Alert archive / Texas / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 885
The Storm Prediction Center issued this severe thunderstorm watch at Nov 15, 2011, 8:57 AM CST for 44 counties in Texas. It was in force for 9 hr.
The area
The outline as issued.
The facts
- Issued
- Nov 15, 2011, 8:57 AM CST (14:57 UTC)
- Expired
- Nov 15, 2011, 6:00 PM CST
- In force
- 9 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 44 counties
Anderson County, TX, Angelina County, TX, Austin County, TX, Brazoria County, TX, Brazos County, TX, Burleson County, TX, Chambers County, TX, Cherokee County, TX, Colorado County, TX, Falls County, TX, Fort Bend County, TX, Freestone County, TX, Galveston County, TX, Grimes County, TX, Hardin County, TX, Harris County, TX, Houston County, TX, Jackson County, TX, Jasper County, TX, Jefferson County, TX, Leon County, TX, Liberty County, TX, Limestone County, TX, Madison County, TX, Matagorda County, TX, Milam County, TX, Montgomery County, TX, Nacogdoches County, TX, Newton County, TX, Orange County, TX, Panola County, TX, Polk County, TX, Robertson County, TX, Rusk County, TX, Sabine County, TX, San Augustine County, TX, San Jacinto County, TX, Shelby 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), 144 km from the middle of the area, began a volume at 14:57 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
- 20%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 40%
- 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
- 20%
- Six or more combined severe hail and wind reports
- 80%
Warnings issued inside it
10 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Nov 15, 1:33 PM CST | Severe Thunderstorm Warning | HGX | Harris | 27 min |
| Nov 15, 1:44 PM CST | Severe Thunderstorm Warning | HGX | Montgomery, Walker | 46 min |
| Nov 15, 2:05 PM CST | Tornado Warning | HGX | Montgomery, San Jacinto | 40 min |
| Nov 15, 2:16 PM CST | Severe Thunderstorm Warning | HGX | Harris, Montgomery | 29 min |
| Nov 15, 2:42 PM CST | Tornado Warning | HGX | Polk, San Jacinto, Trinity | 48 min |
| Nov 15, 4:38 PM CST | Severe Thunderstorm Warning | LCH | Hardin, Jasper, Tyler | 37 min |
| Nov 15, 4:52 PM CST | Tornado Warning | LCH | Hardin, Jasper, Newton, Tyler | 38 min |
| Nov 15, 5:27 PM CST | Tornado Warning | LCH | Jasper, Newton | 48 min |
| Nov 15, 5:43 PM CST | Severe Thunderstorm Warning | LCH | Jasper, Newton, Orange | 46 min |
| Nov 15, 5:59 PM CST | Tornado Warning | LCH | Newton | 21 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
Lake Charles Mun, LA (KLCH), launched 12:00Z, 3.0 hours before the alert went out and 240 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
- 26 J/kg
- Mixed-layer CIN
- -395 J/kg
- Mixed-layer LCL
- 948 m above ground
- 0-6 km bulk shear
- 44 kt
- 0-1 km storm-relative helicity
- 180 m²/s²
- 0-3 km storm-relative helicity
- 109 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.7
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, 6:38 AM CST | Severe Thunderstorm Watch | SPC | Atascosa, Bastrop, Bexar, Blanco, Caldwell, Comal and 10 more | 6 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.