Tornadoes · United States · Georgia · 2011

EF2 tornado, Cannonville to Knott, Georgia, April 27, 2011

From Cannonville to Knott, this EF2 tornado ran 6.7 miles across Troup County on April 27, 2011, touching down at 11:20 PM EDT and reaching 440 yards wide. It killed nobody and injured 6, and did $10 million 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 mph

    Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

  3. EF2111 to 135 mphthis tornado

    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
EF2
Date
April 27, 2011
Touchdown
11:20 PM EDT (03:20 UTC)
Lifted
11:30 PM EDT (03:30 UTC)
On the ground
10 minutes
Path length
6.7 miles (10.8 km)
Path width
440 yards (402 m)
Deaths
0
Injuries
6
Property damage
$10 million
County
Troup County
Touchdown point
32.968, -85.030
Lift-off point
33.016, -84.929
Record number
1104272120-01

The damage survey

10 damage points were recorded along this path by NWS BMX and NWS FFC, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF2. The highest wind the damage implies is 128 mph.

  • End Point of White Plains EF-1 Tornado.
  • Metal outbuilding had minor metal roof damage.

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 highly diffluent, deep upper trough, centered across Texas, took on a negative tilt and began to rotate northeast during this period. A strong maritime-Pacific (mP) cold front accompanied the upper trough through the mid-south into the southeast from the early morning hours of the 27th to the early morning hours of the 28th. An intense low-level jet with winds in excess of 70 knots was noted in advance of this system and tracked across the mid-south early on the 27th, across north Alabama and north Georgia into the early morning hours of the 28th. West-southwest winds aloft were highly diffluent and near 200 mph across this same region. The strong low-level jet brought unseasonably, warm, moist Gulf air northward in advance of the mP cold front. Dewpoints in the 70s and maximum temperatures in the 80s combined with the extremely strong low-level and upper jets to create an almost perfect environment for severe thunderstorms and large devastating tornadoes. Indeed, the tornado outbreak that affected much of the eastern U.S., but particularly the south central and southeastern U.S. during this period, was unprecedented and likely the largest recorded in U.S. history. The tornado outbreak that accompanied this combination of weather features has been termed the 2011 Super Outbreak, an outbreak even worse than the 1994 and 1974 super tornado outbreaks across the eastern U.S. The outbreak affected the South Central, Southeast, Midwest, and even the usually less tornado prone Northeastern United States. Over 330 tornadoes were reported during this outbreak which began on April 25th and continued into the 28th affecting 21 states from Texas to New York. Even isolated tornadoes were noted in Canada. Nearly 350 people died from these tornadoes, of which over 230 of these were in Alabama alone. Four tornadoes on April 27th in Alabama and Mississippi were ranked EF5, the highest tornado damage rating on the Enhanced Fujita Scale. On average, there is only one EF5 tornado per year in the entire U.S.||Widespread and destructive tornadoes occurred on each day of the outbreak, but April 27th was clearly one of the most prolific and destructive tornado days in U.S. history, probably only surpassed by the Tri-State outbreak of 1925 and the Tupelo-Gainesville outbreak of 1936. The 24-hour period from 8 am April 27th to 8 a.m. April 28th is listed by the National Oceanic and Atmospheric Administration (NOAA) as the fourth deadliest tornado outbreak in U.S. history, with the 24 hours commencing April 28th at 8 a.m. as the fifth deadliest tornado day in U.S. history. It has also been determined to be the costliest tornado outbreaks and one of the costliest natural disasters in the U.S., even after adjustments for inflation, with total damages estimated to exceed $10 billion. ||Georgia was heavily impacted by this tornado outbreak, especially the northwest part of the state which bore the brunt of the massive supercell thunderstorms producing killer tornadoes that tracked east-northeast from northern Alabama during the late evening. All together, there were 15 tornadoes affecting 28 counties within the Peachtree City, Georgia 96-county warning area (CWA) of North and Central Georgia. All of these occurred within a 24-hour period commencing at 8 am April 27th. One of these tornadoes was rated an EF4, the first EF4 tornado in Georgia since the Palm Sunday outbreak in 1994. In addition, there were also four EF3 tornadoes. Fifteen tornado-related deaths were observed in north and central Georgia, the most tornado-related deaths within the Peachtree City, Georgia forecast area since its inception in 1994. The previous highest tornado-related death total was 12 on March 20, 1998, when a tornado struck Gainesville, Georgia.||Finally, it should be noted that while the most significant period of severe weather during this outbreak for Georgia was from the afternoon of the 27th through the early morning hours of the 28th, there was an initial round of severe weather across northwest Georgia early on the 27th as a decaying line of severe thunderstorms moved into the region from northeast Alabama. Widespread wind damage and even a few brief weaker tornadoes accompanied this system into the northwest counties of the state.

