EF1 tornado, Williamsburg to Gandsi, Mississippi, September 4, 2011

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.

Rating

EF1

Date

September 4, 2011

Touchdown

8:05 PM CDT (01:05 UTC)

Lifted

8:09 PM CDT (01:09 UTC)

On the ground

4 minutes

Path length

3.9 miles (6.3 km)

Path width

50 yards (46 m)

Deaths

0

Injuries

0

Property damage

$25,000

County

Covington County

Touchdown point

31.596, -89.602

Lift-off point

31.561, -89.550

Record number

1109041905-01

Tropical Depression 13 formed on the evening of September 1, 2011 about 225 miles southwest of the mouth of the Mississippi River with maximum sustained winds of 35 mph. The depression moved very slowly, around 2 mph, across northern portions of the Gulf of Mexico. Through mid day on the 2nd, Tropical Depression 13 remained mostly stationary over the northern Gulf of Mexico, drenching Louisiana with several inches of rain. Around 1 pm on the 2nd, the depression was found to have strengthened to Tropical Storm strength by both Air Force Hurricane Hunter aircraft and local observations on oil rigs, becoming the 12th named storm of 2011. Tropical Storm Lee as it was named, had moved little and was located about 210 miles to the southwest of the mouth of the Mississippi River. Maximum sustained winds of 40 mph were found with the newly named tropical storm and a minimum central pressure of 1003 mb.||Lee continued to move very slowly on the 2nd and 3rd, while heavy rain and strong winds continued to lash southern Louisiana. By mid day on the 3rd, Lee stalled south of the Louisiana coast with sustained winds around 60 mph. Lee continued to meander just along or south of the Louisiana coast through the remainder of the day on the 3rd. During the early morning hours of the 4th, Tropical Storm Lee finally made landfall near Vermillion Bay, LA, with maximum sustained wind speeds of 45 mph. However, Lee was still moving very slowly to the north northeast, dumping large quantities of rain and spawning tornadoes across portions of southern Louisiana, southeastern Mississippi and other portions of the Gulf Coast. ||As the center of Lee continued to trek northward, heavy rain bands spiraled across much of central Mississippi producing significant flooding issues. Rainfall amounts of 4 to 10 inches were common across the NWS Jackson County Warning Area, with a few locations reporting amounts of 10 to 13 inches. Significant flash flooding was reported in the Jackson metro area, along with a few locations in southern Mississippi. Reports from emergency manager officials indicated that at least 50 homes, 60 apartment units and several other buildings were flooded by Monday morning. Numerous vehicles in the Jackson area were flooded, primarily in low-lying parking spots. Dozens of roads and bridges were washed out in central Mississippi. U.S. Highway 80 and Interstate 20 east of Jackson were both closed due to high water. Locations in the Mississippi Delta, northeast Louisiana and southeast Arkansas saw the least amount of rainfall, with amounts generally ranging from one half of an inch to 2 inches. Rivers responded to the large volume of rain, with many points on the Pearl River rising to minor to low-end moderate flooding. Other smaller creeks also came close to flood stage. ||In addition to the significant rainfall and flooding, tornadoes also occurred with Tropical Storm Lee. Four confirmed tornadoes occurred in the Jackson County Warning Area. As is the case with most tropical systems, these tornadoes were very brief and fairly weak. Much of the damage was EF-0 type damage, with mostly trees and limbs coming down. The strongest tornado was rated EF-1 near Collins, MS. Some structural damage occurred along with tree damage. This tornado tracked for 3 miles with maximum estimated winds at 90 mph.||Around 10pm on September 4th, Lee was downgraded to a Tropical Depression with maximum sustained winds of 35 mph. However, these winds were occurring well to the south and southeast of the center out over the Gulf of Mexico. The weakened cyclone was located about 55 miles to the west southwest of McComb, MS. The remnants of Lee got caught up with an approaching cold front and moved quickly to the northeast, dumping rainfall on the Mid-Atlantic region that was doused by Hurricane Irene only a week prior.||Select rainfall totals(inches) from across central Mississippi include Florence, MS(13.55), Forest, MS(12.82), Walnut Grove(12.59), 8mi south Philadelphia, MS(12.03), 5mi east Philadelphia, MS(12.00), 8mi west southwest Hattiesburg, MS(11.64), Prentiss, MS(11.33), and at the Jackson International Airport(11.15).

Two barns were heavily damaged along the tornado path. One home suffered minor roof and structural damage. A number of trees were snapped and uprooted. A wooden light pole was snapped and a couple of power lines downed. Maximum winds were estimated at 90 mph.

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

5 minutes of warning. NWS JAN issued a tornado warning for this county at 01:00 UTC, 5 minutes before the tornado touched down, in force until 01:30 UTC.

The county was under a tornado watch, issued at 20:47 UTC and running to 02:43 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 01:01 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.

The Jackson/Brandon,MS radar (KDGX), 87 km away, was scanning. The volume nearest the touchdown began at 01:03 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.

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 MississippiEvery tornado in Mississippi since 1950Warnings in force in Mississippi nowThe forecast where you are

13 more were confirmed in the United States that day.

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.