Alert archive / Texas / Severe Thunderstorm Watches in 2018
Severe Thunderstorm Watch 57
The Storm Prediction Center issued this severe thunderstorm watch at Apr 30, 2018, 3:47 PM CDT for 7 counties in Oklahoma; 39 counties in Texas. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 30, 2018, 3:47 PM CDT (20:47 UTC)
- Expired
- Apr 30, 2018, 11:00 PM CDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2.5 in
- Strongest gust expected
- 60 kt
All 46 counties
Beaver County, OK, Beckham County, OK, Ellis County, OK, Greer County, OK, Harmon County, OK, Harper County, OK, Roger Mills County, OK, Andrews County, TX, Armstrong County, TX, Borden County, TX, Briscoe County, TX, Carson County, TX, Childress County, TX, Collingsworth County, TX, Cottle County, TX, Crane County, TX, Crosby County, TX, Dawson County, TX, Dickens County, TX, Donley County, TX, Ector County, TX, Floyd County, TX, Gaines County, TX, Garza County, TX, Gray County, TX, Hale County, TX, Hall County, TX, Hansford County, TX, Hemphill County, TX, Hutchinson County, TX, Lipscomb County, TX, Lubbock County, TX, Lynn County, TX, Martin County, TX, Midland County, TX, Motley County, TX, Ochiltree County, TX, Pecos County, TX, Reeves County, TX, Roberts County, TX, Swisher County, TX, Terry County, TX, Upton County, TX, Ward County, TX, Wheeler County, TX, Winkler County, TX
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
- 10%
- 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
- 30%
- Six or more combined severe hail and wind reports
- 60%
Warnings issued inside it
7 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 30, 5:10 PM CDT | Severe Thunderstorm Warning | MAF | Pecos | 65 min |
| Apr 30, 5:49 PM CDT | Severe Thunderstorm Warning | LUB | Childress, Hall | 41 min |
| Apr 30, 6:18 PM CDT | Severe Thunderstorm Warning | LUB | Cottle, Motley | 57 min |
| Apr 30, 6:45 PM CDT | Severe Thunderstorm Warning | MAF | Pecos | 36 min |
| Apr 30, 8:55 PM CDT | Severe Thunderstorm Warning | AMA | Hemphill, Lipscomb | 35 min |
| Apr 30, 9:19 PM CDT | Severe Thunderstorm Warning | AMA | Carson, Donley, Gray | 56 min |
| Apr 30, 10:17 PM CDT | Severe Thunderstorm Warning | AMA | Gray, Hemphill, Roberts, Wheeler | 73 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
Midland Regional, TX (KMAF), launched 12:00Z, 8.8 hours before the alert went out and 154 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
- 34 J/kg
- Mixed-layer CIN
- -458 J/kg
- Mixed-layer LCL
- 952 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- 137 m²/s²
- 0-3 km storm-relative helicity
- 229 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 30, 3:10 PM CDT | Mesoscale Discussion | SPC | Beaver | 3 hr |
Nearby
Severe Thunderstorm Watches in Texas, 2018Severe Thunderstorm Watches in Oklahoma, 2018Every severe thunderstorm watch in 2018
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.