Alert archive / Texas / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 156
The Storm Prediction Center issued this severe thunderstorm watch at Apr 19, 2011, 5:44 PM CDT for 25 counties in Texas. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 19, 2011, 5:44 PM CDT (22:44 UTC)
- Expired
- Apr 19, 2011, 9:40 PM CDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 3 in
- Strongest gust expected
- 60 kt
All 25 counties
Anderson County, TX, Bell County, TX, Blanco County, TX, Bosque County, TX, Burnet County, TX, Coryell County, TX, Ellis County, TX, Falls County, TX, Freestone County, TX, Gillespie County, TX, Hamilton County, TX, Henderson County, TX, Hill County, TX, Hood County, TX, Johnson County, TX, Lampasas County, TX, Leon County, TX, Limestone County, TX, Llano County, TX, McLennan County, TX, Milam County, TX, Mills County, TX, Navarro County, TX, Robertson County, TX, Somervell County, TX
The radar
The Dallas/Ft Worth radar (KFWS), 98 km from the middle of the area, began a volume at 22:44 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
- 30%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 60%
- One or more hailstones of 2 inches or more
- 60%
- Six or more combined severe hail and wind reports
- 80%
Warnings issued inside it
5 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 19, 5:55 PM CDT | Severe Thunderstorm Warning | FWD | Johnson | 65 min |
| Apr 19, 6:52 PM CDT | Severe Thunderstorm Warning | FWD | Johnson | 53 min |
| Apr 19, 7:23 PM CDT | Severe Thunderstorm Warning | FWD | Hill | 67 min |
| Apr 19, 7:37 PM CDT | Severe Thunderstorm Warning | FWD | Johnson | 53 min |
| Apr 19, 8:27 PM CDT | Severe Thunderstorm Warning | FWD | Hill | 44 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, 10.7 hours before the alert went out and 127 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
- 3369 J/kg
- Mixed-layer CIN
- -217 J/kg
- Mixed-layer LCL
- 660 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- 361 m²/s²
- 0-3 km storm-relative helicity
- 398 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 5.1
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 19, 1:40 PM CDT | Mesoscale Discussion | SPC | Collin, Dallas, Delta, Denton, Ellis, Fannin and 10 more | 65 min |
| Apr 19, 2:16 PM CDT | Tornado Watch | SPC | Bowie, Camp, Cass, Collin, Dallas, Delta and 17 more | 10 hr |
| Apr 19, 3:45 PM CDT | Mesoscale Discussion | SPC | Bastrop, Bell, Bexar, Blanco, Bosque, Burleson and 24 more | 60 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.