Tornadoes · United States · Arkansas · 2017
EF1 tornado, Bergman to South Lead Hill, Arkansas, April 4, 2017
From Bergman to South Lead Hill, this EF1 tornado ran 5.0 miles across Boone County on April 4, 2017, touching down at 9:34 PM CDT and reaching 200 yards wide. It killed nobody, and did $80,000 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 4, 2017
- Touchdown
- 9:34 PM CDT (02:34 UTC)
- Lifted
- 9:39 PM CDT (02:39 UTC)
- On the ground
- 5 minutes
- Path length
- 5.0 miles (8.0 km)
- Path width
- 200 yards (183 m)
- Deaths
- 0
- Injuries
- 0
- Property damage
- $80,000
- County
- Boone County
- Touchdown point
- 36.360, -93.027
- Lift-off point
- 36.380, -92.940
- Record number
- 1704042034-01
What the Weather Service recorded
On 4/2/17 severe thunderstorms were noted in south Arkansas. Another system affected north Arkansas on 4/4-5/17 with severe thunderstorms.
Boone County Emergency Management performed an aerial damage survey near the communities of Bergman and Lead Hill in Boone County. A path of damage 3.4 miles in length was found beginning 2.8 miles north-northeast of Bergman, ending 1.7 miles southwest of South Lead Hill. Much of the damage path was characterized by uprooted trees and snapped large tree limbs which converged on the center of the damage path. Damage to several homes was noted along the damage path. The worst of the damage removed part of the roof of a single family residence and destroyed a few outbuildings and several fences.
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 4, 8:31 PM CDT, 1 hour 3 minutes earlier.
Area forecast discussion, Apr 4, 8:31 PM CDT, 1 hour 3 minutes before
Area Forecast Discussion...Update National Weather Service Little Rock AR 830 PM CDT Tue Apr 2017 .Discussion... Area of convection will gradually move east into the CWA this evening and an isolated severe storm will be possible, with mainly large hail and damaging winds the main threats. These storms were associated with an upper low pressure storm system moving through the region. Later tonight, the surface system and cold front will move across AR and push the storms to eastern AR, then on Monday out of AR. Some lighter convection may still be possible mainly over northern AR before the entire system moves out of the region. Models are consistent that winds will be elevated on Wednesday from the west and be 10 to 20 mph with gusts around 30 mph over much of the state, and a lake wind advisory will be issued for most of AR from mid-morning to the evening. Late evening update will fine tune convection chances, timing and include the lake wind advisory. (59) && .Prev Discussion.../ Issued 620 PM CDT Tue Apr 4 2017/ .Aviation... VFR flight conditions will start the forecast. An upper and surface low pressure systems, as well as a cold front, with move across AR tonight to Wednesday morning, and bring VFR ceilings with patchy MVFR ceilings with showers and thunderstorms. The main area affected will be northern AR. An isolated strong to severe storm may be seen. Winds ahead of the system will be southeast at 5 to 15 mph with some gusts to around 20 mph. Winds will become south to southwest later tonight, then west to northwest behind the cold front. Winds will remain elevated behind the front and be 10 to 25 mph with some gusts around 30 to 35 mph on Wednesday. Most of the convection will push east of AR during the day Wednesday. A low level jet will be present this evening and early into the overnight, and some wind shear may be seen at all Tafs. (59) && .Prev Discussion.../ Issued 254 PM CDT Tue Apr 4 2017/ .SHORT TERM...Tonight Through Thursday 19z subjective surface analysis indicates developing low pressure between Lawton and Oklahoma City, with a warm front extending northeastward to southwest Missouri. Strong pressure falls were noted near and to the north of the warm front. Satellite imagery indicates short amplitude yet potent short wave energy moving northeast into southwest Oklahoma. Convection is expected to develop quickly late this afternoon, focused on the warm frontal boundary. Forecast storm motion vectors indicate a northeast movement with storms that develop this afternoon. Much of this activity should affect areas to the northwest of the LZK forecast area. As the evening progresses, convection should obtain a more eastward movement, while overall intensity decreases with increasing stability. Gusty westerly surface winds are expected during the afternoon on Wednesday, in the wake of a cold front moving eastward through the mid south. Afternoon temperatures on Wednesday will average 15-20 degrees lower than those of this afternoon. && .LONG TERM...Thursday Night Through Tuesday A deep upper low pressure system will be over New England to begin the long term period with an upper ridge over the Rockies. The upper low will slowly move through the northeast U.S. through Friday. The upper ridge moves into the Plains for Friday and Saturday...then to the eastern U.S. for Sunday. Another upper low moves into the northern Plains Sunday but