Alert archive / Texas / Tornado Watches in 2015

Tornado Watch 103

April 24, 20154 counties in Arkansas; 13 parishes in Louisiana; 26 counties in Texas

The Storm Prediction Center issued this tornado watch at Apr 24, 2015, 4:45 PM CDT for 4 counties in Arkansas; 13 parishes in Louisiana; 26 counties in Texas. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Apr 24, 2015, 4:45 PM CDT (21:45 UTC)
Expired
Apr 24, 2015, 10:00 PM CDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 43 counties

Columbia County, AR, Lafayette County, AR, Miller County, AR, Union County, AR, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Jackson Parish, LA, Lincoln Parish, LA, Natchitoches Parish, LA, Red River Parish, LA, Sabine Parish, LA, Union Parish, LA, Webster Parish, LA, Winn Parish, LA, Angelina County, TX, Bowie County, TX, Camp County, TX, Cass County, TX, Cherokee County, TX, Franklin County, TX, Gregg County, TX, Harrison County, TX, Houston County, TX, Madison County, TX, Marion County, TX, Morris 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, Smith County, TX, Titus County, TX, Trinity County, TX, Upshur County, TX, Walker County, TX, Wood County, TX

The radar

The Shreveport radar (KSHV), 46 km from the middle of the area, began a volume at 21:46 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
70%
One or more EF2 to EF5 tornadoes
50%
Ten or more severe wind reports
50%
One or more gusts of 65 knots or more
20%
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
95%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 24, 5:03 PM CDTSevere Thunderstorm WarningHGXHouston, Madison27 min
Apr 24, 5:15 PM CDTTornado WarningHGXHouston, Madison, Trinity, Walker30 min
Apr 24, 7:55 PM CDTSevere Thunderstorm WarningSHVHempstead, Lafayette, Little River, Miller, Nevada50 min
Apr 24, 7:59 PM CDTSevere Thunderstorm WarningSHVCamp, Franklin, Smith, Titus, Wood46 min
Apr 24, 8:40 PM CDTSevere Thunderstorm WarningSHVCamp, Gregg, Morris, Smith, Titus, Upshur and 1 more50 min
Apr 24, 8:52 PM CDTTornado WarningSHVUpshur23 min
Apr 24, 9:07 PM CDTSevere Thunderstorm WarningSHVMiller38 min
Apr 24, 9:14 PM CDTSevere Thunderstorm WarningSHVCherokee, Gregg, Harrison, Marion, Nacogdoches, Panola and 3 more46 min
Apr 24, 9:20 PM CDTFlash Flood WarningSHVColumbia, Hempstead, Lafayette, Little River, Miller, Nevada and 1 more3 hr
Apr 24, 9:21 PM CDTTornado WarningSHVCass24 min
Apr 24, 9:44 PM CDTSevere Thunderstorm WarningSHVLafayette, Miller46 min
Apr 24, 9:57 PM CDTSevere Thunderstorm WarningSHVBossier, Caddo, De Soto48 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, 9.8 hours before the alert went out and 55 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 2015-04-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 78 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 2015-04-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 179 square meters per square second.1939587897Sfc1 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
78 J/kg
Mixed-layer CIN
-248 J/kg
Mixed-layer LCL
612 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
179 m²/s²
0-3 km storm-relative helicity
160 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.4

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

438 
WWUS20 KWNS 242142
SEL3  
SPC WW 242142
ARZ000-LAZ000-TXZ000-250300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 103
NWS STORM PREDICTION CENTER NORMAN OK
445 PM CDT FRI APR 24 2015

THE NWS STORM PREDICTION CENTER HAS ISSUED A

* TORNADO WATCH FOR PORTIONS OF 
  EXTREME SOUTHWEST ARKANSAS
  NORTHWEST LOUISIANA
  EAST CENTRAL AND NORTHEAST TEXAS

* EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 445 PM UNTIL
  1000 PM CDT.

