Alert archive / Texas / Severe Thunderstorm Watches in 2009
Severe Thunderstorm Watch 101
The Storm Prediction Center issued this severe thunderstorm watch at Apr 2, 2009, 1:49 AM CDT for 58 counties in Texas. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 2, 2009, 1:49 AM CDT (06:49 UTC)
- Expired
- Apr 2, 2009, 9:10 AM CDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 58 counties
Anderson County, TX, Austin County, TX, Bastrop County, TX, Bell County, TX, Blanco County, TX, Bosque County, TX, Brazoria County, TX, Brazos County, TX, Burleson County, TX, Burnet County, TX, Caldwell County, TX, Chambers County, TX, Colorado County, TX, Coryell County, TX, Ellis County, TX, Falls County, TX, Fayette County, TX, Fort Bend County, TX, Freestone County, TX, Galveston County, TX, Gillespie County, TX, Grimes County, TX, Hamilton County, TX, Harris County, TX, Hays County, TX, Henderson County, TX, Hill County, TX, Houston County, TX, Kaufman County, TX, Kimble County, TX, Lampasas County, TX, Lee County, TX, Leon County, TX, Liberty County, TX, Limestone County, TX, Llano County, TX, Madison County, TX, Mason County, TX, McCulloch County, TX, McLennan County, TX, Menard County, TX, Milam County, TX, Mills County, TX, Montgomery County, TX, Navarro County, TX, Polk County, TX, Robertson County, TX, San Jacinto County, TX, San Saba County, TX, Sutton County, TX, Travis County, TX, Trinity County, TX, Van Zandt County, TX, Walker County, TX, Waller County, TX, Washington County, TX, Wharton County, TX, Williamson County, TX
The radar
The Ft Hood radar (KGRK), 94 km from the middle of the area, began a volume at 06:52 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
- 5%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 20%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 70%
- One or more hailstones of 2 inches or more
- 40%
- Six or more combined severe hail and wind reports
- 80%
Warnings issued inside it
3 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 2, 4:39 AM CDT | Severe Thunderstorm Warning | EWX | Blanco, Burnet, Comal, Hays, Kendall, Travis | 51 min |
| Apr 2, 6:48 AM CDT | Severe Thunderstorm Warning | HGX | Colorado | 27 min |
| Apr 2, 6:56 AM CDT | Severe Thunderstorm Warning | HGX | Colorado | 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
Fort Worth, TX (KFWD), launched 00:00Z, 6.8 hours before the alert went out and 147 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 3418 m above ground
- 0-6 km bulk shear
- 45 kt
- 0-1 km storm-relative helicity
- 89 m²/s²
- 0-3 km storm-relative helicity
- 199 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 |
|---|---|---|---|---|
| Apr 2, 1:32 AM CDT | Mesoscale Discussion | SPC | Anderson, Angelina, Bastrop, Bell, Blanco, Bosque and 62 more | 58 min |
| Apr 2, 4:42 AM CDT | Mesoscale Discussion | SPC | Anderson, Bastrop, Brazos, Burleson, Falls, Freestone and 19 more | 63 min |
| Apr 2, 4:43 AM CDT | Severe Thunderstorm Watch | SPC | Angelina, Bowie, Camp, Cass, Cherokee, Franklin and 17 more | 6 hr |
| Apr 2, 7:36 AM CDT | Mesoscale Discussion | SPC | Angelina, Austin, Brazoria, Chambers, Colorado, Fort Bend and 21 more | 54 min |
Nearby
Severe Thunderstorm Watches in Texas, 2009Every severe thunderstorm watch in 2009
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.