Alert archive / Texas / Tornado Warnings in 1997

Tornado Warning 17, NWS Houston/Galveston, TX

April 11, 1997Brazoria County, Texas

NWS Houston/Galveston, TX issued this tornado warning at Apr 11, 1997, 2:28 AM CDT for Brazoria County, Texas. It was in force for 62 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Apr 11, 1997, 2:28 AM CDT (07:28 UTC)
Expired
Apr 11, 1997, 3:30 AM CDT
In force
62 min
Issued by
NWS Houston/Galveston, TX
Area
Whole counties

County Brazoria County, TX

The radar

The Houston radar (KHGX), 48 km from the middle of the area, began a volume at 07:29 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 00:00Z, 7.5 hours before the alert went out and 240 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 1997-04-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 22 joules per kilogram.LCLLFCEL10008507005003002001001 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.
HodographHodograph, Lake Charles Mun, LA at 00:00Z on 1997-04-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 11 square meters per square second.19395878Sfc1 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
22 J/kg
Mixed-layer CIN
-81 J/kg
Mixed-layer LCL
946 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
11 m²/s²
0-3 km storm-relative helicity
108 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KHOU 110730 RRA
TORHOU
TXC039-110830-
 
BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
228 AM CDT FRI APR 11 1997
 
THE NATIONAL WEATHER SERVICE IN HOUSTON/GALVESTON HAS ISSUED A
TORNADO WARNING EFFECTIVE UNTIL  330 AM CDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN SOUTHEAST TEXAS
 
   ...BRAZORIA COUNTY
 
 
AT 229 AM...A TORNADIC THUNDERSTORM WAS INDICATED NEAR DAMON MOVING EAST
NORTHEAST AT 15 MPH. BONNIE AND ROSHARON ARE IN THE PATH OF THE STORM.
 
 
THIS IS A DANGEROUS STORM SITUATION.  ACT QUICKLY.  IF YOU ARE
IN THE PATH OF THIS TORNADO... GO TO A SMALL INTERIOR ROOM ON
THE LOWEST FLOOR POSSIBLE.  AVOID WINDOWS.  ABANDON CARS AND
MOBILE HOMES FOR A REINFORCED BUILDING.  AS A LAST RESORT GET
INTO A DITCH OR CULVERT.

What forecasters said that day

The local office's own words before this tornado warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Houston/Galveston, TX wrote its last area forecast discussion before this tornado warning went out at Apr 11, 1:22 AM CDT, 1 hour 6 minutes earlier.

Area forecast discussion, Apr 11, 1:22 AM CDT, 1 hour 6 minutes before
SOUTHEAST TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
120 AM CDT FRI APR 11 1997
...VERY DANGEROUS FLOODING SITUTATION UNDERWAY...

MCS THAT MOVED INTO THE SW ZONES SHOULD SLOW IN ITS NORTHEASTWARD
MOVEMENT AND BEGIN TO TURN MORE EAST AFTER 3 AM.  LOW LEVEL/MESOSCALE
FEATURES INDICATING THAT SIGNIFICANT TRAINING WILL BE A PROBLEM
THROUGH 12Z.  AND TO TOP IT ALL OFF IT APPEARS FROM WATER VAPOR THAT
OUTFLOW JET BECOMING PRONOUNCED ON THE WEST SIDE OF THE COMPLEX
HELPING IN THE ORGANIZATION.  RADAR ALREADY INDICATING STORM TOTAL
RAINFALL ACCUMULATIONS OF AROUND 5 INCHES NEAR EL CAMPO AND 9 TO 10
INCHES NEAR HALLETSVILLE! (SOME OF THE PRECIP OVER THESE AREAS MAY BE
GETTING SOME HAIL CONTAMINATION...ALTHOUGH SO FAR NO GROUNDTRUTH BACK
OF HAIL WITH THESE STORMS.)  ALSO OF NOTE THE VERY STRONG MESO ALONG
THE SLOW MOVING PSEUDO WARM FRONT OVER WATER.  AT THIS RATE NOT ONLY
WILL WE HAVE FLOODING PROBLEMS BUT SEVERE AS WELL.  WILL NEED TO
EXPAND FFA A LITTLE FURTHER NORTH AND MUCH FURTHER EAST AND ADD
MENTION OF SEVERE FOR A LARGE PART OF THE AREA...ALTHOUGH THE SPEED
SHEAR IS NOT TREMENDOUS THE TURNING IS IMPRESSIVE AND THE CAPE IS
RATHER APPARENT BY LOOKING AT THE REFLECTIVITY MAXIMA ALOFT A NUMBER
OF STORMS DEVELOPING STRONG MESOS OVER THE SW ZONES.

LATEST 3HR PRECIP ESTIMATES RUNNING IN EXCESS OF 7 INCHES.

45
WILL FOLLOW WITH TEMPS AND POPS AS TIME PERMITS.

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 10, 10:26 PM CDTSevere Thunderstorm WarningHGXMatagorda59 min
Apr 10, 11:40 PM CDTSevere Thunderstorm WarningHGXWharton65 min
Apr 11, 12:45 AM CDTSevere Thunderstorm WarningHGXWharton60 min
Apr 11, 1:07 AM CDTFlash Flood WarningHGXWharton118 min
Apr 11, 1:40 AM CDTTornado WarningHGXWharton65 min
Apr 11, 2:04 AM CDTTornado WarningHGXFort Bend61 min
Apr 11, 2:28 AM CDTFlash Flood WarningHGXFort Bend, Wharton3 hr
Apr 11, 2:40 AM CDTSevere Thunderstorm WarningHGXWharton65 min
Apr 11, 2:58 AM CDTSevere Thunderstorm WarningHGXBrazoria, Fort Bend62 min
Apr 11, 3:42 AM CDTSevere Thunderstorm WarningHGXMatagorda, Wharton33 min
Apr 11, 3:59 AM CDTSevere Thunderstorm WarningHGXBrazoria61 min
Apr 11, 4:08 AM CDTFlash Flood WarningHGXBrazoria3 hr
Apr 11, 4:22 AM CDTTornado WarningHGXBrazoria, Galveston68 min
Apr 11, 5:23 AM CDTSevere Thunderstorm WarningHGXMatagorda67 min
Apr 11, 5:26 AM CDTTornado WarningHGXGalveston64 min
Apr 11, 5:27 AM CDTSevere Thunderstorm WarningHGXHarris63 min
Apr 11, 5:33 AM CDTFlash Flood WarningHGXGalveston3 hr
Apr 11, 5:45 AM CDTSevere Thunderstorm WarningHGXBrazoria60 min
Apr 11, 9:24 AM CDTFlash Flood WarningHGXWharton4 hr
Apr 11, 3:30 PM CDTSevere Thunderstorm WarningHGXHarris60 min
Apr 11, 4:25 PM CDTSevere Thunderstorm WarningHGXHarris, Montgomery65 min
Apr 11, 5:06 PM CDTSevere Thunderstorm WarningHGXLiberty64 min
Apr 11, 5:17 PM CDTSevere Thunderstorm WarningHGXHarris58 min
Apr 11, 6:11 PM CDTTornado WarningHGXHarris49 min
Apr 11, 6:45 PM CDTSevere Thunderstorm WarningHGXChambers60 min
Apr 11, 6:58 PM CDTSevere Thunderstorm WarningHGXHarris32 min

Nearby

Tornado Warnings in Texas, 1997Every tornado warning in 1997Tornadoes in 1997

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.