A damage survey conducted by the National Weather Service Forecast Office in Peachtree City, Georgia confirmed that a second tornado touched down in Troup county, approximately five miles south of LaGrange and then traveled approximately seven miles to the northeast before lifting six miles east of LaGrange. This tornado was an EF2, had a maximum path width of 1/4 mile, with maximum winds estimated to be 120 mph. The tornado did cross Interstate-185 east of LaGrange. Fifteen homes were destroyed along the path of the tornado and another 50 homes sustained minor to moderate damage. The most significant damage occurred along Georgia Highway 219 and Murphy Road near the beginning of the tornado's path, or about two miles south of the LaGrange city limits. About 12 homes were destroyed in this area. One home in this neighborhood was picked up and thrown 50 feet while its sun room was thrown 300 yards. A well built log cabin on a hillside was completely destroyed as it was blown off its foundation in the opposite direction of the tornado's movement. While no fatalities occurred admist all of this damage, there were six injuries resulting from debris and damaged homes. Thousands of trees and many power lines were also down along the path of the tornado.||A total of 41 residential or commercial structures in Troup county were either destroyed, suffered major damage, or sustained minor to moderate damage from the two tornadoes this evening.||It should be noted that the same thunderstorm that spawned this tornado continued on to spawn yet another tornado that tracked across northeast Meriwether into western Spalding and southern Henry county shortly after this event and then later spawned additional tornadoes in east central Georgia as the night continued.||[04/27-04/28/11: Tornado #9, County #1-1, EF2, Troup, 2011:018].

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

The forecast that day

The Storm Prediction Center had this point in a Moderate Risk, with a 0.15 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 00:50 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.

What forecasters said that day

The local office's own words before the tornado touched down, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Atlanta, GA wrote its last area forecast discussion before the tornado touched down at Apr 27, 10:06 PM EDT, 1 hour 14 minutes earlier.

Area forecast discussion, Apr 27, 10:06 PM EDT, 1 hour 14 minutes before
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1006 PM EDT WED APR 27 2011

.UPDATE...

SENDING AN UPDATE MAINLY TO REFRESH WORDING...HAVE MADE SOME MINOR
ADJUSTMENTS TO POPS AND WX GRIDS. EXPECT SEVERE THREAT TO CONTINUE
THROUGH THE OVERNIGHT HOURS WITH SBCAPES AT OR ABOVE 2000 J/KG FOR
A LARGE PORTION OF WEST GEORGIA...EXTENDING UP TO THE METRO
AREA...WITH AT LEAST 500 SBCAPES EVERYWHERE. 0-1KM HELICITY
300-500 M2/S2 ALONG AND AHEAD OF THE FRONT...WHICH STRETCHES FROM
EAST CENTRAL TENNESSEE INTO NORTHERN ALABAMA AT AFD TIME. SPC HAS
EXPANDED THE HIGH RISK TO INCLUDE PORTIONS OF METRO ATLANTA.
OVERALL LOOKS LIKE A PRETTY LONG NIGHT AHEAD OF US STILL TEMPS NOT
FALLING AS QUICKLY AS FORECAST WITH THE FRONT STILL HANGING
BACK...SO HAVE UPDATED HOURLY TRENDS. NO MAJOR CHANGES TO MIN
TEMPS AT THIS TIME. UPDATE WILL BE OUT SHORTLY.

