Alert archive / Alabama / Mesoscale Discussions in 2014

Mesoscale Discussion 1823

October 7, 20147 counties in Alabama; 6 counties in Mississippi; 6 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Oct 7, 2014, 12:59 PM CDT for 7 counties in Alabama; 6 counties in Mississippi; 6 counties in Tennessee. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Oct 7, 2014, 12:59 PM CDT (17:59 UTC)
Expired: Oct 7, 2014, 3:00 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 5%

Counties Colbert County, AL, Franklin County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Morgan County, AL, Alcorn County, MS, Benton County, MS, Marshall County, MS, Prentiss County, MS, Tippah County, MS, Tishomingo County, MS, Franklin County, TN, Giles County, TN, Hardin County, TN, Lawrence County, TN, Lincoln County, TN, McNairy County, TN

The radar

The Columbus AFB radar (KGWX), 99 km from the middle of the area, began a volume at 17:59 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

Nashville Metro, TN (KBNA), launched 12:00Z, 6.0 hours before the alert went out and 197 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: 479 J/kg
Mixed-layer CIN: -106 J/kg
Mixed-layer LCL: 1057 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: 168 m²/s²
0-3 km storm-relative helicity: 203 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 6.1

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
Oct 7, 3:52 AM CDT	Mesoscale Discussion	SPC	Crockett, Dyer, Haywood, Lake, Lauderdale, Obion and 2 more	83 min

Nearby

Mesoscale Discussions in Alabama, 2014 Mesoscale Discussions in Mississippi, 2014 Mesoscale Discussions in Tennessee, 2014 Every mesoscale discussion in 2014

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.