Alert archive / Texas / Mesoscale Discussions in 2015

Mesoscale Discussion 204

April 3, 2015Union County, Arkansas; 15 parishes in Louisiana; 21 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 3, 2015, 5:54 PM CDT for Union County, Arkansas; 15 parishes in Louisiana; 21 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Apr 3, 2015, 5:54 PM CDT (22:54 UTC)
Expired: Apr 3, 2015, 8:00 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 37 counties

Union County, AR, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Grant Parish, LA, Jackson Parish, LA, Lincoln Parish, LA, Natchitoches Parish, LA, Red River Parish, LA, Sabine Parish, LA, Union Parish, LA, Vernon Parish, LA, Webster Parish, LA, Winn Parish, LA, Angelina County, TX, Brazos County, TX, Grimes County, TX, Hardin County, TX, Houston County, TX, Jasper County, TX, Liberty County, TX, Madison County, TX, Montgomery County, TX, Nacogdoches County, TX, Newton County, TX, Panola County, TX, Polk County, TX, Sabine County, TX, San Augustine County, TX, San Jacinto County, TX, Shelby County, TX, Trinity County, TX, Tyler County, TX, Walker County, TX, Waller County, TX

The radar

The Shreveport radar (KSHV), 91 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.

The nearest sounding before it

Shreveport, LA (KBAD), launched 12:00Z, 10.9 hours before the alert went out and 95 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: 3 J/kg
Mixed-layer CIN: -419 J/kg
Mixed-layer LCL: 1123 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: 394 m²/s²
0-3 km storm-relative helicity: 409 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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 2, 7:02 PM CDT	Tornado Watch	SPC	Baxter, Benton, Boone, Carroll, Fulton, Marion	8 hr
Apr 2, 10:12 PM CDT	Mesoscale Discussion	SPC	Benton, Boone, Carroll, Marion	93 min
Apr 3, 1:16 AM CDT	Mesoscale Discussion	SPC	Baxter, Benton, Boone, Carroll, Clay, Craighead and 13 more	59 min
Apr 3, 1:35 AM CDT	Tornado Watch	SPC	Baxter, Boone, Clay, Cleburne, Craighead, Fulton and 14 more	6 hr
Apr 3, 1:52 AM CDT	Severe Thunderstorm Watch	SPC	Benton, Carroll	4 hr
Apr 3, 5:43 AM CDT	Mesoscale Discussion	SPC	Baxter, Clay, Cleburne, Craighead, Fulton, Greene and 13 more	2 hr
Apr 3, 12:14 PM CDT	Tornado Watch	SPC	Mississippi	8 hr
Apr 3, 3:57 PM CDT	Mesoscale Discussion	SPC	Arkansas, Ashley, Bradley, Calhoun, Chicot, Cleveland and 6 more	93 min
Apr 3, 5:55 PM CDT	Severe Thunderstorm Watch	SPC	Ashley, Chicot	4 hr

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.