Alert archive / Tennessee / Mesoscale Discussions in 2008

Mesoscale Discussion 171

February 5, 200816 counties in Alabama; 26 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Feb 5, 2008, 9:39 PM CST for 16 counties in Alabama; 26 counties in Tennessee. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued: Feb 5, 2008, 9:39 PM CST (03:39 UTC)
Expired: Feb 5, 2008, 11:15 PM CST
In force: 96 min
Issued by: the Storm Prediction Center

All 42 counties

Blount County, AL, Colbert County, AL, Cullman County, AL, Fayette 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, Marshall County, AL, Morgan County, AL, Walker County, AL, Winston County, AL, Bedford County, TN, Benton County, TN, Cannon County, TN, Cheatham County, TN, Coffee County, TN, Davidson County, TN, Decatur County, TN, Dickson County, TN, Franklin County, TN, Giles County, TN, Grundy County, TN, Hardin County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Lawrence County, TN, Lewis County, TN, Lincoln County, TN, Marshall County, TN, Maury County, TN, Moore County, TN, Perry County, TN, Rutherford County, TN, Warren County, TN, Wayne County, TN, Williamson County, TN

The radar

The Northeast Alabama radar (KHTX), 98 km from the middle of the area, began a volume at 03:41 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, 3.7 hours before the alert went out and 130 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: 706 J/kg
Mixed-layer CIN: -45 J/kg
Mixed-layer LCL: 812 m above ground
0-6 km bulk shear: 54 kt
0-1 km storm-relative helicity: 300 m²/s²
0-3 km storm-relative helicity: 362 m²/s²
Significant tornado parameter: 1.6
Supercell composite: 3.2

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.

Issued	Product	Office	Counties	Lasted
Feb 5, 10:01 PM CST	Tornado Watch	SPC	Bibb, Blount, Colbert, Cullman, DeKalb, Etowah and 23 more	8 hr
Feb 6, 1:23 AM CST	Tornado Watch	SPC	Choctaw, Clarke, Mobile, Washington	6 hr
Feb 6, 2:41 AM CST	Mesoscale Discussion	SPC	Bibb, Blount, Calhoun, Cherokee, Colbert, Cullman and 25 more	2 hr
Feb 6, 4:06 AM CST	Tornado Watch	SPC	Autauga, Bibb, Blount, Calhoun, Cherokee, Chilton and 24 more	6 hr
Feb 6, 4:27 AM CST	Mesoscale Discussion	SPC	Baldwin, Butler, Clarke, Coffee, Conecuh, Covington and 7 more	2 hr
Feb 6, 5:04 AM CST	Tornado Watch	SPC	Baldwin, Butler, Choctaw, Clarke, Conecuh, Covington and 6 more	5 hr
Feb 6, 6:10 AM CST	Mesoscale Discussion	SPC	Autauga, Barbour, Bibb, Bullock, Butler, Calhoun and 34 more	2 hr
Feb 6, 7:06 AM CST	Tornado Watch	SPC	Barbour, Bullock, Chambers, Coffee, Dale, Geneva and 6 more	6 hr
Feb 6, 10:20 AM CST	Mesoscale Discussion	SPC	Barbour, Bullock, Coffee, Dale, Geneva, Henry and 3 more	85 min
Feb 5, 6:59 PM CST	Mesoscale Discussion	SPC	Cheatham, Davidson, Dickson, Giles, Hickman, Houston and 12 more	91 min
Feb 5, 7:19 PM CST	Tornado Watch	SPC	Benton, Cheatham, Davidson, Dickson, Giles, Hickman and 17 more	6 hr
Feb 5, 8:07 PM CST	Mesoscale Discussion	SPC	Benton, Carroll, Chester, Crockett, Dyer, Fayette and 13 more	83 min
Feb 5, 9:19 PM CST	Mesoscale Discussion	SPC	Cheatham, Clay, Davidson, Dickson, Fentress, Houston and 12 more	86 min
Feb 5, 11:59 PM CST	Tornado Watch	SPC	Campbell, Morgan, Scott	4 hr
Feb 6, 7:49 AM CST	Mesoscale Discussion	SPC	Blount, Carter, Cocke, Grainger, Greene, Hamblen and 11 more	116 min

Nearby

Mesoscale Discussions in Tennessee, 2008 Mesoscale Discussions in Alabama, 2008 Every mesoscale discussion in 2008

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.