Alert archive / Texas / Mesoscale Discussions in 2015

Mesoscale Discussion 442

April 24, 20154 counties in Arkansas; 13 parishes in Louisiana; 44 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 24, 2015, 7:46 PM CDT for 4 counties in Arkansas; 13 parishes in Louisiana; 44 counties in Texas. It was in force for 89 min.

The area

The outline as issued.

The facts

Issued: Apr 24, 2015, 7:46 PM CDT (00:46 UTC)
Expired: Apr 24, 2015, 9:15 PM CDT
In force: 89 min
Issued by: the Storm Prediction Center

All 61 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, Anderson County, TX, Bosque County, TX, Bowie County, TX, Camp County, TX, Cass County, TX, Cherokee County, TX, Collin County, TX, Coryell County, TX, Dallas County, TX, Delta County, TX, Ellis County, TX, Franklin County, TX, Freestone County, TX, Gregg County, TX, Hamilton County, TX, Harrison County, TX, Henderson County, TX, Hill County, TX, Hopkins County, TX, Hunt County, TX, Kaufman County, TX, Lampasas County, TX, Limestone County, TX, Marion County, TX, McCulloch County, TX, McLennan County, TX, Menard County, TX, Mills County, TX, Morris County, TX, Nacogdoches County, TX, Navarro County, TX, Panola County, TX, Rains County, TX, Rockwall County, TX, Rusk County, TX, Sabine County, TX, San Augustine County, TX, San Saba County, TX, Shelby County, TX, Smith County, TX, Titus County, TX, Upshur County, TX, Van Zandt County, TX, Wood County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 126 km from the middle of the area, began a volume at 00:48 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.

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

Tornado Watch 105Apr 24, 9:55 PM CDT

The nearest sounding before it

Shreveport, LA (KBAD), launched 00:00Z, 0.8 hours before the alert went out and 226 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 310 J/kg
Mixed-layer CIN: -118 J/kg
Mixed-layer LCL: 809 m above ground
0-6 km bulk shear: 73 kt
0-1 km storm-relative helicity: 317 m²/s²
0-3 km storm-relative helicity: 428 m²/s²
Significant tornado parameter: 0.5
Supercell composite: 9.9

Open this sounding in Storm Lab

The text

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

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 24, 9:20 PM CDT	Mesoscale Discussion	SPC	Ashley, Chicot, Columbia, Lafayette, Union	55 min
Apr 24, 9:59 PM CDT	Tornado Watch	SPC	Ashley, Bradley, Calhoun, Chicot, Cleveland, Columbia and 5 more	4 hr
Apr 24, 11:45 PM CDT	Mesoscale Discussion	SPC	Caldwell, East Carroll, Franklin, Jackson, Madison, Morehouse and 5 more	90 min
Apr 25, 2:07 AM CDT	Mesoscale Discussion	SPC	Madison	83 min
Apr 25, 7:12 AM CDT	Severe Thunderstorm Watch	SPC	Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Cameron and 10 more	6 hr
Apr 25, 9:35 AM CDT	Mesoscale Discussion	SPC	Acadia, Ascension, Assumption, Avoyelles, Cameron, East Baton Rouge and 27 more	115 min
Apr 25, 10:41 AM CDT	Severe Thunderstorm Watch	SPC	Ascension, Assumption, East Baton Rouge, East Feliciana, Iberville, Jefferson and 16 more	7 hr
Apr 25, 1:50 PM CDT	Mesoscale Discussion	SPC	Orleans, Saint Bernard, Saint Charles, Saint John the Baptist, Saint Tammany, Washington	85 min
Apr 24, 10:55 PM CDT	Mesoscale Discussion	SPC	Cameron	65 min
Apr 25, 2:48 AM CDT	Mesoscale Discussion	SPC	Atascosa, Bandera, Bexar, Caldwell, Comal, DeWitt and 17 more	87 min
Apr 25, 3:09 AM CDT	Severe Thunderstorm Watch	SPC	Atascosa, Austin, Bandera, Bastrop, Bexar, Blanco and 31 more	7 hr
Apr 25, 4:31 AM CDT	Mesoscale Discussion	SPC	Atascosa, Austin, Bandera, Bastrop, Bexar, Caldwell and 23 more	89 min
Apr 25, 6:52 AM CDT	Mesoscale Discussion	SPC	Atascosa, Brazoria, Chambers, DeWitt, Fort Bend, Frio and 11 more	83 min

Nearby

Mesoscale Discussions in Texas, 2015 Mesoscale Discussions in Louisiana, 2015 Mesoscale Discussions in Arkansas, 2015 Every mesoscale discussion 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.