Alert archive / Mississippi / Mesoscale Discussions in 2020

Mesoscale Discussion 452

April 22, 20207 parishes in Louisiana; 8 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 22, 2020, 9:31 PM CDT for 7 parishes in Louisiana; 8 counties in Mississippi. It was in force for 89 min.

The area

The outline as issued.

The facts

Issued: Apr 22, 2020, 9:31 PM CDT (02:31 UTC)
Expired: Apr 22, 2020, 11:00 PM CDT
In force: 89 min
Issued by: the Storm Prediction Center

Counties Avoyelles Parish, LA, Concordia Parish, LA, East Feliciana Parish, LA, Pointe Coupee Parish, LA, Saint Helena Parish, LA, Washington Parish, LA, West Feliciana Parish, LA, Adams County, MS, Amite County, MS, Franklin County, MS, Lawrence County, MS, Lincoln County, MS, Pike County, MS, Walthall County, MS, Wilkinson County, MS

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 00:00Z, 2.5 hours before the alert went out and 198 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: 8 J/kg
Mixed-layer CIN: -206 J/kg
Mixed-layer LCL: 885 m above ground
0-6 km bulk shear: 66 kt
0-1 km storm-relative helicity: 337 m²/s²
0-3 km storm-relative helicity: 666 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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 22, 7:01 PM CDT	Mesoscale Discussion	SPC	Beauregard, Vernon	89 min
Apr 22, 7:41 PM CDT	Mesoscale Discussion	SPC	Vernon	34 min
Apr 22, 8:26 PM CDT	Mesoscale Discussion	SPC	De Soto, Natchitoches, Sabine	94 min
Apr 22, 9:47 PM CDT	Tornado Watch	SPC	Ascension, Catahoula, Concordia, East Baton Rouge, East Feliciana, Franklin and 12 more	9 hr
Apr 22, 10:17 PM CDT	Mesoscale Discussion	SPC	Caldwell, Grant, LaSalle, Natchitoches, Sabine, Winn	88 min
Apr 22, 11:16 PM CDT	Mesoscale Discussion	SPC	Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Caldwell and 15 more	89 min
Apr 23, 12:02 AM CDT	Tornado Watch	SPC	Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Evangeline and 5 more	4 hr
Apr 23, 2:28 AM CDT	Mesoscale Discussion	SPC	Acadia, Ascension, Avoyelles, Concordia, East Baton Rouge, East Feliciana and 17 more	92 min
Apr 23, 1:37 PM CDT	Mesoscale Discussion	SPC	Ascension, East Baton Rouge, East Feliciana, Iberville, Livingston, Saint Helena and 3 more	113 min
Apr 23, 4:05 AM CDT	Tornado Watch	SPC	George, Greene, Hancock, Harrison, Jackson, Pearl River and 3 more	11 hr
Apr 23, 7:43 AM CDT	Mesoscale Discussion	SPC	George, Greene, Harrison, Jackson, Stone	92 min
Apr 23, 4:06 PM CDT	Severe Thunderstorm Watch	SPC	Wayne	113 min

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.