Alert archive / Texas / Tornado Watches in 2009
Tornado Watch 160
The Storm Prediction Center issued this tornado watch at Apr 17, 2009, 10:24 AM CDT for 23 counties in Texas. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 17, 2009, 10:24 AM CDT (15:24 UTC)
- Expired
- Apr 17, 2009, 5:00 PM CDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 23 counties
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, Jefferson County, TX, Liberty County, TX, Madison County, TX, Matagorda County, TX, Montgomery County, TX, Orange County, TX, San Jacinto County, TX, Walker County, TX, Waller County, TX, Washington County, TX, Wharton County, TX
The radar
The Houston radar (KHGX), 33 km from the middle of the area, began a volume at 15:24 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
- 10%
- 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
- 70%
Warnings issued inside it
20 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 17, 10:25 AM CDT | Severe Thunderstorm Warning | HGX | Austin, Colorado | 50 min |
| Apr 17, 11:06 AM CDT | Flash Flood Warning | HGX | Colorado | 114 min |
| Apr 17, 11:12 AM CDT | Severe Thunderstorm Warning | HGX | Austin, Colorado | 48 min |
| Apr 17, 12:13 PM CDT | Severe Thunderstorm Warning | HGX | Austin, Colorado, Waller, Washington | 47 min |
| Apr 17, 12:21 PM CDT | Tornado Warning | HGX | Austin, Colorado, Waller | 39 min |
| Apr 17, 12:30 PM CDT | Tornado Warning | HGX | Austin, Waller, Washington | 36 min |
| Apr 17, 12:45 PM CDT | Flash Flood Warning | HGX | Austin, Colorado, Washington | 3 hr |
| Apr 17, 1:38 PM CDT | Severe Thunderstorm Warning | HGX | Austin, Harris, Waller, Washington | 37 min |
| Apr 17, 1:58 PM CDT | Tornado Warning | HGX | Austin, Harris, Waller, Washington | 21 min |
| Apr 17, 2:38 PM CDT | Flash Flood Warning | HGX | Brazos, Burleson | 3 hr |
| Apr 17, 3:04 PM CDT | Severe Thunderstorm Warning | HGX | Colorado | 56 min |
| Apr 17, 3:27 PM CDT | Severe Thunderstorm Warning | HGX | Harris, Montgomery | 48 min |
| Apr 17, 3:32 PM CDT | Severe Thunderstorm Warning | LCH | Hardin, Jasper, Tyler | 58 min |
| Apr 17, 3:38 PM CDT | Flash Flood Warning | HGX | Austin, Colorado, Fort Bend, Waller, Washington | 112 min |
| Apr 17, 3:43 PM CDT | Severe Thunderstorm Warning | HGX | Harris, Montgomery | 47 min |
| Apr 17, 3:51 PM CDT | Flash Flood Warning | HGX | Harris, Montgomery | 3 hr |
| Apr 17, 3:58 PM CDT | Severe Thunderstorm Warning | HGX | Austin, Colorado | 47 min |
| Apr 17, 4:01 PM CDT | Severe Thunderstorm Warning | HGX | Harris, Liberty, Montgomery | 59 min |
| Apr 17, 4:20 PM CDT | Severe Thunderstorm Warning | HGX | Austin, Fort Bend, Grimes, Harris, Montgomery, Waller | 40 min |
| Apr 17, 4:28 PM CDT | Flash Flood Warning | HGX | Harris, Liberty, Montgomery | 3 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, 3.4 hours before the alert went out and 168 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 673 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- 129 m²/s²
- 0-3 km storm-relative helicity
- 213 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 3.0
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 16, 7:31 PM CDT | Mesoscale Discussion | SPC | Brewster, Kinney, Pecos, Terrell, Val Verde | 89 min |
| Apr 16, 7:43 PM CDT | Mesoscale Discussion | SPC | Anderson, Angelina, Cherokee, Dallas, Ellis, Freestone and 23 more | 62 min |
| Apr 16, 8:36 PM CDT | Mesoscale Discussion | SPC | Andrews, Borden, Briscoe, Castro, Childress, Coke and 34 more | 84 min |
| Apr 16, 9:20 PM CDT | Mesoscale Discussion | SPC | Armstrong, Carson, Collingsworth, Dallam, Deaf Smith, Donley and 14 more | 55 min |
| Apr 16, 10:56 PM CDT | Mesoscale Discussion | SPC | Coke, Concho, Crockett, Fisher, Irion, Jones and 11 more | 94 min |
| Apr 16, 11:35 PM CDT | Severe Thunderstorm Watch | SPC | Bandera, Brown, Callahan, Coleman, Comanche, Concho and 26 more | 6 hr |
| Apr 17, 2:32 AM CDT | Mesoscale Discussion | SPC | Brown, Callahan, Coleman, Comanche, Concho, Eastland and 20 more | 118 min |
| Apr 17, 5:16 AM CDT | Mesoscale Discussion | SPC | Blanco, Burnet, Edwards, Gillespie, Kendall, Kerr and 8 more | 59 min |
| Apr 17, 7:28 AM CDT | Mesoscale Discussion | SPC | Atascosa, Bandera, Bastrop, Bell, Bexar, Blanco and 23 more | 92 min |
| Apr 17, 7:48 AM CDT | Severe Thunderstorm Watch | SPC | Atascosa, Bandera, Bastrop, Bell, Bexar, Blanco and 35 more | 5 hr |
| Apr 17, 9:56 AM CDT | Mesoscale Discussion | SPC | Anderson, Angelina, Atascosa, Austin, Bastrop, Bee and 63 more | 94 min |
| Apr 17, 12:10 PM CDT | Mesoscale Discussion | SPC | Anderson, Angelina, Austin, Brazos, Cherokee, Colorado and 19 more | 3 hr |
| Apr 17, 12:38 PM CDT | Mesoscale Discussion | SPC | Atascosa, Bee, DeWitt, Goliad, Gonzales, Karnes and 7 more | 37 min |
| Apr 17, 12:51 PM CDT | Severe Thunderstorm Watch | SPC | Atascosa, Bee, Calhoun, DeWitt, Fayette, Frio and 10 more | 5 hr |
| Apr 17, 1:45 PM CDT | Mesoscale Discussion | SPC | Brazoria, Chambers, Colorado, Fort Bend, Galveston, Hardin and 11 more | 2 hr |
| Apr 17, 3:19 PM CDT | Mesoscale Discussion | SPC | Aransas, Atascosa, Bastrop, Bee, Bell, Bexar and 31 more | 56 min |
| Apr 17, 3:24 PM CDT | Mesoscale Discussion | SPC | Childress, Collingsworth, Cottle, Foard, Gray, Hansford and 13 more | 96 min |
| Apr 17, 3:44 PM CDT | Tornado Watch | SPC | Aransas, Austin, Bee, Brazoria, Calhoun, Chambers and 22 more | 6 hr |
| Apr 17, 5:00 PM CDT | Severe Thunderstorm Watch | SPC | Baylor, Childress, Collingsworth, Cottle, Foard, Hardeman and 13 more | 5 hr |
| Apr 17, 6:50 PM CDT | Mesoscale Discussion | SPC | Aransas, Bee, Brazoria, Calhoun, Chambers, Colorado and 18 more | 85 min |
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.