Alert archive / Tennessee / Mesoscale Discussions in 2012

Mesoscale Discussion 457

April 5, 20126 states

The Storm Prediction Center issued this mesoscale discussion at Apr 5, 2012, 12:09 PM CDT for 6 states. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued
Apr 5, 2012, 12:09 PM CDT (17:09 UTC)
Expired
Apr 5, 2012, 1:45 PM CDT
In force
96 min
Issued by
the Storm Prediction Center
All 90 counties

Colbert County, AL, Cullman County, AL, Franklin County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marion County, AL, Morgan County, AL, Winston County, AL, Clay County, AR, Craighead County, AR, Crittenden County, AR, Greene County, AR, Mississippi County, AR, Randolph County, AR, Calloway County, KY, Carlisle County, KY, Fulton County, KY, Graves County, KY, Hickman County, KY, Butler County, MO, Carter County, MO, Dunklin County, MO, Mississippi County, MO, New Madrid County, MO, Pemiscot County, MO, Ripley County, MO, Scott County, MO, Stoddard County, MO, Alcorn County, MS, Benton County, MS, DeSoto County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Marshall County, MS, Monroe County, MS, Pontotoc County, MS, Prentiss County, MS, Tate County, MS, Tippah County, MS, Tishomingo County, MS, Union County, MS, Bedford County, TN, Benton County, TN, Cannon County, TN, Carroll County, TN, Cheatham County, TN, Chester County, TN, Coffee County, TN, Crockett County, TN, Davidson County, TN, Decatur County, TN, Dickson County, TN, Dyer County, TN, Fayette County, TN, Franklin County, TN, Gibson County, TN, Giles County, TN, Hardeman County, TN, Hardin County, TN, Haywood County, TN, Henderson County, TN, Henry County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Lake County, TN, Lauderdale County, TN, Lawrence County, TN, Lewis County, TN, Lincoln County, TN, Madison County, TN, Marshall County, TN, Maury County, TN, McNairy County, TN, Montgomery County, TN, Moore County, TN, Obion County, TN, Perry County, TN, Robertson County, TN, Rutherford County, TN, Shelby County, TN, Stewart County, TN, Tipton County, TN, Wayne County, TN, Weakley County, TN, Williamson County, TN, Wilson County, TN

The radar

The Memphis radar (KNQA), 96 km from the middle of the area, began a volume at 17:09 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

Little Rock, AR (KLZK), launched 12:00Z, 5.2 hours before the alert went out and 139 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, Little Rock, AR at 12:00Z on 2012-04-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 42 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, Little Rock, AR at 12:00Z on 2012-04-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -41 square meters per square second.193958Sfc1 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
42 J/kg
Mixed-layer CIN
-132 J/kg
Mixed-layer LCL
1448 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
-41 m²/s²
0-3 km storm-relative helicity
51 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.2

Open this sounding in Storm Lab

The text

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

136 
ACUS11 KWNS 051709
SWOMCD
SPC MCD 051709 
TNZ000-ALZ000-KYZ000-MSZ000-MOZ000-ILZ000-ARZ000-051845-

MESOSCALE DISCUSSION 0457
NWS STORM PREDICTION CENTER NORMAN OK
1209 PM CDT THU APR 05 2012

AREAS AFFECTED...PARTS SERN MO...SWRN KY...NERN AR...WRN AND MIDDLE
TN...NRN MS AND NRN AL

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 051709Z - 051845Z

TRENDS ARE BEING MONITORED FOR AN INCREASING SEVERE THREAT THAT MAY
REQUIRE ONE OR MORE WATCHES THIS AFTERNOON.

WIDELY SCATTERED VIGOROUS CONVECTIVE DEVELOPMENT IS NOW UNDERWAY
BENEATH THE MID-LEVEL COLD CORE OF THE OZARK PLATEAU CLOSED LOW...
THE CENTER OF WHICH IS FORECAST TO REDEVELOP EAST SOUTHEASTWARD OUT
OF CENTRAL ARKANSAS INTO NORTHERN MISSISSIPPI BY 19-21Z.  THE
LOW-LEVEL FOCUS FOR MORE CONCENTRATED DEVELOPMENT REMAINS A BIT
UNCLEAR...BUT THE MOST SUBSTANTIVE DESTABILIZATION APPEARS TO BE
OCCURRING IN ASSOCIATION WITH STRONGER SURFACE HEATING BENEATH THE
DEVELOPING DEFORMATION ZONE ACROSS WESTERN/MIDDLE TENNESSEE AND
PORTIONS OF ADJACENT STATES.  STRONGEST VERTICAL SHEAR EXISTS
BENEATH 30-40 KT SOUTHWESTERLY CYCLONIC 500 MB FLOW ACROSS NORTHERN
ALABAMA INTO MIDDLE TENNESSEE...WHERE PROBABILITIES FOR STORMS
CAPABLE OF PRODUCING AT LEAST MARGINALLY SEVERE HAIL APPEAR HIGHEST.

..KERR.. 04/05/2012

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

ATTN...WFO...OHX...BMX...HUN...PAH...MEG...SGF...

LAT...LON   36949124 37078971 36788770 36488649 35538575 34058652
            33798839 34579020 35469050 36209100 36949124

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, 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, 3:06 PM CDTMesoscale DiscussionSPCColbert, DeKalb, Franklin, Jackson, Lauderdale, Lawrence and 4 more54 min
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 4, 8:31 PM CDTMesoscale DiscussionSPCCalhoun, Clark, Columbia, Conway, Crawford, Dallas and 24 more119 min
Apr 5, 1:35 AM CDTMesoscale DiscussionSPCAshley, Chicot85 min
Apr 5, 1:53 AM CDTTornado WatchSPCAshley, Chicot9 hr
Apr 5, 3:30 AM CDTMesoscale DiscussionSPCAshley, Chicot, Union2 hr
Apr 5, 12:18 PM CDTSevere Thunderstorm WatchSPCCrittenden, Mississippi5 hr
Apr 5, 3:56 AM CDTTornado WatchSPCAmite, Hancock, Harrison, Jackson, Pearl River, Pike and 2 more6 hr
Apr 5, 10:43 AM CDTSevere Thunderstorm WatchSPCClarke, Covington, Forrest, Franklin, Jasper, Jefferson Davis and 7 more4 hr
Apr 5, 2:22 PM CDTMesoscale DiscussionSPCAlcorn, Benton, Calhoun, Chickasaw, DeSoto, Itawamba and 14 more53 min
Apr 5, 12:54 PM CDTMesoscale DiscussionSPCAnderson, Bledsoe, Blount, Bradley, Campbell, Claiborne and 23 more96 min

Nearby

Mesoscale Discussions in Tennessee, 2012Mesoscale Discussions in Mississippi, 2012Mesoscale Discussions in Alabama, 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.