Alert archive / Texas / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 72, NWS Houston/Galveston, TX

May 20, 2001Brazos County, Burleson County, Grimes County, Texas

NWS Houston/Galveston, TX issued this severe thunderstorm warning at May 20, 2001, 11:04 PM CDT for Brazos County, Burleson County, Grimes County, Texas. It was in force for 56 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
May 20, 2001, 11:04 PM CDT (04:04 UTC)
Expired
May 21, 2001, 12:00 AM CDT
In force
56 min
Issued by
NWS Houston/Galveston, TX
Area
Whole counties; the outline is the Mesonet’s reconstruction

Counties Brazos County, TX, Burleson County, TX, Grimes County, TX

What was reported inside it

TimeReportWhereRemark
May 20, 11:15 PM CDTThunderstorm WindIola, TXSheriff's office reported trees down.

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

Fort Worth, TX (KFWD), launched 00:00Z, 4.1 hours before the alert went out and 269 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, Fort Worth, TX at 00:00Z on 2001-05-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1060 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, Fort Worth, TX at 00:00Z on 2001-05-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 55 square meters per square second.1939587897117Sfc1 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
1060 J/kg
Mixed-layer CIN
-18 J/kg
Mixed-layer LCL
2345 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
55 m²/s²
0-3 km storm-relative helicity
134 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.6

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

What forecasters said that day

The local office's own words before this severe thunderstorm 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 severe thunderstorm warning went out at May 20, 9:03 PM CDT, 2 hours 1 minute earlier.

Area forecast discussion, May 20, 9:03 PM CDT, 2 hours 1 minute before
SOUTHEAST TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
903 PM CDT SUN MAY 20 2001

HIGH PRESSURE RIDGE AND SOUTHWESTERLY WINDS BETWEEN 3000 AND 9000 FEET
WERE HELPING TO PROVIDE A DECENT CAP ACROSS SOUTHEAST TEXAS THIS
EVENING.  FORECAST PROBLEM OF THE NIGHT CONCERNS THE PROBABILITY OF
THUNDERSTORMS...THEN SKY CONDITION.

ISOLATED SUPERCELLS HAVE DEVELOPED ALONG A SURFACE BOUNDARY THAT WAS
EVIDENT ON THE IR FROM EASTERN OK SOUTH THROUGH CENTRAL AND SOUTH
TX.  WE WERE CONCERNED EARLIER THAT TWO STORMS WHICH HAD DEVELOPED
OVER THE CRP AND EWX FORECAST AREAS WOULD WORK THEIR WAY INTO THE CLL
AREA...HOWEVER THESE STORMS FELL APART.  CLL DID...HOWEVER...
EXPERIENCE SOME GUSTY SURFACE WINDS FROM THE OUTFLOW THIS PAST HOUR.
MODIFYING THE 00Z CRP SOUNDING TO REFLECT THE STORM MOTIONS SHOW THAT
THE LEFT MOVERS SHOULD BE MORE DOMINATE...THOUGH THIS WILL PROBABLY
BE A MUTE POINT FOR SE TX.  THE MESO-ETA LOOKS REASONABLE IN KEEPING
THE SURFACE BOUNDARY OVER CENTRAL TEXAS TONIGHT...WHICH POINTS TOWARD
THE BEST CHANCES FOR STORMS TO STAY WEST AS WELL.  FOR NOW THINK THE
SLIGHT CHANCE FOR RAIN OVER THE NORTHERN COUNTIES IS STILL GOOD.  THE
MID AND HIGH LEVEL DEBRIS CLOUDS WILL COMBINE WITH LOW CLOUDS COMING
IN FROM THE GULF TO BRING MOSTLY CLOUDY SKIES ACROSS THE AREA ALSO.

WILL KEEP UP THE CAUTION FOR THE BAYS AND COASTAL WATERS.  THE WINDS
MAY REACH TO ADVISORY LEVELS OVER THE BAYS AND WILL DECIDE ON THIS
BEFORE ISSUING THE COASTAL WATERS FORECAST LATER THIS EVENING.  WILL
ISSUE A MARINE WEATHER STATEMENT LATER THIS EVENING CONCERNING THE
EXPECTED COLD FRONTAL PASSAGE MONDAY NIGHT.

.HGX...SCEC ALL WATERS.

PL-40
45

The office that day

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

IssuedProductOfficeCountiesLasted
May 20, 10:31 PM CDTSevere Thunderstorm WarningHGXBurleson29 min
May 21, 2:46 PM CDTSevere Thunderstorm WarningHGXHarris59 min
May 21, 3:58 PM CDTSevere Thunderstorm WarningHGXChambers, Harris47 min

Nearby

Severe Thunderstorm Warnings in Texas, 2001Every severe thunderstorm warning 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.