Tornadoes · United States · Arkansas · 2011

EF1 tornado, Pisgah to Piney Grove, Arkansas, April 25, 2011

Name: EF1 tornado, Pisgah to Piney Grove, Arkansas, April 25, 2011
Start: 2011-04-25T23:29:00.000Z
End: 2011-04-25T23:32:00.000Z
Location: Pisgah to Piney Grove, Arkansas

From Pisgah to Piney Grove, this EF1 tornado ran 4.2 miles across Pike County on April 25, 2011, touching down at 6:29 PM CDT and reaching 250 yards wide. It killed nobody, and did $100,000 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.

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 25, 2011
Touchdown: 6:29 PM CDT (23:29 UTC)
Lifted: 6:32 PM CDT (23:32 UTC)
On the ground: 3 minutes
Path length: 4.2 miles (6.7 km)
Path width: 250 yards (229 m)
Deaths: 0
Injuries: 0
Property damage: $100,000
County: Pike County
Touchdown point: 33.967, -93.545
Lift-off point: 34.004, -93.488
Record number: 1104251729-01

What the Weather Service recorded

From the 24th through the 27th, the arrival of a slow-moving cold front and several low pressure areas aloft triggered several rounds of thunderstorms. Tornadoes, severe storms, and flash flooding resulted. Widespread areal flooding followed the flash flooding. Some of this flooding was due to heavy rain, while some of it was caused by water from rivers, creeks, and bayous backing up onto the land. On the evening of the 25th, devastating tornadoes affected several areas in central Arkansas. More than 140,000 electric customers in Arkansas lost power. Heavy rains during this period were the beginning of the Great Flood of 2011 in Arkansas. Much of the flooding lasted well into May, and some even continued all the way to late June.

The tornado blew down numerous trees, one of which fell on the cab of a tractor-trailer.

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

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 Little Rock, AR wrote its last area forecast discussion before the tornado touched down at Apr 25, 3:29 PM CDT, 3 hours earlier.

Area forecast discussion, Apr 25, 3:29 PM CDT, 3 hours before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LITTLE ROCK AR
329 PM CDT MON APR 25 2011

.DISCUSSION...
MAIN CONCERN IS FORECAST EVENTS DURING THE FIRST 48 HOURS OF THE
VALID FORECAST PERIOD.

CONTINUING TO MONITOR SEVERE CONVECTION ACROSS WESTERN PORTIONS OF
THE FORECAST AREA...AS WELL AS FLASH FLOODING POTENTIAL ACROSS
THE NORTH. STRONGEST CONVECTION CONTINUES TO TRAIN ACROSS AN INSTABILITY
GRADIENT...AND THROUGH AN AXIS OF HIGHEST 0-3KM SHEAR. EXPECT
THIS ACTIVITY TO SPREAD EASTWARD OVERNIGHT...WITH THE OVERALL
INTENSITY SLOWLY WEAKENING.

NEXT ROUND OF SEVERE CONVECTION APPEARS FOR TUESDAY
AFTERNOON....ESPECIALLY ACROSS CENTRAL AND EASTERN SECTIONS.
EXPECT SUFFICIENT RECOVERY FROM OVERNIGHT CONVECTIVE OVERTURNING
TO SUPPORT SEVERE CONVECTION.

55

&&

.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR     59  76  54  66 /  70  40  60  60
CAMDEN AR         63  81  63  75 /  60  40  70  50
HARRISON AR       53  73  49  59 /  70  30  50  60
HOT SPRINGS AR    61  78  59  69 /  70  40  70  60
LITTLE ROCK   AR  62  79  60  71 /  70  40  70  60
MONTICELLO AR     65  83  64  78 /  60  50  70  50
MOUNT IDA AR      59  76  56  66 /  70  30  70  60
MOUNTAIN HOME AR  55  74  50  61 /  70  30  50  60
NEWPORT AR        61  77  57  69 /  70  50  70  60
PINE BLUFF AR     64  81  63  75 /  70  50  70  60
RUSSELLVILLE AR   58  76  55  65 /  70  30  60  60
SEARCY AR         61  77  58  69 /  70  50  70  60
STUTTGART AR      64  80  62  74 /  70  50  70  60
&&

.LZK WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 10 PM CDT THIS EVENING FOR ARKANSAS-
BAXTER-BOONE-BRADLEY-CALHOUN-CLARK-CLEBURNE-CLEVELAND-CONWAY-
DALLAS-DESHA-DREW-FAULKNER-FULTON-GARLAND-GRANT-HOT SPRING-
INDEPENDENCE-IZARD-JACKSON-JEFFERSON-JOHNSON-LINCOLN-LOGAN-
LONOKE-MARION-MONROE-MONTGOMERY-NEWTON-OUACHITA-PERRY-PIKE-POLK-
POPE-PRAIRIE-PULASKI-SALINE-SCOTT-SEARCY-SHARP-STONE-VAN BUREN-
WHITE-WOODRUFF-YELL.

