Alert archive / Texas / Tornado Watches in 2018

Tornado Watch 412

October 13, 20189 counties in Texas

The Storm Prediction Center issued this tornado watch at Oct 13, 2018, 7:40 AM CDT for 9 counties in Texas. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Oct 13, 2018, 7:40 AM CDT (12:40 UTC)
Expired
Oct 13, 2018, 12:00 PM CDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt

Counties Brown County, TX, Coleman County, TX, Concho County, TX, McCulloch County, TX, Menard County, TX, Runnels County, TX, San Saba County, TX, Schleicher County, TX, Tom Green County, TX

The radar

The San Angelo radar (KSJT), 60 km from the middle of the area, began a volume at 12:43 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
60%
One or more EF2 to EF5 tornadoes
20%
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
60%

Warnings issued inside it

12 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Oct 13, 7:43 AM CDTSevere Thunderstorm WarningSJTIrion, Tom Green47 min
Oct 13, 7:54 AM CDTTornado WarningSJTConcho, Tom Green36 min
Oct 13, 8:24 AM CDTTornado WarningSJTConcho36 min
Oct 13, 8:27 AM CDTTornado WarningSJTMenard, Schleicher33 min
Oct 13, 8:53 AM CDTTornado WarningSJTConcho, McCulloch37 min
Oct 13, 9:00 AM CDTFlash Flood WarningSJTTom Green60 min
Oct 13, 9:01 AM CDTSevere Thunderstorm WarningSJTConcho, McCulloch, Menard44 min
Oct 13, 9:39 AM CDTSevere Thunderstorm WarningSJTMcCulloch, San Saba51 min
Oct 13, 9:47 AM CDTSevere Thunderstorm WarningSJTBrown28 min
Oct 13, 10:17 AM CDTTornado WarningSJTMcCulloch, San Saba43 min
Oct 13, 10:40 AM CDTTornado WarningSJTConcho35 min
Oct 13, 10:43 AM CDTTornado WarningSJTMcCulloch, San Saba32 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, 0.7 hours before the alert went out and 230 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.

Skew-T log-pSkew-T log-p diagram, Midland Regional, TX at 12:00Z on 2018-10-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 4 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Midland Regional, TX at 12:00Z on 2018-10-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 175 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
4 J/kg
Mixed-layer CIN
-237 J/kg
Mixed-layer LCL
581 m above ground
0-6 km bulk shear
54 kt
0-1 km storm-relative helicity
175 m²/s²
0-3 km storm-relative helicity
225 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.1

Open this sounding in Storm Lab

The text

As transmitted.

190 
WWUS20 KWNS 131238
SEL2  
SPC WW 131238
TXZ000-131700-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 412
NWS Storm Prediction Center Norman OK
740 AM CDT Sat Oct 13 2018

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Central Texas

* Effective this Saturday morning from 740 AM until NOON CDT.

* Primary threats include...
  A few tornadoes likely
  Isolated damaging wind gusts to 70 mph possible
  Isolated large hail events to 1 inch in diameter possible

SUMMARY...A cyclic tornadic supercell, and other developing storms
in its vicinity, will likely continue through the morning with a
continued threat for tornadoes, as well as isolated large hail and
damaging gusts.

The tornado watch area is approximately along and 35 statute miles
north and south of a line from 10 miles southwest of San Angelo TX
to 35 miles south southeast of Brownwood TX. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU2).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A Tornado Watch means conditions are favorable for
tornadoes and severe thunderstorms in and close to the watch
area. Persons in these areas should be on the lookout for
threatening weather conditions and listen for later statements
and possible warnings.

&&

OTHER WATCH INFORMATION...This tornado watch replaces severe
thunderstorm watch number 411. Watch number 411 will not be in
effect after 740 AM CDT. 

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 1 inch. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean
storm motion vector 26025.

...Thompson

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Oct 12, 7:22 PM CDTMesoscale DiscussionSPCCrane, Crockett, Ector, Glasscock, Irion, Jeff Davis and 9 more2 hr
Oct 12, 8:14 PM CDTSevere Thunderstorm WatchSPCAndrews, Brewster, Crane, Culberson, Ector, Glasscock and 13 more8 hr
Oct 12, 10:58 PM CDTMesoscale DiscussionSPCCrane, Ector, Glasscock, Loving, Midland, Pecos and 6 more2 hr
Oct 13, 1:40 AM CDTMesoscale DiscussionSPCConcho, Crane, Crockett, Ector, Gillespie, Glasscock and 16 more65 min
Oct 13, 1:59 AM CDTSevere Thunderstorm WatchSPCConcho, Crockett, Irion, Kimble, McCulloch, Mason and 5 more6 hr
Oct 13, 7:47 AM CDTMesoscale DiscussionSPCBell, Bosque, Brown, Burnet, Coleman, Comanche and 13 more118 min
Oct 13, 9:54 AM CDTTornado WatchSPCAnderson, Bell, Bosque, Burnet, Comanche, Coryell and 22 more9 hr
Oct 13, 11:04 AM CDTMesoscale DiscussionSPCAnderson, Bell, Bosque, Brown, Burnet, Comanche and 27 more116 min
Oct 13, 1:56 PM CDTMesoscale DiscussionSPCAnderson, Bell, Brazos, Burleson, Burnet, Cherokee and 23 more2 hr
Oct 13, 3:06 PM CDTTornado WatchSPCAngelina, Cherokee, Gregg, Harrison, Houston, Madison and 7 more5 hr
Oct 13, 5:34 PM CDTMesoscale DiscussionSPCAnderson, Bell, Falls, Freestone, Leon, Milam and 1 more56 min
Oct 13, 6:41 PM CDTMesoscale DiscussionSPCAngelina, Harrison, Houston, Madison, Nacogdoches, Panola and 4 more94 min

Nearby

Tornado Watches in Texas, 2018Every tornado 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.