Tornadoes · United States · Texas · 2017

EF0 tornado, Perry Lndg, Texas, August 25, 2017

This EF0 tornado ran 0.2 miles across Brazoria County on August 25, 2017, touching down at 3:30 PM CDT and reaching 30 yards wide. It killed nobody, and did $30,000 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.

  1. EF065 to 85 mphthis tornado

    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 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.

The record

Rating
EF0
Date
August 25, 2017
Touchdown
3:30 PM CDT (20:30 UTC)
Lifted
3:31 PM CDT (20:31 UTC)
On the ground
1 minutes
Path length
0.2 miles (0.4 km)
Path width
30 yards (27 m)
Deaths
0
Injuries
0
Property damage
$30,000
County
Brazoria County
Touchdown point
28.981, -95.483
Lift-off point
28.984, -95.485
Record number
1708251430-01

The damage survey

1 damage points were recorded along this path by NWS HGX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 62 mph.

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

Harvey made landfall as a category 4 hurricane near Rockport, Texas during the evening of August 25th. The storm then weakened to a tropical storm and slowed, looping back and tracking over SE Texas then back over the Gulf of Mexico making a second landfall along the Louisiana coast during the early morning hours of August 30th. Over that 5 day period over Southeast Texas TS Harvey produced catastrophic flooding with a large area of 30 to 60 inches of rain, 23 tornadoes, tropical storm force winds and a moderate storm surge near Matagorda Bay. In some of the heavier bands rain fell at a rate of over 5 inches per hour. This copious record amount of rain over a led to catastrophic flooding. Thousands of homes, businesses, and roads were flooded due to flash flooding and sheet flow from long duration intense rain. Main stem rivers and adjoining tributaries, creeks and bayous reached full capacity and came out of their banks and this also contributed to the massive flooding across southeastern Texas.

Very brief tornado touched down near HWY 36 with numerous trees snapped or downed. Barn also damaged.

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

The warnings

27 minutes of warning. NWS HGX issued a tornado warning for this county at 20:03 UTC, 27 minutes before the tornado touched down, in force until 20:30 UTC.

The county was under a tornado watch, issued at 19:02 UTC and running to 06:49 UTC.

Issued (UTC)ExpiredProductOffice
09:00 UTC08:04 UTCFlash Flood WatchHGX
19:02 UTC06:49 UTCTornado WatchHGX
19:08 UTC19:24 UTCTornado WarningHGX
20:03 UTC20:30 UTCTornado WarningHGX
20:09 UTC20:45 UTCTornado WarningHGX
20:48 UTC21:15 UTCTornado WarningHGX
21:07 UTC21:30 UTCTornado WarningHGX
21:37 UTC23:30 UTCFlood AdvisoryHGX
22:19 UTC22:45 UTCTornado WarningHGX
22:31 UTC22:45 UTCTornado WarningHGX
22:42 UTC23:15 UTCTornado WarningHGX
22:45 UTC23:15 UTCTornado WarningHGX
23:08 UTC23:34 UTCTornado WarningHGX
23:13 UTC23:45 UTCTornado WarningHGX
23:35 UTC00:00 UTCTornado WarningHGX
23:39 UTC00:15 UTCTornado WarningHGX
23:53 UTC00:15 UTCTornado WarningHGX
00:08 UTC00:45 UTCTornado WarningHGX
00:42 UTC02:45 UTCFlood AdvisoryHGX
00:45 UTC01:15 UTCTornado WarningHGX
01:18 UTC01:45 UTCTornado WarningHGX
01:33 UTC02:00 UTCTornado WarningHGX
02:05 UTC02:30 UTCTornado WarningHGX
02:21 UTC02:30 UTCTornado WarningHGX
02:38 UTC03:15 UTCTornado WarningHGX
02:40 UTC03:00 UTCTornado WarningHGX
02:42 UTC03:00 UTCTornado WarningHGX
03:00 UTC03:30 UTCTornado WarningHGX
04:33 UTC09:30 UTCFlood AdvisoryHGX
04:50 UTC05:15 UTCTornado WarningHGX

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 Slight Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 19:40 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 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.

Corpus Christi, TX (KCRP), 12:00Z

8.5 hours before the tornado, 229 km from the path. August 25, 2017.

Skew-T log-pSkew-T log-p diagram, Corpus Christi, TX at 12:00Z on 2017-08-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 298 joules per kilogram, CIN -48, lifted condensation level 696 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°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, Corpus Christi, TX at 12:00Z on 2017-08-25The 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 124 square meters per square second, 0 to 6 km bulk shear 15 knots.193958Sfc1 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
298 J/kg
Mixed-layer CIN
-48 J/kg
Surface CAPE
981 J/kg
Mixed-layer LCL
696 m above ground
0-6 km bulk shear
15 kt
0-1 km bulk shear
21 kt
0-1 km storm-relative helicity
124 m²/s²
0-3 km storm-relative helicity
75 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.6 K/km

Open this sounding in Storm Lab

Corpus Christi, TX (KCRP), 00:00Z

3.5 hours after it, 229 km from the path. August 26, 2017.

