Alert archive / Texas / Tornado Watches in 2003
Tornado Watch 11
The Storm Prediction Center issued this tornado watch at Feb 21, 2003, 9:40 AM CST for 17 parishes in Louisiana; 31 counties in Texas. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Feb 21, 2003, 9:40 AM CST (15:40 UTC)
- Expired
- Feb 21, 2003, 4:00 PM CST
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
All 48 counties
Acadia Parish, LA, Allen Parish, LA, Beauregard Parish, LA, Calcasieu Parish, LA, Caldwell Parish, LA, Cameron Parish, LA, Evangeline Parish, LA, Grant Parish, LA, Jefferson Davis Parish, LA, Lafayette Parish, LA, LaSalle Parish, LA, Natchitoches Parish, LA, Rapides Parish, LA, Sabine Parish, LA, Saint Landry Parish, LA, Vernon Parish, LA, Winn Parish, LA, Angelina County, TX, Austin County, TX, Brazoria County, TX, Brazos County, TX, Burleson County, TX, Chambers County, TX, Colorado County, TX, Fort Bend County, TX, Galveston County, TX, Grimes County, TX, Hardin County, TX, Harris County, TX, Jackson County, TX, Jasper County, TX, Jefferson County, TX, Liberty County, TX, Madison County, TX, Matagorda County, TX, Montgomery County, TX, Newton County, TX, Orange County, TX, Polk County, TX, Sabine County, TX, San Augustine County, TX, San Jacinto County, TX, Trinity County, TX, Tyler County, TX, Walker County, TX, Waller County, TX, Washington County, TX, Wharton County, TX
The radar
The Houston radar (KHGX), 119 km from the middle of the area, began a volume at 15:42 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
11 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 21, 10:08 AM CST | Severe Thunderstorm Warning | SHV | Sabine | 52 min |
| Feb 21, 12:20 PM CST | Severe Thunderstorm Warning | HGX | Brazoria, Galveston | 40 min |
| Feb 21, 1:32 PM CST | Severe Thunderstorm Warning | HGX | Fort Bend | 43 min |
| Feb 21, 1:45 PM CST | Severe Thunderstorm Warning | HGX | Harris | 60 min |
| Feb 21, 2:20 PM CST | Severe Thunderstorm Warning | HGX | Montgomery | 55 min |
| Feb 21, 2:44 PM CST | Flash Flood Warning | SHV | Sabine | 4 hr |
| Feb 21, 2:54 PM CST | Severe Thunderstorm Warning | HGX | Liberty | 66 min |
| Feb 21, 3:13 PM CST | Flash Flood Warning | SHV | Angelina | 4 hr |
| Feb 21, 3:15 PM CST | Severe Thunderstorm Warning | HGX | Polk | 45 min |
| Feb 21, 3:35 PM CST | Flash Flood Warning | LCH | Vernon | 3 hr |
| Feb 21, 3:46 PM CST | Flash Flood Warning | SHV | Grant, Jackson, Natchitoches, Winn | 4 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, 3.7 hours before the alert went out and 158 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
- 543 J/kg
- Mixed-layer CIN
- -114 J/kg
- Mixed-layer LCL
- 433 m above ground
- 0-6 km bulk shear
- 45 kt
- 0-1 km storm-relative helicity
- 253 m²/s²
- 0-3 km storm-relative helicity
- 274 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 6.2
The text
As transmitted, in the capitals the NWS used until 2016.
