee nowThe forecast where you are
The other tornadoes of April 13, 2009
5 more were confirmed in the United States that day.
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.