Skew-T log-pSkew-T log-p diagram, Corpus Christi, TX at 00:00Z on 2017-08-26Temperature 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 -28233, lifted condensation level 1132 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 km2 km3 km6 km9 km-30°-20°-10°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, Corpus Christi, TX at 00:00Z on 2017-08-26The 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 12 square meters per square second, 0 to 6 km bulk shear 4 knots.193958Sfc1 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
-28233 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1132 m above ground
0-6 km bulk shear
4 kt
0-1 km bulk shear
3 kt
0-1 km storm-relative helicity
12 m²/s²
0-3 km storm-relative helicity
-18 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
6.6 K/km

Open this sounding in Storm Lab

The radar

The Houston radar (KHGX), 67 km away, was scanning. The volume nearest the touchdown began at 20:28 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)ReportWhereCountyRemark
20:22 UTCTORNADO1 Wsw Jones CreekBrazoria, TXA VERY BRIEF EF-0 TORNADO TOUCHED DOWN NEAR COUNTY RD 301 AND HWY 36 WITH NUMEROUS TREES SNAPPED AND/OR DOWNED. ONE BARN WAS ALSO DAMAGED.
20:25 UTCTORNADO 01 Wsw Jones CreekBrazoria, TXA VERY BRIEF EF-0 TORNADO TOUCHED DOWN NEAR COUNTY RD 301 AND HWY 36 WITH NUMEROUS TREES SNAPPED AND/OR DOWNED. ONE BARN WAS ALSO DAMAGED.
20:30 UTCTORNADO 01 Sse BrazoriaBrazoria, TXA BRIEF TORNADO CROSSED HWY 36 WITH ONE DOWNED POWERLINE AND SEVERAL TREES SNAPPED AND/OR DOWNED.
20:30 UTCTORNADO 05 Ne MatagordaMatagorda, TXSHED AND FENCE DAMAGE REPORTED FROM A TORNADO IN SARGENT.
20:30 UTCTORNADO1 Sse BrazoriaBrazoria, TXA BRIEF TORNADO CROSSED HWY 36 WITH ONE DOWNED POWERLINE AND SEVERAL TREES SNAPPED AND/OR DOWNED.
20:30 UTCTORNADO5 Ne MatagordaMatagorda, TXSHED AND FENCE DAMAGE REPORTED FROM A TORNADO IN SARGENT
20:45 UTCTORNADO10 S Bay CityMatagorda, TXSHED AND FENCE DAMAGE REPORTED FROM A TORNADO IN SARGENT
21:14 UTCTORNADO -117 Sw Jones CreekMatagorda, TXA BRIEF YET STRONG TORNADO MOVED ONSHORE ALONG THE COAST IN SARGENT CAUSING SIGNIFICANT DAMAGE TO ONE HOME AS WELL AS OVERTURNING A MOTORHOME. NUMEROUS TREES WERE SNAPPED AND/OR DOWNED ALONG THE PATH AS WELL AS MINOR ROO
21:14 UTCTORNADO 117 Sw Jones CreekMatagorda, TXA BRIEF YET STRONG TORNADO MOVED ONSHORE ALONG THE COAST IN SARGENT CAUSING SIGNIFICANT DAMAGE TO ONE HOME AS WELL AS OVERTURNING A MOTORHOME. NUMEROUS TREES WERE SNAPPED AND/OR DOWNED ALONG THE PATH AS WELL AS MINOR ROO
21:14 UTCTORNADO17 Sw Jones CreekMatagorda, TXA BRIEF YET STRONG TORNADO MOVED ONSHORE ALONG THE COAST IN SARGENT CAUSING SIGNIFICANT DAMAGE TO ONE HOME AS WELL AS OVERTURNING A MOTORHOME. NUMEROUS TREES WERE SNAPPED AND/OR DOWNED ALONG THE PATH AS WELL AS MINOR ROO
23:09 UTCTORNADO 05 Wsw AngletonBrazoria, TXA HIGH-END EF-0 TORNADO TOUCHED DOWN JUST EAST OF WEST COLUMBIA DAMAGING NUMEROUS TREES... ROOFS... AND OUTBUILDINGS IN A NEIGHBORHOOD OFF OF HIGHWAY 35 AND RIVER ROAD. A BARN AND SEVERAL OUTBUILDINGS WERE ALSO DESTROYED
23:09 UTCTORNADO 05 Wsw AngletonBrazoria, TXA HIGH-END EF-0 TORNADO TOUCHED DOWN JUST EAST OF WEST COLUMBIA DAMAGING NUMEROUS TREES... ROOFS...AND OUTBUILDINGS IN A NEIGHBORHOOD OFF OF HIGHWAY 35 AND RIVER ROAD. A BARN AND SEVERAL OUTBUILDINGS WERE ALSO DESTROYED

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

This ground now

The live radar over the trackEvery 2017 tornado in TexasEvery tornado in Texas since 1950Warnings in force in Texas nowThe forecast where you are

The other tornadoes of August 25, 2017

8 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
August 252:18 PM CDTEF0Galveston, TX0.120$500
August 254:08 PM CDTEF1Matagorda, TX2.250$500,000
August 254:14 PM CDTEF0Calhoun, TX0.220$10,000
August 256:11 PM CDTEF0Brazoria, TX4.050$100,000
August 2510:44 PM CDTEF0Brazoria, TX4.850$100,000
August 2512:28 AM CDTEF0Brazoria, TX4.350$50,000
August 2512:50 AM CDTEF1Brazoria, TX1.650$1.0 million
August 2512:56 AM CDTEF1Fort Bend, TX1.5100$500,000

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.