Alert archive / Texas / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 853
The Storm Prediction Center issued this severe thunderstorm watch at Sep 18, 2011, 4:06 PM CDT for 57 counties in Texas. It was in force for 9 hr.
The area
The outline as issued.
The facts
- Issued
- Sep 18, 2011, 4:06 PM CDT (21:06 UTC)
- Expired
- Sep 19, 2011, 1:00 AM CDT
- In force
- 9 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 57 counties
Anderson County, TX, Bosque County, TX, Brown County, TX, Callahan County, TX, Coke County, TX, Coleman County, TX, Collin County, TX, Comanche County, TX, Concho County, TX, Cooke County, TX, Coryell County, TX, Crockett County, TX, Dallas County, TX, Delta County, TX, Denton County, TX, Eastland County, TX, Ellis County, TX, Erath County, TX, Fannin County, TX, Freestone County, TX, Grayson County, TX, Hamilton County, TX, Henderson County, TX, Hill County, TX, Hood County, TX, Hopkins County, TX, Hunt County, TX, Irion County, TX, Jack County, TX, Johnson County, TX, Kaufman County, TX, Kimble County, TX, Lamar County, TX, Lampasas County, TX, Leon County, TX, Limestone County, TX, Mason County, TX, McCulloch County, TX, McLennan County, TX, Menard County, TX, Mills County, TX, Navarro County, TX, Palo Pinto County, TX, Parker County, TX, Rains County, TX, Rockwall County, TX, Runnels County, TX, San Saba County, TX, Schleicher County, TX, Somervell County, TX, Stephens County, TX, Sterling County, TX, Sutton County, TX, Tarrant County, TX, Tom Green County, TX, Van Zandt County, TX, Wise County, TX
The radar
The Dyess AFB radar (KDYX), 92 km from the middle of the area, began a volume at 21:06 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
- 5%
- Ten or more severe wind reports
- 60%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 70%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 95%
Warnings issued inside it
27 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 18, 4:11 PM CDT | Severe Thunderstorm Warning | FWD | Cooke, Grayson | 49 min |
| Sep 18, 4:59 PM CDT | Severe Thunderstorm Warning | FWD | Cooke, Grayson | 61 min |
| Sep 18, 5:17 PM CDT | Severe Thunderstorm Warning | FWD | Comanche, Eastland, Erath | 58 min |
| Sep 18, 5:21 PM CDT | Severe Thunderstorm Warning | SJT | Kimble | 39 min |
| Sep 18, 5:26 PM CDT | Severe Thunderstorm Warning | FWD | Grayson | 34 min |
| Sep 18, 5:30 PM CDT | Severe Thunderstorm Warning | SJT | Kimble | 45 min |
| Sep 18, 5:55 PM CDT | Severe Thunderstorm Warning | FWD | Fannin, Grayson | 65 min |
| Sep 18, 6:00 PM CDT | Severe Thunderstorm Warning | SJT | McCulloch | 45 min |
| Sep 18, 6:30 PM CDT | Severe Thunderstorm Warning | FWD | Comanche, Eastland | 60 min |
| Sep 18, 7:00 PM CDT | Severe Thunderstorm Warning | FWD | Collin, Fannin, Grayson, Hunt | 60 min |
| Sep 18, 7:23 PM CDT | Severe Thunderstorm Warning | FWD | Hopkins, Hunt, Rains | 67 min |
| Sep 18, 7:42 PM CDT | Severe Thunderstorm Warning | FWD | Dallas | 63 min |
| Sep 18, 7:56 PM CDT | Severe Thunderstorm Warning | FWD | Collin, Fannin, Grayson, Hunt, Rockwall | 64 min |
| Sep 18, 8:29 PM CDT | Severe Thunderstorm Warning | FWD | Delta, Hopkins, Hunt, Rains | 61 min |
| Sep 18, 8:43 PM CDT | Severe Thunderstorm Warning | FWD | Hamilton, Mills | 62 min |
| Sep 18, 8:44 PM CDT | Severe Thunderstorm Warning | FWD | Dallas, Hunt, Kaufman, Rockwall, Tarrant | 46 min |
| Sep 18, 8:56 PM CDT | Severe Thunderstorm Warning | FWD | Hunt, Rains, Van Zandt | 34 min |
| Sep 18, 9:20 PM CDT | Severe Thunderstorm Warning | FWD | Dallas, Ellis, Hunt, Johnson, Kaufman, Rains and 2 more | 55 min |
| Sep 18, 9:39 PM CDT | Severe Thunderstorm Warning | FWD | Bosque | 66 min |
| Sep 18, 9:53 PM CDT | Severe Thunderstorm Warning | FWD | Henderson, Navarro | 52 min |
| Sep 18, 10:11 PM CDT | Severe Thunderstorm Warning | FWD | Bosque, Hill, Johnson | 54 min |
| Sep 18, 10:15 PM CDT | Severe Thunderstorm Warning | FWD | Ellis, Kaufman, Van Zandt | 45 min |
| Sep 18, 10:22 PM CDT | Severe Thunderstorm Warning | FWD | Hill | 38 min |
| Sep 18, 10:42 PM CDT | Severe Thunderstorm Warning | FWD | Anderson, Freestone, Henderson, Navarro | 63 min |
| Sep 18, 10:55 PM CDT | Severe Thunderstorm Warning | FWD | Ellis, Hill | 39 min |
| Sep 18, 11:36 PM CDT | Severe Thunderstorm Warning | FWD | Bosque, McLennan | 54 min |
| Sep 19, 12:29 AM CDT | Severe Thunderstorm Warning | FWD | Bell, Coryell, Falls, Limestone, McLennan | 45 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
Fort Worth, TX (KFWD), launched 12:00Z, 9.1 hours before the alert went out and 105 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
- 581 J/kg
- Mixed-layer CIN
- -136 J/kg
- Mixed-layer LCL
- 1222 m above ground
- 0-6 km bulk shear
- 22 kt
- 0-1 km storm-relative helicity
- 73 m²/s²
- 0-3 km storm-relative helicity
- 139 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 17, 10:17 PM CDT | Mesoscale Discussion | SPC | Cooke, Grayson, Montague, Wise | 88 min |
| Sep 18, 3:59 PM CDT | Mesoscale Discussion | SPC | Bosque, Brown, Callahan, Coleman, Collin, Comanche and 46 more | 31 min |
| Sep 18, 5:41 PM CDT | Severe Thunderstorm Watch | SPC | Bowie, Camp, Cass, Cherokee, Franklin, Gregg and 12 more | 7 hr |
| Sep 18, 6:18 PM CDT | Mesoscale Discussion | SPC | Bandera, Bexar, Blanco, Comal, Edwards, Hays and 6 more | 57 min |
| Sep 18, 6:48 PM CDT | Mesoscale Discussion | SPC | Lamar, Red River | 57 min |
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.