Alert archive / Texas / Tornado Watches in 2009
Tornado Watch 203
The Storm Prediction Center issued this tornado watch at Apr 27, 2009, 3:58 PM CDT for 16 counties in Texas. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 27, 2009, 3:58 PM CDT (20:58 UTC)
- Expired
- Apr 27, 2009, 9:00 PM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 70 kt
Counties 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, Lavaca County, TX, Liberty County, TX, Matagorda County, TX, Montgomery County, TX, Victoria County, TX, Wharton County, TX
The radar
The Houston radar (KHGX), 116 km from the middle of the area, began a volume at 21:00 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.
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 40%
- 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
- 40%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 80%
Warnings issued inside it
19 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 27, 4:04 PM CDT | Tornado Warning | EWX | DeWitt | 26 min |
| Apr 27, 4:06 PM CDT | Severe Thunderstorm Warning | EWX | DeWitt, Gonzales, Lavaca | 39 min |
| Apr 27, 4:23 PM CDT | Tornado Warning | EWX | DeWitt, Lavaca | 52 min |
| Apr 27, 4:55 PM CDT | Tornado Warning | HGX | Austin, Fort Bend, Waller, Wharton | 35 min |
| Apr 27, 5:07 PM CDT | Tornado Warning | HGX | Harris, Montgomery | 38 min |
| Apr 27, 5:21 PM CDT | Flash Flood Warning | HGX | Austin, Colorado, Fort Bend, Harris, Montgomery, Waller and 1 more | 3 hr |
| Apr 27, 5:34 PM CDT | Tornado Warning | HGX | Harris, Montgomery | 41 min |
| Apr 27, 5:37 PM CDT | Severe Thunderstorm Warning | CRP | Goliad, Victoria | 53 min |
| Apr 27, 5:39 PM CDT | Severe Thunderstorm Warning | CRP | Victoria | 36 min |
| Apr 27, 5:46 PM CDT | Tornado Warning | HGX | Harris, Montgomery | 44 min |
| Apr 27, 5:52 PM CDT | Severe Thunderstorm Warning | HGX | Brazoria, Fort Bend, Harris | 38 min |
| Apr 27, 5:54 PM CDT | Severe Thunderstorm Warning | CRP | Goliad, Refugio, Victoria | 51 min |
| Apr 27, 6:02 PM CDT | Tornado Warning | HGX | Brazoria, Fort Bend, Harris | 28 min |
| Apr 27, 6:04 PM CDT | Severe Thunderstorm Warning | CRP | Aransas, Goliad, Refugio | 56 min |
| Apr 27, 6:19 PM CDT | Severe Thunderstorm Warning | CRP | Calhoun, Refugio, Victoria | 41 min |
| Apr 27, 6:27 PM CDT | Severe Thunderstorm Warning | HGX | Brazoria, Chambers, Fort Bend, Galveston, Harris, Liberty and 1 more | 63 min |
| Apr 27, 7:03 PM CDT | Flash Flood Warning | HGX | Brazoria, Chambers, Fort Bend, Galveston, Harris, Liberty and 1 more | 117 min |
| Apr 27, 7:23 PM CDT | Severe Thunderstorm Warning | CRP | Aransas, Calhoun, Refugio | 29 min |
| Apr 27, 7:26 PM CDT | Severe Thunderstorm Warning | HGX | Brazoria, Chambers, Galveston, Harris, Liberty | 64 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 12:00Z, 9.0 hours before the alert went out and 204 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
- 1236 J/kg
- Mixed-layer CIN
- -230 J/kg
- Mixed-layer LCL
- 508 m above ground
- 0-6 km bulk shear
- 35 kt
- 0-1 km storm-relative helicity
- 119 m²/s²
- 0-3 km storm-relative helicity
- 258 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.6
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 26, 8:04 PM CDT | Tornado Watch | SPC | Blanco, Brown, Burnet, Callahan, Coke, Coleman and 30 more | 7 hr |
| Apr 26, 8:42 PM CDT | Mesoscale Discussion | SPC | Archer, Baylor, Childress, Clay, Collingsworth, Cottle and 14 more | 2 hr |
| Apr 26, 10:46 PM CDT | Mesoscale Discussion | SPC | Blanco, Brown, Callahan, Coke, Coleman, Concho and 22 more | 119 min |
| Apr 27, 1:49 AM CDT | Mesoscale Discussion | SPC | Brown, Callahan, Coke, Coleman, Concho, Crockett and 24 more | 86 min |
| Apr 27, 2:44 AM CDT | Severe Thunderstorm Watch | SPC | Brown, Callahan, Coke, Coleman, Concho, Crockett and 23 more | 7 hr |
| Apr 27, 5:36 AM CDT | Mesoscale Discussion | SPC | Bosque, Brown, Coke, Comanche, Concho, Coryell and 17 more | 84 min |
| Apr 27, 6:08 AM CDT | Tornado Watch | SPC | Anderson, Bastrop, Bell, Blanco, Bosque, Brazos and 33 more | 7 hr |
| Apr 27, 7:43 AM CDT | Mesoscale Discussion | SPC | Coke, Concho, Crockett, Irion, Kimble, McCulloch and 8 more | 92 min |
| Apr 27, 7:55 AM CDT | Severe Thunderstorm Watch | SPC | Bandera, Bexar, Comal, Edwards, Frio, Guadalupe and 9 more | 5 hr |
| Apr 27, 8:59 AM CDT | Mesoscale Discussion | SPC | Anderson, Angelina, Bell, Brazos, Burleson, Burnet and 38 more | 91 min |
| Apr 27, 9:28 AM CDT | Severe Thunderstorm Watch | SPC | Bowie, Camp, Cass, Cherokee, Franklin, Gregg and 12 more | 12 hr |
| Apr 27, 11:42 AM CDT | Mesoscale Discussion | SPC | Anderson, Bastrop, Bell, Blanco, Brazos, Burleson and 19 more | 63 min |
| Apr 27, 12:00 PM CDT | Mesoscale Discussion | SPC | Atascosa, Bandera, Bexar, Comal, Edwards, Kendall and 6 more | 60 min |
| Apr 27, 1:14 PM CDT | Mesoscale Discussion | SPC | Bowie, Camp, Cass, Gregg, Harrison, Marion and 8 more | 91 min |
| Apr 27, 2:24 PM CDT | Mesoscale Discussion | SPC | Angelina, Bowie, Cass, Cherokee, Gregg, Harrison and 10 more | 66 min |
| Apr 27, 2:57 PM CDT | Severe Thunderstorm Watch | SPC | Bowie, Cass, Harrison, Marion, Panola, Shelby | 6 hr |
| Apr 27, 3:50 PM CDT | Mesoscale Discussion | SPC | Aransas, Austin, Bee, Brazoria, Calhoun, Chambers and 20 more | 85 min |
| Apr 27, 5:59 PM CDT | Mesoscale Discussion | SPC | Borden, Dawson, Fisher, Garza, Kent, Lynn and 4 more | 2 hr |
| Apr 27, 6:30 PM CDT | Mesoscale Discussion | SPC | Aransas, Brazoria, Calhoun, Chambers, Galveston, Hardin and 4 more | 2 hr |
Nearby
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.