Alert archive / Tennessee / Mesoscale Discussions in 2008

Mesoscale Discussion 641

April 11, 20084 states

The Storm Prediction Center issued this mesoscale discussion at Apr 11, 2008, 5:34 PM CDT for 4 states. It was in force for 56 min.

The area

The outline as issued.

The facts

Issued
Apr 11, 2008, 5:34 PM CDT (22:34 UTC)
Expired
Apr 11, 2008, 6:30 PM CDT
In force
56 min
Issued by
the Storm Prediction Center
All 75 counties

Bibb County, AL, Blount County, AL, Calhoun County, AL, Cherokee County, AL, Clay County, AL, Cleburne County, AL, Cullman County, AL, DeKalb County, AL, Etowah County, AL, Fayette County, AL, Jackson County, AL, Jefferson County, AL, Madison County, AL, Marshall County, AL, Morgan County, AL, Randolph County, AL, Shelby County, AL, St. Clair County, AL, Talladega County, AL, Tuscaloosa County, AL, Walker County, AL, Winston County, AL, Bartow County, GA, Carroll County, GA, Catoosa County, GA, Chattooga County, GA, Cherokee County, GA, Cobb County, GA, Coweta County, GA, Dade County, GA, Douglas County, GA, Fannin County, GA, Floyd County, GA, Gilmer County, GA, Gordon County, GA, Haralson County, GA, Heard County, GA, Murray County, GA, Paulding County, GA, Pickens County, GA, Polk County, GA, Walker County, GA, Whitfield County, GA, Cherokee County, NC, Anderson County, TN, Bledsoe County, TN, Blount County, TN, Bradley County, TN, Campbell County, TN, Claiborne County, TN, Cumberland County, TN, Fentress County, TN, Franklin County, TN, Grainger County, TN, Grundy County, TN, Hamblen County, TN, Hamilton County, TN, Hancock County, TN, Jefferson County, TN, Knox County, TN, Loudon County, TN, Marion County, TN, McMinn County, TN, Meigs County, TN, Monroe County, TN, Morgan County, TN, Polk County, TN, Rhea County, TN, Roane County, TN, Scott County, TN, Sequatchie County, TN, Sevier County, TN, Union County, TN, Van Buren County, TN, White County, TN

The radar

The Northeast Alabama radar (KHTX), 80 km from the middle of the area, began a volume at 22:35 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

Birmingham, AL (KBMX), launched 12:00Z, 10.6 hours before the alert went out and 148 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, Birmingham, AL at 12:00Z on 2008-04-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 33 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, Birmingham, AL at 12:00Z on 2008-04-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 217 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
33 J/kg
Mixed-layer CIN
-160 J/kg
Mixed-layer LCL
566 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
217 m²/s²
0-3 km storm-relative helicity
271 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

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 11, 2:15 AM CDTMesoscale DiscussionSPCLauderdale2 hr
Apr 11, 10:15 AM CDTTornado WatchSPCColbert, Cullman, DeKalb, Fayette, Franklin, Greene and 15 more5 hr
Apr 11, 1:15 PM CDTMesoscale DiscussionSPCAutauga, Bibb, Blount, Calhoun, Cherokee, Chilton and 33 more2 hr
Apr 11, 3:00 PM CDTTornado WatchSPCBlount, Calhoun, Cherokee, Cullman, DeKalb, Etowah and 13 more5 hr
Apr 11, 3:07 PM CDTSevere Thunderstorm WatchSPCAutauga, Bibb, Butler, Chambers, Chilton, Choctaw and 18 more8 hr
Apr 10, 7:48 PM CDTMesoscale DiscussionSPCBenton, Carroll, Cheatham, Chester, Crockett, Decatur and 21 more57 min
Apr 10, 8:22 PM CDTSevere Thunderstorm WatchSPCCarroll, Chester, Crockett, Decatur, Dyer, Fayette and 14 more5 hr
Apr 10, 9:54 PM CDTMesoscale DiscussionSPCBenton, Carroll, Chester, Crockett, Decatur, Dickson and 15 more66 min
Apr 10, 11:34 PM CDTMesoscale DiscussionSPCBenton, Carroll, Chester, Crockett, Decatur, Dyer and 17 more56 min

Nearby

Mesoscale Discussions in Tennessee, 2008Mesoscale Discussions in Alabama, 2008Mesoscale Discussions in Georgia, 2008Every 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.