Alert archive / Tennessee / Mesoscale Discussions in 2013

Mesoscale Discussion 1021

June 10, 20134 counties in Alabama; 28 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Jun 10, 2013, 5:05 PM CDT for 4 counties in Alabama; 28 counties in Tennessee. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued
Jun 10, 2013, 5:05 PM CDT (22:05 UTC)
Expired
Jun 10, 2013, 6:30 PM CDT
In force
85 min
Issued by
the Storm Prediction Center
All 32 counties

Jackson County, AL, Lauderdale County, AL, Limestone County, AL, Madison County, AL, Bedford County, TN, Bledsoe County, TN, Cannon County, TN, Coffee County, TN, Cumberland County, TN, DeKalb County, TN, Franklin County, TN, Giles County, TN, Grundy County, TN, Jackson County, TN, Lawrence County, TN, Lewis County, TN, Lincoln County, TN, Marion County, TN, Marshall County, TN, Maury County, TN, Moore County, TN, Overton County, TN, Putnam County, TN, Rutherford County, TN, Sequatchie County, TN, Smith County, TN, Trousdale County, TN, Van Buren County, TN, Warren County, TN, White County, TN, Williamson County, TN, Wilson County, TN

The radar

The Northeast Alabama radar (KHTX), 69 km from the middle of the area, began a volume at 22:06 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, 10.1 hours before the alert went out and 73 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 2013-06-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 439 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 2013-06-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 21 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
439 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
498 m above ground
0-6 km bulk shear
59 kt
0-1 km storm-relative helicity
21 m²/s²
0-3 km storm-relative helicity
41 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.

584 
ACUS11 KWNS 102205
SWOMCD
SPC MCD 102205 
TNZ000-GAZ000-ALZ000-102330-

MESOSCALE DISCUSSION 1021
NWS STORM PREDICTION CENTER NORMAN OK
0505 PM CDT MON JUN 10 2013

AREAS AFFECTED...MIDDLE TN...FAR NRN AL

CONCERNING...TORNADO WATCH 294...

VALID 102205Z - 102330Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 294 CONTINUES.

SUMMARY...SEVERE THREAT APPEARS RATHER LOCALIZED AND SHOULD REMAIN
SO NEAR-TERM AS PRIMARY BELT OF FORCED ASCENT SHIFTS DOWNSTREAM OF
WW 294. DOWNSTREAM WW INTO NRN AL NOT ANTICIPATED ATTM.

DISCUSSION...THE HIGHER MID-LEVEL REFLECTIVITY CORES ASSOCIATED WITH
TN VALLEY CONVECTION HAVE REMAINED ACROSS CNTRL KY AND ARE ABOUT TO
CROSS WW 294 INTO WW 295 IN ERN TN. THIS TREND SHOULD CONTINUE OVER
THE NEXT COUPLE OF HOURS AS WELL-DEFINED SHORTWAVE TROUGH IN WATER
VAPOR IMAGERY SHIFTS EWD. WITH A W/NWLY LOW/MID-LEVEL FLOW REGIME IN
THE WAKE OF THE TROUGH AXIS PASSING...WARMING/SUBSIDENCE MAY PROVE
DETRIMENTAL TO SUSTAINING MORE THAN JUST A MARGINAL SEVERE THREAT
NEAR-TERM ACROSS MIDDLE TN. STILL...SUFFICIENT LOW-LEVEL VEERING
WITH HEIGHT EXISTS IN THE OHX VWP FOR A RISK OF A BRIEF TORNADO OR
TWO.

..GRAMS.. 06/10/2013

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

ATTN...WFO...MRX...FFC...OHX...HUN...

LAT...LON   36458617 36488512 36108485 34868551 34818558 34548586
            34598723 34968773 35588761 36158671 36458617

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 9, 7:30 PM CDTMesoscale DiscussionSPCColbert, Lauderdale60 min
Jun 10, 1:32 PM CDTMesoscale DiscussionSPCAnderson, Bedford, Bledsoe, Campbell, Cannon, Cheatham and 48 more88 min
Jun 10, 1:56 PM CDTTornado WatchSPCBedford, Benton, Cannon, Cheatham, Clay, Coffee and 33 more7 hr
Jun 10, 2:02 PM CDTSevere Thunderstorm WatchSPCAnderson, Bledsoe, Blount, Bradley, Campbell, Carter and 26 more7 hr
Jun 10, 5:27 PM CDTMesoscale DiscussionSPCAnderson, Bledsoe, Blount, Bradley, Campbell, Claiborne and 21 more93 min

Nearby

Mesoscale Discussions in Tennessee, 2013Mesoscale Discussions in Alabama, 2013Every mesoscale discussion in 2013

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.