Alert archive / Tennessee / Mesoscale Discussions in 2013

Mesoscale Discussion 25

January 13, 201320 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Jan 13, 2013, 10:11 AM CST for 20 counties in Tennessee. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued: Jan 13, 2013, 10:11 AM CST (16:11 UTC)
Expired: Jan 13, 2013, 11:45 AM CST
In force: 94 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Bedford County, TN, Cannon County, TN, Cheatham County, TN, Coffee County, TN, Davidson County, TN, DeKalb County, TN, Dickson County, TN, Hickman County, TN, Jackson County, TN, Lewis County, TN, Marshall County, TN, Maury County, TN, Rutherford County, TN, Smith County, TN, Sumner County, TN, Trousdale County, TN, Warren County, TN, White County, TN, Williamson County, TN, Wilson County, TN

The radar

The Nashville radar (KOHX), 39 km from the middle of the area, began a volume at 16:10 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, 4.2 hours before the alert went out and 26 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: 36 J/kg
Mixed-layer CIN: -86 J/kg
Mixed-layer LCL: 632 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: 359 m²/s²
0-3 km storm-relative helicity: 389 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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
Jan 12, 9:25 PM CST	Mesoscale Discussion	SPC	Lake	2 hr
Jan 13, 2:46 PM CST	Mesoscale Discussion	SPC	Bedford, Cannon, Clay, Coffee, Davidson, DeKalb and 15 more	119 min

Nearby

Mesoscale Discussions in Tennessee, 2013 Every mesoscale discussion in 2013

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.