Tornadoes · United States · Alabama · 2011

EF1 tornado, Elliot Xrds to Ider, Alabama, April 27, 2011

Name: EF1 tornado, Elliot Xrds to Ider, Alabama, April 27, 2011
Start: 2011-04-27T12:18:00.000Z
End: 2011-04-27T12:22:00.000Z
Location: Elliot Xrds to Ider, Alabama

From Elliot Xrds to Ider, this EF1 tornado ran 4.0 miles across DeKalb County on April 27, 2011, touching down at 7:18 AM 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.

EF065 to 85 mph
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mphthis tornado
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
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.
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.
EF4166 to 200 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
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.
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 27, 2011
Touchdown: 7:18 AM CDT (12:18 UTC)
Lifted: 7:22 AM CDT (12:22 UTC)
On the ground: 4 minutes
Path length: 4.0 miles (6.5 km)
Path width: 50 yards (46 m)
Deaths: 0
Injuries: 0
County: DeKalb County
Touchdown point: 34.600, -85.584
Lift-off point: 34.652, -85.550
Record number: 1104270618-01

The damage survey

12 damage points were recorded along this path by NWS FFC and NWS HUN, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF4. The highest wind the damage implies is 185 mph.

End point in Alabama of Lakeview to Rainsville to Cartersville EF-5 Tornado.
End point of Section-Flat Rock, GA EF-4 Tornado in Alabama.

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 powerful storm system roared across the Southeast United States on Wednesday, April 27, 2011. In the wake of this system, hundreds of people were left injured and/or homeless, along with approximately 100 people who lost their lives in the northern Alabama area alone. Some of the devastation was literally unimaginable with countless homes, neighborhoods and even portions of cities or towns either partially or completely destroyed. This storm system would be responsible for one of the largest and deadliest tornado outbreaks to ever impact much of the southeastern region.| |The powerful storm system that affected the National Weather Service, Huntsville service area would actually occur in three separate waves of severe weather that day. The first occurred during the early morning hours of April 27, 2011 roughly between the hours of 2 AM and 8 AM CDT, while the second occurred during the late-morning to early afternoon period. The third and most devastating wave occurred during the afternoon hours on Wednesday, with some of the most violent and destructive tornadoes to affect the central Tennessee Valley area in recent decades.| |The worst areas impacted by these storms included the towns of Phil Campbell and Oak Grove in eastern Franklin County Alabama, Mt. Hope in western Lawrence County and the Tanner Community in eastern Limestone County. Along a line connecting these areas tracked an EF5 tornado with peak winds around 210 mph, the strongest and most violent on the Enhanced Fujita Scale. ||Other areas impacted by the storms include the city of Cullman, where extensive damage occurred to buildings in the downtown area, and to the town of Fairview, both of which are located in Cullman County. Downstream, further significant damage occurred to the Ruth and Oak Grove communities in Marshall County. In addition, the communities of Rainsville and Sylvania along with the towns of Henagar and Ider in DeKalb County were severely impacted. Fatalities in DeKalb County alone numbered at least 33 people. Furthermore, the towns of Flat Rock, Higdon and Pisgah in Jackson County sustained incredible damage. The tornadoes that affected these areas were rated as an EF4 with maximum winds near 190 mph.||In most of these areas alone, numerous people lost their lives. These represent just several of the communities and towns impacted by the events of April 27, 2011. While the majority of the analysis and survey work conducted by the National Weather Service, Huntsville and its partners have been completed, there will undoubtedly be countless research studies conducted by both academia and operational personnel in order to further evaluate and understand the complex processes associated with this near unprecedented severe weather outbreak.

The tornado touched down very briefly in the Henagar area and tracked northward. |Numerous large trees, some old oak trees, were snapped. Other large trees were uprooted as well along this portion of the track in DeKalb County.