FLASH FLOOD WATCH THROUGH WEDNESDAY MORNING FOR ARKANSAS-BRADLEY-
CALHOUN-CLARK-CLEBURNE-CLEVELAND-CONWAY-DALLAS-DESHA-DREW-
FAULKNER-GARLAND-GRANT-HOT SPRING-INDEPENDENCE-JACKSON-JEFFERSON-
LINCOLN-LOGAN-LONOKE-MONROE-MONTGOMERY-OUACHITA-PERRY-PIKE-POLK-
POPE-PRAIRIE-PULASKI-SALINE-SCOTT-VAN BUREN-WHITE-WOODRUFF-YELL.

FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR BAXTER-BOONE-
FULTON-IZARD-JOHNSON-MARION-NEWTON-SEARCY-SHARP-STONE.

&&

Hazardous weather outlook, Apr 25, 2:12 PM CDT, 4 hours 17 minutes before

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE LITTLE ROCK AR
212 PM CDT MON APR 25 2011

ARZ003>007-012>016-021>025-030>034-037>047-052>057-062>069-261000-
ARKANSAS-BAXTER-BOONE-BRADLEY-CALHOUN-CLARK-CLEBURNE-CLEVELAND-
CONWAY-DALLAS-DESHA-DREW-FAULKNER-FULTON-GARLAND-GRANT-HOT SPRING-
INDEPENDENCE-IZARD-JACKSON-JEFFERSON-JOHNSON-LINCOLN-LOGAN-LONOKE-
MARION-MONROE-MONTGOMERY-NEWTON-OUACHITA-PERRY-PIKE-POLK-POPE-
PRAIRIE-PULASKI-SALINE-SCOTT-SEARCY-SHARP-STONE-VAN BUREN-WHITE-
WOODRUFF-YELL-
212 PM CDT MON APR 25 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR A LARGE PART OF ARKANSAS.

.DAY ONE...THIS AFTERNOON AND TONIGHT

HEAVY RAINFALL AND FLOODING CONTINUE TO BE A CONCERN ACROSS THE
STATE...AS SHOWERS AND THUNDERSTORMS CONTINUE TO MOVE ACROSS
ARKANSAS. RAINFALL AMOUNTS THROUGH TONIGHT WILL AVERAGE ONE TO THREE
INCHES...WITH LOCALLY HIGHER AMOUNTS. THIS RAINFALL WILL FALL OVER
SATURATED GROUND...WITH FLASH FLOODING POSSIBLE. A FLASH FLOOD WATCH
IS IN EFFECT FOR ENTIRE AREA.

IN ADDITION TO FLASH FLOODING...RIVER FLOODING IS ALSO A CONCERN...
AS THE RIVERS RISE DUE TO RUNOFF. THE MAIN AREAS OF CONCERN FOR
TODAY ARE IN THE WHITE RIVER BASIN...INCLUDING THE BUFFALO...
SPRING...ELEVEN POINT...BLACK AND WHITE RIVERS.

STRONG TO SEVERE THUNDERSTORMS ARE MOVING INTO ARKANSAS THIS
AFTERNOON. SHOWERS AND THUNDERSTORMS FROM LAST NIGHT HAVE LEFT A
BOUNDARY DRAPED ACROSS THE CENTRAL PART OF THE STATE. CONTINUED RAIN
SHOWERS NORTH OF THIS BOUNDARY WILL SOMEWHAT MINIMIZE THE TORNADO
THREAT IN FAR NORTHWEST PARTS OF THE STATE...WITH LARGE HAIL BEING
THE MAIN THREAT. HOWEVER...ALONG AND SOUTH OF THE BOUNDARY...THE
THREAT WILL REMAIN FOR ISOLATED TORNADOES IN ADDITION TO POTENTIALLY
VERY LARGE HAIL AND DAMAGING WINDS. THE TORNADO THREAT MAY BE
MAXIMIZED IN CENTRAL ARKANSAS THIS EVENING IN VICINITY OF THE
BOUNDARY.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

HEAVY RAINFALL WILL CONTINUE TO BE A CONCERN THROUGH WEDNESDAY...AS
SHOWERS AND THUNDERSTORMS WILL MOVE OVER AREAS THAT HAVE ALREADY
RECEIVED SEVERAL INCHES OF RAIN. RAINFALL AMOUNTS THROUGH MIDWEEK
MAY EXCEED 5 INCHES...WITH A FLASH FLOOD WATCH IN EFFECT THROUGH
TUESDAY NIGHT. IN ADDITION...RIVER FLOODING WILL REMAIN A
CONCERN...AS IT WILL TAKE SOME TIME FOR ALL THE WATER TO MOVE
DOWNSTREAM.

