Alert archive / Tennessee / Mesoscale Discussions in 2012

Mesoscale Discussion 1512

July 19, 201237 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Jul 19, 2012, 11:26 PM EDT for 37 counties in Tennessee. It was in force for 64 min.

The area

The outline as issued.

The facts

Issued
Jul 19, 2012, 11:26 PM EDT (03:26 UTC)
Expired
Jul 20, 2012, 12:30 AM EDT
In force
64 min
Issued by
the Storm Prediction Center
All 37 counties

Anderson County, TN, Benton County, TN, Campbell County, TN, Cannon County, TN, Cheatham County, TN, Claiborne County, TN, Clay County, TN, Cumberland County, TN, Davidson County, TN, DeKalb County, TN, Dickson County, TN, Fentress County, TN, Grainger County, TN, Hancock County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Jackson County, TN, Knox County, TN, Macon County, TN, Montgomery County, TN, Morgan County, TN, Overton County, TN, Pickett County, TN, Putnam County, TN, Roane County, TN, Robertson County, TN, Rutherford County, TN, Scott County, TN, Smith County, TN, Stewart County, TN, Sumner County, TN, Trousdale County, TN, Union County, TN, White County, TN, Williamson County, TN, Wilson County, TN

The radar

The Nashville radar (KOHX), 79 km from the middle of the area, began a volume at 03:27 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 00:00Z, 3.4 hours before the alert went out and 79 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-pSkew-T log-p diagram, Nashville Metro, TN at 00:00Z on 2012-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2853 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Nashville Metro, TN at 00:00Z on 2012-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -3 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
2853 J/kg
Mixed-layer CIN
-14 J/kg
Mixed-layer LCL
1475 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
-3 m²/s²
0-3 km storm-relative helicity
50 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.

IssuedProductOfficeCountiesLasted
Jul 19, 8:35 PM EDTSevere Thunderstorm WatchSPCAnderson, Campbell, Cannon, Cheatham, Claiborne, Clay and 29 more4 hr

Nearby

Mesoscale Discussions in Tennessee, 2012Every 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.