Alert archive / Tennessee / Mesoscale Discussions in 2012

Mesoscale Discussion 406

April 1, 2012Rabun County, Georgia; 13 counties in North Carolina; 17 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Apr 1, 2012, 2:31 PM EDT for Rabun County, Georgia; 13 counties in North Carolina; 17 counties in Tennessee. It was in force for 89 min.

The area

The outline as issued.

The facts

Issued
Apr 1, 2012, 2:31 PM EDT (18:31 UTC)
Expired
Apr 1, 2012, 4:00 PM EDT
In force
89 min
Issued by
the Storm Prediction Center
All 31 counties

Rabun County, GA, Buncombe County, NC, Graham County, NC, Haywood County, NC, Henderson County, NC, Jackson County, NC, Macon County, NC, Madison County, NC, McDowell County, NC, Mitchell County, NC, Polk County, NC, Swain County, NC, Transylvania County, NC, Yancey County, NC, Anderson County, TN, Blount County, TN, Campbell County, TN, Cocke County, TN, Fentress County, TN, Grainger County, TN, Greene County, TN, Hamblen County, TN, Jefferson County, TN, Knox County, TN, Loudon County, TN, Monroe County, TN, Morgan County, TN, Roane County, TN, Sevier County, TN, Unicoi County, TN, Union County, TN

The radar

The Knoxville radar (KMRX), 36 km from the middle of the area, began a volume at 18:31 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, 6.5 hours before the alert went out and 282 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 12:00Z on 2012-04-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1040 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 12:00Z on 2012-04-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 94 square meters per square second.1939587897Sfc1 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
1040 J/kg
Mixed-layer CIN
-92 J/kg
Mixed-layer LCL
805 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
94 m²/s²
0-3 km storm-relative helicity
87 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.1

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.

IssuedProductOfficeCountiesLasted
Mar 31, 8:27 PM EDTMesoscale DiscussionSPCBartow, Carroll, Catoosa, Chattooga, Cherokee, Cobb and 15 more63 min
Apr 1, 12:33 AM EDTMesoscale DiscussionSPCHardeman57 min

Nearby

Mesoscale Discussions in Tennessee, 2012Mesoscale Discussions in North Carolina, 2012Mesoscale Discussions in Georgia, 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.