Alert archive / Mississippi / Mesoscale Discussions in 2013

Mesoscale Discussion 76

January 29, 201311 counties in Arkansas; 15 parishes in Louisiana; 20 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Jan 29, 2013, 4:37 PM CST for 11 counties in Arkansas; 15 parishes in Louisiana; 20 counties in Mississippi. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Jan 29, 2013, 4:37 PM CST (22:37 UTC)
Expired: Jan 29, 2013, 7:00 PM CST
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 80%

All 46 counties

Arkansas County, AR, Ashley County, AR, Bradley County, AR, Chicot County, AR, Desha County, AR, Drew County, AR, Lee County, AR, Lincoln County, AR, Monroe County, AR, Phillips County, AR, St. Francis County, AR, Caldwell Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, East Carroll Parish, LA, Franklin Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Ouachita Parish, LA, Richland Parish, LA, Tensas Parish, LA, Union Parish, LA, West Carroll Parish, LA, Winn Parish, LA, Adams County, MS, Bolivar County, MS, Claiborne County, MS, Coahoma County, MS, Copiah County, MS, DeSoto County, MS, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Jefferson County, MS, Leflore County, MS, Quitman County, MS, Sharkey County, MS, Sunflower County, MS, Tallahatchie County, MS, Tunica County, MS, Warren County, MS, Washington County, MS, Yazoo County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 145 km from the middle of the area, began a volume at 22:39 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 10Jan 29, 5:40 PM CST

The nearest sounding before it

Jackson, MS (KJAN), launched 12:00Z, 10.6 hours before the alert went out and 135 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: 2 J/kg
Mixed-layer CIN: -3 J/kg
Mixed-layer LCL: 529 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 181 m²/s²
0-3 km storm-relative helicity: 306 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
Jan 29, 7:26 AM CST	Tornado Watch	SPC	Benton, Carroll, Crawford, Madison, Washington	10 hr
Jan 29, 9:46 AM CST	Mesoscale Discussion	SPC	Crawford, Franklin, Hempstead, Howard, Johnson, Little River and 9 more	119 min
Jan 29, 10:59 AM CST	Tornado Watch	SPC	Franklin, Hempstead, Howard, Johnson, Little River, Logan and 9 more	8 hr
Jan 29, 11:05 AM CST	Mesoscale Discussion	SPC	Benton, Carroll, Crawford, Madison, Washington	55 min
Jan 29, 11:54 AM CST	Mesoscale Discussion	SPC	Baxter, Boone, Fulton, Izard, Marion, Newton and 3 more	96 min
Jan 29, 12:35 PM CST	Tornado Watch	SPC	Baxter, Boone, Cleburne, Conway, Fulton, Izard and 6 more	7 hr
Jan 29, 1:19 PM CST	Mesoscale Discussion	SPC	Benton, Boone, Carroll, Crawford, Madison, Washington	56 min
Jan 29, 2:15 PM CST	Mesoscale Discussion	SPC	Howard, Little River, Logan, Polk, Scott, Sebastian and 1 more	2 hr
Jan 29, 3:31 PM CST	Mesoscale Discussion	SPC	Baxter, Benton, Boone, Carroll, Cleburne, Crawford and 12 more	89 min
Jan 29, 4:58 PM CST	Mesoscale Discussion	SPC	Baxter, Boone, Bradley, Calhoun, Clark, Cleburne and 47 more	92 min
Jan 29, 5:37 PM CST	Tornado Watch	SPC	Arkansas, Ashley, Baxter, Boone, Bradley, Calhoun and 62 more	8 hr
Jan 29, 5:51 PM CST	Mesoscale Discussion	SPC	Caddo	114 min

Nearby

Mesoscale Discussions in Mississippi, 2013 Mesoscale Discussions in Louisiana, 2013 Mesoscale Discussions in Arkansas, 2013 Every mesoscale discussion in 2013

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.