Alert archive / Tennessee / Mesoscale Discussions in 2011

Mesoscale Discussion 447

April 15, 20114 states

The Storm Prediction Center issued this mesoscale discussion at Apr 15, 2011, 8:15 PM CDT for 4 states. It was in force for 60 min.

The area

The outline as issued.

The facts

Issued
Apr 15, 2011, 8:15 PM CDT (01:15 UTC)
Expired
Apr 15, 2011, 9:15 PM CDT
In force
60 min
Issued by
the Storm Prediction Center
All 79 counties

Champaign County, IL, Clark County, IL, Coles County, IL, Crawford County, IL, Cumberland County, IL, DeWitt County, IL, Douglas County, IL, Edgar County, IL, Edwards County, IL, Lawrence County, IL, McLean County, IL, Piatt County, IL, Wabash County, IL, Daviess County, IN, Dubois County, IN, Gibson County, IN, Greene County, IN, Knox County, IN, Martin County, IN, Perry County, IN, Pike County, IN, Posey County, IN, Spencer County, IN, Sullivan County, IN, Vanderburgh County, IN, Vigo County, IN, Warrick County, IN, Allen County, KY, Breckinridge County, KY, Butler County, KY, Caldwell County, KY, Calloway County, KY, Christian County, KY, Crittenden County, KY, Daviess County, KY, Edmonson County, KY, Grayson County, KY, Hancock County, KY, Henderson County, KY, Hopkins County, KY, Logan County, KY, Lyon County, KY, Marshall County, KY, McLean County, KY, Muhlenberg County, KY, Ohio County, KY, Simpson County, KY, Todd County, KY, Trigg County, KY, Union County, KY, Warren County, KY, Webster County, KY, Bedford County, TN, Benton County, TN, Carroll County, TN, Cheatham County, TN, Davidson County, TN, Decatur County, TN, Dickson County, TN, Giles County, TN, Henderson County, TN, Henry County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Lawrence County, TN, Lewis County, TN, Lincoln County, TN, Marshall County, TN, Maury County, TN, Montgomery County, TN, Perry County, TN, Robertson County, TN, Rutherford County, TN, Stewart County, TN, Sumner County, TN, Wayne County, TN, Williamson County, TN, Wilson County, TN

The radar

The Evansville,IN radar (KVWX), 86 km from the middle of the area, began a volume at 01:17 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 00:00Z, 1.3 hours before the alert went out and 181 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 00:00Z on 2011-04-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 17 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 00:00Z on 2011-04-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 471 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
17 J/kg
Mixed-layer CIN
-126 J/kg
Mixed-layer LCL
773 m above ground
0-6 km bulk shear
65 kt
0-1 km storm-relative helicity
471 m²/s²
0-3 km storm-relative helicity
487 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.

107 
ACUS11 KWNS 160115
SWOMCD
SPC MCD 160115 
KYZ000-TNZ000-INZ000-ILZ000-160215-

MESOSCALE DISCUSSION 0447
NWS STORM PREDICTION CENTER NORMAN OK
0815 PM CDT FRI APR 15 2011

AREAS AFFECTED...ERN IL/SWRN INDIANA/WRN KY/MIDDLE TN

CONCERNING...TORNADO WATCH 142...143...

VALID 160115Z - 160215Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 142...143...CONTINUES.

SEVERE THREAT SLOWLY DIMINISHING...AND THUS NEW WW ISSUANCE IS NOT
EXPECTED.

LATEST RADAR TRENDS SHOW A SLOW DECREASE IN OVERALL CONVECTIVE
INTENSITY...WHICH IS EXPECTED TO CONTINUE AS SLOW DIURNAL AIRMASS
STABILIZATION CONTINUES.  STRONGEST STORMS REMAIN ATTM INVOF THE TN
RIVER VALLEY...AND EXPECT LIMITED SEVERE THREAT TO CONTINUE OVER THE
NEXT 1-2 HOURS -- PARTICULARLY WITH THIS PORTION OF THE CONVECTIVE
BAND...WITH A BIT LESSER POTENTIAL NWD INTO ERN IL.  BEYOND
02Z...THREAT SHOULD BE INSUFFICIENT TO WARRANT NEW WW ISSUANCE.

..GOSS.. 04/16/2011

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

ATTN...WFO...LMK...OHX...IND...HUN...PAH...LOT...ILX...MEG...

LAT...LON   35028761 35598867 38078809 38998805 40838959 40458838
            38768670 37058607 35088646 35028761

Nearby

Mesoscale Discussions in Tennessee, 2011Mesoscale Discussions in Kentucky, 2011Mesoscale Discussions in Indiana, 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.