Alert archive / Tennessee / Mesoscale Discussions in 2012

Mesoscale Discussion 350

March 24, 20129 counties in Alabama; Chattooga County, Dade County, Walker County, Georgia; 12 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Mar 24, 2012, 4:52 PM CDT for 9 counties in Alabama; Chattooga County, Dade County, Walker County, Georgia; 12 counties in Tennessee. It was in force for 53 min.

The area

The outline as issued.

The facts

Issued
Mar 24, 2012, 4:52 PM CDT (21:52 UTC)
Expired
Mar 24, 2012, 5:45 PM CDT
In force
53 min
Issued by
the Storm Prediction Center
All 24 counties

Cullman County, AL, DeKalb County, AL, Jackson County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marshall County, AL, Morgan County, AL, Chattooga County, GA, Dade County, GA, Walker County, GA, Bedford County, TN, Coffee County, TN, Franklin County, TN, Giles County, TN, Grundy County, TN, Hamilton County, TN, Lawrence County, TN, Lincoln County, TN, Marion County, TN, Marshall County, TN, Moore County, TN, Sequatchie County, TN

The radar

The Northeast Alabama radar (KHTX), 29 km from the middle of the area, began a volume at 21:56 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, 9.9 hours before the alert went out and 130 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 2012-03-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 4 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 2012-03-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 16 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
4 J/kg
Mixed-layer CIN
-26 J/kg
Mixed-layer LCL
1094 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
16 m²/s²
0-3 km storm-relative helicity
65 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.

805 
ACUS11 KWNS 242152
SWOMCD
SPC MCD 242152 
TNZ000-GAZ000-ALZ000-242245-

MESOSCALE DISCUSSION 0350
NWS STORM PREDICTION CENTER NORMAN OK
0452 PM CDT SAT MAR 24 2012

AREAS AFFECTED...SRN MIDDLE TN...NORTH AL...FAR NWRN GA

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 242152Z - 242245Z

A FEW STRONG STORMS PRODUCING HAIL AND GUSTY WINDS WILL BE POSSIBLE
ACROSS SRN MIDDLE TN...NORTH AL...AND FAR NWRN GA THROUGH SUNSET.
ANY INSTANCES OF SVR STORMS WILL BE SPORADIC AND MARGINAL...AND...AS
SUCH...THE ISSUANCE OF A WW IS NOT WARRANTED.

CONVECTION HAS RECENTLY SHOWN SOME SIGNS OF INTENSIFICATION OVER
PARTS OF SRN MIDDLE TN AND NORTH AL ALONG SEWD-MOVING LOW-LEVEL
CONVERGENCE BANDS BENEATH COLD MID-LEVEL TEMPERATURES ATTENDANT TO A
CLOSED LOW OVER THE OH/TN RIVER VALLEY REGION. POCKETS OF INSOLATION
AHEAD OF THE CONVERGENCE BANDS HAVE STEEPENED LOW-LEVEL LAPSE
RATES...YIELDING SUFFICIENT /ALBEIT MARGINAL/ SBCAPE SUCH THAT
DEEPER CONVECTION WILL BE OF CONCERN ACROSS THE DISCUSSION AREA.
SMALL HAIL AND GUSTY WINDS WILL BE POSSIBLE WITH THIS ACTIVITY. A
BAND OF ENHANCED DEEP-LAYER FLOW OVER THE SRN FRINGES OF THE CLOSED
LOW IS BEING MANIFESTED IN THE UNIDIRECTIONAL WLY WIND PROFILE
SAMPLED BY THE HUNTSVILLE VWP DATA...WHICH FEATURE 43 KT OF SFC-6-KM
BULK SHEAR. THIS MAY SUPPORT A FEW INSTANCES OF MORE
ORGANIZED/PERSISTENT LINE SEGMENTS OR MULTICELL CLUSTERS WITH AN
ISOLATED/BRIEF THREAT FOR MARGINALLY SVR HAIL/WIND. HOWEVER...THE
ABSENCE OF GREATER BUOYANCY WILL PREVENT A MORE ROBUST THREAT FROM
ENSUING. THE THREAT FOR STRONG/SVR STORMS SHOULD CEASE QUICKLY AFTER
SUNSET AS THE NOCTURNAL STABILIZATION COMMENCES.

..COHEN.. 03/24/2012

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

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

LAT...LON   35678650 35658539 35038514 34458529 34048623 34188732
            34778786 35318734 35678650

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 24, 9:16 AM CDTMesoscale DiscussionSPCAppling, Atkinson, Bacon, Berrien, Brantley, Bryan and 25 more59 min
Mar 24, 9:45 AM CDTSevere Thunderstorm WatchSPCAppling, Atkinson, Bacon, Brantley, Bryan, Bulloch and 23 more8 hr
Mar 24, 11:29 AM CDTMesoscale DiscussionSPCAppling, Atkinson, Bacon, Brantley, Bryan, Bulloch and 19 more61 min
Mar 24, 3:16 PM CDTMesoscale DiscussionSPCRichmond59 min
Mar 24, 3:19 PM CDTMesoscale DiscussionSPCBrantley, Camden, Charlton, Clinch, Echols, Glynn and 6 more86 min
Mar 24, 5:25 PM CDTMesoscale DiscussionSPCBrantley, Bryan, Camden, Charlton, Chatham, Clinch and 8 more65 min
Mar 23, 8:06 PM CDTMesoscale DiscussionSPCClay, Davidson, DeKalb, Jackson, Macon, Robertson and 5 more54 min
Mar 23, 10:16 PM CDTMesoscale DiscussionSPCBledsoe, Bradley, Clay, Cumberland, DeKalb, Fentress and 18 more89 min

Nearby

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