Alert archive / Mississippi / Mesoscale Discussions in 2023

Mesoscale Discussion 75

January 18, 20236 parishes in Louisiana; 29 counties in Mississippi; Fayette County, Tennessee

The Storm Prediction Center issued this mesoscale discussion at Jan 18, 2023, 5:47 PM CST for 6 parishes in Louisiana; 29 counties in Mississippi; Fayette County, Tennessee. It was in force for 118 min.

The area

The outline as issued.

The facts

Issued: Jan 18, 2023, 5:47 PM CST (23:47 UTC)
Expired: Jan 18, 2023, 7:45 PM CST
In force: 118 min
Issued by: the Storm Prediction Center
Concerning: Tornado watch 25

All 36 counties

Catahoula Parish, LA, Concordia Parish, LA, East Carroll Parish, LA, Franklin Parish, LA, Madison Parish, LA, Tensas Parish, LA, Adams County, MS, Benton County, MS, Calhoun County, MS, Carroll County, MS, Claiborne County, MS, Copiah County, MS, DeSoto County, MS, Grenada County, MS, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Jefferson County, MS, Lafayette County, MS, Leflore County, MS, Madison County, MS, Marshall County, MS, Montgomery County, MS, Panola County, MS, Quitman County, MS, Sharkey County, MS, Sunflower County, MS, Tallahatchie County, MS, Tate County, MS, Tippah County, MS, Warren County, MS, Washington County, MS, Yalobusha County, MS, Yazoo County, MS, Fayette County, TN

The radar

The Jackson/Brandon,MS radar (KDGX), 114 km from the middle of the area, began a volume at 23:48 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 nearest sounding before it

Little Rock, AR (KLZK), launched 12:00Z, 11.8 hours before the alert went out and 183 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: 597 J/kg
Mixed-layer CIN: -22 J/kg
Mixed-layer LCL: 487 m above ground
0-6 km bulk shear: 76 kt
0-1 km storm-relative helicity: 249 m²/s²
0-3 km storm-relative helicity: 244 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.7

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
Jan 18, 7:28 AM CST	Mesoscale Discussion	SPC	Bossier, Caddo, Claiborne, De Soto, Red River, Webster	2 hr
Jan 18, 9:02 AM CST	Tornado Watch	SPC	Beauregard, Bienville, Bossier, Caddo, Claiborne, De Soto and 10 more	9 hr
Jan 18, 11:48 AM CST	Mesoscale Discussion	SPC	Bienville, Bossier, Caddo, Claiborne, De Soto, Lincoln and 3 more	87 min
Jan 18, 12:30 PM CST	Mesoscale Discussion	SPC	Caldwell, Catahoula, East Carroll, Franklin, Grant, LaSalle and 7 more	90 min
Jan 18, 2:34 PM CST	Tornado Watch	SPC	Caldwell, Catahoula, Concordia, East Carroll, Franklin, Grant and 11 more	7 hr
Jan 18, 3:31 PM CST	Mesoscale Discussion	SPC	Allen, Beauregard, Caldwell, Catahoula, East Carroll, Franklin and 12 more	89 min

Nearby

Mesoscale Discussions in Mississippi, 2023 Mesoscale Discussions in Louisiana, 2023 Mesoscale Discussions in Tennessee, 2023 Every mesoscale discussion in 2023

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.