EF1 tornado, Leander to Liberty Hill, Texas, May 20, 2018

1. EF065 to 85 mph

   Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

2. EF186 to 110 mphthis tornado

   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.

Rating

EF1

Date

May 20, 2018

Touchdown

8:22 AM CDT (13:22 UTC)

Lifted

8:43 AM CDT (13:43 UTC)

On the ground

21 minutes

Path length

5.1 miles (8.2 km)

Path width

50 yards (46 m)

Deaths

0

Injuries

0

Property damage

$50,000

County

Williamson County

Touchdown point

30.590, -97.824

Lift-off point

30.663, -97.839

Record number

1805200722-01

5 damage points were recorded along this path by NWS EWX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 90 mph.

• Tree damage along the highway, stop sign blown down.
• Large branch down on east side of the road.

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

Thunderstorms developed in southerly flow in the warm sector ahead of a cold front. One of these storms produced a tornado. Later in the day additional storms formed in a line along the front moved through our central area where one produced damaging wind gusts.

A National Weather Service storm survey found a weak tornado touched down near Hero Way on the north side of Leander. The team found roof and tree damage just north of this road at several residences. The tornado then tracked north and went parallel to Ronald Reagan Blvd. where they observed tree damage on the west side of the road. The tornado then crossed Highway 29, weakened considerably, and finally dissipated near the entrance of the Santa Rita Ranch subdivision. The final rating of the tornado is EF1 based on the roof and tree damage seen around Hero Way. The |remainder of the tornado track had weak EF0 damage. The estimated peak wind speed was 90 mph.

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

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down. One was issued for the county at another hour that day.

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 Storm Prediction Center had this point in a Marginal Risk. The outlook in force was issued at 12:53 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 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.

The Ft Hood radar (KGRK), 44 km away, was scanning. The volume nearest the touchdown began at 13:19 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.

Local storm reports within 60 km of the path, in the three hours either side.

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

The live radar over the trackEvery 2018 tornado in TexasEvery tornado in Texas since 1950Warnings in force in Texas nowThe forecast where you are

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.

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.