Tornadoes · United States · Mississippi · 2017

EF0 tornado, Theo, Mississippi, March 27, 2017

This EF0 tornado ran 0.2 miles across Alcorn County on March 27, 2017, touching down at 1:59 PM CDT and reaching 50 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.

  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 27, 2017
Touchdown
1:59 PM CDT (18:59 UTC)
Lifted
2:00 PM CDT (19:00 UTC)
On the ground
1 minutes
Path length
0.2 miles (0.3 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
County
Alcorn County
Touchdown point
34.936, -88.717
Lift-off point
34.937, -88.714
Record number
1703271259-01

What the Weather Service recorded

A potent upper level disturbance generated numerous severe thunderstorms across the Midsouth from roughly noon through the early evening hours of March 27th. All severe weather threats were observed.

Brief touchdown near the small town of Theo.

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

The warnings

23 minutes of warning. NWS MEG issued a tornado warning for this county at 18:36 UTC, 23 minutes before the tornado touched down, in force until 19:15 UTC.

The county was under a severe thunderstorm watch, issued at 17:11 UTC and running to 01:00 UTC.

Issued (UTC)ExpiredProductOffice
17:11 UTC01:00 UTCSevere Thunderstorm WatchMEG
18:09 UTC19:00 UTCSevere Thunderstorm WarningMEG
18:36 UTC19:15 UTCTornado WarningMEG
19:10 UTC19:31 UTCTornado WarningMEG

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 Enhanced Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 16:30 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.

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

7.0 hours before the tornado, 113 km from the path. March 27, 2017.

Skew-T log-pSkew-T log-p diagram, Little Rock, AR at 12:00Z on 2017-03-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1 joules per kilogram, CIN -250, lifted condensation level 1438 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 12:00Z on 2017-03-27The 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 222 square meters per square second, 0 to 6 km bulk shear 52 knots.19395878Sfc1 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
1 J/kg
Mixed-layer CIN
-250 J/kg
Surface CAPE
1 J/kg
Mixed-layer LCL
1438 m above ground
0-6 km bulk shear
52 kt
0-1 km bulk shear
27 kt
0-1 km storm-relative helicity
222 m²/s²
0-3 km storm-relative helicity
369 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3
0-3 km lapse rate
4.5 K/km

Open this sounding in Storm Lab

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

5.0 hours after it, 113 km from the path. March 28, 2017.

Skew-T log-pSkew-T log-p diagram, Little Rock, AR at 00:00Z on 2017-03-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 120 joules per kilogram, CIN -52, lifted condensation level 1300 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 2017-03-28The 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 37 square meters per square second, 0 to 6 km bulk shear 36 knots.19395878Sfc1 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
120 J/kg
Mixed-layer CIN
-52 J/kg
Surface CAPE
712 J/kg
Mixed-layer LCL
1300 m above ground
0-6 km bulk shear
36 kt
0-1 km bulk shear
13 kt
0-1 km storm-relative helicity
37 m²/s²
0-3 km storm-relative helicity
246 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
7.1 K/km

Open this sounding in Storm Lab

The radar

The Memphis radar (KNQA), 115 km away, was scanning. The volume nearest the touchdown began at 18:59 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
17:55 UTCHAIL 24 W AshlandBenton, MSSEVERAL REPORTS OF HEN EGG SIZE HAIL IN THE SNOW LAKE SHORES AREA ON SNOW LAKE.
18:02 UTCHAIL 1AshlandBenton, MSQUARTER SIZED HAIL IN ASHLAND TOWN SQUARE.
18:06 UTCHAIL 2.75AshlandBenton, MS
19:00 UTCTORNADO3 Nw TheoAlcorn, MSA TORNADO WAS OBSERVED ALONG HIGHWAY 72 NEAR COUNTRY ROAD 608 JUST NORTHWEST OF THEO. THE TORNADO WAS ON THE GROUND FOR APPROXIMATELY 5 MINUTES.
19:07 UTCHAIL 1New AlbanyUnion, MS
19:07 UTCHAIL 1New AlbanyUnion, MS
19:10 UTCHAIL 1KirkvilleItawamba, MS
19:50 UTCHAIL 1BoonevillePrentiss, MS
20:05 UTCHAIL 1BaldwynLee, MS
20:05 UTCHAIL 1.75MariettaPrentiss, MS

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

This ground now

The live radar over the trackEvery 2017 tornado in MississippiEvery tornado in Mississippi since 1950Warnings in force in Mississippi nowThe forecast where you are

The other tornadoes of March 27, 2017

5 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
March 272:27 PM CDTEF0Trigg, KY4.4125$75,000
March 274:59 PM CDTEF0Henderson, TN6.450$10,000
March 275:05 PM CDTEF1Metcalfe, KY0.3100$300,000
March 275:18 PM CDTEF1Decatur, TN5.5100$150,000
March 276:12 PM CDTEF1Lewis, TN9.8500$110,000

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.