Alert archive / Tennessee / Mesoscale Discussions in 2011

Mesoscale Discussion 347

April 4, 20118 counties in Kentucky; 47 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Apr 4, 2011, 2:08 PM CDT for 8 counties in Kentucky; 47 counties in Tennessee. It was in force for 67 min.

The area

The outline as issued.

The facts

Issued
Apr 4, 2011, 2:08 PM CDT (19:08 UTC)
Expired
Apr 4, 2011, 3:15 PM CDT
In force
67 min
Issued by
the Storm Prediction Center
All 55 counties

Allen County, KY, Clinton County, KY, Cumberland County, KY, McCreary County, KY, Monroe County, KY, Russell County, KY, Wayne County, KY, Whitley County, KY, Anderson County, TN, Bedford County, TN, Bledsoe County, TN, Campbell County, TN, Cannon County, TN, Clay County, TN, Coffee County, TN, Cumberland County, TN, Davidson County, TN, DeKalb County, TN, Fentress County, TN, Franklin County, TN, Giles County, TN, Grundy County, TN, Hamilton County, TN, Jackson 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, Moore County, TN, Morgan County, TN, Overton County, TN, Pickett County, TN, Putnam County, TN, Rhea County, TN, Roane County, TN, Rutherford County, TN, Scott County, TN, Sequatchie County, TN, Smith 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 Nashville radar (KOHX), 86 km from the middle of the area, began a volume at 19:09 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 nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 7.1 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, Nashville Metro, TN at 12:00Z on 2011-04-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 68 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 2011-04-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 370 square meters per square second.19395878Sfc1 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
68 J/kg
Mixed-layer CIN
-640 J/kg
Mixed-layer LCL
855 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
370 m²/s²
0-3 km storm-relative helicity
507 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

The text

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

265 
ACUS11 KWNS 041908
SWOMCD
SPC MCD 041908 
TNZ000-KYZ000-GAZ000-ALZ000-042015-

MESOSCALE DISCUSSION 0347
NWS STORM PREDICTION CENTER NORMAN OK
0208 PM CDT MON APR 04 2011

AREAS AFFECTED...MIDDLE TN

CONCERNING...TORNADO WATCH 92...

VALID 041908Z - 042015Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 92 CONTINUES.

LEADING EDGE OF STRONGLY FORCED/VERY FAST-MOVING QLCS EXTENDED FROM
SUMNER TO WAYNE COUNTIES AS OF 1900Z. RECENT FORWARD PROPAGATION OF
60-70 KT SUGGESTS THE LINE SHOULD REACH THE ERN EXTENT OF WW 92 NEAR
21Z. AMBIENT AIR MASS OVER MIDDLE TN REMAINS QUITE FAVORABLE FOR
WIDESPREAD DAMAGING WINDS /LOCALLY SIGNIFICANT/ AND TRANSIENT
CIRCULATIONS WITH ISOLATED TORNADOES. 18Z BNA RAOB SAMPLED SFC-1 KM
SHEAR OF 50 KT WITH A VEER-BACK MID-LEVEL WIND PROFILE SIGNATURE.
DOWNSTREAM AIR MASS DESTABILIZATION WILL SUPPORT PRIMARILY A
DAMAGING WIND THREAT CONTINUING E OF WW 92 WHERE A NEW SEVERE TSTM
WATCH HAS BEEN JUST ISSUED FOR ERN TN.

..GRAMS.. 04/04/2011

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

ATTN...WFO...MRX...JKL...FFC...LMK...OHX...HUN...MEG...

LAT...LON   35198802 36538680 36968585 37018472 36888390 36548372
            36038388 35148493 34958542 34918566 34938624 34918693
            35028785 35198802

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 4, 4:30 AM CDTSevere Thunderstorm WatchSPCBoone, Campbell, Kenton8 hr
Apr 4, 6:53 AM CDTMesoscale DiscussionSPCBoone, Breckinridge, Caldwell, Carroll, Crittenden, Daviess and 16 more2 hr
Apr 4, 7:22 AM CDTTornado WatchSPCBallard, Breckinridge, Butler, Caldwell, Calloway, Carlisle and 24 more7 hr
Apr 4, 11:34 AM CDTTornado WatchSPCAdair, Allen, Anderson, Barren, Bourbon, Boyle and 43 more5 hr
Apr 4, 11:50 AM CDTMesoscale DiscussionSPCBoone, Campbell, Kenton25 min
Apr 4, 1:25 PM CDTMesoscale DiscussionSPCAdair, Allen, Anderson, Barren, Bath, Bell and 74 more65 min
Apr 4, 2:05 PM CDTSevere Thunderstorm WatchSPCBath, Bell, Boyd, Breathitt, Carter, Clay and 33 more6 hr
Apr 4, 3:49 PM CDTMesoscale DiscussionSPCBell, Boyd, Breathitt, Carter, Clay, Elliott and 21 more56 min
Apr 4, 5:00 PM CDTMesoscale DiscussionSPCBell, Boyd, Breathitt, Clay, Floyd, Harlan and 12 more90 min
Apr 4, 10:25 AM CDTMesoscale DiscussionSPCBedford, Cannon, Cheatham, Davidson, Decatur, Dickson and 19 more2 hr
Apr 4, 1:03 PM CDTTornado WatchSPCFranklin, Lincoln, Moore7 hr

Nearby

Mesoscale Discussions in Tennessee, 2011Mesoscale Discussions in Kentucky, 2011Every mesoscale discussion in 2011

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.