Alert archive / Mississippi / Mesoscale Discussions in 2017

Mesoscale Discussion 801

May 20, 201725 counties in Alabama; 12 parishes in Louisiana; 64 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at May 20, 2017, 2:12 PM CDT for 25 counties in Alabama; 12 parishes in Louisiana; 64 counties in Mississippi. It was in force for 93 min.

The area

The outline as issued.

The facts

Issued: May 20, 2017, 2:12 PM CDT (19:12 UTC)
Expired: May 20, 2017, 3:45 PM CDT
In force: 93 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

All 101 counties

Bibb County, AL, Choctaw County, AL, Clarke County, AL, Colbert County, AL, Cullman County, AL, Fayette County, AL, Franklin County, AL, Greene County, AL, Hale County, AL, Jefferson County, AL, Lamar County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Marengo County, AL, Marion County, AL, Morgan County, AL, Perry County, AL, Pickens County, AL, Shelby County, AL, Sumter County, AL, Tuscaloosa County, AL, Walker County, AL, Washington County, AL, Winston County, AL, Concordia Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Livingston Parish, LA, Madison Parish, LA, Pointe Coupee Parish, LA, Saint Helena Parish, LA, Tangipahoa Parish, LA, Tensas Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Adams County, MS, Alcorn County, MS, Amite County, MS, Attala County, MS, Calhoun County, MS, Carroll County, MS, Chickasaw County, MS, Choctaw County, MS, Claiborne County, MS, Clarke County, MS, Clay County, MS, Copiah County, MS, Covington County, MS, Forrest County, MS, Franklin County, MS, Greene County, MS, Grenada County, MS, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Itawamba County, MS, Jasper County, MS, Jefferson County, MS, Jefferson Davis County, MS, Jones County, MS, Kemper County, MS, Lafayette County, MS, Lamar County, MS, Lauderdale County, MS, Lawrence County, MS, Leake County, MS, Lee County, MS, Lincoln County, MS, Lowndes County, MS, Madison County, MS, Marion County, MS, Monroe County, MS, Montgomery County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Oktibbeha County, MS, Pearl River County, MS, Perry County, MS, Pike County, MS, Pontotoc County, MS, Prentiss County, MS, Rankin County, MS, Scott County, MS, Sharkey County, MS, Simpson County, MS, Smith County, MS, Tippah County, MS, Tishomingo County, MS, Union County, MS, Walthall County, MS, Warren County, MS, Wayne County, MS, Webster County, MS, Wilkinson County, MS, Winston County, MS, Yalobusha County, MS, Yazoo County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 115 km from the middle of the area, began a volume at 19:13 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, 7.2 hours before the alert went out and 119 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: 1158 J/kg
Mixed-layer CIN: -7 J/kg
Mixed-layer LCL: 605 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: 21 m²/s²
0-3 km storm-relative helicity: 55 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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Nearby

Mesoscale Discussions in Mississippi, 2017 Mesoscale Discussions in Alabama, 2017 Mesoscale Discussions in Louisiana, 2017 Every mesoscale discussion in 2017

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.