Tornadoes · United States · Arkansas · 2012

EF1 tornado, Sheridan, Arkansas, December 20, 2012

This EF1 tornado ran 0.6 miles across Grant County on December 20, 2012, touching down at 1:25 AM CST and reaching 200 yards wide. It killed nobody and injured 1, and did $175,000 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 mph

    Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

  2. EF186 to 110 mphthis tornado

    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
EF1
Date
December 20, 2012
Touchdown
1:25 AM CST (07:25 UTC)
Lifted
1:26 AM CST (07:26 UTC)
On the ground
1 minutes
Path length
0.6 miles (1.0 km)
Path width
200 yards (183 m)
Deaths
0
Injuries
1
Property damage
$175,000
County
Grant County
Touchdown point
34.297, -92.448
Lift-off point
34.299, -92.437
Record number
1212200125-01

What the Weather Service recorded

Numerous thunderstorms developed in advance of a strong cold front on the evening of the 19th and continued into the wee hours of the 20th. Some of the storms became severe, producing damaging winds. There was one tornado as well. Just before the rain came to an end, winds brought in dust into Arkansas, causing a mud rain and dirtying thousands of cars. The dust was picked up by a dust storm in West Texas on the 19th.

A double-wide mobile home was destroyed; the owner suffered minor injuries. The roof of a house was badly damaged. A couple of additional houses had minor roof damage, and one had a couple of windows blown out. Several shop buildings were damaged or destroyed. A camper was overturned. Trees and power lines were blown down. One of the trees fell on a carport, crushing a pickup truck and a car.

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 severe thunderstorm watch, issued at 07:10 UTC and running to 07:53 UTC.

Issued (UTC)ExpiredProductOffice
06:00 UTC10:15 UTCLake Wind AdvisoryLZK
07:00 UTC07:45 UTCSevere Thunderstorm WarningLZK
07:10 UTC07:53 UTCSevere Thunderstorm WatchLZK
07:37 UTC08:02 UTCSevere Thunderstorm WarningLZK
10:15 UTC00:00 UTCWind AdvisoryLZK

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 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.

Little Rock, AR (KLZK), 00:00Z

7.4 hours before the tornado, 236 km from the path. December 20, 2012.

Skew-T log-pSkew-T log-p diagram, Little Rock, AR at 00:00Z on 2012-12-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 7 joules per kilogram, CIN -260, lifted condensation level 803 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, Little Rock, AR at 00:00Z on 2012-12-20The 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 529 square meters per square second, 0 to 6 km bulk shear 78 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
7 J/kg
Mixed-layer CIN
-260 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
803 m above ground
0-6 km bulk shear
78 kt
0-1 km bulk shear
43 kt
0-1 km storm-relative helicity
529 m²/s²
0-3 km storm-relative helicity
617 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
3.7 K/km

Open this sounding in Storm Lab

Little Rock, AR (KLZK), 12:00Z

4.6 hours after it, 236 km from the path. December 20, 2012.

Skew-T log-pSkew-T log-p diagram, Little Rock, AR at 12:00Z on 2012-12-20Temperature 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 -86753, lifted condensation level 1357 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 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, Little Rock, AR at 12:00Z on 2012-12-20The 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 -208 square meters per square second, 0 to 6 km bulk shear 95 knots.1939587897117136Sfc1 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
-86753 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1357 m above ground
0-6 km bulk shear
95 kt
0-1 km bulk shear
25 kt
0-1 km storm-relative helicity
-208 m²/s²
0-3 km storm-relative helicity
-405 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
3.3 K/km

Open this sounding in Storm Lab

The radar

The Little Rock radar (KLZK), 62 km away, was scanning. The volume nearest the touchdown began at 07:25 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
06:50 UTCTSTM WND DMGJoanClark, ARTREES WERE DOWNED IN AND AROUND TOWN.
06:55 UTCTSTM WND DMGDonaldsonHot Spring, ARTREES WERE DOWNED IN THE AREA.
07:25 UTCTSTM WND DMG3 Wsw SheridanGrant, ARA POSSIBLE BRIEF TORNADO WAS SPAWNED. A MOBILE HOME AND SEVERAL SHEDS WERE DAMAGED OR DESTROYED. ONE INJURY WAS REPORTED. NUMEROUS TREES WERE DOWNED...WITH SOME TREES ON HOUSES AND VEHICLES. TREES WERE ALSO BLOCKING ROAD
07:25 UTCTSTM WND DMGSheridanGrant, ARA POSSIBLE BRIEF TORNADO WAS SPAWNED. SEVERAL HOUSES AND MOBILE HOMES WERE DAMAGED. SOME INJURIES WERE BEING REPORTED. NUMEROUS TREES WERE DOWNED AND WERE BLOCKING ROADS.
07:25 UTCTORNADO 11 Wsw SheridanGrant, AR*** 1 INJ *** AN EF1 TORNADO HAS BEEN CONFIRMED BY SURVEY TEAM. A DOUBLE WIDE MOBILE HOME WAS DESTROYED. SURVEY TEAM IS CONTINUING THE SURVEY AND MORE DETAILS WILL BECOME AVAILABLE LATER THIS AFTERNOON.
07:30 UTCTSTM WND DMGSheridanGrant, ARTREES AND POWER LINES WERE DOWNED...WITH POWER OUTAGES NOTED.
07:45 UTCTSTM WND DMGWhite HallJefferson, ARTREES WERE DOWNED AT WHITE HALL WITH WIND GUSTS ESTIMATED AT 60 TO 70 MPH.

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

This ground now

The live radar over the trackEvery 2012 tornado in ArkansasEvery tornado in Arkansas since 1950Warnings in force in Arkansas nowThe forecast where you are

The other tornadoes of December 20, 2012

2 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
December 204:49 AM CSTEF1Mobile, AL6.775
December 205:42 PM ESTEF0Taylor, FL0.010

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.