* PRIMARY THREATS INCLUDE...
  A FEW TORNADOES LIKELY
  SCATTERED LARGE HAIL LIKELY WITH ISOLATED VERY LARGE HAIL EVENTS
    TO 2 INCHES IN DIAMETER POSSIBLE
  SCATTERED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

SUMMARY...SCATTERED STORMS DEVELOPING IN THE WARM SECTOR ACROSS E TX
AND NW LA WILL POTENTIALLY BECOME SUPERCELLS WITH THE RISK FOR
TORNADOES...LARGE HAIL...AND DAMAGING WINDS THROUGH THIS EVENING. 
OTHER SEVERE STORMS WILL LIKELY MOVE EWD FROM N CENTRAL INTO NE TX
LATER THIS EVENING...WITH A TORNADO RISK AS WELL.  A STRONG TORNADO
OR TWO WILL BE POSSIBLE...ESPECIALLY WITH STORMS MOVING ALONG THE
STALLED FRONT CLOSE TO I-20 THIS EVENING.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE
MILES EAST AND WEST OF A LINE FROM 25 MILES WEST NORTHWEST OF EL
DORADO ARKANSAS TO 10 MILES SOUTHEAST OF HUNTSVILLE TEXAS.  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 99...WW 100...WW 101...WW
102...

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 25035.


...THOMPSON

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 24, 3:58 PM CDTMesoscale DiscussionSPCColumbia, Lafayette, Miller, Union92 min
Apr 24, 10:29 AM CDTMesoscale DiscussionSPCAllen, Beauregard, Calcasieu, Jefferson Davis91 min
Apr 24, 11:53 AM CDTMesoscale DiscussionSPCAcadia, Allen, Assumption, Beauregard, Calcasieu, Cameron and 7 more97 min
Apr 24, 12:18 PM CDTTornado WatchSPCAcadia, Allen, Avoyelles, Beauregard, Calcasieu, Cameron and 10 more5 hr
Apr 24, 1:58 PM CDTMesoscale DiscussionSPCAcadia, Ascension, Assumption, Cameron, East Baton Rouge, Iberia and 15 more92 min
Apr 24, 3:15 PM CDTTornado WatchSPCAscension, Assumption, Iberville, Jefferson, Lafourche, Orleans and 6 more5 hr
Apr 23, 9:34 PM CDTMesoscale DiscussionSPCBandera, Dimmit, Edwards, Frio, Jim Hogg, Kinney and 10 more56 min
Apr 24, 2:36 AM CDTMesoscale DiscussionSPCDimmit, La Salle, McMullen, Webb, Zavala84 min
Apr 24, 3:01 AM CDTSevere Thunderstorm WatchSPCAtascosa, Dimmit, Frio, La Salle, Live Oak, McMullen and 5 more4 hr
Apr 24, 5:41 AM CDTMesoscale DiscussionSPCAtascosa, Bandera, Dimmit, Duval, Edwards, Frio and 10 more94 min
Apr 24, 11:12 AM CDTMesoscale DiscussionSPCBosque, Brown, Callahan, Coke, Coleman, Collin and 43 more2 hr
Apr 24, 12:56 PM CDTMesoscale DiscussionSPCChildress, Collingsworth, Cottle, Crosby, Dickens, Foard and 3 more94 min
Apr 24, 2:10 PM CDTTornado WatchSPCAnderson, Bell, Bosque, Brown, Callahan, Coke and 52 more8 hr
Apr 24, 4:56 PM CDTMesoscale DiscussionSPCAtascosa, Dimmit, Duval, Frio, Jim Hogg, Kinney and 9 more94 min
Apr 24, 6:01 PM CDTMesoscale DiscussionSPCDallas, Ellis, Erath, Hood, Johnson, Kaufman and 3 more59 min
Apr 24, 6:53 PM CDTSevere Thunderstorm WatchSPCAtascosa, Bee, Brooks, Cameron, DeWitt, Dimmit and 19 more6 hr

Nearby

Tornado Watches in Texas, 2015Tornado Watches in Louisiana, 2015Tornado Watches in Arkansas, 2015Every tornado watch in 2015

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.