A tornado producing damage of EF-1 intensity with peak winds of up to 100 mph touched down near Mentone. The tornado first touched down west of County Road 89 north of downtown Mentone. The tornado moved along a ridge line uprooting many softwood and hardwood trees and snapping them sporadically. The tornado eventually straddled the road further north partially removing a roof to a residence and snapping numerous trees in this area. The tornado lifted about a mile shy of the Georgia state line.

A tornado of EF-1 intensity producing wind speeds of up to 110 mph tracked out of Jackson County and took a short path into DeKalb County. Details are limited with this tornado path as later this same day, a violent tornado of EF-4 intensity struck the same area in a similar path making it very difficult to distinguish damage between the two tornadoes.

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

The warnings

10 minutes of warning. NWS HUN issued a tornado warning for this county at 12:08 UTC, 10 minutes before the tornado touched down, in force until 12:45 UTC.

The county was under a tornado watch, issued at 07:36 UTC and running to 13:00 UTC.

Issued (UTC)	Expired	Product	Office
07:36 UTC	13:00 UTC	Tornado Watch	HUN
10:00 UTC	01:00 UTC	Wind Advisory	HUN
11:44 UTC	12:30 UTC	Severe Thunderstorm Warning	HUN
11:45 UTC	12:30 UTC	Severe Thunderstorm Warning	HUN
11:52 UTC	12:09 UTC	Tornado Warning	HUN
12:08 UTC	12:45 UTC	Tornado Warning	HUN
12:24 UTC	12:45 UTC	Tornado Warning	HUN
12:25 UTC	12:45 UTC	Severe Thunderstorm Warning	HUN
14:53 UTC	18:45 UTC	Tornado Watch	HUN
17:40 UTC	18:45 UTC	Severe Thunderstorm Warning	HUN
18:11 UTC	18:45 UTC	Tornado Warning	HUN
18:29 UTC	21:30 UTC	Flash Flood Warning	HUN
18:45 UTC	02:33 UTC	Tornado Watch	HUN
21:11 UTC	21:41 UTC	Tornado Warning	HUN
21:30 UTC	02:30 UTC	Flash Flood Warning	HUN
22:39 UTC	23:15 UTC	Tornado Warning	HUN
23:08 UTC	23:45 UTC	Tornado Warning	HUN
23:36 UTC	00:00 UTC	Tornado Warning	HUN
02:00 UTC	02:28 UTC	Severe Thunderstorm Warning	HUN
02:26 UTC	16:30 UTC	Flood Warning	HUN

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 High Risk, with a 0.30 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 06:10 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 Huntsville, AL wrote its last area forecast discussion before the tornado touched down at Apr 27, 5:45 AM CDT, 1 hour 33 minutes earlier.

Area forecast discussion, Apr 27, 5:45 AM CDT, 1 hour 33 minutes before

AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE HUNTSVILLE AL
545 AM CDT WED APR 27 2011

...HIGH RISK FOR SEVERE WEATHER TODAY...
...POTENTIAL FOR WIDESPREAD TORNADO OUTBREAK WITH LONG-TRACK
TORNADIC SUPERCELLS TODAY...

.UPDATE...FOR 12Z TAFS.
&&

.AVIATION...
BAND OF SEVERE THUNDERSTORMS WILL EXIT KHSV VCNTY BFR 12Z.  -RA/RA
WITH EMBEDDED CG LTG WL CONTINUE THRU 13-14Z BEHIND THE LINE.  A
BREAK IN THE ACTIVITY IS EXPECTED BFR ADDITIONAL THUNDERSTORMS DVLP
LATER TODAY WITH A HIGH RISK OF SEVERE WX.
&&

.DISCUSSION...A COMPLICATED SCENARIO EVOLVING TODAY WITH INITIAL
CONVECTION ASSOCIATED WITH SIGNIFICANT WIND SHEAR AND INSTABILITY
LIKELY MOVING ACROSS NORTHWEST ALABAMA BY 08-12Z THIS MORNING. THIS
ACTIVITY SHOULD RAPIDLY MOVE ACROSS NORTH CENTRAL AND NORTHEAST
ALABAMA DURING THE MORNING HOURS.

FORECAST MODELS ARE HAVING SOME DIFFICULTY HANDLING THE INSTABILITY,
WIND SHEAR, AND MCV'S MOVING WITHIN THE TROUGH ITSELF. HOWEVER, IT
DOES APPEAR BY CURRENT TRENDS, THAT UPPER LEVEL FORCING WILL BE
SUFFICIENT TO SUPPORT WIDESPREAD CONVECTION TODAY. TURNING TO
INSTABILITY AND WIND SHEAR, THE ENVIRONMENT WILL BE EXTREMELY
UNSTABLE...ESPECIALLY DURING THE AFTERNOON AND EVENING HOURS AHEAD
OF THE COLD FRONT. CURVED HODOGRAPHS AND WIND SHEAR VALUES (AT TIMES
EXTREMELY HIGH) ALONG WITH INSTABILITY PARAMETERS ALL SUPPORT THE
POTENTIAL FOR A WIDESPREAD TORNADO OUTBREAK ACROSS SOUTHERN MIDDLE
TN AND NORTH ALABAMA. JUST TO GIVE FOLKS AN IDEA OF WHAT KIND OF
VALUES WE ARE SEEING BTWN 17-00Z:

1) SBCAPES ARE FORECAST TO BE 2500-3500 J/KG
2) 0-3KM SRH IS FORECAST TO BE 500-700 M2/S2
3) 0-3KM EHIS ARE FORECAST TO BE 4-8 M2/S2 OVER PORTIONS OF N
CENTRAL AL.
4) SFC DEWPOINTS ARE FORECAST TO BE BTWN 65-69F (POSSIBLY INTO THE
LOW 70S) DURING THE DAY.

IN ADDITION, A LLJ OF 65-75 KTS IS FORECAST TO REMAIN ACROSS THE
AREA THROUGHOUT MOST OF THE DAY. THE SFC LOW ASSOCIATED WITH THE
COLD FRONT WILL ALSO MOVE JUST TO THE NORTHWEST OF NW AL FROM S AR
(12Z TODAY) TO CENTRAL TN BY 18-23Z MEANING THAT CELLS CLOSER TO THE
SFC LOW IN THESE CASES TENDS TO DEVELOP OR MAINTAIN TORNADIC
ACTIVITY. UPPER LEVEL DIVERGENCE LOCATED JUST TO THE NE OF THE TN
VALLEY IS ALSO QUITE PRONOUNCED.

THEREFORE, GIVEN ALL OF THE ABOVE INFO., IT DOES APPEAR THAT LONG
TRACK TORNADIC SUPERCELLS ARE LIKELY ACROSS THE TN VALLEY. DAMAGING
WINDS AND LARGE HAIL ARE ALSO LIKELY WITH THESE STORMS. THOUGH HAIL
APPEARS TO BE THE LESSOR OF THE TWO. IT IS DIFFICULT TO SAY EXACTLY
WHEN THE CELLS WILL DEVELOP GIVEN THIS MORNING'S CONVECTION, BUT THE
TIME PERIOD WHEN ALL OF THESE INGREDIENTS APPEAR TO COME TOGETHER
APPEARS TO BE BTWN 17Z-00Z.

AS THE COLD FRONT APPROACHES THE TN VALLEY, EXPECTING AND REMAINING
FAST-MOVING SUPERCELLS TO BE CONGEALED INTO A QLCS WITH DAMAGING
WINDS AND BOWING SEGMENTS TO FINISH OFF THE SEVERE WEATHER THREAT.
THE FROPA TIMING SHOULD BE BTWN 21-03Z ACROSS NW AL (ENTERING) AND
03-06 ACROSS NE AL (EXITING).

AS IF WE NEEDED ANY MORE THREATS...FLASH FLOODING IS ALSO QUITE
LIKELY WITH CELLS TRAINING ALONG THE SAME AREAS ALONG WITH PROLIFIC
RAINFALL PRODUCING SUPERCELLS WOULD ACT TO CAUSE A CHALLENGING
FORECAST PROBLEM. GIVEN THE RECENT RAINFALL OVER NW AL, THOSE AREAS
APPEAR TO HAVE THE HIGHEST THREAT FOR FLASH FLOODING. WILL LEAVE THE
FLASH FLOOD WATCH IN PLACE.

AS MENTIONED PREVIOUSLY, THE LLJ WILL BE QUITE STRONG TODAY WHICH
MAY CAUSE INCREASED WINDS ACROSS THE AREA. THUS, WILL KEEP WIND
ADVISORY IN PLACE AS WELL.

BEHIND THE COLD FRONT CAA SHOULD QUICKLY DRY THE ATMOSPHERE FROM THE
WARM AND MUGGY CONDITIONS FELT TODAY INTO COOLER AND DRY BY LATE
WEDNESDAY NIGHT INTO THURSDAY. DAYTIME HIGHS WILL REGISTER CLOSE TO
THE 70 DEGREE MARK FOR THURSDAY WITH SUNNY CONDITIONS ON THE
BACKSIDE OF THE TROUGH. OVERNIGHT LOWS SHOULD ALSO EXPERIENCE A DROP
INTO THE UPPER 40S TO LOW 50S ON THURSDAY NIGHT WITH DAYTIME HIGHS
RECOVERING INTO THE MID 70S BY FRIDAY WITHIN RIDGE BUILDING. THERE
MAY BE A BRIEF TIME PERIOD OF CLOUDS ON SATURDAY AS A FEW WAVES OF
ENERGY CROSS THE REGION ATOP THE RIDGE. OTHERWISE, CONDITIONS SHOULD
BE PLEASANT WITH HIGHS IN THE LOW 80S FOR BOTH SATURDAY AND SUNDAY.

BY SATURDAY, ANOTHER LONGWAVE TROUGH CROSSING THE PACIFIC NORTHWEST
INTO THE ROCKIES WILL APPROACH THE AREA ON SUNDAY. THE MED RANGE
MODELS ARE CONTINUING TO HAVE TROUBLE WITH THE STRENGTH OF THE RIDGE
OVER THE SOUTHEAST AND THIS IS LIKELY WHY THE TIMING OF THIS SYSTEM
IS CONTINUING TO SLOW THIS SYSTEM DOWN. FOR NOW, WILL TAKE A
COMPROMISE SOLUTION AND TAKE OUT THUNDERSTORMS FOR SUNDAY AND KEEP
THEM FOR SUNDAY NIGHT INTO MONDAY NIGHT.
&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...FLASH FLOOD WATCH THROUGH THIS EVENING FOR THE FOLLOWING ZONES:
     COLBERT...CULLMAN...DEKALB...FRANKLIN AL...JACKSON...
     LAUDERDALE...LAWRENCE...LIMESTONE...MADISON...MARSHALL...
     MORGAN.

     WIND ADVISORY UNTIL 8 PM CDT THIS EVENING FOR THE FOLLOWING ZONES:
     COLBERT...CULLMAN...DEKALB...FRANKLIN AL...JACKSON...
     LAUDERDALE...LAWRENCE...LIMESTONE...MADISON...MARSHALL...
     MORGAN.

TN...FLASH FLOOD WATCH THROUGH THIS EVENING FOR THE FOLLOWING ZONES:
     FRANKLIN TN...LINCOLN...MOORE.

     WIND ADVISORY UNTIL 8 PM CDT THIS EVENING FOR THE FOLLOWING ZONES:
     FRANKLIN TN...LINCOLN...MOORE.

&&

AVIATION...KULA
DISCUSSION...SL.77

Hazardous weather outlook, Apr 27, 3:24 AM CDT, 3 hours 54 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HUNTSVILLE AL
324 AM CDT WED APR 27 2011

ALZ001>010-016-TNZ076-096-097-271815-
LAUDERDALE-COLBERT-FRANKLIN AL-LAWRENCE-LIMESTONE-MADISON-MORGAN-
MARSHALL-JACKSON-DEKALB-CULLMAN-MOORE-LINCOLN-FRANKLIN TN-
324 AM CDT WED APR 27 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH ALABAMA AND PORTIONS OF
SOUTHERN MIDDLE TENNESSEE.

.DAY ONE...TODAY AND TONIGHT...

A TORNADO WATCH IS IN EFFECT FOR ALL OF NORTHERN ALABAMA AND SOUTHERN
MIDDLE TENNESSEE THROUGH 8 AM CDT.

THUNDERSTORM ACTIVITY OVER EASTERN MISSISSIPPI WILL BEGIN AFFECTING
NORTHWEST ALABAMA AROUND 4 AM. THE PRIMARY THREATS WILL BE
TORNADOES...DAMAGING WINDS...LARGE HAIL AND VERY HEAVY RAINFALL.

STRONG TO SEVERE THUNDERSTORMS MAY BE ONGOING THIS MORNING...
PARTICULARLY ACROSS NORTHWEST ALABAMA.

THE ATMOSPHERE WILL BECOME VERY UNSTABLE...CREATING A VOLATILE
SITUATION ACROSS THE TENNESSEE VALLEY TODAY. THE POTENTIAL FOR A
SIGNIFICANT SEVERE WEATHER OUTBREAK WILL INCREASE...ESPECIALLY FROM
THE LATE MORNING INTO THE EARLY EVENING. SEVERE STORMS ARE EXPECTED
TO FORM AHEAD OF...AND ALONG A STRONG COLD FRONT AND MOVE RAPIDLY
ACROSS THE REGION. A POTENTIAL FOR STRONG...LONG TRACK TORNADOES
EXISTS...IN ADDITION TO DAMAGING WINDS...LARGE HAIL AND VERY HEAVY
RAINFALL. RESIDENTS ACROSS THE TENNESSEE VALLEY ARE URGED TO REMAIN
ALERT FOR LATER STATEMENTS AND POSSIBLE WARNINGS.

THE HEAVY RAINFALL FROM THESE THUNDERSTORMS IS EXPECTED TO INCREASE
THE POTENTIAL FOR FLASH FLOODING...WHICH WILL EVENTUALLY EVOLVE
INTO A SMALL STREAM AND RIVER FLOODING EVENT OVER THE NEXT FEW DAYS.
PLEASE REFER TO THE FLASH FLOOD WATCH FOR FURTHER INFORMATION ON THIS
THREAT. ALSO...WINDS OUTSIDE OF THUNDERSTORM ACTIVITY WILL LIKELY
REACH ADVISORY CRITERIA...THEREFORE A WIND ADVISORY WILL BE IN EFFECT
THROUGH 8 PM WEDNESDAY EVENING.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY...

THERE IS ANOTHER CHANCE FOR THUNDERSTORMS LATE THIS WEEKEND...AS
ANOTHER COLD FRONT PUSHES ACROSS THE AREA.

.SPOTTER CALL TO ACTION STATEMENT...

ACTIVATION OF STORM SPOTTERS AND EMERGENCY MANAGEMENT PERSONNEL WILL
BE REQUESTED BEFORE DAYBREAK...ESPECIALLY FOR THE WESTERN HALF OF THE
AREA. ACTIVATION IS LIKELY DURING THE DAY ON WEDNESDAY FOR THE ENTIRE
AREA.

RSB/DD

In the hours before

Local storm report, Apr 27, 7:02 AM CDT, 16 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HUNTSVILLE AL
702 AM CDT WED APR 27 2011

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

0641 AM     TORNADO          GUNTERSVILLE            34.36N 86.29W
04/27/2011                   MARSHALL           AL   EMERGENCY MNGR

            TRAINED SPOTTERS REPORTED POSSIBLE TORNADO TOUCHDOWN
            ALONG HIGHWAY 205 AND 431 JUST SOUTH OF GUNTERSVILLE.

&&

DJN

Local storm report, Apr 27, 7:04 AM CDT, 14 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HUNTSVILLE AL
704 AM CDT WED APR 27 2011

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

0608 AM     TSTM WND DMG     CARMARGO                35.08N 86.64W
04/27/2011                   LINCOLN            TN   LAW ENFORCEMENT

            TREES AND POWERLINES DOWN.

&&

DJN

Local storm report, Apr 27, 7:06 AM CDT, 12 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HUNTSVILLE AL
706 AM CDT WED APR 27 2011

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

0426 AM     TSTM WND DMG     N FLORENCE              34.80N 87.68W
04/27/2011                   LAUDERDALE         AL   TRAINED SPOTTER

            POWER OUTAGES AND A WIND GUST TO 70 MPH WAS REPORTED.

&&

KWEBER

Local storm report, Apr 27, 7:11 AM CDT, 7 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HUNTSVILLE AL
711 AM CDT WED APR 27 2011

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

0625 AM     TSTM WND DMG     ARAB                    34.32N 86.50W
04/27/2011                   MARSHALL           AL   TRAINED SPOTTER

            TREES DOWN ON HOMES ALONG HIGHWAY 231 SOUTH OF ARAB.
            POSSIBLE TORNADO.

&&

DJN

Local storm report, Apr 27, 7:14 AM CDT, 4 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HUNTSVILLE AL
714 AM CDT WED APR 27 2011

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

0420 AM     TORNADO          4 WSW OAKLAND           34.82N 87.87W
04/27/2011                   LAUDERDALE         AL   EMERGENCY MNGR

            *** 1 INJ *** AN EMA EMPLOYEE WITNESSED A TORNADO AT THE
            INTERSECTION OF CR 189 AND CR221. THE EMPLOYEE WAS
            INJURED BY BROKEN GLASS IN HIS VEHICLE. DAMAGE TO CHURCH
            AND RESIDENCE.

&&

DJN

Local storm report, Apr 27, 7:17 AM CDT, 1 minute before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HUNTSVILLE AL
717 AM CDT WED APR 27 2011

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

0427 AM     TSTM WND DMG     1 SE WATERLOO           34.91N 88.05W
04/27/2011                   LAUDERDALE         AL   EMERGENCY MNGR

            TREES AND POWERLINES DOWN.

&&

DJN

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), 12:00Z

0.3 hours before the tornado, 171 km from the path. April 27, 2011.

Skew-T log-p

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.

Hodograph

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: 748 J/kg
Mixed-layer CIN: -41 J/kg
Surface CAPE: 758 J/kg
Mixed-layer LCL: 501 m above ground
0-6 km bulk shear: 51 kt
0-1 km bulk shear: 44 kt
0-1 km storm-relative helicity: 345 m²/s²
0-3 km storm-relative helicity: 460 m²/s²
Significant tornado parameter: 1.5
Supercell composite: 5.4
0-3 km lapse rate: 4.5 K/km

Open this sounding in Storm Lab

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

11.7 hours after it, 171 km from the path. April 28, 2011.

Skew-T log-p

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.

Hodograph

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

The radar

The Northeast Alabama radar (KHTX), 58 km away, was scanning. The volume nearest the touchdown began at 12:17 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)	Report	Where	County	Remark
11:02 UTC	TSTM WND DMG	5 Ese Centre	Cherokee, AL	SIGNIFICANT STRUCTURAL DAMAGE TO NEW BETHEL CHURCH ON HWY 411N.
11:50 UTC	TSTM WND DMG	4 Nw Chigger Hill	Dekalb, AL	STRUCTURAL DAMAGE ALONG COUNTY ROAD 50 NEAR GROVE OAK. POSSIBLE TORNADO. TIME ESTIMATED FROM RADAR.
11:54 UTC	TSTM WND DMG	Pisgah	Jackson, AL	REPORTS OF STUCTURAL DAMAGE...NUMEROUS TREES DOWN...AND POWERLINES DOWN ALONG A PATH FROM PISGAH TO FLAT ROCK NEAR CR 120. POSSIBLE TORNADO DAMAGE.
11:58 UTC	TSTM WND DMG	5 Ese Slackland	Cherokee, AL	TREE ON HOUSE ON COUNTY ROAD 5.
12:00 UTC	TSTM WND DMG	Langston	Jackson, AL	LARGE TREES DOWN ON VEHICLES. TIME ESTIMATED FROM RADAR. POSSIBLE TORNADO.
12:02 UTC	TSTM WND DMG	3 Nnw Centre	Cherokee, AL	TREES DOWN IN TEH TATES CHAPEL COMMUNITY.
12:05 UTC	TSTM WND DMG	Centre	Cherokee, AL	A LARGE TREE FELL ON A HOME ALONG HIGHWAY 411 NORTH. ONE PERSON WAS TRAPPED. NUMEROUS TREES DOWN AROUND THE AREA.
12:05 UTC	TSTM WND DMG	Centre	Cherokee, AL	A LARGE TREE FELL ON A HOME ALONG HIGHWAY 411 NORTH. ON PERSON WAS TRAPPED.
12:05 UTC	TSTM WND DMG	Section	Jackson, AL	NUMEROUS TREES DOWN BETWEEN SECTION AND MACEDONIA ALONG HIGHWAY 35. TIME ESTIMATED FROM RADAR.
12:06 UTC	TSTM WND DMG	5 Ese Centre	Cherokee, AL	SIGNIFICANT STRUCTURAL DAMAGE TO NEW BETHEL CHURCH ON HWY 411N.

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

This ground now

The live radar over the track Every 2011 tornado in Alabama Every tornado in Alabama since 1950 Warnings in force in Alabama now The forecast where you are

The other tornadoes of April 27, 2011

209 more were confirmed in the United States that day.

