Tornadoes · United States · Tennessee · 2009

EF0 tornado, Dunlap, Tennessee, March 28, 2009

This EF0 tornado ran 1.0 miles across Sequatchie County on March 28, 2009, touching down at 8:53 PM CDT and reaching 30 yards wide. It killed nobody, and did $30,000 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.

  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
March 28, 2009
Touchdown
8:53 PM CDT (01:53 UTC)
Lifted
8:55 PM CDT (01:55 UTC)
On the ground
2 minutes
Path length
1.0 miles (1.6 km)
Path width
30 yards (27 m)
Deaths
0
Injuries
0
Property damage
$30,000
County
Sequatchie County
Touchdown point
35.350, -85.360
Lift-off point
35.350, -85.360
Record number
0903281953-01

What the Weather Service recorded

A strong cold front extending south from an Ohio Valley surface low moved through Southeast Tennessee during the evening and produced a line of severe thunderstoms. Moderate instability and southeasterly flow ahead of the line of storms aided the development of an isolated supercell thunderstorm. A brief...weak tornado passed just southeast of Dunlap, Tennessee during the late evening hours.

An EF0 tornado with winds estimated around 80 mph was observed near Lewis Road. Several trees were reported down along with significant damage to a house garage.

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.

The county was under a tornado watch, issued at 00:44 UTC and running to 04:00 UTC.

Issued (UTC)ExpiredProductOffice
00:44 UTC04:00 UTCTornado WatchMRX
01:09 UTC02:15 UTCSevere Thunderstorm WarningMRX

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 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 00:59 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

1.9 hours before the tornado, 142 km from the path. March 29, 2009.

Skew-T log-pSkew-T log-p diagram, Nashville Metro, TN at 00:00Z on 2009-03-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 471 joules per kilogram, CIN -29, lifted condensation level 1203 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, Nashville Metro, TN at 00:00Z on 2009-03-29The 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 315 square meters per square second, 0 to 6 km bulk shear 80 knots.1939587897117Sfc1 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
471 J/kg
Mixed-layer CIN
-29 J/kg
Surface CAPE
537 J/kg
Mixed-layer LCL
1203 m above ground
0-6 km bulk shear
80 kt
0-1 km bulk shear
30 kt
0-1 km storm-relative helicity
315 m²/s²
0-3 km storm-relative helicity
366 m²/s²
Significant tornado parameter
0.8
Supercell composite
4.1
0-3 km lapse rate
7.7 K/km

Open this sounding in Storm Lab

Nashville Metro, TN (KBNA), 12:00Z

10.1 hours after it, 142 km from the path. March 29, 2009.

Skew-T log-pSkew-T log-p diagram, Nashville Metro, TN at 12:00Z on 2009-03-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -93805, lifted condensation level 903 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 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, Nashville Metro, TN at 12:00Z on 2009-03-29The 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 259 square meters per square second, 0 to 6 km bulk shear 51 knots.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
-93805 J/kg
Surface CAPE
11 J/kg
Mixed-layer LCL
903 m above ground
0-6 km bulk shear
51 kt
0-1 km bulk shear
30 kt
0-1 km storm-relative helicity
259 m²/s²
0-3 km storm-relative helicity
240 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
3.9 K/km

Open this sounding in Storm Lab

The radar

The Northeast Alabama radar (KHTX), 81 km away, was scanning. The volume nearest the touchdown began at 01:53 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
01:45 UTCTSTM WND DMG3 Sw DunlapSequatchie, TNSEVERAL TREES DOWN.
01:45 UTCTSTM WND DMG6 Ssw DunlapSequatchie, TNONE TREE DOWN ON FRANK TATE ROAD. REPORTED BY DISPATCH.
01:50 UTCTSTM WND DMGDunlapSequatchie, TNA TREE FELL ONTO A HOUSE IN DUNLAP. NO INJURIES REPORTED.
01:53 UTCTORNADO2 Se DunlapSequatchie, TNEF0 TORNADO...WITH WINDS ESTIMATED AROUND 80 MPH...WAS OBSERVED NEAR LEWIS ROAD. PATH LENGTH WAS AROUND ONE MILE...WITH A WIDTH OF 30 YARDS. SEVERAL TREES WERE REPORTED DOWN ALONG WITH SIGNIFICANT STRUCTURAL DAMAGE TO A
02:00 UTCTSTM WND DMG2 E DunlapSequatchie, TNA GARAGE BLOWN 40 YARDS OFF ITS FOUNDATION AND SEVERAL TREES DOWN.

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 March 28, 2009

13 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
March 282:58 AM CDTEF1Smith, MS0.8200$500,000
March 2810:50 AM EDTEF0Dooly, GA0.350$100,000
March 284:23 PM CDTEF1Union, KY2.175$60,000
March 285:31 PM EDTEF1Clarendon, SC4.0330
March 284:40 PM CDTEF3Union, KY12.34002$540,000
March 285:38 PM CDTEF1Cheatham, TN5.0100$100,000
March 285:38 PM CDTEF0Daviess, KY0.230
March 287:00 PM CDTEF1Rutherford, TN1.050$4.4 million
March 287:01 PM CDTEF1Franklin, TN1.560$30,000
March 289:08 PM EDTEF2Bladen, NC1.640$200,000
March 288:11 PM CDTEF0Jackson, AL1.640$15,000
March 288:16 PM CDTEF1DeKalb, AL2.550$20,000
March 289:36 PM EDTEF0Bladen, NC0.110$1,000

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.