STRONG TO SEVERE THUNDERSTORMS WILL AGAIN BE POSSIBLE TUESDAY...AS A
COLD FRONT MOVES INTO THE STATE. THE BEST THREAT FOR SEVERE STORMS
MAY HOLD OFF UNTIL LATE TUESDAY AFTERNOON OR TUESDAY EVENING...WHEN
EXPLOSIVE DEVELOPMENT WILL BE POSSIBLE. THE MAIN CONCERNS WILL AGAIN
BE VERY LARGE HAIL AND ISOLATED TORNADOES...ESPECIALLY ACROSS THE
SOUTHEAST HALF OF THE STATE. THIS AREA IS IN A MODERATE RISK FOR
SEVERE WEATHER...WITH A SLIGHT RISK ACROSS THE NORTHWEST HALF.

HIGH PRESSURE WILL FINALLY BRING AN END TO THE RAINFALL WEDNESDAY
NIGHT...BUT RIVER FLOODING WILL REMAIN A CONCERN EVEN AFTER THE
RAINFALL ENDS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED FOR THE NEXT SEVERAL DAYS...FOR
SEVERE WEATHER AND FLOODING CONCERNS.

&&

VISIT NWS LITTLE ROCK ON THE WEB. GO TO HTTP://WEATHER.GOV AND
CLICK ON CENTRAL ARKANSAS.

58/63

In the hours before

Local storm report, Apr 25, 6:01 PM CDT, 28 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LITTLE ROCK AR
601 PM CDT MON APR 25 2011

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

0521 PM     TSTM WND DMG     LAKE OUACHITA STATE PAR 34.62N 93.19W
04/25/2011                   GARLAND            AR   AMATEUR RADIO

            CONSIDERABLE DAMAGE WAS REPORTED AT LAKE OUACHITA STATE
            PARK.

&&

57

Local storm report, Apr 25, 6:02 PM CDT, 27 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LITTLE ROCK AR
602 PM CDT MON APR 25 2011

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

0558 PM     FUNNEL CLOUD     PINEY                   34.50N 93.14W
04/25/2011                   GARLAND            AR   LAW ENFORCEMENT

            FUNNEL CLOUD WAS REPORTED NEAR PINEY.

&&

55

Local storm report, Apr 25, 6:03 PM CDT, 26 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LITTLE ROCK AR
603 PM CDT MON APR 25 2011

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

0601 PM     HAIL             SUNSHINE                34.47N 93.23W
04/25/2011  E1.00 INCH       GARLAND            AR   LAW ENFORCEMENT

&&

55

Local storm report, Apr 25, 6:07 PM CDT, 22 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LITTLE ROCK AR
607 PM CDT MON APR 25 2011

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

0607 PM     HAIL             4 W ROYAL               34.52N 93.30W
04/25/2011  E1.75 INCH       GARLAND            AR   LAW ENFORCEMENT

&&

55

Local storm report, Apr 25, 6:15 PM CDT, 14 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LITTLE ROCK AR
615 PM CDT MON APR 25 2011

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

0610 PM     HAIL             PINEY                   34.50N 93.14W
04/25/2011  E1.00 INCH       GARLAND            AR   LAW ENFORCEMENT

0613 PM     HAIL             HOT SPRINGS             34.49N 93.05W
04/25/2011  E1.00 INCH       GARLAND            AR   TRAINED SPOTTER

            QUARTER SIZED HAIL WAS REPORTED 1 MILE WEST OF HOT
            SPRINGS AIRPORT.

&&

57

Local storm report, Apr 25, 6:19 PM CDT, 10 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LITTLE ROCK AR
619 PM CDT MON APR 25 2011

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

0615 PM     HAIL             HOT SPRINGS             34.49N 93.05W
04/25/2011  E1.75 INCH       GARLAND            AR   TRAINED SPOTTER

&&

61

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.

Shreveport, LA (KSHV), 12:00Z

11.5 hours before the tornado, 169 km from the path. April 25, 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: 1213 J/kg
Mixed-layer CIN: -34 J/kg
Surface CAPE: 1595 J/kg
Mixed-layer LCL: 759 m above ground
0-6 km bulk shear: 44 kt
0-1 km bulk shear: 26 kt
0-1 km storm-relative helicity: 231 m²/s²
0-3 km storm-relative helicity: 491 m²/s²
Significant tornado parameter: 2.2
Supercell composite: 11.5
0-3 km lapse rate: 4.9 K/km

Open this sounding in Storm Lab

Shreveport, LA (KSHV), 00:00Z

0.5 hours after it, 169 km from the path. April 26, 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: 782 J/kg
Mixed-layer CIN: -155 J/kg
Surface CAPE: 1515 J/kg
Mixed-layer LCL: 1445 m above ground
0-6 km bulk shear: 45 kt
0-1 km bulk shear: 30 kt
0-1 km storm-relative helicity: 262 m²/s²
0-3 km storm-relative helicity: 553 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 15.0
0-3 km lapse rate: 5.9 K/km

Open this sounding in Storm Lab

The surface observations

Arkadelphia (ADF), 43 km from the path, in the two hours either side.

