Alert archive / Georgia / Mesoscale Discussions in 2012

Mesoscale Discussion 1413

July 5, 201223 counties in Alabama; 47 counties in Georgia; 19 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Jul 5, 2012, 6:20 PM CDT for 23 counties in Alabama; 47 counties in Georgia; 19 counties in Tennessee. It was in force for 115 min.

The area

The outline as issued.

The facts

Issued
Jul 5, 2012, 6:20 PM CDT (23:20 UTC)
Expired
Jul 5, 2012, 8:15 PM CDT
In force
115 min
Issued by
the Storm Prediction Center
All 89 counties

Blount County, AL, Calhoun County, AL, Chambers County, AL, Cherokee County, AL, Chilton County, AL, Clay County, AL, Cleburne County, AL, Coosa County, AL, Cullman County, AL, DeKalb County, AL, Elmore County, AL, Etowah County, AL, Jackson County, AL, Lee County, AL, Limestone County, AL, Madison County, AL, Marshall County, AL, Morgan County, AL, Randolph County, AL, Shelby County, AL, St. Clair County, AL, Talladega County, AL, Tallapoosa County, AL, Barrow County, GA, Bartow County, GA, Butts County, GA, Carroll County, GA, Catoosa County, GA, Chattooga County, GA, Cherokee County, GA, Clayton County, GA, Cobb County, GA, Coweta County, GA, Dade County, GA, Dawson County, GA, DeKalb County, GA, Douglas County, GA, Fayette County, GA, Floyd County, GA, Forsyth County, GA, Fulton County, GA, Gilmer County, GA, Gordon County, GA, Gwinnett County, GA, Haralson County, GA, Harris County, GA, Heard County, GA, Henry County, GA, Jasper County, GA, Jones County, GA, Lamar County, GA, Meriwether County, GA, Monroe County, GA, Morgan County, GA, Murray County, GA, Newton County, GA, