Alert archive / Texas / Severe Thunderstorm Watches in 2012
Severe Thunderstorm Watch 137
The Storm Prediction Center issued this severe thunderstorm watch at Apr 3, 2012, 7:35 PM CDT for 19 counties in Texas. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 3, 2012, 7:35 PM CDT (00:35 UTC)
- Expired
- Apr 4, 2012, 3:00 AM CDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
Counties Austin County, TX, Bastrop County, TX, Brazos County, TX, Burleson County, TX, Colorado County, TX, Fayette County, TX, Grimes County, TX, Houston County, TX, Lavaca County, TX, Lee County, TX, Liberty County, TX, Madison County, TX, Montgomery County, TX, Polk County, TX, San Jacinto County, TX, Trinity County, TX, Walker County, TX, Waller County, TX, Washington County, TX
The radar
The Ft Hood radar (KGRK), 130 km from the middle of the area, began a volume at 00:36 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
- 30%
- One or more hailstones of 2 inches or more
- 20%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
8 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 3, 8:51 PM CDT | Severe Thunderstorm Warning | HGX | Houston | 39 min |
| Apr 3, 9:12 PM CDT | Severe Thunderstorm Warning | HGX | Brazos, Grimes, Madison | 48 min |
| Apr 3, 9:28 PM CDT | Severe Thunderstorm Warning | HGX | Houston | 47 min |
| Apr 3, 9:57 PM CDT | Severe Thunderstorm Warning | HGX | Brazos, Grimes, Madison, Walker | 48 min |
| Apr 4, 12:29 AM CDT | Severe Thunderstorm Warning | HGX | Polk, Trinity | 46 min |
| Apr 4, 12:44 AM CDT | Severe Thunderstorm Warning | HGX | Montgomery, Walker | 46 min |
| Apr 4, 1:52 AM CDT | Severe Thunderstorm Warning | HGX | Montgomery, San Jacinto, Walker | 38 min |
| Apr 4, 2:31 AM CDT | Severe Thunderstorm Warning | HGX | Liberty, Polk, San Jacinto | 59 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 00:00Z, 0.6 hours before the alert went out and 275 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
- 705 J/kg
- Mixed-layer CIN
- -39 J/kg
- Mixed-layer LCL
- 593 m above ground
- 0-6 km bulk shear
- 56 kt
- 0-1 km storm-relative helicity
- -113 m²/s²
- 0-3 km storm-relative helicity
- -19 m²/s²
- Significant tornado parameter
- -0.4
- Supercell composite
- -2.0
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 3, 8:47 PM CDT | Mesoscale Discussion | SPC | Angelina, Cherokee, Houston, Nacogdoches, Panola, Rusk and 3 more | 58 min |
| Apr 3, 9:48 PM CDT | Severe Thunderstorm Watch | SPC | Angelina, Cherokee, Hardin, Jasper, Jefferson, Nacogdoches and 8 more | 8 hr |
| Apr 3, 11:24 PM CDT | Mesoscale Discussion | SPC | Angelina, Austin, Colorado, Jasper, Lavaca, Montgomery and 10 more | 96 min |
| Apr 4, 2:29 AM CDT | Mesoscale Discussion | SPC | Chambers, Hardin, Harris, Jefferson, Liberty, Orange and 2 more | 91 min |
| Apr 4, 12:19 PM CDT | Mesoscale Discussion | SPC | Aransas, Austin, Bee, Brazoria, Calhoun, Chambers and 25 more | 86 min |
| Apr 4, 12:55 PM CDT | Severe Thunderstorm Watch | SPC | Aransas, Bee, Brazoria, Brooks, Calhoun, Cameron and 19 more | 6 hr |
| Apr 4, 3:32 PM CDT | Mesoscale Discussion | SPC | Aransas, Brazoria, Calhoun, Galveston, Kleberg, Matagorda and 1 more | 88 min |
Nearby
Severe Thunderstorm Watches in Texas, 2012Every severe thunderstorm watch in 2012
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.