should move into the Great Lakes for Monday and Tuesday. Southwest flow will return to Arkansas for Sunday night through Tuesday. Models are in good agreement with a dry period Thursday night through Sunday with high pressure generally in control. The high moves east of Arkansas Sunday and moisture will return. A cold front moves into the Plains Monday and we will see rain chances increase over Arkansas on Sunday night and Monday then decrease on Tuesday. The cold front moves through Arkansas on Tuesday. After a cool Friday, temperatures will return to above normal values. && .PRELIMINARY POINT TEMPS/POPS... Batesville AR 57 60 44 62 / 40 20 10 0 Camden AR 57 64 45 70 / 20 10 0 0 Harrison AR 51 53 40 58 / 70 40 10 0 Hot Springs AR 56 60 45 67 / 40 20 0 0 Little Rock AR 59 61 46 66 / 30 20 10 0 Monticello AR 61 65 47 67 / 20 10 0 0 Mount Ida AR 53 58 43 66 / 50 20 0 0 Mountain Home AR 53 57 41 61 / 60 40 10 0 Newport AR 58 62 45 62 / 30 20 10 10 Pine Bluff AR 59 63 46 67 / 20 10 0 0 Russellville AR 54 57 43 65 / 60 20 0 0 Searcy AR 57 61 43 64 / 30 20 10 0 Stuttgart AR 61 63 45 65 / 30 10 10 10 && .LZK Watches/Warnings/Advisories...NONE. && Short Term...55 / Long Term...51
Hazardous weather outlook, Apr 4, 7:30 PM CDT, 2 hours 4 minutes before
Hazardous Weather Outlook...Update National Weather Service Little Rock AR 730 PM CDT Tue Apr 4 2017 ARZ003>007-012>016-021>025-030>034-037>047-052>057-062>069-051000- Boone-Marion-Baxter-Fulton-Sharp-Newton-Searcy-Stone-Izard- Independence-Johnson-Pope-Van Buren-Cleburne-Jackson-Logan-Conway- Faulkner-White-Woodruff-Scott-Yell-Perry-Polk-Montgomery-Garland- Saline-Pulaski-Lonoke-Prairie-Monroe-Pike-Clark-Hot Spring-Grant- Jefferson-Arkansas-Dallas-Cleveland-Lincoln-Desha-Ouachita-Calhoun- Bradley-Drew- 730 PM CDT Tue Apr 4 2017 This Hazardous Weather Outlook is for a Large Part of Arkansas. .DAY ONE...Tonight Showers and thunderstorms are forecast to move into western Arkansas this evening, and move across the state tonight. The storms are ahead of a storm system to the west of Arkansas. This activity will affect much of northern and parts of central Arkansas, while less over southern areas. A few strong or severe storms will be possible, primarily this evening, over northwest Arkansas. Large hail and damaging winds are the main threats. The storms are expected to gradually weaken as the move across the state overnight. .DAYS TWO THROUGH SEVEN...Wednesday through Monday Windy conditions are expected during the late morning to evening on Wednesday. Cooler air will move into the region Wednesday and Thursday. Patchy frost will be possible in sheltered valley areas of northern and western Arkansas early Friday morning. .Spotter Information Statement... Limited spotter activation may be required across northwest sections during the evening hours. && Visit NWS Little Rock on the web. Go to http://weather.gov/lzk. 55/44/57/59
In the hours before
Special weather statement, Apr 4, 8:56 PM CDT, 38 minutes before
Special Weather Statement
National Weather Service Little Rock AR
856 PM CDT TUE APR 4 2017
ARZ003-012-050245-
Newton AR-Boone AR-
856 PM CDT TUE APR 4 2017
...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN NEWTON AND BOONE
COUNTIES UNTIL 945 PM CDT...
At 856 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Berryville to Rudd to near Kingston to
Pettigrew. Movement was northeast at 45 mph.
Wind gusts up to 50 mph will be possible with these storms.
Locations impacted include...
Harrison... Bergman...
Omaha... Myrtle...
Roberson Hollow... Self...
Erbie... Upper Buffalo Wilderness Area...
Red Bank... Lost Valley State Park...
Capps... Alpena...
Crumpler Subdivision... Batavia...
Bear Creek Springs... New Hope in Boone County...
Marble Falls... Ridgeway...
Gaither... Burlington...
LAT...LON 3649 9299 3629 9301 3590 9327 3583 9352
3588 9352 3589 9350 3594 9349 3597 9345
3608 9344 3608 9348 3612 9348 3612 9330
3650 9329
TIME...MOT...LOC 0156Z 234DEG 38KT 3637 9352 3622 9348 3602 9354 3581
9367
64The 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.
Springfield, MO (KSGF), 00:00Z
2.6 hours before the tornado, 94 km from the path. April 5, 2017.
- Mixed-layer CAPE
- 326 J/kg
- Mixed-layer CIN
- -51 J/kg
- Surface CAPE
- 793 J/kg
- Mixed-layer LCL
- 1384 m above ground
- 0-6 km bulk shear
- 58 kt
- 0-1 km bulk shear
- 25 kt
- 0-1 km storm-relative helicity
- 312 m²/s²
- 0-3 km storm-relative helicity
- 743 m²/s²
- Significant tornado parameter
- 1.0
- Supercell composite
- 12.5
- 0-3 km lapse rate
- 6.8 K/km
The surface observations
Harrison/Boone Co. (HRO), 20 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 Springfield radar (KSGF), 103 km away, was scanning. The volume nearest the touchdown began at 02:34 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 2017 tornado in ArkansasEvery tornado in Arkansas since 1950Warnings in force in Arkansas nowThe forecast where you are
The other tornadoes of April 4, 2017
2 more were confirmed in the United States that day.
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.