Tornadoes · United States · Texas · 1998

F0 tornado, Brenham, Texas, October 17, 1998

This F0 tornado ran 1.0 miles across Washington County on October 17, 1998, touching down at 7:50 PM CDT and reaching 30 yards wide. It killed nobody.

The rating scale

Tracks are drawn in the color of the rating. The Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

  1. F040 to 72 mphthis tornado

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

  2. F173 to 112 mph

    Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

  3. F2113 to 157 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. F3158 to 206 mph

    Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

  5. F4207 to 260 mph

    Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

  6. F5261 to 318 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
F0
Date
October 17, 1998
Touchdown
7:50 PM CDT (00:50 UTC)
Path length
1.0 miles (1.6 km)
Path width
30 yards (27 m)
Deaths
0
Injuries
0
County
Washington County
Touchdown point
30.170, -96.330
Lift-off point
30.170, -96.330
Record number
1382

What the Weather Service recorded

DPS reported tornado. No damage reported.

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

The warnings

55 minutes of warning. NWS HGX issued a tornado warning for this county at 23:55 UTC, 55 minutes before the tornado touched down, in force until 00:55 UTC.

Issued (UTC)ExpiredProductOffice
23:55 UTC00:55 UTCTornado WarningHGX
01:31 UTC05:20 UTCFlash Flood WarningHGX
10:21 UTC15:00 UTCFlash Flood WarningHGX
15:01 UTC19:00 UTCFlash Flood 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 General Thunderstorms Risk. The outlook in force was issued at 05:06 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), 00:00Z

0.8 hours before the tornado, 289 km from the path. October 18, 1998.

Skew-T log-pSkew-T log-p diagram, Corpus Christi, TX at 00:00Z on 1998-10-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 2574 joules per kilogram, CIN 0, lifted condensation level 538 meters above ground. Wind barbs in knots down the right edge.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°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 1998-10-18The 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 87 square meters per square second, 0 to 6 km bulk shear 26 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
2574 J/kg
Mixed-layer CIN
0 J/kg
Surface CAPE
2456 J/kg
Mixed-layer LCL
538 m above ground
0-6 km bulk shear
26 kt
0-1 km bulk shear
17 kt
0-1 km storm-relative helicity
87 m²/s²
0-3 km storm-relative helicity
145 m²/s²
Significant tornado parameter
1.2
Supercell composite
8.5
0-3 km lapse rate
5.4 K/km

Open this sounding in Storm Lab

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

11.2 hours after it, 289 km from the path. October 18, 1998.

Skew-T log-pSkew-T log-p diagram, Corpus Christi, TX at 12:00Z on 1998-10-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 2494 joules per kilogram, CIN 0, lifted condensation level 515 meters above ground. Wind barbs in knots down the right edge.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°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 1998-10-18The 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 77 square meters per square second, 0 to 6 km bulk shear 25 knots.1939Sfc1 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
2494 J/kg
Mixed-layer CIN
0 J/kg
Surface CAPE
2663 J/kg
Mixed-layer LCL
515 m above ground
0-6 km bulk shear
25 kt
0-1 km bulk shear
19 kt
0-1 km storm-relative helicity
77 m²/s²
0-3 km storm-relative helicity
111 m²/s²
Significant tornado parameter
0.7
Supercell composite
4.7
0-3 km lapse rate
5.3 K/km

Open this sounding in Storm Lab

The surface observations

College Station (CLL), 47 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
22:53 UTC71700° 0 kt1013.2TSRA BR
23:20 UTC71.669.8 1013.2
23:30 UTC71.669.8330° 6 kt1013.2
23:53 UTC7170 4 kt1013.2+TSRA BR
00:07 UTC71.669.8330° 7 kt1013.2
00:13 UTC71.669.8320° 7 kt1013.2
00:42 UTC71.671.6140° 5 kt1014.2
00:53 UTC7170110° 8 kt1013.9+TSRA BR
01:12 UTC71.669.8130° 7 kt1013.9
01:42 UTC71.671.6110° 6 kt1014.2
01:53 UTC7271120° 8 kt1014.2TSRA BR
02:23 UTC71.671.690° 7 kt1014.2

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

This ground now

The live radar over the trackEvery 1998 tornado in TexasEvery tornado in Texas since 1950Warnings in force in Texas nowThe forecast where you are

The other tornadoes of October 17, 1998

11 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
October 171:00 AM CDTF0Harris, TX1.030$20,000
October 1710:15 AM CDTF2Navarro, TX3.510014$100,000
October 1711:17 AM CDTF2Coryell, TX0.130$50,000
October 1711:55 AM CDTF0Navarro, TX0.130
October 171:25 PM CDTF0Hill, TX0.130
October 171:30 PM CDTF1Bastrop, TX0.11001$30,000
October 172:10 PM CDTF1Bastrop, TX0.2100$50,000
October 173:20 PM CDTF1Burleson, TX5.080$500,000
October 173:28 PM CDTF2Burleson, TX3.5100$1.5 million
October 174:40 PM CDTF1Brazos, TX3.580$20,000
October 176:36 PM CDTF0Victoria, TX0.230

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.