Alert archive / Mississippi / Mesoscale Discussions in 2021

Mesoscale Discussion 205

March 17, 20215 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Mar 17, 2021, 1:19 PM CDT for 5 counties in Mississippi. It was in force for 86 min.

The area

The outline as issued.

The facts

Issued: Mar 17, 2021, 1:19 PM CDT (18:19 UTC)
Expired: Mar 17, 2021, 2:45 PM CDT
In force: 86 min
Issued by: the Storm Prediction Center
Concerning: Tornado watch 29

Counties Jefferson Davis County, MS, Lawrence County, MS, Lincoln County, MS, Simpson County, MS, Smith County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 55 km from the middle of the area, began a volume at 18:23 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

Jackson, MS (KJAN), launched 12:00Z, 6.3 hours before the alert went out and 59 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: 687 J/kg
Mixed-layer CIN: -86 J/kg
Mixed-layer LCL: 713 m above ground
0-6 km bulk shear: 61 kt
0-1 km storm-relative helicity: 218 m²/s²
0-3 km storm-relative helicity: 178 m²/s²
Significant tornado parameter: 0.6
Supercell composite: 4.9

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
Mar 17, 5:34 AM CDT	Mesoscale Discussion	SPC	Alcorn, Benton, Bolivar, Calhoun, Coahoma, DeSoto and 15 more	86 min
Mar 17, 5:53 AM CDT	Tornado Watch	SPC	Alcorn, Benton, Bolivar, Calhoun, Chickasaw, Coahoma and 20 more	7 hr
Mar 17, 7:38 AM CDT	Mesoscale Discussion	SPC	Alcorn, Benton, Coahoma, DeSoto, Itawamba, Lafayette and 11 more	67 min
Mar 17, 10:56 AM CDT	Mesoscale Discussion	SPC	Attala, Choctaw, Clarke, Clay, Copiah, Covington and 26 more	2 hr
Mar 17, 11:36 AM CDT	Tornado Watch PDS	SPC	Attala, Choctaw, Clarke, Clay, Copiah, Covington and 28 more	7 hr
Mar 17, 12:02 PM CDT	Mesoscale Discussion	SPC	Clarke, Jones, Wayne	58 min
Mar 17, 12:15 PM CDT	Mesoscale Discussion	SPC	Bolivar, Calhoun, Carroll, Claiborne, Coahoma, Grenada and 22 more	90 min
Mar 17, 12:57 PM CDT	Tornado Watch PDS	SPC	Adams, Alcorn, Benton, Bolivar, Calhoun, Carroll and 32 more	6 hr
Mar 17, 1:45 PM CDT	Mesoscale Discussion	SPC	Amite, Forrest, George, Greene, Hancock, Harrison and 9 more	90 min
Mar 17, 2:38 PM CDT	Tornado Watch	SPC	Amite, Hancock, Harrison, Jackson, Pearl River, Pike and 2 more	8 hr
Mar 17, 2:56 PM CDT	Mesoscale Discussion	SPC	Adams, Attala, Bolivar, Calhoun, Carroll, Chickasaw and 41 more	94 min
Mar 17, 5:49 PM CDT	Mesoscale Discussion	SPC	Clarke, Covington, Forrest, George, Greene, Jasper and 13 more	86 min
Mar 17, 6:09 PM CDT	Mesoscale Discussion	SPC	Alcorn, Benton, Bolivar, Calhoun, Carroll, Chickasaw and 25 more	66 min
Mar 17, 6:48 PM CDT	Tornado Watch PDS	SPC	Attala, Choctaw, Clarke, Clay, Covington, Forrest and 20 more	8 hr

Nearby

Mesoscale Discussions in Mississippi, 2021 Every mesoscale discussion in 2021

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.