Alert archive / Texas / Tornado Warnings in 2001

Tornado Warning 21, NWS Houston/Galveston, TX

September 20, 2001Harris County, Texas

NWS Houston/Galveston, TX issued this tornado warning at Sep 20, 2001, 7:20 PM CDT for Harris County, Texas. It was in force for 40 min. 1 report came from inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties, with what was reported inside it.

The facts

Issued
Sep 20, 2001, 7:20 PM CDT (00:20 UTC)
Expired
Sep 20, 2001, 8:00 PM CDT
In force
40 min
Issued by
NWS Houston/Galveston, TX
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Harris County, TX

What was reported inside it

TimeReportWhereRemark
Sep 20, 7:45 PM CDTHail 0.75Jersey Village, TX

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 00:00Z, 0.3 hours before the alert went out and 225 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Lake Charles Mun, LA at 00:00Z on 2001-09-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3819 joules per kilogram.LCLEL10008507005003002001001 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.
HodographHodograph, Lake Charles Mun, LA at 00:00Z on 2001-09-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -7 square meters per square second.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.
Mixed-layer CAPE
3819 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
1197 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
-7 m²/s²
0-3 km storm-relative helicity
42 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.6

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

547 
WFUS54 KHGX 210022
TORHOU
TXC201-210100-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
720 PM CDT THU SEP 20 2001

THE NATIONAL WEATHER SERVICE HAS ISSUED A

* TORNADO WARNING FOR...
  HARRIS COUNTY IN SOUTHEAST TEXAS

* UNTIL 800 PM CDT

* AT 713 PM CDT...DOPPLER RADAR INDICATED A THUNDERSTORM CAPABLE OF  
PRODUCING A TORNADO NEAR THE GALLERIA...MOVING NORTHEAST AT 15 MPH. 
THIS TORNADO WARNING REPLACES THE SEVERE THUNDERSTORM WARNING 
PREVIOUSLY IN EFFECT.

* LOCATIONS IN THE PATH OF THE TORNADO INCLUDE...MUCH OF DOWNTOWN 
HOUSTON...ALDINE...HUNTERS CREEK VILLAGE.

MOVE TO A SMALL INTERIOR ROOM ON THE LOWEST FLOOR. ABANDON YOUR CAR
OR MOBILE HOME FOR A STRONG SHELTER NOW

PLEASE REPORT SEVERE WEATHER TO THE COUNTY SHERIFF...LOCAL POLICE...
OR DEPARTMENT OF PUBLIC SAFETY. THEY WILL RELAY YOUR REPORT TO THE
NATIONAL WEATHER SERVICE.

LAT...LON 2974 9571 2967 9558 2975 9540 2992 9520
          3005 9548

The office that day

Everything else NWS Houston/Galveston, TX issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 21, 2:26 PM CDTSevere Thunderstorm WarningHGXChambers, Harris, Liberty34 min
Sep 21, 3:02 PM CDTSevere Thunderstorm WarningHGXLiberty28 min
Sep 21, 3:51 PM CDTSevere Thunderstorm WarningHGXHouston24 min
Sep 21, 4:26 PM CDTSevere Thunderstorm WarningHGXAustin49 min
Sep 21, 4:29 PM CDTSevere Thunderstorm WarningHGXMontgomery46 min
Sep 21, 4:45 PM CDTSevere Thunderstorm WarningHGXHarris30 min
Sep 21, 5:46 PM CDTSevere Thunderstorm WarningHGXGalveston, Harris29 min
Sep 21, 5:50 PM CDTSevere Thunderstorm WarningHGXBrazoria, Fort Bend25 min
Sep 21, 6:15 PM CDTSevere Thunderstorm WarningHGXBrazoria, Galveston, Harris45 min
Sep 21, 6:19 PM CDTSevere Thunderstorm WarningHGXChambers, Liberty41 min

Nearby

Tornado Warnings in Texas, 2001Every tornado warning in 2001Tornadoes in 2001

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.