Alert archive / Tennessee / Mesoscale Discussions in 2012

Mesoscale Discussion 462

April 5, 201210 counties in Alabama; Cherokee County, Clay County, North Carolina; 66 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Apr 5, 2012, 3:06 PM CDT for 10 counties in Alabama; Cherokee County, Clay County, North Carolina; 66 counties in Tennessee. It was in force for 54 min.

The area

The outline as issued.

The facts

Issued
Apr 5, 2012, 3:06 PM CDT (20:06 UTC)
Expired
Apr 5, 2012, 4:00 PM CDT
In force
54 min
Issued by
the Storm Prediction Center
All 78 counties

Colbert County, AL, DeKalb County, AL, Franklin County, AL, Jackson County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marshall County, AL, Morgan County, AL, Cherokee County, NC, Clay County, NC, Anderson County, TN, Bedford County, TN, Bledsoe County, TN, Blount County, TN, Bradley County, TN, Campbell County, TN, Cannon County, TN, Cheatham County, TN, Claiborne County, TN, Clay County, TN, Cocke County, TN, Coffee County, TN, Cumberland County, TN, Davidson County, TN, DeKalb County, TN, Dickson County, TN, Fentress County, TN, Franklin County, TN, Giles County, TN, Grainger County, TN, Grundy County, TN, Hamblen County, TN, Hamilton County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Jackson County, TN, Jefferson 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, McMinn County, TN, Meigs County, TN, Monroe County, TN, Montgomery County, TN, Moore County, TN, Morgan County, TN, Overton County, TN, Perry County, TN, Pickett County, TN, Polk County, TN, Putnam County, TN, Rhea County, TN, Roane County, TN, Robertson County, TN, Rutherford County, TN, Scott County, TN, Sequatchie County, TN, Sevier County, TN, Smith County, TN, Stewart 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), 85 km from the middle of the area, began a volume at 20:08 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, 8.1 hours before the alert went out and 166 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 2012-04-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 670 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 2012-04-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -15 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
670 J/kg
Mixed-layer CIN
-22 J/kg
Mixed-layer LCL
805 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
-15 m²/s²
0-3 km storm-relative helicity
57 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.6

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

044 
ACUS11 KWNS 052007
SWOMCD
SPC MCD 052006
NCZ000-TNZ000-VAZ000-KYZ000-GAZ000-ALZ000-MSZ000-052100-

MESOSCALE DISCUSSION 0462
NWS STORM PREDICTION CENTER NORMAN OK
0306 PM CDT THU APR 05 2012

AREAS AFFECTED...NRN AL...FAR WRN NC...MIDDLE/ERN TN

CONCERNING...SEVERE THUNDERSTORM WATCH 147...

VALID 052006Z - 052100Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 147
CONTINUES.

SURFACE ANALYSIS AT 19-20Z SHOWS ONE AREA OF LOW PRESSURE OVER NWRN
TN...AND ANOTHER OVER ERN TN. A STATIONARY FRONT EXTENDS EWD ACROSS
MIDDLE TN TOWARD THE ERN TN LOW...WHILE A COLD FRONT ARCS SEWD FROM
THE NWRN TN LOW INTO ERN AL. STORMS ARE EXPANDING IN COVERAGE ALONG
THE WRN TN-ERN AL FRONTAL SEGMENT...WHILE ISOLATED TO SCATTERED
THUNDERSTORMS CONTINUE TO PERSIST ALONG THE MIDDLE/ERN TN STATIONARY
FRONT. THE SURFACE AIRMASS BETWEEN THE TWO FRONTAL BOUNDARIES
REMAINS WARM AND MOIST...WHICH SUPPORTS MLCAPE VALUES FROM 500-1000
J/KG. AS SUCH...STORMS WILL CONTINUE TO POSE A THREAT FOR LARGE HAIL
AND DAMAGING WIND GUSTS.

..GARNER.. 04/05/2012

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...GSP...MRX...JKL...FFC...LMK...OHX...BMX...HUN...
PAH...MEG...

LAT...LON   34998559 34528550 34228583 34128632 34298649 34348817
            35038800 36688806 36638362 35958290 35768297 35498390
            35378404 35218401 35238369 35018364 34998559

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 5, 7:36 AM CDTMesoscale DiscussionSPCChoctaw, Greene, Hale, Marengo, Perry, Pickens and 2 more54 min
Apr 5, 9:14 AM CDTSevere Thunderstorm WatchSPCAutauga, Barbour, Bibb, Bullock, Butler, Chambers and 34 more8 hr
Apr 5, 10:41 AM CDTMesoscale DiscussionSPCAutauga, Bibb, Butler, Chilton, Choctaw, Clarke and 15 more94 min
Apr 5, 12:09 PM CDTMesoscale DiscussionSPCColbert, Cullman, Franklin, Lauderdale, Lawrence, Limestone and 4 more96 min
Apr 5, 1:12 PM CDTMesoscale DiscussionSPCBarbour, Bullock, Chambers, Clay, Coffee, Covington and 11 more93 min
Apr 5, 1:21 PM CDTSevere Thunderstorm WatchSPCColbert, DeKalb, Franklin, Jackson, Lauderdale, Lawrence and 4 more8 hr
Apr 5, 1:58 PM CDTSevere Thunderstorm WatchSPCCoffee, Dale, Geneva, Henry, Houston6 hr
Apr 5, 3:46 PM CDTMesoscale DiscussionSPCBlount, Calhoun, Cullman, Etowah, Fayette, Jefferson and 7 more59 min
Apr 5, 3:49 PM CDTMesoscale DiscussionSPCGeneva, Henry, Houston86 min
Apr 5, 6:14 PM CDTSevere Thunderstorm WatchSPCAutauga, Bibb, Blount, Bullock, Calhoun, Chambers and 21 more3 hr
Apr 5, 6:15 PM CDTMesoscale DiscussionSPCAutauga, Bibb, Blount, Bullock, Calhoun, Chambers and 23 more45 min
Apr 5, 12:03 PM CDTMesoscale DiscussionSPCBuncombe, Clay, Cleveland, Gaston, Haywood, Henderson and 10 more87 min
Apr 5, 12:47 PM CDTSevere Thunderstorm WatchSPCBuncombe, Cleveland, Gaston, Graham, Haywood, Henderson and 9 more7 hr
Apr 5, 12:54 PM CDTMesoscale DiscussionSPCCherokee, Clay, Graham, Haywood, Macon, Madison and 1 more96 min
Apr 5, 2:37 PM CDTMesoscale DiscussionSPCBuncombe, Clay, Cleveland, Gaston, Graham, Haywood and 13 more53 min
Apr 5, 12:18 PM CDTSevere Thunderstorm WatchSPCCarroll, Chester, Crockett, Decatur, Dyer, Fayette and 14 more5 hr
Apr 5, 2:22 PM CDTMesoscale DiscussionSPCBenton, Carroll, Chester, Crockett, Decatur, Dyer and 16 more53 min

Nearby

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