Alert archive / Mississippi / Mesoscale Discussions in 2012

Mesoscale Discussion 1418

July 6, 20124 states

The Storm Prediction Center issued this mesoscale discussion at Jul 6, 2012, 2:36 PM CDT for 4 states. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued: Jul 6, 2012, 2:36 PM CDT (19:36 UTC)
Expired: Jul 6, 2012, 4:00 PM CDT
In force: 84 min
Issued by: the Storm Prediction Center
Chance of a watch: 60%

All 59 counties

Colbert County, AL, Franklin County, AL, Lauderdale County, AL, Crittenden County, AR, Cross County, AR, Lee County, AR, Mississippi County, AR, Phillips County, AR, Poinsett County, AR, St. Francis County, AR, Alcorn County, MS, Benton County, MS, Calhoun County, MS, Chickasaw County, MS, Clay County, MS, Coahoma County, MS, DeSoto County, MS, Grenada County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Marshall County, MS, Monroe County, MS, Panola County, MS, Pontotoc County, MS, Prentiss County, MS, Quitman County, MS, Tallahatchie County, MS, Tate County, MS, Tippah County, MS, Tishomingo County, MS, Tunica County, MS, Union County, MS, Webster County, MS, Yalobusha County, MS, Benton County, TN, Carroll County, TN, Chester County, TN, Crockett County, TN, Decatur County, TN, Fayette County, TN, Gibson County, TN, Hardeman County, TN, Hardin County, TN, Haywood County, TN, Henderson County, TN, Henry County, TN, Houston County, TN, Humphreys County, TN, Lauderdale County, TN, Lawrence County, TN, Lewis County, TN, Madison County, TN, McNairy County, TN, Perry County, TN, Shelby County, TN, Stewart County, TN, Tipton County, TN, Wayne County, TN

The radar

The Memphis radar (KNQA), 110 km from the middle of the area, began a volume at 19:39 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 watches that followed

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

The nearest sounding before it

Little Rock, AR (KLZK), launched 12:00Z, 7.6 hours before the alert went out and 105 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: 1117 J/kg
Mixed-layer CIN: -126 J/kg
Mixed-layer LCL: 1748 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 2 m²/s²
0-3 km storm-relative helicity: 38 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

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 6, 2:58 PM CDT	Severe Thunderstorm Watch	SPC	Colbert, Franklin, Lamar, Lauderdale, Lawrence, Marion	5 hr
Jul 6, 5:08 PM CDT	Severe Thunderstorm Watch	SPC	Bibb, Dallas, Fayette, Greene, Hale, Lamar and 6 more	4 hr
Jul 6, 6:15 PM CDT	Mesoscale Discussion	SPC	Greene, Pickens, Sumter	2 hr
Jul 6, 12:42 PM CDT	Mesoscale Discussion	SPC	Clay, Greene, Mississippi	93 min

Nearby

Mesoscale Discussions in Mississippi, 2012 Mesoscale Discussions in Tennessee, 2012 Mesoscale Discussions in Arkansas, 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.