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

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

The radar

The Little Rock radar (KLZK), 149 km away, was scanning. The volume nearest the touchdown began at 23:29 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 track Every 2011 tornado in Arkansas Every tornado in Arkansas since 1950 Warnings in force in Arkansas now The forecast where you are

The other tornadoes of April 25, 2011

45 more were confirmed in the United States that day.

Date	Time	Rating	Where	Path (mi)	Width (yd)	Deaths	Injuries	Damage
April 25	9:05 AM CDT	EF0	Hempstead, AR	7.6	100
April 25	1:55 PM CDT	EF0	Hood, TX	2.5	150
April 25	2:00 PM CDT	EF0	Hood, TX	0.4	25
April 25	2:02 PM CDT	EF0	McCurtain, OK	9.2	75
April 25	2:55 PM CDT	EF1	Polk, AR	5.8	50			$250,000
April 25	3:00 PM CDT	EF0	Somervell, TX	0.8	50
April 25	3:10 PM CDT	EF0	Johnson, TX	2.6	400
April 25	3:15 PM CDT	EF0	Johnson, TX	0.9	150
April 25	3:32 PM CDT	EF1	Cherokee, TX	8.6	75			$500
April 25	4:23 PM CDT	EF0	Hill, TX	0.7	30
April 25	4:23 PM CDT	EF1	Christian, KY	1.5	275			$100,000
April 25	4:24 PM CDT	EF1	Garland, AR	9.3	300			$600,000
April 25	4:35 PM CDT	EF1	Pike, AR	11.6	800			$290,000
April 25	4:56 PM CDT	EF2	Garland, AR	5.9	200		9	$3.0 million
April 25	5:00 PM CDT	EF1	Pike, AR	4.3	300			$200,000
April 25	5:02 PM CDT	EF2	Garland, AR	14.4	300		10	$5.0 million
April 25	5:18 PM CDT	EF0	McCurtain, OK	2.5	50			$5,000
April 25	5:20 PM CDT	EF0	Ellis, TX	0.5	50			$25,000
April 25	5:37 PM CDT	EF0	Sevier, AR	7.4	70
April 25	5:47 PM CDT	EF1	Wayne, MO	11.8	200			$25,000
April 25	5:58 PM CDT	EF1	Wayne, MO	5.9	500			$70,000
April 25	6:07 PM CDT	EF3	Garland, AR	16.8	300	1	20	$23 million
April 25	6:21 PM CDT	EF1	Perry, AR	6.0	300			$700,000
April 25	6:30 PM CDT	EF1	Bollinger, MO	2.8	70			$200,000
April 25	6:48 PM CDT	EF1	Pulaski, AR	1.6	400			$250,000
April 25	6:48 PM CDT	EF2	Pulaski, AR	51.3	2,900	4	16	$53 million
April 25	6:53 PM CDT	EF0	Limestone, TX	1.3	100
April 25	6:59 PM CDT	EF0	Freestone, TX	0.8	100
April 25	7:06 PM CDT	EF1	Faulkner, AR	1.1	50			$100,000
April 25	7:25 PM CDT	EF0	Freestone, TX	3.5	500
April 25	7:35 PM CDT	EF0	Leon, TX	0.9	100
April 25	7:46 PM CDT	EF2	Pulaski, AR	5.2	350		4	$125 million
April 25	7:53 PM CDT	EF1	Lonoke, AR	21.9	800			$390,000
April 25	8:15 PM CDT	EF1	Prairie, AR	6.2	100			$25,000
April 25	8:24 PM CDT	EF1	White, AR	8.9	100			$1.0 million
April 25	9:15 PM CDT	EF1	Houston, TX	0.2	30			$50,000
April 25	9:37 PM CDT	EF1	Angelina, TX	7.7	250			$400,000
April 25	9:45 PM CDT	EF1	Trinity, TX	0.6	100			$30,000
April 25	10:13 PM CDT	EF0	Angelina, TX	0.7	25			$2,000
April 25	11:45 PM CDT	EF1	Weakley, TN to KY	15.4	225			$150,000
April 25	11:47 PM CDT	EF0	Henderson, TN	17.0	200			$20,000
April 25	12:30 AM CDT	EF0	Polk, TX	0.1	20			$1,000
April 25	12:30 AM CDT	EF0	Calloway, KY	0.8	175			$80,000
April 25	12:37 AM CDT	EF1	Lyon, KY	3.2	50			$150,000
April 25	12:40 AM CDT	EF1	Lyon, KY	15.4	100			$200,000

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.