172 WWUS20 KWNS 211539 SEL1 SPC WW 211540 LAZ000-TXZ000-CWZ000-212200- URGENT - IMMEDIATE BROADCAST REQUESTED TORNADO WATCH NUMBER 11 STORM PREDICTION CENTER NORMAN OK 940 AM CST FRI FEB 21 2003 THE STORM PREDICTION CENTER HAS ISSUED A TORNADO WATCH FOR PORTIONS OF CENTRAL AND SOUTHERN LOUISIANA SOUTHEAST TEXAS COASTAL WATERS EFFECTIVE THIS FRIDAY MORNING AND AFTERNOON FROM 940 AM UNTIL 400 PM CST. 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 ALONG AND 80 STATUTE MILES NORTH AND SOUTH OF A LINE FROM 65 MILES NORTH NORTHWEST OF PALACIOS TEXAS TO 20 MILES EAST SOUTHEAST OF ALEXANDRIA 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 10. WATCH NUMBER 10 WILL NOT BE IN EFFECT AFTER 940 AM CST. CONTINUE...WW 9... DISCUSSION...DEVELOPING SURFACE LOW NEAR VCT WILL DEEPEN NEWD INTO NWRN LA BY THIS EVENING WITH WARM FRONT NOW JUST INLAND SURGING NWD ACROSS SERN TX/SRN LA. APPROACH OF STRONG UPPER TROUGH AND WIND MAX NOW APPROAHCING LOWER RIO GRANDE VALLEY WILL SUPPORT DEVELOPMENT OF SEVERE THUNDERSTORMS AHEAD OF SURFACE LOW AND INLAND ALONG AND S OF WARM FRONT. DEEP LAYER SHEAR IS FAVORABLE FOR SUPERCELLS AND TORNADOS...PARTICULARLY VICINITY OF WARM FRONT WHERE LOW LEVEL SHEAR WILL BE ENHANCED. 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 24035. ...HALES 300,0915 282,0963 304,0963 322,0915
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 21, 1:43 AM CST | Mesoscale Discussion | SPC | Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Cameron and 6 more | 2 hr |
| Feb 21, 4:35 AM CST | Mesoscale Discussion | SPC | Ascension, Assumption, Avoyelles, Concordia, East Baton Rouge, East Feliciana and 16 more | 115 min |
| Feb 21, 9:02 AM CST | Mesoscale Discussion | SPC | Beauregard, Calcasieu, Cameron, Sabine, Vernon | 58 min |
| Feb 21, 11:47 AM CST | Mesoscale Discussion | SPC | Acadia, Allen, Beauregard, Calcasieu, Cameron, Evangeline and 4 more | 118 min |
| Feb 21, 3:32 PM CST | Mesoscale Discussion | SPC | Allen, Beauregard, Calcasieu, Evangeline, Jefferson Davis, Vernon | 118 min |
| Feb 21, 3:40 PM CST | Tornado Watch | SPC | Acadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 32 more | 6 hr |
| Feb 21, 5:20 PM CST | Mesoscale Discussion | SPC | Claiborne, East Carroll, Franklin, Jackson, Lincoln, Madison and 5 more | 4 hr |
| Feb 21, 5:50 PM CST | Mesoscale Discussion | SPC | Acadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 32 more | 115 min |
| Feb 21, 2:43 AM CST | Mesoscale Discussion | SPC | Dimmit, Edwards, Frio, Kinney, La Salle, Maverick and 5 more | 3 hr |
| Feb 21, 3:53 AM CST | Mesoscale Discussion | SPC | Aransas, Austin, Brazoria, Calhoun, Colorado, Fort Bend and 13 more | 3 hr |
| Feb 21, 4:10 AM CST | Severe Thunderstorm Watch | SPC | Atascosa, Bandera, Bastrop, Bexar, Blanco, Brazos and 26 more | 6 hr |
| Feb 21, 4:25 AM CST | Tornado Watch | SPC | Austin, Brazoria, Brazos, Burleson, Calhoun, Colorado and 15 more | 6 hr |
| Feb 21, 5:58 AM CST | Mesoscale Discussion | SPC | Atascosa, Bandera, Bastrop, Bexar, Blanco, Brazos and 26 more | 2 hr |
| Feb 21, 6:16 AM CST | Mesoscale Discussion | SPC | Austin, Brazoria, Brazos, Burleson, Calhoun, Colorado and 17 more | 119 min |
| Feb 21, 1:30 PM CST | Mesoscale Discussion | SPC | Hardin, Harris, Jasper, Liberty, Montgomery, Newton and 3 more | 2 hr |
Nearby
Tornado Watches in Texas, 2003Tornado Watches in Louisiana, 2003Every tornado watch in 2003
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.