Alert archive / Mississippi / Mesoscale Discussions in 2012

Mesoscale Discussion 1514

July 20, 20124 states

The Storm Prediction Center issued this mesoscale discussion at Jul 20, 2012, 12:47 PM CDT for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Jul 20, 2012, 12:47 PM CDT (17:47 UTC)
Expired: Jul 20, 2012, 3:15 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 60%

All 101 counties

Choctaw County, AL, Fayette County, AL, Greene County, AL, Hale County, AL, Lamar County, AL, Marengo County, AL, Marion County, AL, Pickens County, AL, Sumter County, AL, Tuscaloosa County, AL, Ashley County, AR, Chicot County, AR, Union County, AR, Avoyelles Parish, LA, Bienville Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Claiborne Parish, LA, Concordia Parish, LA, East Carroll Parish, LA, East Feliciana Parish, LA, Franklin Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Pointe Coupee Parish, LA, Rapides Parish, LA, Richland Parish, LA, Saint Helena Parish, LA, Tangipahoa Parish, LA, Tensas Parish, LA, Union Parish, LA, Washington Parish, LA, West Carroll Parish, LA, West Feliciana Parish, LA, Winn Parish, LA, Adams County, MS, Amite County, MS, Attala County, MS, Bolivar 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, Grenada County, MS, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Jasper County, MS, Jefferson County, MS, Jefferson Davis County, MS, Jones County, MS, Kemper County, MS, Lamar County, MS, Lauderdale County, MS, Lawrence County, MS, Leake County, MS, Lee County, MS, Leflore 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, Perry County, MS, Pike County, MS, Pontotoc County, MS, Rankin County, MS, Scott County, MS, Sharkey County, MS, Simpson County, MS, Smith County, MS, Sunflower County, MS, Tallahatchie County, MS, Walthall County, MS, Warren County, MS, Washington 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), 43 km from the middle of the area, began a volume at 17:50 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, 5.8 hours before the alert went out and 35 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: 979 J/kg
Mixed-layer CIN: -152 J/kg
Mixed-layer LCL: 912 m above ground
0-6 km bulk shear: 10 kt
0-1 km storm-relative helicity: 135 m²/s²
0-3 km storm-relative helicity: 180 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.3

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 20, 2:17 PM CDT	Mesoscale Discussion	SPC	Autauga, Bibb, Blount, Bullock, Calhoun, Chambers and 29 more	2 hr
Jul 20, 3:45 PM CDT	Mesoscale Discussion	SPC	Hempstead, Howard, Lafayette, Little River, Miller, Nevada and 2 more	3 hr
Jul 20, 3:03 PM CDT	Mesoscale Discussion	SPC	Acadia, Allen, Ascension, Assumption, Calcasieu, Cameron and 7 more	2 hr

Nearby

Mesoscale Discussions in Mississippi, 2012 Mesoscale Discussions in Louisiana, 2012 Mesoscale Discussions in Alabama, 2012 Every mesoscale discussion in 2012

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.