TDP

&&

.PREV DISCUSSION... /ISSUED 730 PM EDT WED APR 27 2011/

PREV DISCUSSION... /ISSUED 505 PM EDT WED APR 27 2011/

SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
THE STRONG SOUTHERLY FLOW CONTINUES TO BRING A VERY WARM AND MOIST
AIR MASS INTO THE AREA...HELPING TO CREATE A VERY UNSTABLE AIR MASS.
THIS ENVIRONMENT HAS THE POTENTIAL OF PRODUCING STRONG TO SEVERE
THUNDERSTORMS...DAMAGING WINDS...LARGE HAIL AND EVEN TORNADOES OUT
AHEAD OF THE APPROACHING COLD FRONT. THIS WILL CONTINUE INTO THE
EVENING FOR MUCH OF THE AREA...SPREADING SOUTH AND EAST DURING THE
OVERNIGHT HOURS INTO THURSDAY MORNING WHEN THE ASSOCIATED COLD FRONT
IS EXPECTED TO NEAR THE GEORGIA COAST. A LARGE AREA OF HIGH PRESSURE
MOVING ACROSS THE SOUTHERN PLAINS WILL USHER IN A DRIER AIR MASS
DURING THE DAY THURSDAY. THE DRY CONDITIONS WILL CONTINUE THROUGH
FRIDAY.

LONG TERM /SATURDAY THROUGH WEDNESDAY/...
THE HIGH WILL PROGRESS THROUGH THE TENNESSEE VALLEY TO THE MID
ATLANTIC REGION SATURDAY WHILE KEEPING THE DRIER AIR OVER THE
AREA. A STORM SYSTEM OVER THE GREAT LAKES AND EASTERN CANADA WILL
PUSH TO THE NORTHEAST AND THE TRAILING COLD FRONT WILL STRETCH TO
THE MID MISSISSIPPI RIVER VALLEY SUNDAY NIGHT. THE FRONT WILL
APPROACH NORTHERN GEORGIA MONDAY POSING THE NEXT THREAT OF MORE
SHOWERS INTO TUESDAY NIGHT. FAIR WEATHER TO BECOME DOMINATE
WEDNESDAY AS HIGH PRESSURE RETURNS...BRINGING IN A DRIER AIR MASS.

FIRE WEATHER...
WILL CONTINUE WITH FIRE DANGER STATEMENT ACROSS CENTRAL
GA...ALTHOUGH WINDS ACROSS SC/SE/EC SECTIONS MARGINAL. FUELS REMAIN
DRY IN THIS AREA AS THERE HAS BEEN LITTLE WIDESPREAD RAIN IN RECENT
WEEKS.

37

AVIATION...
00Z UPDATE...
SUPERCELLS TO THE WEST WILL MOVE INTO THE ATL CSG AREA BY 04Z AND
INTO MCN/AHN AREA BETWEEN 05Z AND 06Z. WILL ADD WIND GUSTS TO
40KTS WITH THE TSRA IN ATL/CSG WITH SLIGHTLY WEAKER WINDS IN
AHN/MCN. THE COLD FRONT WILL SWEEP ACROSS THE CWA AND THIS WILL
BRING THE CONVECTION TO AN END. WINDS WILL REMAIN GUSTY OUT OF THE
SOUTH SOUTHWEST AHEAD OF THE FRONT...SHIFTING TO THE WEST
NORTHWEST BEHIND THE FRONT. SPEEDS WILL DIMINISH AFTER FROPA...BUT
INCREASE TO 15G25KT BY 17Z THU. CIGS WILL BECOME MVFR/IFR
TONIGHT...MAINLY WITH THE TSRA AND INCREASE TO VFR BY LATE
THURSDAY MORNING.

//ATL CONFIDENCE...
00Z UPDATE...
MEDUIM TO HIGH ON ALL ELEMENTS

17

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          62  75  47  79 /  90  20  10   5
ATLANTA         58  72  50  76 /  90  10   5   5
BLAIRSVILLE     55  70  44  73 / 100  10  10   5
CARTERSVILLE    58  70  43  77 / 100  10   5   5
COLUMBUS        65  75  50  80 /  90  20   5   5
GAINESVILLE     59  73  50  77 / 100  10  10   5
MACON           67  79  46  81 /  90  20  10   5
ROME            55  72  45  78 / 100  10   5   5
PEACHTREE CITY  61  71  42  78 /  90  10   5   5
VIDALIA         70  82  55  79 /  50  30  10   5

