Alert archive / Tennessee / Mesoscale Discussions in 2012

Mesoscale Discussion 1124

June 11, 20126 states

The Storm Prediction Center issued this mesoscale discussion at Jun 11, 2012, 3:29 PM CDT for 6 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jun 11, 2012, 3:29 PM CDT (20:29 UTC)
Expired
Jun 11, 2012, 5:30 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 98 counties

Colbert County, AL, Franklin County, AL, Lauderdale County, AL, Arkansas County, AR, Cleveland County, AR, Crittenden County, AR, Cross County, AR, Dallas County, AR, Garland County, AR, Grant County, AR, Hot Spring County, AR, Jefferson County, AR, Lee County, AR, Lincoln County, AR, Lonoke County, AR, Monroe County, AR, Perry County, AR, Phillips County, AR, Prairie County, AR, Pulaski County, AR, Saline County, AR, St. Francis County, AR, Woodruff County, AR, Hardin County, IL, Johnson County, IL, Massac County, IL, Pope County, IL, Pulaski County, IL, Union County, IL, Ballard County, KY, Caldwell County, KY, Calloway County, KY, Carlisle County, KY, Christian County, KY, Crittenden County, KY, Fulton County, KY, Graves County, KY, Hickman County, KY, Hopkins County, KY, Livingston County, KY, Lyon County, KY, Marshall County, KY, McCracken County, KY, Todd County, KY, Trigg County, KY, Alcorn County, MS, Benton County, MS, Calhoun County, MS, Chickasaw County, MS, Coahoma County, MS, DeSoto 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, Quitman County, MS, Tallahatchie County, MS, Tate County, MS, Tippah County, MS, Tishomingo County, MS, Tunica County, MS, Union County, MS, Yalobusha County, MS, Benton County, TN, Carroll County, TN, Cheatham County, TN, Chester County, TN, Crockett County, TN, Decatur County, TN, Dickson County, TN, Dyer County, TN, Fayette County, TN, Gibson 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, Lauderdale County, TN, Lawrence County, TN, Lewis County, TN, Madison County, TN, McNairy County, TN, Montgomery County, TN, Obion County, TN, Perry County, TN, Shelby County, TN, Stewart County, TN, Tipton County, TN, Wayne County, TN, Weakley County, TN

The radar

The Memphis radar (KNQA), 46 km from the middle of the area, began a volume at 20:30 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, 8.5 hours before the alert went out and 81 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 2012-06-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2451 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 2012-06-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 86 square meters per square second.1939Sfc1 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
2451 J/kg
Mixed-layer CIN
-37 J/kg
Mixed-layer LCL
786 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
86 m²/s²
0-3 km storm-relative helicity
120 m²/s²
Significant tornado parameter
0.7
Supercell composite
4.9

Open this sounding in Storm Lab

The text

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

186 
ACUS11 KWNS 112030
SWOMCD
SPC MCD 112029
TNZ000-KYZ000-ALZ000-ILZ000-MSZ000-MOZ000-ARZ000-112230-

MESOSCALE DISCUSSION 1124
NWS STORM PREDICTION CENTER NORMAN OK
0329 PM CDT MON JUN 11 2012

AREAS AFFECTED...AR...MO...IL...KY...TN...MS...AL

CONCERNING...SEVERE THUNDERSTORM WATCH 373...

VALID 112029Z - 112230Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 373
CONTINUES.

SUMMARY...DAMAGING WINDS AND HAIL WILL ACCOMPANY QLCS SPREADING SEWD
INTO WRN TN/KY...ERN AR....NRN MS...AND NWRN AL OVER THE NEXT FEW
HOURS.

DISCUSSION...VIGOROUS DEEP CONVECTION COMPRISES MATURE LARGE SCALE
BOWING SQUALL LINE FROM THE CONFLUENCE OF THE OH/MS RIVERS SWD INTO
WRN TN AND THEN WWD ACROSS ERN/CNTRL AR LATE THIS AFTERNOON.
DAMAGING WINDS OF 60-70 MPH HAVE OCCURRED NEAR THE APEX OF THIS
SQUALL LINE...FROM NERN AR TO THE MO BOOTHEEL OVER THE PAST HOUR.
EXPECT THESE CONDITIONS MAY ACCOMPANY THE STORMS NOW MOVING ACROSS
THE MEMPHIS AREA.

BASED ON THE LONGER-TERM LARGE SCALE MOTION OF THE SQUALL LINE AT
ABOUT 40 KT...WITH A SMALL ADJUSTMENT MADE FOR POSSIBLE ACCELERATION
NEAR THE APEX OF THE BOW...THE LINE WILL MOVE INTO NRN MS WITHIN THE
NEXT HOUR AND TO THE EDGE OF THE WATCH IN TN/KY BY ABOUT 22Z OR 500
PM CDT. ALSO EXPECT NWRN AL TO EXPERIENCE THE AFFECTS OF THIS SQUALL
LINE BETWEEN 500-600 PM CDT.

..CARBIN.. 06/11/2012

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

ATTN...WFO...LMK...OHX...BMX...HUN...PAH...MEG...JAN...LZK...

LAT...LON   33778823 33829024 33959049 34109079 34019142 33819162
            33819288 34689355 34949367 35039264 35119169 35449115
            35519006 36188929 36878913 37218936 37598941 37588807
            37378782 37588735 37048728 37058705 36668694 35608722
            35428719 34848720 34728724 34658743 34308750 34188812
            33778823

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 11, 12:22 PM CDTMesoscale DiscussionSPCGeneva, Henry, Houston53 min
Jun 11, 1:12 PM CDTMesoscale DiscussionSPCColbert, Franklin, Lauderdale, Limestone93 min
Jun 11, 1:28 PM CDTSevere Thunderstorm WatchSPCColbert, Cullman, Franklin, Lauderdale, Lawrence7 hr
Jun 11, 5:05 PM CDTMesoscale DiscussionSPCColbert, Franklin, Lauderdale, Lawrence55 min
Jun 11, 5:17 PM CDTSevere Thunderstorm WatchSPCAutauga, Bibb, Blount, Calhoun, Chambers, Chilton and 28 more6 hr
Jun 11, 9:31 AM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Clay, Cleburne and 16 more59 min
Jun 11, 9:45 AM CDTSevere Thunderstorm WatchSPCBaxter, Benton, Boone, Carroll, Clay, Cleburne and 23 more6 hr
Jun 11, 3:59 PM CDTMesoscale DiscussionSPCCrawford, Polk, Scott, Sebastian, Washington91 min
Jun 11, 11:23 AM CDTMesoscale DiscussionSPCAlexander, Clay, Effingham, Franklin, Gallatin, Hamilton and 15 more97 min

Nearby

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