Tornadoes · United States · Texas · 2017
EF0 tornado, Galveston, Texas, August 25, 2017
This EF0 tornado ran 0.1 miles across Galveston County on August 25, 2017, touching down at 2:18 PM CDT and reaching 20 yards wide. It killed nobody, and did $500 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 mphthis tornado
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mph
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
- EF0
- Date
- August 25, 2017
- Touchdown
- 2:18 PM CDT (19:18 UTC)
- Lifted
- 2:19 PM CDT (19:19 UTC)
- On the ground
- 1 minutes
- Path length
- 0.1 miles (0.2 km)
- Path width
- 20 yards (18 m)
- Deaths
- 0
- Injuries
- 0
- Property damage
- $500
- County
- Galveston County
- Touchdown point
- 29.310, -94.770
- Lift-off point
- 29.312, -94.770
- Record number
- 1708251318-01
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.
Funnel cloud sighting with fence damage near Ferry Road.
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
The warnings
4 minutes of warning. NWS HGX issued a tornado warning for this county at 19:14 UTC, 4 minutes before the tornado touched down, in force until 19:45 UTC.
The county was under a tornado watch, issued at 19:02 UTC and running to 06:49 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 09:00 UTC | 08:04 UTC | Flash Flood Watch | HGX |
| 18:48 UTC | 19:15 UTC | Tornado Warning | HGX |
| 19:02 UTC | 06:49 UTC | Tornado Watch | HGX |
| 19:14 UTC | 19:45 UTC | Tornado Warning | HGX |
| 19:41 UTC | 20:00 UTC | Tornado Warning | HGX |
| 19:44 UTC | 19:55 UTC | Tornado Warning | HGX |
| 20:42 UTC | 21:15 UTC | Tornado Warning | HGX |
| 21:07 UTC | 21:30 UTC | Tornado Warning | HGX |
| 21:37 UTC | 23:30 UTC | Flood Advisory | HGX |
| 23:39 UTC | 00:15 UTC | Tornado Warning | HGX |
| 23:53 UTC | 00:03 UTC | Tornado Warning | HGX |
| 00:42 UTC | 02:45 UTC | Flood Advisory | HGX |
| 00:45 UTC | 01:15 UTC | Tornado Warning | HGX |
| 01:33 UTC | 02:00 UTC | Tornado Warning | HGX |
| 02:33 UTC | 03:00 UTC | Tornado Warning | HGX |
| 02:40 UTC | 03:00 UTC | Tornado Warning | HGX |
| 04:50 UTC | 05:15 UTC | Tornado Warning | HGX |
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 16:04 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.
Lake Charles Mun, LA (KLCH), 12:00Z
7.3 hours before the tornado, 176 km from the path. August 25, 2017.
- Mixed-layer CAPE
- 1337 J/kg
- Mixed-layer CIN
- -25 J/kg
- Surface CAPE
- 884 J/kg
- Mixed-layer LCL
- 748 m above ground
- 0-6 km bulk shear
- 20 kt
- 0-1 km bulk shear
- 19 kt
- 0-1 km storm-relative helicity
- 102 m²/s²
- 0-3 km storm-relative helicity
- 124 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 4.5 K/km
Lake Charles Mun, LA (KLCH), 00:00Z
4.7 hours after it, 176 km from the path. August 26, 2017.
- Mixed-layer CAPE
- 275 J/kg
- Mixed-layer CIN
- -69 J/kg
- Surface CAPE
- 810 J/kg
- Mixed-layer LCL
- 739 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km bulk shear
- 26 kt
- 0-1 km storm-relative helicity
- 119 m²/s²
- 0-3 km storm-relative helicity
- 253 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 1.3
- 0-3 km lapse rate
- 4.5 K/km
The radar
The Houston radar (KHGX), 35 km away, was scanning. The volume nearest the touchdown began at 19:17 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 |
|---|---|---|---|---|
| 19:23 UTC | TORNADO 0 | 9 Ne Galveston | Galveston, TX | PUBLIC REPORTS A FUNNEL CLOUD AND A METAL FENCE DAMAGED NEAR FERRY RD IN GALVESTON |
| 19:23 UTC | TORNADO 0 | 9 Ne Galveston | Galveston, TX | PUBLIC REPORTS A FUNNEL CLOUD AND A METAL FENCE DAMAGED NEAR FERRY RD IN GALVESTON. |
| 19:23 UTC | TORNADO | 9 Ne Galveston | Galveston, TX | PUBLIC REPORTS A FUNNEL CLOUD AND A METAL FENCE DAMAGED NEAR FERRY RD IN GALVESTON |
| 20:47 UTC | TORNADO 0 | 9 Ne Galveston | Galveston, TX | TORNADO DAMAGED MCDONALDS SIGN AT SEAWALL BLVD AND BROADWAY AVE. ALSO DAMAGE TO AWNINGS AT APARTMENT COMPLEX. |
| 20:47 UTC | TORNADO | 9 Ne Galveston | Galveston, TX | TORNADO DAMAGED MCDONALDS SIGN AT SEAWALL BLVD AND BROADWAY AVE. |
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.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| August 25 | 3:30 PM CDT | EF0 | Brazoria, TX | 0.2 | 30 | $30,000 | ||
| August 25 | 4:08 PM CDT | EF1 | Matagorda, TX | 2.2 | 50 | $500,000 | ||
| August 25 | 4:14 PM CDT | EF0 | Calhoun, TX | 0.2 | 20 | $10,000 | ||
| August 25 | 6:11 PM CDT | EF0 | Brazoria, TX | 4.0 | 50 | $100,000 | ||
| August 25 | 10:44 PM CDT | EF0 | Brazoria, TX | 4.8 | 50 | $100,000 | ||
| August 25 | 12:28 AM CDT | EF0 | Brazoria, TX | 4.3 | 50 | $50,000 | ||
| August 25 | 12:50 AM CDT | EF1 | Brazoria, TX | 1.6 | 50 | $1.0 million | ||
| August 25 | 12:56 AM CDT | EF1 | Fort Bend, TX | 1.5 | 100 | $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.