Alert archive / Mississippi / Mesoscale Discussions in 2020

Mesoscale Discussion 403

April 19, 20207 parishes in Louisiana; 27 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 19, 2020, 11:06 AM CDT for 7 parishes in Louisiana; 27 counties in Mississippi. It was in force for 54 min.

The area

The outline as issued.

The facts

Issued: Apr 19, 2020, 11:06 AM CDT (16:06 UTC)
Expired: Apr 19, 2020, 12:00 PM CDT
In force: 54 min
Issued by: the Storm Prediction Center
Chance of a watch: 95%

All 34 counties

Avoyelles Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, Franklin Parish, LA, Madison Parish, LA, Richland Parish, LA, Tensas Parish, LA, Adams County, MS, Amite County, MS, Claiborne County, MS, Clarke County, MS, Copiah County, MS, Covington County, MS, Forrest County, MS, Franklin County, MS, Hinds County, MS, Jasper County, MS, Jefferson County, MS, Jefferson Davis County, MS, Jones County, MS, Lamar County, MS, Lawrence County, MS, Lincoln County, MS, Marion County, MS, Perry County, MS, Pike County, MS, Rankin County, MS, Scott County, MS, Simpson County, MS, Smith County, MS, Walthall County, MS, Warren County, MS, Wayne County, MS, Wilkinson County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 45 km from the middle of the area, began a volume at 16:09 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, 4.1 hours before the alert went out and 48 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: 776 J/kg
Mixed-layer CIN: -84 J/kg
Mixed-layer LCL: 610 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: 323 m²/s²
0-3 km storm-relative helicity: 329 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 5.7

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
Apr 18, 8:27 PM CDT	Mesoscale Discussion	SPC	Bienville, Bossier, Caddo, Claiborne, De Soto, Red River and 1 more	2 hr
Apr 18, 8:56 PM CDT	Mesoscale Discussion	SPC	Acadia, Allen, Ascension, Assumption, Cameron, East Baton Rouge and 26 more	2 hr
Apr 19, 8:41 AM CDT	Tornado Watch	SPC	Allen, Beauregard, Bienville, Bossier, Caddo, Calcasieu and 18 more	6 hr
Apr 19, 10:45 AM CDT	Mesoscale Discussion	SPC	Caldwell, De Soto, Grant, Jackson, LaSalle, Natchitoches and 5 more	2 hr
Apr 19, 11:45 AM CDT	Tornado Watch	SPC	Catahoula, Concordia, East Carroll, Franklin, Madison, Morehouse and 3 more	9 hr
Apr 19, 12:39 PM CDT	Mesoscale Discussion	SPC	Beauregard, Calcasieu, Vernon	66 min
Apr 19, 12:47 PM CDT	Mesoscale Discussion	SPC	Avoyelles, Bienville, Caldwell, Catahoula, Concordia, De Soto and 14 more	58 min
Apr 19, 2:03 PM CDT	Mesoscale Discussion	SPC	Acadia, Allen, Assumption, Avoyelles, Beauregard, Calcasieu and 23 more	57 min
Apr 19, 2:39 PM CDT	Tornado Watch	SPC	Acadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 39 more	9 hr
Apr 19, 3:07 PM CDT	Mesoscale Discussion	SPC	Madison, Tensas	113 min
Apr 19, 5:40 PM CDT	Mesoscale Discussion	SPC	Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Catahoula and 18 more	2 hr
Apr 19, 6:37 PM CDT	Mesoscale Discussion	SPC	Washington	53 min
Apr 19, 2:34 AM CDT	Mesoscale Discussion	SPC	Attala, Bolivar, Calhoun, Carroll, Chickasaw, Choctaw and 29 more	116 min
Apr 19, 3:56 PM CDT	Tornado Watch	SPC	George, Greene, Perry, Stone, Wayne	6 hr

Nearby

Mesoscale Discussions in Mississippi, 2020 Mesoscale Discussions in Louisiana, 2020 Every mesoscale discussion in 2020

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.