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
TORNADO WATCH UNTIL 2 AM EDT THURSDAY FOR THE FOLLOWING ZONES:
BANKS...BARROW...BARTOW...BUTTS...CARROLL...CATOOSA...
CHATTAHOOCHEE...CHATTOOGA...CHEROKEE...CLARKE...CLAYTON...COBB...
COWETA...CRAWFORD...DADE...DAWSON...DEKALB...DOUGLAS...FANNIN...
FAYETTE...FLOYD...FORSYTH...GILMER...GORDON...GREENE...
GWINNETT...HALL...HARALSON...HARRIS...HEARD...HENRY...JACKSON...
JASPER...LAMAR...LUMPKIN...MADISON...MARION...MERIWETHER...
MONROE...MORGAN...MURRAY...MUSCOGEE...NEWTON...NORTH FULTON...
OCONEE...OGLETHORPE...PAULDING...PICKENS...PIKE...POLK...
PUTNAM...ROCKDALE...SCHLEY...SOUTH FULTON...SPALDING...STEWART...
TALBOT...TAYLOR...TOWNS...TROUP...UNION...UPSON...WALKER...
WALTON...WEBSTER...WHITE...WHITFIELD.

&&
Hazardous weather outlook, Apr 27, 6:28 AM EDT, 16 hours 52 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
628 AM EDT WED APR 27 2011

GAZ001>009-011>016-019>025-027-030>039-041>062-066>076-078>086-
089>098-102>113-281030-
BALDWIN-BANKS-BARROW-BARTOW-BIBB-BLECKLEY-BUTTS-CARROLL-CATOOSA-
CHATTAHOOCHEE-CHATTOOGA-CHEROKEE-CLARKE-CLAYTON-COBB-COWETA-
CRAWFORD-CRISP-DADE-DAWSON-DEKALB-DODGE-DOOLY-DOUGLAS-EMANUEL-
FANNIN-FAYETTE-FLOYD-FORSYTH-GILMER-GLASCOCK-GORDON-GREENE-
GWINNETT-HALL-HANCOCK-HARALSON-HARRIS-HEARD-HENRY-HOUSTON-JACKSON-
JASPER-JEFFERSON-JOHNSON-JONES-LAMAR-LAURENS-LUMPKIN-MACON-
MADISON-MARION-MERIWETHER-MONROE-MONTGOMERY-MORGAN-MURRAY-
MUSCOGEE-NEWTON-NORTH FULTON-OCONEE-OGLETHORPE-PAULDING-PEACH-
PICKENS-PIKE-POLK-PULASKI-PUTNAM-ROCKDALE-SCHLEY-SOUTH FULTON-
SPALDING-STEWART-SUMTER-TALBOT-TALIAFERRO-TAYLOR-TELFAIR-TOOMBS-
TOWNS-TREUTLEN-TROUP-TWIGGS-UNION-UPSON-WALKER-WALTON-WARREN-
WASHINGTON-WEBSTER-WHEELER-WHITE-WHITFIELD-WILCOX-WILKES-
WILKINSON-
628 AM EDT WED APR 27 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH AND CENTRAL GEORGIA.

.DAY ONE...TODAY AND TONIGHT
NUMEROUS SEVERE THUNDERSTORMS AND TORNADOES LIKELY THIS AFTERNOON
AND TONIGHT FOR MUCH OF NORTH GEORGIA. A FEW SEVERE THUNDERSTORMS
AND ISOLATED TORNADOES POSSIBLE FOR CENTRAL GEORGIA TONIGHT.

.SYNOPSIS...
A STRONG STORM SYSTEM WILL BE MOVING INTO THE MID MISSISSIPPI
VALLEY THIS AFTERNOON WITH A COLD FRONT TRAILING ALONG THE
MISSISSIPPI RIVER. THIS STORM SYSTEM WILL MOVE EASTWARD THIS
AFTERNOON AND EVENING...MOVING ACROSS GEORGIA OVERNIGHT.

.PRIMARY HAZARDS...
THE PRIMARY HAZARDS WILL BE TORNADOES...LARGE HAIL...AND
WIDESPREAD DAMAGING WINDS FOR MUCH OF NORTH GEORGIA...ESPECIALLY
FAR NORTHWEST GEORGIA THIS AFTERNOON AND EVENING. A FEW TORNADOES
AND SEVERE THUNDERSTORMS ARE ALSO POSSIBLE ACROSS CENTRAL GEORGIA
THIS EVENING AND AFTER MIDNIGHT.

