Alert archive / Texas / Tornado Watches in 2007

Tornado Watch 98

March 31, 200723 counties in Texas

The Storm Prediction Center issued this tornado watch at Mar 31, 2007, 3:17 AM CDT for 23 counties in Texas. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Mar 31, 2007, 3:17 AM CDT (08:17 UTC)
Expired
Mar 31, 2007, 10:00 AM CDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 23 counties

Aransas County, TX, Austin County, TX, Bee County, TX, Brazoria County, TX, Calhoun County, TX, Chambers County, TX, Colorado County, TX, DeWitt County, TX, Fort Bend County, TX, Galveston County, TX, Goliad County, TX, Harris County, TX, Jackson County, TX, Karnes County, TX, Lavaca County, TX, Liberty County, TX, Live Oak County, TX, Matagorda County, TX, Montgomery County, TX, Refugio County, TX, Victoria County, TX, Waller County, TX, Wharton County, TX

The radar

The Corpus Christi radar (KCRP), 143 km from the middle of the area, began a volume at 08:17 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
30%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Mar 31, 4:04 AM CDTSevere Thunderstorm WarningCRPBee41 min
Mar 31, 4:14 AM CDTSevere Thunderstorm WarningEWXLavaca61 min
Mar 31, 4:22 AM CDTSevere Thunderstorm WarningHGXAustin, Colorado38 min
Mar 31, 4:30 AM CDTSevere Thunderstorm WarningHGXColorado, Jackson, Wharton45 min
Mar 31, 4:36 AM CDTSevere Thunderstorm WarningEWXDeWitt54 min
Mar 31, 4:57 AM CDTTornado WarningCRPGoliad33 min
Mar 31, 4:59 AM CDTSevere Thunderstorm WarningHGXAustin, Colorado46 min
Mar 31, 5:14 AM CDTSevere Thunderstorm WarningHGXAustin, Colorado, Fort Bend, Wharton61 min
Mar 31, 5:26 AM CDTTornado WarningHGXColorado, Wharton49 min
Mar 31, 5:43 AM CDTFlash Flood WarningCRPGoliad2 hr
Mar 31, 5:52 AM CDTFlash Flood WarningEWXLavaca3 hr
Mar 31, 5:58 AM CDTFlash Flood WarningCRPVictoria2 hr
Mar 31, 6:05 AM CDTTornado WarningHGXFort Bend, Harris29 min
Mar 31, 6:23 AM CDTSevere Thunderstorm WarningHGXBrazoria, Fort Bend, Galveston, Harris42 min
Mar 31, 7:44 AM CDTFlash Flood WarningCRPGoliad2 hr
Mar 31, 7:50 AM CDTFlash Flood WarningCRPVictoria115 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Corpus Christi, TX (KCRP), launched 00:00Z, 8.3 hours before the alert went out and 140 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, Corpus Christi, TX at 00:00Z on 2007-03-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 294 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, Corpus Christi, TX at 00:00Z on 2007-03-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 42 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
294 J/kg
Mixed-layer CIN
-219 J/kg
Mixed-layer LCL
811 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
42 m²/s²
0-3 km storm-relative helicity
131 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

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

000
WWUS20 KWNS 310815
SEL8  
SPC WW 310815
TXZ000-CWZ000-311500-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 98
NWS STORM PREDICTION CENTER NORMAN OK
315 AM CDT SAT MAR 31 2007

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF 

       SOUTHEAST TEXAS
       COASTAL WATERS

EFFECTIVE THIS SATURDAY MORNING FROM 315 AM UNTIL 1000 AM CDT.

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

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 85 STATUTE
MILES EAST AND WEST OF A LINE FROM 30 MILES SOUTHEAST OF BEEVILLE
TEXAS TO 30 MILES NORTH NORTHEAST OF HOUSTON TEXAS.  FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU8).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND 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.

OTHER WATCH INFORMATION...CONTINUE...WW 97...

DISCUSSION...LINE OF INTENSE THUNDERSTORMS OVER CENTRAL TX IS
EXPECTED TO PERSIST THROUGH THE MORNING AND APPROACH THE MIDDLE TX
GULF COAST BY DAYBREAK.  MODERATELY MOIST/UNSTABLE AIRMASS WILL POSE
A RISK OF HAIL AND DAMAGING WINDS IN STRONGER CELLS.  INCREASING
SOUTHERLY LOW LEVEL JET WILL ALSO AID IN THE POTENTIAL FOR ISOLATED
TORNADOES.

AVIATION...TORNADOES AND 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 27030.


...HART

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 30, 7:38 PM CDTMesoscale DiscussionSPCAnderson, Atascosa, Bandera, Bastrop, Bell, Bexar and 74 more2 hr
Mar 30, 9:48 PM CDTMesoscale DiscussionSPCAtascosa, Bandera, Bastrop, Bell, Bexar, Blanco and 49 more117 min
Mar 30, 10:06 PM CDTMesoscale DiscussionSPCAngelina, Bowie, Camp, Cass, Cherokee, Franklin and 16 more84 min
Mar 30, 10:28 PM CDTSevere Thunderstorm WatchSPCBowie, Camp, Cass, Cherokee, Franklin, Gregg and 10 more8 hr
Mar 30, 11:53 PM CDTMesoscale DiscussionSPCAnderson, Atascosa, Bandera, Bastrop, Bell, Bexar and 45 more67 min
Mar 31, 2:12 AM CDTMesoscale DiscussionSPCAransas, Atascosa, Austin, Bastrop, Bee, Brazoria and 32 more93 min
Mar 31, 2:40 AM CDTMesoscale DiscussionSPCBowie, Cass, Cherokee, Gregg, Harrison, Marion and 2 more95 min
Mar 31, 5:30 AM CDTMesoscale DiscussionSPCAransas, Austin, Bee, Brazoria, Calhoun, Chambers and 16 more2 hr
Mar 31, 7:08 AM CDTMesoscale DiscussionSPCAransas, Bee, Brazoria, Calhoun, Chambers, Fort Bend and 14 more67 min
Mar 31, 8:40 AM CDTSevere Thunderstorm WatchSPCJasper, Newton, Orange, Sabine, San Augustine5 hr

Nearby

Tornado Watches in Texas, 2007Every tornado watch in 2007

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.