Date	Time	Rating	Where	Path (mi)	Width (yd)	Deaths	Injuries	Damage
April 27	1:12 AM CDT	EF1	Yazoo, MS	9.7	250			$70,000
April 27	1:15 AM CDT	EF1	Leflore, MS	27.7	50			$50,000
April 27	1:24 AM CDT	EF1	Leflore, MS	3.2	100			$50,000
April 27	1:36 AM CDT	EF0	LaSalle Parish, LA	8.0	100			$40,000
April 27	1:40 AM CDT	EF2	Holmes, MS	12.3	1,760			$100,000
April 27	1:40 AM CDT	EF3	Holmes, MS	23.0	1,760			$700,000
April 27	1:51 AM CDT	EF2	Attala, MS	23.0	860			$553,000
April 27	1:51 AM CDT	EF0	Holmes, MS	1.7	50			$25,000
April 27	1:59 AM CDT	EF2	Holmes, MS	8.8	880			$10,000
April 27	2:06 AM CDT	EF1	Grenada, MS	1.9	150			$60,000
April 27	2:17 AM CDT	EF2	Montgomery, MS	11.7	1,760			$425,000
April 27	2:20 AM CDT	EF1	Attala, MS	0.5	50			$25,000
April 27	2:25 AM CDT	EF2	Choctaw, MS	6.8	1,750		2	$350,000
April 27	2:29 AM CDT	EF1	Winston, MS	4.2	150			$85,000
April 27	2:29 AM CDT	EF3	Choctaw, MS	58.7	1,800		25	$5.4 million
April 27	2:37 AM CDT	EF2	Webster, MS	13.3	1,320	1	5	$605,000
April 27	2:47 AM CDT	EF1	Winston, MS	7.3	200			$60,000
April 27	3:20 AM CDT	EF1	Noxubee, MS	6.2	150			$300,000
April 27	3:43 AM CDT	EF2	Tishomingo, MS	9.3	150		1	$500,000
April 27	4:01 AM CDT	EF1	Lauderdale, AL to TN	9.2	200			$1,000
April 27	4:03 AM CDT	EF2	Kemper, MS to AL	35.2	1,410			$3.2 million
April 27	4:19 AM CDT	EF1	Lauderdale, AL	1.8	100		1
April 27	4:27 AM CDT	EF2	Pickens, AL	14.4	1,232			$1.8 million
April 27	4:41 AM CDT	EF3	Pickens, AL	22.5	704			$741,000
April 27	5:03 AM CDT	EF1	Fayette, AL	7.3	176		4	$1.4 million
April 27	5:17 AM CDT	EF3	Tuscaloosa, AL	20.3	200			$9.3 million
April 27	5:18 AM CDT	EF3	Walker, AL	18.9	375		20	$13 million
April 27	5:38 AM CDT	EF2	Lincoln, TN	25.9	400
April 27	5:40 AM CDT	EF1	Marshall, TN	2.9	100			$75,000
April 27	5:47 AM CDT	EF0	Rutherford, TN	2.1	50			$8,000
April 27	5:48 AM CDT	EF2	Cullman, AL	30.3	880	1
April 27	5:50 AM CDT	EF1	Shelby, AL	3.4	100			$3.7 million
April 27	5:50 AM CDT	EF1	Lawrence, TN	2.7	150		1	$11,000
April 27	5:52 AM CDT	EF0	Rutherford, TN	1.6	75			$50,000
April 27	5:53 AM CDT	EF2	Blount, AL	3.2	200		3	$9.3 million
April 27	5:54 AM CDT	EF2	Jefferson, AL	7.8	200		20	$18 million
April 27	6:12 AM CDT	EF1	Blount, AL	14.8	200			$42,000
April 27	6:13 AM CDT	EF2	Moore, TN	2.0	75			$25,000
April 27	6:16 AM CDT	EF2	St. Clair, AL	3.8	200		5	$865,000
April 27	6:20 AM CDT	EF1	Marshall, AL	11.0	75
April 27	6:24 AM CDT	EF0	Smith, TN	3.4	50			$5,000
April 27	6:24 AM CDT	EF1	Marshall, AL	6.4	100
April 27	6:30 AM CDT	EF2	Marshall, AL	20.0	880
April 27	6:30 AM CDT	EF1	Marshall, AL	4.6	50
April 27	6:30 AM CDT	EF1	Marshall, AL	3.4	100
April 27	6:30 AM CDT	EF1	Marshall, AL	5.7	50
April 27	6:32 AM CDT	EF1	Green, KY	3.1	150
April 27	6:35 AM CDT	EF1	Marshall, AL	4.9	100
April 27	6:35 AM CDT	EF1	Marshall, AL	0.3	50			$10,000
April 27	6:43 AM CDT	EF0	Marshall, AL	2.8	75
April 27	6:45 AM CDT	EF0	Coffee, TN	1.7	50			$5,000
April 27	6:45 AM CDT	EF1	Marshall, AL	4.8	200
April 27	6:45 AM CDT	EF1	Marshall, AL	6.9	300
April 27	6:47 AM CDT	EF1	Jackson, TN	3.3	100			$10,000
April 27	6:49 AM CDT	EF0	Jackson, TN	2.0	50			$20,000
April 27	6:49 AM CDT	EF1	Marshall, AL	1.6	100
April 27	6:50 AM CDT	EF1	Warren, TN	13.2	100			$100,000
April 27	6:58 AM CDT	EF1	DeKalb, AL	27.9	300	1
April 27	7:02 AM CDT	EF1	Monroe, KY	5.9	550
April 27	7:10 AM CDT	EF2	DeKalb, AL	5.8	200			$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.