.DISCUSSION...
A VERY WARM AND MOIST AIR MASS WILL BE IN PLACE ACROSS GEORGIA
TODAY AHEAD OF THE COLD FRONT WHICH WILL BE MOVING EASTWARD FROM
THE MISSISSIPPI VALLEY. THE ATMOSPHERE WILL BE VERY UNSTABLE TODAY
AND WIND FIELDS ALOFT WILL BE HIGHLY SHEARED. A LOW LEVEL JET OF
60KT OR MORE IS EXPECTED TO MOVE ACROSS GEORGIA THIS AFTERNOON AND
EVENING. THIS WILL SUPPORT NUMEROUS SEVERE THUNDERSTORMS AND
TORNADOES OVER MUCH OF NORTH GEORGIA THIS AFTERNOON AND TONIGHT.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY
THERE IS A CHANCE OF THUNDERSTORMS MONDAY...MONDAY NIGHT...AND
TUESDAY. OTHERWISE NO HAZARDOUS WEATHER IS EXPECTED.

.SPOTTER INFORMATION STATEMENT...
SPOTTERS SHOULD BE PREPARED FOR ACTIVATION ESPECIALLY FOR THIS
AFTERNOON AND TONIGHT ACROSS NORTH GEORGIA.

In the hours before

Local storm report, Apr 27, 10:32 PM EDT, 48 minutes before
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Local storm report, Apr 27, 10:38 PM EDT, 42 minutes before
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Local storm report, Apr 27, 11:03 PM EDT, 17 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1103 PM EDT WED APR 27 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1050 PM     TSTM WND DMG     WNW MOUNTAIN SCENE      34.86N 83.73W
04/27/2011                   TOWNS              GA   EMERGENCY MNGR

            TOWNS COUNTY EMERGENCY MANAGEMENT REPORTS A TREE DOWNED
            ONTO A HOUSE ON THE SOUTHERN END OF THE COUNTY.

&&

RGARCIA
Local storm report, Apr 27, 11:06 PM EDT, 14 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
1106 PM EDT WED APR 27 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1049 PM     TSTM WND DMG     SALACOA VALLEY          34.38N 84.59W
04/27/2011                   CHEROKEE           GA   EMERGENCY MNGR

            CHEROKEE COUNTY EMERGENCY MANAGEMENT IS REPORTING SEVERAL
            TREES DOWN IN SALACOA VALLEY.

&&

RGARCIA

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.

Peachtre/Fal Fld, GA (KFFC), 00:00Z

3.3 hours before the tornado, 61 km from the path. April 28, 2011.

Skew-T log-pSkew-T log-p diagram, Peachtre/Fal Fld, GA at 00:00Z on 2011-04-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1215 joules per kilogram, CIN -15, lifted condensation level 1433 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, Peachtre/Fal Fld, GA at 00:00Z on 2011-04-28The 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 244 square meters per square second, 0 to 6 km bulk shear 49 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
1215 J/kg
Mixed-layer CIN
-15 J/kg
Surface CAPE
1868 J/kg
Mixed-layer LCL
1433 m above ground
0-6 km bulk shear
49 kt
0-1 km bulk shear
29 kt
0-1 km storm-relative helicity
244 m²/s²
0-3 km storm-relative helicity
408 m²/s²
Significant tornado parameter
1.6
Supercell composite
15.2
0-3 km lapse rate
7.6 K/km

Open this sounding in Storm Lab

Peachtre/Fal Fld, GA (KFFC), 12:00Z

8.7 hours after it, 61 km from the path. April 28, 2011.

Skew-T log-pSkew-T log-p diagram, Peachtre/Fal Fld, GA at 12:00Z on 2011-04-28Temperature 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 -59505, lifted condensation level 1351 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, Peachtre/Fal Fld, GA at 12:00Z on 2011-04-28The 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 -167 square meters per square second, 0 to 6 km bulk shear 72 knots.1939587897Sfc1 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
-59505 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1351 m above ground
0-6 km bulk shear
72 kt
0-1 km bulk shear
29 kt
0-1 km storm-relative helicity
-167 m²/s²
0-3 km storm-relative helicity
46 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1
0-3 km lapse rate
4.7 K/km

Open this sounding in Storm Lab

The surface observations

La_grange (LGC), 9 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
00:00 UTC

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

The radar

The Atlanta radar (KFFC), 56 km away, was scanning. The volume nearest the touchdown began at 03:21 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.

