Tornadoes · United States · Louisiana · 2011

EF1 tornado, Franklinton, Louisiana, April 4, 2011

This EF1 tornado ran 0.2 miles across Washington Parish on April 4, 2011, touching down at 6:40 PM CDT and reaching 75 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 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
April 4, 2011
Touchdown
6:40 PM CDT (23:40 UTC)
Path length
0.2 miles (0.3 km)
Path width
75 yards (69 m)
Deaths
0
Injuries
0
Property damage
$30,000
County
Washington Parish
Touchdown point
30.850, -90.140
Lift-off point
30.850, -90.140
Record number
1104041740-01

The damage survey

18 damage points were recorded along this path by NWS LIX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 107 mph.

  • Tree uprooted on Leblanc Rd.
  • Trees snapped and uprooted.
  • Unsecured mobile home rolled onto side.
  • Numerous softwood and hardwood trees were snapped or uprooted.

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

What the Weather Service recorded

A strong storm system over the middle Mississippi River Valley pushed a cold front through southeast Louisiana. A squall line developed in advance of the front and produced numerous reports of severe weather.

A large portion of the roof structure was completely removed from one home. Several very large trees were completely uprooted. Two single wide mobile homes also had roof damage. Damage path length was approximately 0.2 miles. Path width of 75 yards. Winds were rated as high end EF1 with maximum wind speeds of 105 mph.

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 22:30 UTC and running to 00:53 UTC.

Issued (UTC)ExpiredProductOffice
15:54 UTC22:30 UTCTornado WatchLIX
16:08 UTC00:00 UTCWind AdvisoryLIX
22:30 UTC00:53 UTCTornado WatchLIX
23:03 UTC23:45 UTCSevere Thunderstorm WarningLIX
23:08 UTC00:15 UTCSevere Thunderstorm WarningLIX
23:51 UTC00:45 UTCSevere Thunderstorm WarningLIX

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 19:53 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.

Slidell Radar S, LA (KSIL), 12:00Z

11.7 hours before the tornado, 79 km from the path. April 4, 2011.

Skew-T log-pSkew-T log-p diagram, Slidell Radar S, LA at 12:00Z on 2011-04-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1669 joules per kilogram, CIN -67, lifted condensation level 624 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, Slidell Radar S, LA at 12:00Z on 2011-04-04The 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 88 square meters per square second, 0 to 6 km bulk shear 17 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
1669 J/kg
Mixed-layer CIN
-67 J/kg
Surface CAPE
2167 J/kg
Mixed-layer LCL
624 m above ground
0-6 km bulk shear
17 kt
0-1 km bulk shear
29 kt
0-1 km storm-relative helicity
88 m²/s²
0-3 km storm-relative helicity
245 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.7 K/km

Open this sounding in Storm Lab

Slidell Radar S, LA (KSIL), 00:00Z

0.3 hours after it, 79 km from the path. April 5, 2011.

Skew-T log-pSkew-T log-p diagram, Slidell Radar S, LA at 00:00Z on 2011-04-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 3275 joules per kilogram, CIN 0, lifted condensation level 562 meters above ground. Wind barbs in knots down the right edge.LCLEL10008507005003002001001 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, Slidell Radar S, LA at 00:00Z on 2011-04-05The 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 245 square meters per square second, 0 to 6 km bulk shear 44 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
3275 J/kg
Mixed-layer CIN
0 J/kg
Surface CAPE
3034 J/kg
Mixed-layer LCL
562 m above ground
0-6 km bulk shear
44 kt
0-1 km bulk shear
35 kt
0-1 km storm-relative helicity
245 m²/s²
0-3 km storm-relative helicity
249 m²/s²
Significant tornado parameter
4.7
Supercell composite
20.4
0-3 km lapse rate
6.1 K/km

Open this sounding in Storm Lab

What was reported nearby

Local storm reports within 60 km of the path, in the three hours either side.

