Tornadoes · United States · Arkansas · 2011

EF0 tornado, Ebenezer to Malvern, Arkansas, May 20, 2011

From Ebenezer to Malvern, this EF0 tornado ran 3.1 miles across Hot Spring County on May 20, 2011, touching down at 5:48 PM CDT and reaching 100 yards wide. It killed nobody, and did $25,000 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
May 20, 2011
Touchdown
5:48 PM CDT (22:48 UTC)
Lifted
5:55 PM CDT (22:55 UTC)
On the ground
7 minutes
Path length
3.1 miles (5.0 km)
Path width
100 yards (91 m)
Deaths
0
Injuries
0
Property damage
$25,000
County
Hot Spring County
Touchdown point
34.330, -92.838
Lift-off point
34.354, -92.792
Record number
1105201648-01

What the Weather Service recorded

A warm, humid air mass over Arkansas, a stalled front to the northwest of the area, and the periodic passage of low pressure aloft, brought rounds of thunderstorms to Arkansas from the 20th through the morning of the 24th. These storms produced an isolated tornado, along with large hail, damaging winds, and heavy rains from time to time.

Many large limbs and a few trees were blown down. At an apartment complex, shingles were blown off most of the roofs. Several houses also had shingles taken off.

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

The warnings

10 minutes of warning. NWS LZK issued a tornado warning for this county at 22:38 UTC, 10 minutes before the tornado touched down, in force until 23:15 UTC.

The county was under a tornado watch, issued at 16:05 UTC and running to 22:59 UTC.

Issued (UTC)ExpiredProductOffice
14:15 UTC14:28 UTCSevere Thunderstorm WarningLZK
16:05 UTC22:59 UTCTornado WatchLZK
21:49 UTC22:13 UTCSevere Thunderstorm WarningLZK
21:54 UTC22:45 UTCTornado WarningLZK
22:38 UTC23:15 UTCTornado WarningLZK
22:59 UTC02:16 UTCTornado WatchLZK
23:14 UTC23:34 UTCSevere Thunderstorm WarningLZK
02:41 UTC05:30 UTCFlash Flood WarningLZK
03:59 UTC08:00 UTCFlash Flood WarningLZK

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 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.

Shreveport, LA (KSHV), 12:00Z

10.8 hours before the tornado, 225 km from the path. May 20, 2011.

Skew-T log-pSkew-T log-p diagram, Shreveport, LA at 12:00Z on 2011-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 2656 joules per kilogram, CIN -44, lifted condensation level 648 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°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, Shreveport, LA at 12:00Z on 2011-05-20The 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 151 square meters per square second, 0 to 6 km bulk shear 15 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
2656 J/kg
Mixed-layer CIN
-44 J/kg
Surface CAPE
2171 J/kg
Mixed-layer LCL
648 m above ground
0-6 km bulk shear
15 kt
0-1 km bulk shear
27 kt
0-1 km storm-relative helicity
151 m²/s²
0-3 km storm-relative helicity
231 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.7 K/km

Open this sounding in Storm Lab

Shreveport, LA (KSHV), 00:00Z

1.2 hours after it, 225 km from the path. May 21, 2011.

Skew-T log-pSkew-T log-p diagram, Shreveport, LA at 00:00Z on 2011-05-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1940 joules per kilogram, CIN -23, lifted condensation level 1407 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°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, Shreveport, LA at 00:00Z on 2011-05-21The 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 116 square meters per square second, 0 to 6 km bulk shear 19 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
1940 J/kg
Mixed-layer CIN
-23 J/kg
Surface CAPE
3204 J/kg
Mixed-layer LCL
1407 m above ground
0-6 km bulk shear
19 kt
0-1 km bulk shear
19 kt
0-1 km storm-relative helicity
116 m²/s²
0-3 km storm-relative helicity
248 m²/s²
Significant tornado parameter
0.0
Supercell composite
9.0
0-3 km lapse rate
7.8 K/km

Open this sounding in Storm Lab

The radar

The Little Rock radar (KLZK), 75 km away, was scanning. The volume nearest the touchdown began at 22:48 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
21:12 UTCTORNADO3 Sw MalvernHot Spring, ARA BRIEF TORNADO OCCURRED IN HOT SPRING COUNTY. THE STORM TRACKED FROM 2.7 MILES SW OF MALVERN TO 1.3 MILES SE OF MALVERN AND HAD A PATH LENGTH OF 3.2 MILES. THE STORM WAS RATED AS AN EF0 ON THE ENHANCED FUJITA SCALE. DAM
22:18 UTCHAIL 16 E BismarckHot Spring, ARTHIS HAIL OCCURRED AT DEROCHE.
22:32 UTCFUNNEL CLOUD2 Ne FriendshipHot Spring, ARFUNNEL CLOUDS WERE REPORTED AT MILE MARKERS 84 AND 87 ON INTERSTATE 30.
22:48 UTCTORNADO 03 Sw MalvernHot Spring, ARA BRIEF TORNADO OCCURRED IN HOT SPRING COUNTY. THE STORM TRACKED FROM 2.7 MILES SW OF MALVERN TO 1.3 MILES SE OF MALVERN AND HAD A PATH LENGTH OF 3.2 MILES. THE STORM WAS RATED AS AN EF0 ON THE ENHANCED FUJITA SCALE. DAM
23:03 UTCFUNNEL CLOUDMalvernHot Spring, AR
23:03 UTCHAIL 1.75MalvernHot Spring, AR
23:17 UTCHAIL 0.55 Nw TraskwoodSaline, AR1/4 TO 1/2 INCH DIAMETER HAIL FELL AT MILE MARKER 106 ON INTERSTATE 30.
23:25 UTCHAIL 12 E LonsdaleSaline, ARQUARTER SIZED HAIL EAST OF LONSDALE ON HWY 70.
23:56 UTCHAIL 0.75BryantSaline, ARWINDS TO 40 MPH OCCURRED WITH THE HAIL.

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

This ground now

The live radar over the trackEvery 2011 tornado in ArkansasEvery tornado in Arkansas since 1950Warnings in force in Arkansas nowThe forecast where you are

The other tornadoes of May 20, 2011

5 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 208:20 AM CDTEF0Washington, AR0.550$1,000
May 209:37 AM CDTEF1Mayes, OK1.5100$35,000
May 205:36 PM CDTEF0Red River, TX1.650
May 206:38 PM CDTEF0Harrison, TX6.850
May 208:27 PM MDTEF1Prairie, MT0.166$75,000

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.