Alert archive / Tennessee / Mesoscale Discussions in 2011

Mesoscale Discussion 636

April 27, 201142 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Apr 27, 2011, 6:38 PM EDT for 42 counties in Tennessee. It was in force for 97 min.

The area

The outline as issued.

The facts

Issued
Apr 27, 2011, 6:38 PM EDT (22:38 UTC)
Expired
Apr 27, 2011, 8:15 PM EDT
In force
97 min
Issued by
the Storm Prediction Center
All 42 counties

Anderson County, TN, Bedford County, TN, Bledsoe County, TN, Blount County, TN, Bradley County, TN, Cannon County, TN, Coffee County, TN, Cumberland County, TN, Davidson County, TN, DeKalb County, TN, Franklin County, TN, Giles County, TN, Grainger County, TN, Grundy County, TN, Hamblen County, TN, Hamilton County, TN, Jackson County, TN, Jefferson County, TN, Knox County, TN, Loudon County, TN, Marshall County, TN, Maury County, TN, McMinn County, TN, Meigs County, TN, Monroe County, TN, Moore County, TN, Morgan County, TN, Overton County, TN, Polk County, TN, Putnam County, TN, Rhea County, TN, Roane County, TN, Rutherford County, TN, Sequatchie County, TN, Sevier County, TN, Smith County, TN, Union County, TN, Van Buren County, TN, Warren County, TN, White County, TN, Williamson County, TN, Wilson County, TN

The watches that followed

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

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 10.6 hours before the alert went out and 99 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 2011-04-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 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 2011-04-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -84 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
714 m above ground
0-6 km bulk shear
57 kt
0-1 km storm-relative helicity
-84 m²/s²
0-3 km storm-relative helicity
-38 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
Apr 26, 8:59 PM EDTMesoscale DiscussionSPCBedford, Cheatham, Davidson, Dickson, Giles, Hardin and 11 more2 hr
Apr 26, 10:13 PM EDTMesoscale DiscussionSPCBenton, Carroll, Chester, Crockett, Dyer, Fayette and 16 more62 min
Apr 26, 10:58 PM EDTTornado WatchSPCBedford, Benton, Cannon, Carroll, Cheatham, Chester and 40 more7 hr
Apr 27, 3:26 AM EDTTornado WatchSPCFranklin, Lincoln, Moore6 hr
Apr 27, 5:33 AM EDTMesoscale DiscussionSPCBedford, Cannon, Clay, Coffee, Cumberland, DeKalb and 15 more57 min
Apr 27, 6:07 AM EDTTornado WatchSPCBedford, Bledsoe, Cannon, Clay, Coffee, Cumberland and 27 more5 hr
Apr 27, 7:25 AM EDTMesoscale DiscussionSPCFayette, Hardeman, Shelby, Tipton65 min
Apr 27, 8:34 AM EDTTornado WatchSPCAnderson, Blount, Bradley, Campbell, Claiborne, Grainger and 13 more4 hr
Apr 27, 9:08 AM EDTTornado WatchSPCFranklin, Lincoln, Moore6 hr
Apr 27, 11:27 AM EDTTornado WatchSPCAnderson, Bedford, Bledsoe, Blount, Bradley, Cannon and 29 more6 hr
Apr 27, 12:02 PM EDTTornado Watch PDSSPCHardin, McNairy8 hr
Apr 27, 12:39 PM EDTMesoscale DiscussionSPCBledsoe, Blount, Bradley, Cannon, Coffee, DeKalb and 16 more66 min
Apr 27, 1:08 PM EDTMesoscale DiscussionSPCBenton, Carroll, Cheatham, Chester, Crockett, Decatur and 21 more67 min
Apr 27, 1:42 PM EDTSevere Thunderstorm WatchSPCBenton, Carroll, Cheatham, Chester, Crockett, Davidson and 27 more5 hr
Apr 27, 2:03 PM EDTMesoscale DiscussionSPCBledsoe, Blount, Bradley, Grundy, Hamilton, Loudon and 10 more57 min
Apr 27, 2:05 PM EDTMesoscale DiscussionSPCFranklin, Giles, Lawrence, Lincoln, Marshall, Maury and 1 more85 min
Apr 27, 2:42 PM EDTTornado Watch PDSSPCFranklin, Lincoln, Moore8 hr
Apr 27, 3:22 PM EDTMesoscale DiscussionSPCAnderson, Blount, Campbell, Carter, Claiborne, Cocke and 17 more83 min
Apr 27, 3:56 PM EDTMesoscale DiscussionSPCFranklin, Lincoln, Marion2 hr
Apr 27, 4:06 PM EDTMesoscale DiscussionSPCBenton, Carroll, Cheatham, Chester, Crockett, Davidson and 22 more54 min
Apr 27, 4:29 PM EDTTornado WatchSPCCarroll, Chester, Crockett, Decatur, Dyer, Fayette and 13 more5 hr
Apr 27, 4:36 PM EDTTornado Watch PDSSPCAnderson, Bedford, Benton, Bledsoe, Blount, Bradley and 66 more8 hr

Nearby

Mesoscale Discussions in Tennessee, 2011Every mesoscale discussion in 2011

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.