This ground now

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

The other tornadoes of April 27, 2011

209 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 271:12 AM CDTEF1Yazoo, MS9.7250$70,000
April 271:15 AM CDTEF1Leflore, MS27.750$50,000
April 271:24 AM CDTEF1Leflore, MS3.2100$50,000
April 271:36 AM CDTEF0LaSalle Parish, LA8.0100$40,000
April 271:40 AM CDTEF2Holmes, MS12.31,760$100,000
April 271:40 AM CDTEF3Holmes, MS23.01,760$700,000
April 271:51 AM CDTEF2Attala, MS23.0860$553,000
April 271:51 AM CDTEF0Holmes, MS1.750$25,000
April 271:59 AM CDTEF2Holmes, MS8.8880$10,000
April 272:06 AM CDTEF1Grenada, MS1.9150$60,000
April 272:17 AM CDTEF2Montgomery, MS11.71,760$425,000
April 272:20 AM CDTEF1Attala, MS0.550$25,000
April 272:25 AM CDTEF2Choctaw, MS6.81,7502$350,000
April 272:29 AM CDTEF1Winston, MS4.2150$85,000
April 272:29 AM CDTEF3Choctaw, MS58.71,80025$5.4 million
April 272:37 AM CDTEF2Webster, MS13.31,32015$605,000
April 272:47 AM CDTEF1Winston, MS7.3200$60,000
April 273:20 AM CDTEF1Noxubee, MS6.2150$300,000
April 273:43 AM CDTEF2Tishomingo, MS9.31501$500,000
April 274:01 AM CDTEF1Lauderdale, AL to TN9.2200$1,000
April 274:03 AM CDTEF2Kemper, MS to AL35.21,410$3.2 million
April 274:19 AM CDTEF1Lauderdale, AL1.81001
April 274:27 AM CDTEF2Pickens, AL14.41,232$1.8 million
April 274:41 AM CDTEF3Pickens, AL22.5704$741,000
April 275:03 AM CDTEF1Fayette, AL7.31764$1.4 million
April 275:17 AM CDTEF3Tuscaloosa, AL20.3200$9.3 million
April 275:18 AM CDTEF3Walker, AL18.937520$13 million
April 275:38 AM CDTEF2Lincoln, TN25.9400
April 275:40 AM CDTEF1Marshall, TN2.9100$75,000
April 275:47 AM CDTEF0Rutherford, TN2.150$8,000
April 275:48 AM CDTEF2Cullman, AL30.38801
April 275:50 AM CDTEF1Shelby, AL3.4100$3.7 million
April 275:50 AM CDTEF1Lawrence, TN2.71501$11,000
April 275:52 AM CDTEF0Rutherford, TN1.675$50,000
April 275:53 AM CDTEF2Blount, AL3.22003$9.3 million
April 275:54 AM CDTEF2Jefferson, AL7.820020$18 million
April 276:12 AM CDTEF1Blount, AL14.8200$42,000
April 276:13 AM CDTEF2Moore, TN2.075$25,000
April 276:16 AM CDTEF2St. Clair, AL3.82005$865,000
April 276:20 AM CDTEF1Marshall, AL11.075
April 276:24 AM CDTEF0Smith, TN3.450$5,000
April 276:24 AM CDTEF1Marshall, AL6.4100
April 276:30 AM CDTEF2Marshall, AL20.0880
April 276:30 AM CDTEF1Marshall, AL4.650
April 276:30 AM CDTEF1Marshall, AL3.4100
April 276:30 AM CDTEF1Marshall, AL5.750
April 276:32 AM CDTEF1Green, KY3.1150
April 276:35 AM CDTEF1Marshall, AL4.9100
April 276:35 AM CDTEF1Marshall, AL0.350$10,000
April 276:43 AM CDTEF0Marshall, AL2.875
April 276:45 AM CDTEF0Coffee, TN1.750$5,000
April 276:45 AM CDTEF1Marshall, AL4.8200
April 276:45 AM CDTEF1Marshall, AL6.9300
April 276:47 AM CDTEF1Jackson, TN3.3100$10,000
April 276:49 AM CDTEF0Jackson, TN2.050$20,000
April 276:49 AM CDTEF1Marshall, AL1.6100
April 276:50 AM CDTEF1Warren, TN13.2100$100,000
April 276:58 AM CDTEF1DeKalb, AL27.93001
April 277:02 AM CDTEF1Monroe, KY5.9550
April 277:10 AM CDTEF2DeKalb, AL5.8200$30,000

All 210 of them

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.