Alert archive / Texas / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 884
The Storm Prediction Center issued this severe thunderstorm watch at Nov 15, 2011, 6:38 AM CST for 16 counties in Texas. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Nov 15, 2011, 6:38 AM CST (12:38 UTC)
- Expired
- Nov 15, 2011, 1:00 PM CST
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
Counties Atascosa County, TX, Bastrop County, TX, Bexar County, TX, Blanco County, TX, Caldwell County, TX, Comal County, TX, DeWitt County, TX, Fayette County, TX, Gonzales County, TX, Guadalupe County, TX, Hays County, TX, Karnes County, TX, Lavaca County, TX, Lee County, TX, Travis County, TX, Wilson County, TX
The radar
The Austin/San Antonio radar (KEWX), 22 km from the middle of the area, began a volume at 12:37 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
- 10%
- One or more EF2 to EF5 tornadoes
- 2%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 20%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 50%
Warnings issued inside it
1 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Nov 15, 12:26 PM CST | Severe Thunderstorm Warning | EWX | Fayette, Lavaca | 34 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, 0.6 hours before the alert went out and 232 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
- 1492 J/kg
- Mixed-layer CIN
- -59 J/kg
- Mixed-layer LCL
- 541 m above ground
- 0-6 km bulk shear
- 44 kt
- 0-1 km storm-relative helicity
- 182 m²/s²
- 0-3 km storm-relative helicity
- 214 m²/s²
- Significant tornado parameter
- 2.0
- Supercell composite
- 10.7
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Nov 15, 12:02 AM CST | Mesoscale Discussion | SPC | Bandera, Bexar, Dimmit, Edwards, Frio, Kerr and 8 more | 2 hr |
| Nov 15, 2:14 AM CST | Severe Thunderstorm Watch | SPC | Bandera, Dimmit, Edwards, Frio, Gillespie, Kendall and 10 more | 7 hr |
| Nov 15, 5:35 AM CST | Mesoscale Discussion | SPC | Atascosa, Bexar, Blanco, Comal, Duval, Frio and 10 more | 85 min |
| Nov 15, 8:57 AM CST | Severe Thunderstorm Watch | SPC | Anderson, Angelina, Austin, Brazoria, Brazos, Burleson and 38 more | 9 hr |
| Nov 15, 10:35 AM CST | Mesoscale Discussion | SPC | Atascosa, Bexar, Blanco, Comal, Duval, Frio and 10 more | 115 min |
| Nov 15, 2:30 PM CST | Mesoscale Discussion | SPC | Angelina, Chambers, Galveston, Hardin, Houston, Jasper and 15 more | 2 hr |
| Nov 15, 3:49 PM CST | Mesoscale Discussion | SPC | Bowie, Camp, Cass, Delta, Fannin, Franklin and 6 more | 116 min |
| Nov 15, 5:44 PM CST | Mesoscale Discussion | SPC | Newton, Orange, Sabine | 61 min |
| Nov 15, 5:56 PM CST | Tornado Watch | SPC | Newton, Orange, Sabine | 7 hr |
Nearby
Severe Thunderstorm Watches in Texas, 2011Every severe thunderstorm watch in 2011
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.