Time (UTC)ReportWhereCountyRemark
23:35 UTCTSTM WND DMGAmiteTangipahoa, LASEVERAL TREES AND A FEW POWERLINES DOWNED.
23:40 UTCTSTM WND DMG2 W FranklintonWashington, LAROOF DAMAGED AND POSSIBLY BLOWN OFF OF FRAMED HOUSE NEAR INTERSECTION OF BOGUE CHITTO RIVER AND LOUISIANA STATE HIGHWAY 25. TIME ESTIMATED/CORRECTED BASED ON RADAR.
23:40 UTCTORNADOFranklintonWashington, LALARGE PORTION OF ROOF STRUCTURE COMPLETELY REMOVED FROM ONE HOME. SEVERAL VERY LARGE TREES COMPLETELY UPROOTED. TWO SINGLE WIDE MOBILE HOMES ALSO HAD ROOF DAMAGE. DAMAGE PATH LENGTH APPROXIMATELY 0.2 MILES AND MAXIMUM DA
23:42 UTCTSTM WND DMG2 Sw HammondTangipahoa, LATREES DOWN ALONG I-12 NEAR I-55 INTERCHANGE.
23:50 UTCTSTM WND DMG1 W FranklintonWashington, LAROOF DAMAGED AND POSSIBLY BLOWN OFF OF FRAMED HOUSE NEAR INTERSECTION OF BOGUE CHITTO RIVER AND LOUISIANA STATE HIGHWAY 25.
23:55 UTCTSTM WND DMGFranklintonWashington, LAA FEW TREES AND POWERLINE POLES DOWNED BY THUNDERSTORM WINDS.
00:01 UTCTSTM WND DMG6 Wnw SunWashington, LATRAILER LIFTED OF THE GROUND AND A FEW CAMPER TRAILERS FLIPPED OVER.
00:01 UTCTORNADO 110 Sw BogalusaWashington, LATRAILER LIFTED OF THE GROUND AND ANOTHER CAMPER AND BLOWN ABOUT 20 YARDS. SHEET METAL AND TIN ROOFING AND AWNING BLOWN 50 TO 75 YARDS AWAY AND WRAPPED AROUND ONE TREE TRUNK THAT ABOUT 20 FEET HIGH. NUMEROUS HARDWOODS AND
00:15 UTCTSTM WND DMG4 Sse BushSt. Tammany, LALARGE OAK TREE UPROOTED AND FELL ON HOUSE JUST OFF HWY. 41. LARGE PORTION OF HOUSE WAS CRUSHED.
00:18 UTCTSTM WND DMGMandevilleSt. Tammany, LANUMEROUS TREES DOWN IN OLD MANDEVILLE BLOCKING...VILLERE RD AND MONROE ST. POWER OUT ACROSS MUCH OF THE AREA SOUTH OF HIGHWAY 190 AND EAST CAUSEWAY APPROACH AND WEST OF HIGHWAY 59.
00:22 UTCTSTM WND DMG1 W MandevilleSt. Tammany, LALARGER TREE ABOUT 3 TO 4 FEET THICK IN DIAMETER BLOWN DOWN BLOCKING HIGHWAY 190 BETWEEN COLBERT AND SOULT STREET. NUMEROUS POWER OUTAGES EAST OF HIGHWAY 59 TO SOULT STREET...NORTH OF HIGHWAY 190 AND SOUTH OF HIGHWYA 1088
00:25 UTCTSTM WND DMG3 Ene MandevilleSt. Tammany, LATREES DOWN IN FOREST BROOK SUBDIVISION OFF HWY 1088 ON MESA CT, BLUFF CT, AND RANGE CT. TIME ESTIMATED BASED ON RADAR.
00:35 UTCTSTM WND DMG3 Ne MandevilleSt. Tammany, LAFENCE DOWNED ON FOREST BROOKE AVE.
00:35 UTCTSTM WND GST 60MandevilleSt. Tammany, LANWS EMPLOYEE REPORTS POWER FLASHES IN MANDEVILLE AND ESTIMATES 60 MPH WINDS.

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 LouisianaEvery tornado in Louisiana since 1950Warnings in force in Louisiana nowThe forecast where you are

The other tornadoes of April 4, 2011

42 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 48:10 AM CDTEF1Little River, AR4.8150$25,000
April 48:38 AM CDTEF1Hempstead, AR3.9100$300,000
April 48:40 AM CDTEF2Hempstead, AR1.82002$500,000
April 48:50 AM CDTEF1Miller, AR2.6150$100,000
April 49:08 AM CDTEF1Clark, AR4.0200$50,000
April 49:28 AM CDTEF1Columbia, AR0.975$75,000
April 410:12 AM CDTEF1Union, AR1.3100$150,000
April 410:18 AM CDTEF1Ballard, KY3.7200$40,000
April 410:20 AM CDTEF2Ballard, KY6.43001$700,000
April 410:30 AM CDTEF0McCracken, KY0.550$30,000
April 411:55 AM CDTEF1Muhlenberg, KY7.1150$100,000
April 412:04 PM CDTEF2Christian, KY5.32007$2.0 million
April 412:26 PM CDTEF1Butler, KY3.450
April 412:38 PM CDTEF1Grayson, KY3.4125
April 412:41 PM CDTEF1Grayson, KY1.0200
April 41:19 PM CDTEF1Humphreys, TN2.975$150,000
April 41:33 PM CDTEF1Dickson, TN7.3150$110,000
April 41:52 PM CDTEF0Cheatham, TN0.850$2,000
April 42:20 PM CDTEF1Davidson, TN4.9100$500,000
April 42:42 PM CDTEF1Grant Parish, LA9.3275$250,000
April 43:46 PM EDTEF0Licking, OH0.950$60,000
April 42:55 PM CDTEF1Monroe, KY0.275
April 42:58 PM CDTEF2LaSalle Parish, LA12.6440$110,000
April 43:14 PM CDTEF1Clinton, KY0.3150
April 43:16 PM CDTEF0Clinton, KY0.260
April 43:43 PM CDTEF2Tensas Parish, LA to MS28.08801$4.0 million
April 45:03 PM EDTEF1Whitley, KY1.7880$200,000
April 44:42 PM CDTEF1Hinds, MS4.0440$20,000
April 46:21 PM EDTEF1Floyd, KY0.4100$10,000
April 46:36 PM EDTEF0McMinn, TN0.125$10,000
April 45:36 PM CDTEF1Simpson, MS7.41,320$550,000
April 45:48 PM CDTEF1Lincoln, MS17.3600$1.5 million
April 46:42 PM CDTEF1Livingston Parish, LA0.550$10,000
April 46:50 PM CDTEF0Saint James Parish, LA0.950$50,000
April 47:01 PM CDTEF1Washington Parish, LA0.275$50,000
April 47:43 PM CDTEF1Pearl River, MS0.350$30,000
April 47:43 PM CDTEF1Greene, MS19.4100$500,000
April 49:33 PM EDTEF1Gilmer, GA2.6880$1.0 million
April 49:34 PM EDTEF0Gilmer, GA1.8880$500,000
April 48:45 PM CDTEF1Jackson, MS0.175$35,000
April 41:25 AM EDTEF1Surry, NC2.7250$1.0 million
April 41:30 AM EDTEF1Bibb, GA1.150$300,000

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.