Alert archive / Texas / Tornado Watches in 2019

Tornado Watch 39

April 6, 201913 parishes in Louisiana; 18 counties in Texas

The Storm Prediction Center issued this tornado watch at Apr 6, 2019, 5:54 PM CDT for 13 parishes in Louisiana; 18 counties in Texas. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Apr 6, 2019, 5:54 PM CDT (22:54 UTC)
Expired
Apr 6, 2019, 10:00 PM CDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 31 counties

Bienville Parish, LA, Caldwell Parish, LA, De Soto Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Red River Parish, LA, Sabine Parish, LA, Union Parish, LA, Winn Parish, LA, Angelina County, TX, Brazos County, TX, Burleson County, TX, Cherokee County, TX, Grimes County, TX, Houston County, TX, Madison County, TX, Nacogdoches County, TX, Panola County, TX, Polk County, TX, Rusk County, TX, Sabine County, TX, San Augustine County, TX, San Jacinto County, TX, Shelby County, TX, Trinity County, TX, Walker County, TX, Washington County, TX

The radar

The Shreveport radar (KSHV), 159 km from the middle of the area, began a volume at 22:57 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
30%
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
30%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 6, 5:55 PM CDTTornado WarningHGXHouston20 min
Apr 6, 6:02 PM CDTTornado WarningHGXMadison28 min
Apr 6, 6:10 PM CDTSevere Thunderstorm WarningSHVCherokee, Nacogdoches, Rusk65 min
Apr 6, 6:17 PM CDTSevere Thunderstorm WarningHGXHouston13 min
Apr 6, 6:23 PM CDTTornado WarningSHVCherokee, Nacogdoches, Rusk52 min
Apr 6, 6:28 PM CDTTornado WarningHGXHouston, Madison32 min
Apr 6, 6:35 PM CDTSevere Thunderstorm WarningHGXBrazos, Grimes, Madison25 min
Apr 6, 6:59 PM CDTSevere Thunderstorm WarningHGXHouston, Madison46 min
Apr 6, 7:13 PM CDTSevere Thunderstorm WarningSHVNacogdoches, Panola, Rusk, Shelby23 min
Apr 6, 7:42 PM CDTFlash Flood WarningSHVJackson, Lincoln, Union3 hr
Apr 6, 7:44 PM CDTSevere Thunderstorm WarningHGXHouston, Trinity46 min
Apr 6, 8:06 PM CDTSevere Thunderstorm WarningSHVGrant, Natchitoches, Winn39 min
Apr 6, 8:15 PM CDTSevere Thunderstorm WarningSHVCherokee, Nacogdoches21 min
Apr 6, 8:53 PM CDTSevere Thunderstorm WarningSHVGrant, Jackson, Natchitoches, Winn37 min
Apr 6, 9:14 PM CDTSevere Thunderstorm WarningSHVSan Augustine, Shelby46 min
Apr 6, 9:28 PM CDTSevere Thunderstorm WarningSHVJackson, Winn47 min
Apr 6, 9:32 PM CDTSevere Thunderstorm WarningSHVJackson, Lincoln, Ouachita, Union43 min
Apr 6, 9:34 PM CDTSevere Thunderstorm WarningSHVCaldwell, Grant, LaSalle, Winn41 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

Shreveport, LA (KBAD), launched 12:00Z, 10.9 hours before the alert went out and 167 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, Shreveport, LA at 12:00Z on 2019-04-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 242 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, Shreveport, LA at 12:00Z on 2019-04-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 179 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
242 J/kg
Mixed-layer CIN
-295 J/kg
Mixed-layer LCL
570 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
179 m²/s²
0-3 km storm-relative helicity
240 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.3

Open this sounding in Storm Lab

The text

As transmitted.

185 
WWUS20 KWNS 062252
SEL9  
SPC WW 062252
LAZ000-TXZ000-070300-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 39
NWS Storm Prediction Center Norman OK
555 PM CDT Sat Apr 6 2019

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Northern Louisiana
  Eastern Texas

* Effective this Saturday afternoon and evening from 555 PM until
  1000 PM CDT.

* Primary threats include...
  A couple tornadoes possible
  Isolated very large hail events to 2 inches in diameter possible
  Isolated damaging wind gusts to 70 mph possible

SUMMARY...Clusters of strong to severe storms should persist for a
few more hours this evening with all hazards possible.

The tornado watch area is approximately along and 40 statute miles
either side of a line from 25 miles west of College Station TX to 70
miles northeast of Natchitoches LA. For a complete depiction of the
watch see the associated watch outline update (WOUS64 KWNS WOU9).

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 38...

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 2 inches. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean
storm motion vector 22025.

...Grams

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 6, 4:48 PM CDTMesoscale DiscussionSPCBienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 12 more117 min
Apr 5, 7:10 PM CDTMesoscale DiscussionSPCAndrews, Armstrong, Borden, Briscoe, Castro, Cochran and 42 more2 hr
Apr 6, 1:41 AM CDTMesoscale DiscussionSPCAndrews, Borden, Childress, Coke, Cottle, Crane and 25 more94 min
Apr 6, 7:58 AM CDTMesoscale DiscussionSPCArcher, Brown, Clay, Coleman, Comanche, Cooke and 11 more92 min
Apr 6, 9:08 AM CDTMesoscale DiscussionSPCAnderson, Angelina, Austin, Bandera, Bastrop, Bell and 46 more3 hr
Apr 6, 10:35 AM CDTTornado WatchSPCAnderson, Angelina, Bastrop, Bell, Blanco, Brazos and 47 more7 hr
Apr 6, 1:09 PM CDTMesoscale DiscussionSPCAnderson, Angelina, Bastrop, Bell, Blanco, Bosque and 44 more96 min
Apr 6, 3:03 PM CDTMesoscale DiscussionSPCAnderson, Angelina, Bastrop, Bell, Blanco, Bosque and 44 more87 min

Nearby

Tornado Watches in Texas, 2019Tornado Watches in Louisiana, 2019Every tornado watch in 2019

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.