Alert archive / Tennessee / Mesoscale Discussions in 2011

Mesoscale Discussion 171

February 28, 201111 counties in Alabama; 20 counties in Mississippi; 60 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Feb 28, 2011, 5:47 AM CST for 11 counties in Alabama; 20 counties in Mississippi; 60 counties in Tennessee. It was in force for 28 min.

The area

The outline as issued.

The facts

Issued
Feb 28, 2011, 5:47 AM CST (11:47 UTC)
Expired
Feb 28, 2011, 6:15 AM CST
In force
28 min
Issued by
the Storm Prediction Center
All 91 counties

Colbert County, AL, Franklin County, AL, Jackson County, AL, Lamar County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marion County, AL, Morgan County, AL, Winston County, AL, Alcorn County, MS, Benton County, MS, Calhoun County, MS, Chickasaw County, MS, Clay County, MS, Grenada County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Marshall County, MS, Monroe County, MS, Panola County, MS, Pontotoc County, MS, Prentiss County, MS, Tallahatchie County, MS, Tippah County, MS, Tishomingo County, MS, Union County, MS, Webster County, MS, Yalobusha County, MS, Anderson County, TN, Bedford County, TN, Bledsoe County, TN, Campbell County, TN, Cannon County, TN, Cheatham County, TN, Chester County, TN, Claiborne County, TN, Clay County, TN, Coffee County, TN, Cumberland County, TN, Davidson County, TN, Decatur County, TN, DeKalb County, TN, Dickson County, TN, Fentress County, TN, Franklin County, TN, Giles County, TN, Grainger County, TN, Grundy County, TN, Hamilton County, TN, Hancock County, TN, Hardeman County, TN, Hardin County, TN, Henderson County, TN, Hickman County, TN, Humphreys County, TN, Jackson County, TN, Knox County, TN, Lawrence County, TN, Lewis County, TN, Lincoln County, TN, Loudon County, TN, Macon County, TN, Marion County, TN, Marshall County, TN, Maury County, TN, McNairy County, TN, Meigs County, TN, Moore County, TN, Morgan County, TN, Overton County, TN, Perry County, TN, Pickett County, TN, Putnam County, TN, Rhea County, TN, Roane County, TN, Rutherford County, TN, Scott County, TN, Sequatchie County, TN, Smith County, TN, Sumner County, TN, Trousdale County, TN, Union County, TN, Van Buren County, TN, Warren County, TN, Wayne County, TN, White County, TN, Williamson County, TN, Wilson County, TN

The radar

The Northeast Alabama radar (KHTX), 60 km from the middle of the area, began a volume at 11:49 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 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 00:00Z, 11.8 hours before the alert went out and 94 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 2011-02-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 184 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 2011-02-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 245 square meters per square second.1939587897117Sfc1 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
184 J/kg
Mixed-layer CIN
-38 J/kg
Mixed-layer LCL
1385 m above ground
0-6 km bulk shear
63 kt
0-1 km storm-relative helicity
245 m²/s²
0-3 km storm-relative helicity
304 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.2

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
Feb 28, 5:59 AM CSTTornado WatchSPCColbert, Cullman, DeKalb, Fayette, Franklin, Jackson and 10 more7 hr
Feb 28, 11:25 AM CSTMesoscale DiscussionSPCBlount, Colbert, Cullman, DeKalb, Fayette, Franklin and 11 more95 min
Feb 28, 12:19 PM CSTMesoscale DiscussionSPCAutauga, Baldwin, Barbour, Bullock, Butler, Clarke and 15 more86 min
Feb 28, 12:29 PM CSTTornado WatchSPCAutauga, Barbour, Bibb, Blount, Bullock, Calhoun and 41 more7 hr
Feb 28, 3:36 PM CSTMesoscale DiscussionSPCAutauga, Bibb, Bullock, Calhoun, Chambers, Cherokee and 24 more84 min
Feb 28, 5:16 PM CSTMesoscale DiscussionSPCBaldwin, Barbour, Butler, Clarke, Coffee, Conecuh and 12 more89 min
Feb 28, 5:28 AM CSTMesoscale DiscussionSPCAlcorn, Attala, Benton, Bolivar, Calhoun, Carroll and 50 more62 min
Feb 28, 1:05 AM CSTMesoscale DiscussionSPCBenton, Carroll, Chester, Crockett, Decatur, Dyer and 18 more25 min
Feb 28, 1:33 AM CSTTornado WatchSPCBenton, Carroll, Cheatham, Chester, Crockett, Dickson and 19 more7 hr

Nearby

Mesoscale Discussions in Tennessee, 2011Mesoscale Discussions in Mississippi, 2011Mesoscale Discussions in Alabama, 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; radar from the NEXRAD Level II archive.