EF0 tornado, Natchez, Louisiana, May 25, 2011

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.

Rating

EF0

Date

May 25, 2011

Touchdown

10:22 PM CDT (03:22 UTC)

Lifted

10:26 PM CDT (03:26 UTC)

On the ground

4 minutes

Path length

1.4 miles (2.2 km)

Path width

50 yards (46 m)

Deaths

0

Injuries

0

County

Natchitoches Parish

Touchdown point

31.689, -93.032

Lift-off point

31.709, -93.030

Record number

1105252122-01

Severe thunderstorms developed along and ahead of a dry line which moved out of north Texas and southern Oklahoma. Shear was very strong ahead of the dry line in the lower and mid levels of the atmosphere. The result was wind damage, hail and a few tornadoes reported across the region.

The National Weather Service conducted a storm survey in Natchitoches Parish LA near Natchez and concluded that damage was the result of an EF0 Tornado. A few hardwood trees had small limbs and branches broken off along Highway 494 about a mile northeast of Natchez. The tops of several large trees were seen broken off out in the field north of Highway 494 and west of Fish Hatchery Road. The tornado continued to the north-northeast where it paralleled Fish Hatchery Road. Numerous trees had their tops twisted off, large branches snapped, and several small limbs broken off about a mile north on Fish Hatchery Road north of Highway 494. The tornado continued north-northeastward across the Cane River into the Plantation Point subdivision where it knocked a few trees down and broke a few large branches out of trees before lifting. Maximum winds are estimated at 70-75 mph.

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

6 minutes of warning. NWS SHV issued a tornado warning for this county at 03:16 UTC, 6 minutes before the tornado touched down, in force until 04:00 UTC.

The county was under a tornado watch, issued at 02:46 UTC and running to 05:02 UTC.

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 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 00:57 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 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.

Nattchitoches Regional Airport (IER), 8 km from the path, in the two hours either side.

From the Iowa Environmental Mesonet's archive of airport observations.

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

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

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

93 more were confirmed in the United States that day.

All 94 of them

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.

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.