Alert archive / Mississippi / Mesoscale Discussions in 2018

Mesoscale Discussion 1094

July 19, 2018Chicot County, Desha County, Phillips County, Arkansas; East Carroll Parish, Madison Parish, West Carroll Parish, Louisiana; 23 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Jul 19, 2018, 11:21 PM CDT for Chicot County, Desha County, Phillips County, Arkansas; East Carroll Parish, Madison Parish, West Carroll Parish, Louisiana; 23 counties in Mississippi. It was in force for 114 min.

The area

The outline as issued.

The facts

Issued: Jul 19, 2018, 11:21 PM CDT (04:21 UTC)
Expired: Jul 20, 2018, 1:15 AM CDT
In force: 114 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

All 29 counties

Chicot County, AR, Desha County, AR, Phillips County, AR, East Carroll Parish, LA, Madison Parish, LA, West Carroll Parish, LA, Attala County, MS, Bolivar County, MS, Calhoun County, MS, Carroll County, MS, Coahoma County, MS, Grenada County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Lafayette County, MS, Leflore County, MS, Madison County, MS, Montgomery County, MS, Panola County, MS, Quitman County, MS, Sharkey County, MS, Sunflower County, MS, Tallahatchie County, MS, Warren County, MS, Washington County, MS, Webster County, MS, Yalobusha County, MS, Yazoo County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 137 km from the middle of the area, began a volume at 04:21 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 00:00Z, 4.4 hours before the alert went out and 129 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: 1931 J/kg
Mixed-layer CIN: -27 J/kg
Mixed-layer LCL: 1476 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 12 m²/s²
0-3 km storm-relative helicity: 119 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.5

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
Jul 19, 7:07 PM CDT	Severe Thunderstorm Watch	SPC	Baxter, Boone, Carroll, Cleburne, Fulton, Independence and 10 more	3 hr
Jul 19, 8:02 PM CDT	Mesoscale Discussion	SPC	Arkansas, Baxter, Clark, Cleburne, Cleveland, Conway and 40 more	118 min
Jul 19, 8:54 PM CDT	Severe Thunderstorm Watch	SPC	Arkansas, Bradley, Calhoun, Clark, Clay, Cleveland and 35 more	114 min
Jul 20, 9:25 AM CDT	Mesoscale Discussion	SPC	Arkansas, Cleburne, Crittenden, Cross, Faulkner, Independence and 13 more	2 hr
Jul 20, 12:58 PM CDT	Mesoscale Discussion	SPC	Clay	62 min
Jul 20, 3:46 PM CDT	Mesoscale Discussion	SPC	Baxter, Boone, Fulton, Izard, Marion, Randolph and 2 more	59 min
Jul 20, 3:58 PM CDT	Severe Thunderstorm Watch	SPC	Baxter, Clay, Craighead, Cross, Fulton, Greene and 8 more	6 hr
Jul 20, 5:54 PM CDT	Mesoscale Discussion	SPC	Crittenden, Lee, Phillips, St. Francis	3 hr
Jul 20, 6:22 PM CDT	Tornado Watch	SPC	Crittenden, Lee, Mississippi, Phillips, St. Francis	8 hr
Jul 20, 1:23 PM CDT	Mesoscale Discussion	SPC	Attala, Carroll, Choctaw, Clarke, Copiah, Covington and 20 more	97 min
Jul 20, 2:11 PM CDT	Severe Thunderstorm Watch	SPC	Clarke, Covington, Forrest, Hinds, Jasper, Jefferson Davis and 14 more	3 hr

Nearby

Mesoscale Discussions in Mississippi, 2018 Mesoscale Discussions in Arkansas, 2018 Mesoscale Discussions in Louisiana, 2018 Every mesoscale discussion in 2018

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.