Alert archive / Texas / Severe Thunderstorm Watches in 2018
Severe Thunderstorm Watch 9
The Storm Prediction Center issued this severe thunderstorm watch at Mar 17, 2018, 2:20 PM CDT for 43 counties in Texas. It was in force for 9 hr.
The area
The outline as issued.
The facts
- Issued
- Mar 17, 2018, 2:20 PM CDT (19:20 UTC)
- Expired
- Mar 17, 2018, 11:00 PM CDT
- In force
- 9 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 3 in
- Strongest gust expected
- 60 kt
All 43 counties
Anderson County, TX, Bell County, TX, Bosque County, TX, Brown County, TX, Callahan County, TX, Coleman County, TX, Comanche County, TX, Coryell County, TX, Dallas County, TX, Eastland County, TX, Ellis County, TX, Erath County, TX, Falls County, TX, Freestone County, TX, Hamilton County, TX, Henderson County, TX, Hill County, TX, Hood County, TX, Houston County, TX, Johnson County, TX, Kaufman County, TX, Lampasas County, TX, Leon County, TX, Limestone County, TX, Madison County, TX, McCulloch County, TX, McLennan County, TX, Milam County, TX, Mills County, TX, Navarro County, TX, Palo Pinto County, TX, Parker County, TX, Rains County, TX, Robertson County, TX, Rockwall County, TX, Runnels County, TX, San Saba County, TX, Shackelford County, TX, Somervell County, TX, Stephens County, TX, Tarrant County, TX, Taylor County, TX, Van Zandt County, TX
The radar
The Dallas/Ft Worth radar (KFWS), 78 km from the middle of the area, began a volume at 19:22 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
- 10%
- Ten or more severe hail reports
- 60%
- One or more hailstones of 2 inches or more
- 40%
- Six or more combined severe hail and wind reports
- 90%
Warnings issued inside it
14 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 17, 2:51 PM CDT | Severe Thunderstorm Warning | SJT | Brown | 24 min |
| Mar 17, 2:53 PM CDT | Severe Thunderstorm Warning | FWD | Comanche, Eastland | 40 min |
| Mar 17, 4:23 PM CDT | Severe Thunderstorm Warning | FWD | Coryell | 67 min |
| Mar 17, 4:56 PM CDT | Severe Thunderstorm Warning | FWD | Bell, Coryell, McLennan | 64 min |
| Mar 17, 5:43 PM CDT | Severe Thunderstorm Warning | FWD | Bell, Falls, McLennan | 62 min |
| Mar 17, 5:55 PM CDT | Severe Thunderstorm Warning | SJT | San Saba | 50 min |
| Mar 17, 6:31 PM CDT | Severe Thunderstorm Warning | FWD | Lampasas | 59 min |
| Mar 17, 6:39 PM CDT | Severe Thunderstorm Warning | FWD | Falls | 36 min |
| Mar 17, 7:22 PM CDT | Severe Thunderstorm Warning | FWD | Falls, Leon, Limestone, Robertson | 53 min |
| Mar 17, 8:00 PM CDT | Severe Thunderstorm Warning | FWD | Bell, Milam | 40 min |
| Mar 17, 8:20 PM CDT | Severe Thunderstorm Warning | FWD | Leon | 55 min |
| Mar 17, 8:29 PM CDT | Severe Thunderstorm Warning | HGX | Houston, Madison | 46 min |
| Mar 17, 9:06 PM CDT | Severe Thunderstorm Warning | HGX | Houston, Madison, Trinity, Walker | 39 min |
| Mar 17, 9:40 PM CDT | Severe Thunderstorm Warning | HGX | Houston, Trinity, Walker | 35 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, 7.3 hours before the alert went out and 98 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
- 2469 m above ground
- 0-6 km bulk shear
- 48 kt
- 0-1 km storm-relative helicity
- 70 m²/s²
- 0-3 km storm-relative helicity
- -22 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 |
|---|---|---|---|---|
| Mar 17, 1:15 PM CDT | Mesoscale Discussion | SPC | Anderson, Bell, Bosque, Brown, Callahan, Cherokee and 30 more | 3 hr |
| Mar 17, 5:25 PM CDT | Mesoscale Discussion | SPC | Anderson, Bell, Coryell, Falls, Freestone, Henderson and 7 more | 2 hr |
| Mar 17, 5:45 PM CDT | Mesoscale Discussion | SPC | Caldwell, Comal, Guadalupe, Hays, Travis, Wilson | 90 min |
Nearby
Severe Thunderstorm Watches in Texas, 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; radar from the NEXRAD Level II archive.