Alert archive / Mississippi / Mesoscale Discussions in 2017

Mesoscale Discussion 148

February 7, 201718 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Feb 7, 2017, 12:22 PM CST for 18 counties in Mississippi. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Feb 7, 2017, 12:22 PM CST (18:22 UTC)
Expired: Feb 7, 2017, 2:45 PM CST
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 40%

Counties Attala County, MS, Calhoun County, MS, Carroll County, MS, Chickasaw County, MS, Choctaw County, MS, Clay County, MS, Grenada County, MS, Holmes County, MS, Humphreys County, MS, Leflore County, MS, Montgomery County, MS, Oktibbeha County, MS, Pontotoc County, MS, Sunflower County, MS, Tallahatchie County, MS, Webster County, MS, Winston County, MS, Yalobusha County, MS

The radar

The Columbus AFB radar (KGWX), 109 km from the middle of the area, began a volume at 18:22 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

Little Rock, AR (KBYH), launched 12:00Z, 6.4 hours before the alert went out and 130 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: 1313 J/kg
Mixed-layer CIN: -74 J/kg
Mixed-layer LCL: 797 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 408 m²/s²
0-3 km storm-relative helicity: 384 m²/s²
Significant tornado parameter: 2.3
Supercell composite: 11.9

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
Feb 6, 10:59 PM CST	Severe Thunderstorm Watch	SPC	Coahoma, DeSoto, Panola, Quitman, Tallahatchie, Tate and 1 more	9 hr
Feb 7, 5:59 AM CST	Mesoscale Discussion	SPC	Adams, Amite, Claiborne, Clarke, Copiah, Covington and 28 more	2 hr
Feb 7, 7:28 AM CST	Mesoscale Discussion	SPC	Alcorn, Benton, DeSoto, Marshall, Tate, Tippah and 1 more	2 hr
Feb 7, 7:54 AM CST	Tornado Watch	SPC	Adams, Amite, Claiborne, Clarke, Copiah, Covington and 34 more	11 hr
Feb 7, 10:18 AM CST	Mesoscale Discussion	SPC	Adams, Amite, Claiborne, Copiah, Covington, Forrest and 26 more	117 min
Feb 7, 12:56 PM CST	Mesoscale Discussion	SPC	Clarke, Covington, Forrest, George, Greene, Hancock and 18 more	64 min
Feb 7, 5:39 PM CST	Mesoscale Discussion	SPC	Wayne	96 min

Nearby

Mesoscale Discussions in Mississippi, 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.