Alert archive / Texas / Tornado Watches in 2018

Tornado Watch 413

October 13, 201828 counties in Texas

The Storm Prediction Center issued this tornado watch at Oct 13, 2018, 9:54 AM CDT for 28 counties in Texas. It was in force for 9 hr.

The area

The outline as issued.

The facts

Issued
Oct 13, 2018, 9:54 AM CDT (14:54 UTC)
Expired
Oct 13, 2018, 7:00 PM CDT
In force
9 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 28 counties

Anderson County, TX, Bell County, TX, Bosque County, TX, Burnet County, TX, Comanche County, TX, Coryell 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, Johnson County, TX, Kaufman County, TX, Lampasas County, TX, Leon County, TX, Limestone County, TX, Llano County, TX, McLennan County, TX, Milam County, TX, Mills County, TX, Navarro County, TX, Robertson County, TX, Somervell County, TX, Van Zandt County, TX, Williamson County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 93 km from the middle of the area, began a volume at 14:55 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
50%
One or more EF2 to EF5 tornadoes
30%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
10%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Oct 13, 9:56 AM CDTTornado WarningFWDComanche, Eastland21 min
Oct 13, 11:00 AM CDTSevere Thunderstorm WarningFWDErath, Hamilton45 min
Oct 13, 12:16 PM CDTTornado WarningFWDEllis, Johnson29 min
Oct 13, 12:44 PM CDTTornado WarningFWDEllis46 min
Oct 13, 12:47 PM CDTSevere Thunderstorm WarningFWDEllis, Hill, Navarro43 min
Oct 13, 12:52 PM CDTTornado WarningFWDHill, Navarro38 min
Oct 13, 1:23 PM CDTTornado Warning Tornado observedFWDEllis, Hill, Navarro52 min
Oct 13, 1:34 PM CDTSevere Thunderstorm WarningFWDKaufman41 min
Oct 13, 1:39 PM CDTSevere Thunderstorm WarningFWDBosque, Hill40 min
Oct 13, 1:47 PM CDTTornado WarningFWDNavarro28 min
Oct 13, 2:08 PM CDTTornado WarningFWDMcLennan52 min
Oct 13, 2:12 PM CDTTornado Warning Tornado observedFWDHenderson, Navarro48 min
Oct 13, 2:55 PM CDTTornado WarningFWDAnderson, Henderson50 min
Oct 13, 3:09 PM CDTTornado WarningFWDLimestone51 min
Oct 13, 3:34 PM CDTTornado WarningFWDFreestone41 min
Oct 13, 3:40 PM CDTTornado WarningFWDAnderson13 min
Oct 13, 4:08 PM CDTTornado Warning Tornado observedFWDFreestone, Leon52 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, 2.9 hours before the alert went out and 122 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, Fort Worth, TX at 12:00Z on 2018-10-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 5 joules per kilogram.LCLEL10008507005003002001001 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, Fort Worth, TX at 12:00Z on 2018-10-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 258 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
5 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
469 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
258 m²/s²
0-3 km storm-relative helicity
268 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.7

Open this sounding in Storm Lab

The text

As transmitted.

241 
WWUS20 KWNS 131451
SEL3  
SPC WW 131451
TXZ000-132300-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 413
NWS Storm Prediction Center Norman OK
955 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 and evening from 955 AM until
  600 PM CDT.

* Primary threats include...
  A few tornadoes and a couple intense tornadoes possible
  Scattered damaging wind gusts to 70 mph possible

SUMMARY...Persistent supercell structures across the Concho Valley
and Big Country will spread east into this afternoon across central
Texas. Rich low-level moisture and strong wind profiles will support
a risk for tornadoes and damaging winds.

The tornado watch area is approximately along and 60 statute miles
north and south of a line from 70 miles south southwest of
Stephenville TX to 35 miles east of Corsicana TX. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU3).

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...CONTINUE...WW 412...

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 450. Mean
storm motion vector 26025.

...Grams

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, 7:40 AM CDTTornado WatchSPCBrown, Coleman, Concho, McCulloch, Menard, Runnels and 3 more4 hr
Oct 13, 7:47 AM CDTMesoscale DiscussionSPCBell, Bosque, Brown, Burnet, Coleman, Comanche and 13 more118 min
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.