Alert archive / Louisiana / Mesoscale Discussions in 2018

Mesoscale Discussion 210

April 3, 2018Ashley County, Chicot County, Union County, Arkansas; 22 parishes in Louisiana; 11 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 3, 2018, 4:33 PM CDT for Ashley County, Chicot County, Union County, Arkansas; 22 parishes in Louisiana; 11 counties in Mississippi. It was in force for 57 min.

The area

The outline as issued.

The facts

Issued: Apr 3, 2018, 4:33 PM CDT (21:33 UTC)
Expired: Apr 3, 2018, 5:30 PM CDT
In force: 57 min
Issued by: the Storm Prediction Center
Chance of a watch: 95%

All 36 counties

Ashley County, AR, Chicot County, AR, Union County, AR, Bienville Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Claiborne Parish, LA, Concordia Parish, LA, East Carroll Parish, LA, Franklin Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Red River Parish, LA, Richland Parish, LA, Tensas Parish, LA, Union Parish, LA, Webster Parish, LA, West Carroll Parish, LA, Winn Parish, LA, Adams County, MS, Claiborne County, MS, Copiah County, MS, Hinds County, MS, Humphreys County, MS, Issaquena County, MS, Jefferson County, MS, Sharkey County, MS, Warren County, MS, Washington County, MS, Yazoo County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 171 km from the middle of the area, began a volume at 21:37 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.

The nearest sounding before it

Jackson, MS (KJAN), launched 12:00Z, 9.6 hours before the alert went out and 161 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: 179 J/kg
Mixed-layer CIN: -308 J/kg
Mixed-layer LCL: 682 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 162 m²/s²
0-3 km storm-relative helicity: 149 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 3, 10:26 AM CDT	Severe Thunderstorm Watch	SPC	Columbia, Hempstead, Howard, Lafayette, Little River, Miller and 2 more	8 hr
Apr 3, 12:57 PM CDT	Mesoscale Discussion	SPC	Baxter, Clark, Clay, Cleburne, Conway, Craighead and 39 more	2 hr
Apr 3, 1:33 PM CDT	Tornado Watch	SPC	Arkansas, Baxter, Boone, Bradley, Calhoun, Clark and 51 more	7 hr
Apr 3, 1:55 PM CDT	Mesoscale Discussion	SPC	Little River	95 min
Apr 3, 3:34 PM CDT	Mesoscale Discussion	SPC	Arkansas, Clark, Clay, Cleburne, Cleveland, Conway and 39 more	86 min
Apr 3, 4:51 PM CDT	Severe Thunderstorm Watch	SPC	Ashley, Chicot, Union	5 hr
Apr 3, 5:19 PM CDT	Mesoscale Discussion	SPC	Beauregard, Vernon	86 min
Apr 3, 5:51 PM CDT	Severe Thunderstorm Watch	SPC	Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Evangeline and 4 more	6 hr
Apr 3, 6:51 PM CDT	Mesoscale Discussion	SPC	Alcorn, Benton, Calhoun, Carroll, Chickasaw, Clay and 19 more	114 min

Nearby

Mesoscale Discussions in Louisiana, 2018 Mesoscale Discussions in Mississippi, 2018 Mesoscale Discussions in Arkansas, 2018 Every mesoscale discussion 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.