Alert archive / Texas / Severe Thunderstorm Watches in 2002

Severe Thunderstorm Watch 76

April 7, 200220 counties in Texas

The Storm Prediction Center issued this severe thunderstorm watch at Apr 7, 2002, 11:00 PM CDT for 20 counties in Texas. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Apr 7, 2002, 11:00 PM CDT (04:00 UTC)
Expired
Apr 8, 2002, 3:00 AM CDT
In force
4 hr
Issued by
the Storm Prediction Center

Counties Angelina County, TX, Austin County, TX, Brazoria County, TX, Brazos County, TX, Colorado County, TX, Fort Bend County, TX, Grimes County, TX, Harris County, TX, Houston County, TX, Jackson County, TX, Leon County, TX, Madison County, TX, Montgomery County, TX, Polk County, TX, San Jacinto County, TX, Trinity County, TX, Walker County, TX, Waller County, TX, Washington County, TX, Wharton County, TX

The radar

The Houston radar (KHGX), 96 km from the middle of the area, began a volume at 04:00 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.

Warnings issued inside it

7 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Apr 7, 11:16 PM CDTSevere Thunderstorm WarningHGXAustin, Washington59 min
Apr 7, 11:33 PM CDTSevere Thunderstorm WarningHGXHarris, Waller57 min
Apr 8, 12:06 AM CDTSevere Thunderstorm WarningHGXMontgomery54 min
Apr 8, 12:25 AM CDTSevere Thunderstorm WarningHGXSan Jacinto35 min
Apr 8, 12:31 AM CDTSevere Thunderstorm WarningHGXFort Bend, Harris59 min
Apr 8, 1:35 AM CDTSevere Thunderstorm WarningHGXBrazoria55 min
Apr 8, 1:42 AM CDTTornado WarningHGXBrazoria, Galveston48 min

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 00:00Z, 4.0 hours before the alert went out and 266 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 2002-04-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 645 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 2002-04-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 115 square meters per square second.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.
Mixed-layer CAPE
645 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
735 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
115 m²/s²
0-3 km storm-relative helicity
193 m²/s²
Significant tornado parameter
0.3
Supercell composite
2.4

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 080352
SEL6  
SPC WW 080349
TXZ000-CWZ000-080800-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 76
STORM PREDICTION CENTER NORMAN OK
1049 PM CDT SUN APR 7 2002

THE STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

   SOUTHEAST TEXAS                              
   AND ADJACENT COASTAL WATERS                     

EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 1100 PM UNTIL
300 AM CDT.

HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS ALONG AND 50 STATUTE MILES
EAST AND WEST OF A LINE FROM 75 MILES SOUTHWEST OF HOUSTON TEXAS TO
30 MILES WEST NORTHWEST OF LUFKIN TEXAS.

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. 
PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE
WARNINGS.  SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE
TORNADOES.

OTHER WATCH INFORMATION...  CONTINUE...WW 75...

DISCUSSION...LINE OF STRONG/SEVERE STORMS WILL TRACK EASTWARD INTO
THE UPPER TX GULF COAST REGION DURING THE NEXT FEW HOURS.  AIRMASS
IS MOIST AND MODERATELY UNSTABLE ACROSS THIS AREA...SUGGESTING A
CONTINUED THREAT OF DAMAGING WINDS AND HAIL IN STRONGER CELLS.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES.  EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.  MEAN STORM
MOTION VECTOR 27040.

...HART

285,0965 312,0960 312,0942 285,0951

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 7, 8:00 PM CDTSevere Thunderstorm WatchSPCAtascosa, Bastrop, Bell, Burleson, Caldwell, Collin and 36 more5 hr
Apr 8, 1:00 AM CDTSevere Thunderstorm WatchSPCAransas, Atascosa, Bee, Bexar, DeWitt, Frio and 12 more4 hr
Apr 8, 1:15 AM CDTSevere Thunderstorm WatchSPCChambers, Hardin, Jasper, Jefferson, Liberty, Newton and 4 more5 hr
Apr 8, 3:00 AM CDTSevere Thunderstorm WatchSPCAustin, Brazoria, Calhoun, Colorado, Fort Bend, Galveston and 7 more5 hr

Nearby

Severe Thunderstorm Watches in Texas, 2002Every severe thunderstorm watch in 2002

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.