Alert archive / Texas / Tornado Watches in 2004
Tornado Watch 143
The Storm Prediction Center issued this tornado watch at May 1, 2004, 9:45 AM CDT for 6 parishes in Louisiana; 12 counties in Texas. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- May 1, 2004, 9:45 AM CDT (14:45 UTC)
- Expired
- May 1, 2004, 3:00 PM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
Counties Allen Parish, LA, Beauregard Parish, LA, Calcasieu Parish, LA, Cameron Parish, LA, Jefferson Davis Parish, LA, Vernon Parish, LA, Brazoria County, TX, Chambers County, TX, Fort Bend County, TX, Galveston County, TX, Hardin County, TX, Harris County, TX, Jefferson County, TX, Liberty County, TX, Matagorda County, TX, Newton County, TX, Orange County, TX, Wharton County, TX
The radar
The Houston radar (KHGX), 27 km from the middle of the area, began a volume at 14:45 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
4 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 1, 10:20 AM CDT | Severe Thunderstorm Warning | HGX | Chambers, Liberty | 55 min |
| May 1, 11:41 AM CDT | Tornado Warning | HGX | Galveston | 34 min |
| May 1, 11:44 AM CDT | Flash Flood Warning | HGX | Brazoria, Galveston | 2 hr |
| May 1, 11:58 AM CDT | Flash Flood Warning | HGX | Fort Bend, Harris, Liberty | 2 hr |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Lake Charles Mun, LA (KLCH), launched 12:00Z, 2.8 hours before the alert went out and 170 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.
- Mixed-layer CAPE
- 326 J/kg
- Mixed-layer CIN
- -239 J/kg
- Mixed-layer LCL
- 978 m above ground
- 0-6 km bulk shear
- 43 kt
- 0-1 km storm-relative helicity
- 153 m²/s²
- 0-3 km storm-relative helicity
- 263 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 9.3
The text
As transmitted, in the capitals the NWS used until 2016.
000
WWUS20 KWNS 011441
SEL3
SPC WW 011445
LAZ000-TXZ000-CWZ000-012000-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 143
NWS STORM PREDICTION CENTER NORMAN OK
945 AM CDT SAT MAY 1 2004
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
SOUTHWEST LOUISIANA
UPPER TEXAS COASTAL PLAIN
COASTAL WATERS
EFFECTIVE THIS SATURDAY MORNING AND AFTERNOON FROM 945 AM UNTIL
300 PM CDT.
TORNADOES...HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.
THE TORNADO WATCH AREA IS ALONG AND 55 STATUTE MILES NORTH AND
SOUTH OF A LINE FROM 5 MILES SOUTHWEST OF PALACIOS TEXAS TO 40
MILES SOUTHEAST OF FORT POLK LOUISIANA.
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...THIS TORNADO WATCH REPLACES TORNADO
WATCH NUMBER 141. WATCH NUMBER 141 WILL NOT BE IN EFFECT AFTER 945
AM CDT. CONTINUE...WW 142...
DISCUSSION...SQUALL LINE WILL CONTINUE TO MOVE SEWD TO NEAR THE
UPPER TX COAST BY MIDDAY...AND ACROSS SW LA THROUGH EARLY AFTERNOON.
RICH LOW-LEVEL MOISTURE /DEWPOINTS IN THE LOWER 70S/ AND STRONG
LOW-LEVEL SHEAR WILL SUPPORT THE THREAT OF A COUPLE OF TORNADOES
WITH STORMS EMBEDDED IN THE LINE...ALONG WITH THE POSSIBILITY OF
DAMAGING WINDS AND ISOLATED LARGE HAIL.
AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
550. MEAN STORM MOTION VECTOR 28020.
...THOMPSON
292,0961 312,0924 295,0924 275,0961SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 30, 11:56 PM CDT | Mesoscale Discussion | SPC | Beauregard, Calcasieu, Cameron, Jefferson Davis | 94 min |
| May 1, 12:50 AM CDT | Severe Thunderstorm Watch | SPC | Bossier, Caddo | 6 hr |
| May 1, 2:38 AM CDT | Mesoscale Discussion | SPC | Bienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 10 more | 37 min |
| May 1, 3:10 AM CDT | Severe Thunderstorm Watch | SPC | Bienville, Bossier, Claiborne, De Soto, Jackson, Lincoln and 7 more | 6 hr |
| May 1, 5:13 AM CDT | Mesoscale Discussion | SPC | Bienville, Bossier, Caddo, Claiborne, De Soto, Jackson and 6 more | 92 min |
| May 1, 7:24 AM CDT | Mesoscale Discussion | SPC | Natchitoches, Sabine, Winn | 96 min |
| May 1, 1:45 PM CDT | Mesoscale Discussion | SPC | East Baton Rouge, East Feliciana, Iberville, Livingston, Saint Helena, Saint Tammany and 3 more | 3 hr |
| May 1, 4:00 PM CDT | Severe Thunderstorm Watch | SPC | Washington | 5 hr |
| Apr 30, 7:00 PM CDT | Mesoscale Discussion | SPC | Bosque, Brown, Coleman, Comanche, Concho, Eastland and 11 more | 90 min |
| Apr 30, 7:22 PM CDT | Mesoscale Discussion | SPC | Anderson, Bowie, Camp, Cass, Cherokee, Delta and 25 more | 83 min |
| Apr 30, 7:40 PM CDT | Severe Thunderstorm Watch | SPC | Anderson, Bowie, Camp, Delta, Ellis, Fannin and 20 more | 5 hr |
| Apr 30, 8:14 PM CDT | Mesoscale Discussion | SPC | Archer, Clay, Collin, Cooke, Denton, Grayson and 8 more | 91 min |
| Apr 30, 9:07 PM CDT | Mesoscale Discussion | SPC | Bosque, Brown, Comanche, Coryell, Erath, Hamilton and 8 more | 53 min |
| Apr 30, 9:54 PM CDT | Mesoscale Discussion | SPC | Anderson, Bowie, Camp, Delta, Ellis, Franklin and 19 more | 96 min |
| Apr 30, 10:34 PM CDT | Mesoscale Discussion | SPC | Brown, Coleman, Concho, Crockett, Edwards, Irion and 15 more | 86 min |
| Apr 30, 11:35 PM CDT | Severe Thunderstorm Watch | SPC | Blanco, Concho, Crockett, Edwards, Gillespie, Irion and 13 more | 5 hr |
| May 1, 1:34 AM CDT | Mesoscale Discussion | SPC | Atascosa, Bandera, Bexar, Blanco, Comal, Concho and 24 more | 86 min |
| May 1, 1:49 AM CDT | Mesoscale Discussion | SPC | Anderson, Bell, Cherokee, Falls, Freestone, Henderson and 5 more | 86 min |
| May 1, 3:28 AM CDT | Mesoscale Discussion | SPC | Atascosa, Bandera, Bexar, Blanco, Concho, Crockett and 23 more | 92 min |
| May 1, 3:41 AM CDT | Mesoscale Discussion | SPC | Austin, Brazoria, Brazos, Burleson, Chambers, Colorado and 18 more | 64 min |
| May 1, 3:50 AM CDT | Tornado Watch | SPC | Angelina, Austin, Bastrop, Brazos, Burleson, Chambers and 25 more | 6 hr |
| May 1, 5:40 AM CDT | Severe Thunderstorm Watch | SPC | Atascosa, Bee, Bexar, Caldwell, DeWitt, Dimmit and 17 more | 6 hr |
| May 1, 6:08 AM CDT | Mesoscale Discussion | SPC | Angelina, Austin, Brazos, Burleson, Chambers, Colorado and 24 more | 97 min |
| May 1, 7:33 AM CDT | Mesoscale Discussion | SPC | Atascosa, Bee, Bexar, Caldwell, DeWitt, Dimmit and 16 more | 87 min |
| May 1, 7:47 AM CDT | Mesoscale Discussion | SPC | Austin, Bastrop, Brazos, Burleson, Chambers, Colorado and 23 more | 88 min |
| May 1, 9:16 AM CDT | Mesoscale Discussion | SPC | Brazoria, Chambers, Fort Bend, Galveston, Hardin, Harris and 3 more | 59 min |
| May 1, 9:36 AM CDT | Mesoscale Discussion | SPC | Nueces | 114 min |
| May 1, 9:55 AM CDT | Severe Thunderstorm Watch | SPC | Brooks, Cameron, Hidalgo, Jim Hogg, Kenedy, Kleberg and 3 more | 5 hr |
| May 1, 11:15 AM CDT | Mesoscale Discussion | SPC | Kenedy | 2 hr |
| May 1, 1:14 PM CDT | Mesoscale Discussion | SPC | Willacy | 2 hr |
Nearby
Tornado Watches in Texas, 2004Tornado Watches in Louisiana, 2004Every tornado watch in 2004
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.