Alert archive / Texas / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 259
The Storm Prediction Center issued this severe thunderstorm watch at May 1, 2011, 1:40 AM CDT for Bryan County, Love County, Marshall County, Oklahoma; 37 counties in Texas. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- May 1, 2011, 1:40 AM CDT (06:40 UTC)
- Expired
- May 1, 2011, 9:00 AM CDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2.5 in
- Strongest gust expected
- 60 kt
All 40 counties
Bryan County, OK, Love County, OK, Marshall County, OK, Archer County, TX, Baylor County, TX, Brown County, TX, Callahan County, TX, Clay County, TX, Coleman County, TX, Collin County, TX, Comanche County, TX, Cooke County, TX, Dallas County, TX, Denton County, TX, Eastland County, TX, Ellis County, TX, Erath County, TX, Fannin County, TX, Grayson County, TX, Haskell County, TX, Hood County, TX, Hunt County, TX, Jack County, TX, Johnson County, TX, Jones County, TX, Kaufman County, TX, Knox County, TX, Montague County, TX, Palo Pinto County, TX, Parker County, TX, Rockwall County, TX, Runnels County, TX, Shackelford County, TX, Somervell County, TX, Stephens County, TX, Tarrant County, TX, Taylor County, TX, Throckmorton County, TX, Wise County, TX, Young County, TX
The radar
The Dyess AFB radar (KDYX), 89 km from the middle of the area, began a volume at 06:42 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
- 10%
- One or more gusts of 65 knots or more
- 5%
- Ten or more severe hail reports
- 50%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 80%
Warnings issued inside it
26 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 1, 2:06 AM CDT | Severe Thunderstorm Warning | SJT | Haskell | 39 min |
| May 1, 2:27 AM CDT | Severe Thunderstorm Warning | FWD | Erath, Hood, Palo Pinto, Parker | 63 min |
| May 1, 2:32 AM CDT | Severe Thunderstorm Warning | SJT | Haskell, Throckmorton | 58 min |
| May 1, 3:09 AM CDT | Severe Thunderstorm Warning | FWD | Young | 51 min |
| May 1, 3:21 AM CDT | Severe Thunderstorm Warning | FWD | Hood, Johnson, Parker, Tarrant | 54 min |
| May 1, 3:34 AM CDT | Severe Thunderstorm Warning | OUN | Baylor, Foard, Knox, Wilbarger | 56 min |
| May 1, 3:46 AM CDT | Severe Thunderstorm Warning | FWD | Jack, Young | 44 min |
| May 1, 4:12 AM CDT | Severe Thunderstorm Warning | FWD | Dallas, Ellis, Johnson, Tarrant | 48 min |
| May 1, 4:27 AM CDT | Severe Thunderstorm Warning | FWD | Jack, Montague, Wise | 48 min |
| May 1, 4:32 AM CDT | Severe Thunderstorm Warning | OUN | Archer, Baylor, Clay | 58 min |
| May 1, 4:41 AM CDT | Severe Thunderstorm Warning | FWD | Cooke | 49 min |
| May 1, 4:58 AM CDT | Severe Thunderstorm Warning | FWD | Dallas, Ellis, Kaufman | 43 min |
| May 1, 5:28 AM CDT | Severe Thunderstorm Warning | OUN | Jefferson, Love | 62 min |
| May 1, 5:30 AM CDT | Severe Thunderstorm Warning | FWD | Montague | 30 min |
| May 1, 6:05 AM CDT | Severe Thunderstorm Warning | FWD | Grayson | 25 min |
| May 1, 6:09 AM CDT | Severe Thunderstorm Warning | FWD | Montague | 36 min |
| May 1, 6:15 AM CDT | Severe Thunderstorm Warning | OUN | Carter, Jefferson, Johnston, Love, Marshall | 60 min |
| May 1, 6:27 AM CDT | Severe Thunderstorm Warning | OUN | Bryan | 48 min |
| May 1, 6:34 AM CDT | Severe Thunderstorm Warning | SJT | Callahan, Shackelford | 41 min |
| May 1, 6:56 AM CDT | Severe Thunderstorm Warning | FWD | Eastland, Stephens, Young | 64 min |
| May 1, 7:04 AM CDT | Severe Thunderstorm Warning | FWD | Collin, Cooke, Denton, Grayson | 56 min |
| May 1, 7:15 AM CDT | Severe Thunderstorm Warning | OUN | Atoka, Bryan | 45 min |
| May 1, 7:46 AM CDT | Severe Thunderstorm Warning | FWD | Eastland, Erath, Palo Pinto | 44 min |
| May 1, 7:50 AM CDT | Severe Thunderstorm Warning | OUN | Bryan | 60 min |
| May 1, 8:21 AM CDT | Severe Thunderstorm Warning | FWD | Erath, Hood, Palo Pinto, Parker | 54 min |
| May 1, 8:58 AM CDT | Severe Thunderstorm Warning | FWD | Tarrant | 46 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, 6.7 hours before the alert went out and 112 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
- 277 J/kg
- Mixed-layer CIN
- -315 J/kg
- Mixed-layer LCL
- 1957 m above ground
- 0-6 km bulk shear
- 49 kt
- 0-1 km storm-relative helicity
- 97 m²/s²
- 0-3 km storm-relative helicity
- 148 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.2
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 30, 11:39 PM CDT | Mesoscale Discussion | SPC | McCurtain | 66 min |
| May 1, 1:16 AM CDT | Mesoscale Discussion | SPC | McCurtain | 59 min |
| May 1, 3:19 AM CDT | Mesoscale Discussion | SPC | Caddo, Carter, Comanche, Cotton, Garvin, Grady and 10 more | 86 min |
| May 1, 4:45 AM CDT | Tornado Watch | SPC | McCurtain | 4 hr |
| May 1, 7:29 AM CDT | Mesoscale Discussion | SPC | Atoka, Bryan, Carter, Choctaw, Coal, Comanche and 11 more | 91 min |
| May 1, 8:30 AM CDT | Mesoscale Discussion | SPC | Bryan, Choctaw, McCurtain, Pushmataha | 30 min |
| May 1, 8:45 AM CDT | Severe Thunderstorm Watch | SPC | McCurtain | 6 hr |
| May 1, 5:42 PM CDT | Mesoscale Discussion | SPC | McCurtain | 3 hr |
| Apr 30, 9:26 PM CDT | Mesoscale Discussion | SPC | Bowie, Camp, Cass, Franklin, Gregg, Harrison and 8 more | 64 min |
| May 1, 1:14 AM CDT | Mesoscale Discussion | SPC | Bosque, Brown, Callahan, Coleman, Collin, Comanche and 28 more | 2 hr |
| May 1, 12:12 PM CDT | Mesoscale Discussion | SPC | Anderson, Bowie, Camp, Cass, Cherokee, Collin and 28 more | 93 min |
| May 1, 12:47 PM CDT | Tornado Watch | SPC | Anderson, Bowie, Camp, Cass, Cherokee, Freestone and 11 more | 8 hr |
| May 1, 3:18 PM CDT | Mesoscale Discussion | SPC | Anderson, Bowie, Camp, Cass, Cherokee, Franklin and 21 more | 87 min |
| May 1, 5:43 PM CDT | Mesoscale Discussion | SPC | Anderson, Bowie, Camp, Cass, Cherokee, Franklin and 21 more | 92 min |
Nearby
Severe Thunderstorm Watches in Texas, 2011Severe Thunderstorm Watches in Oklahoma, 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.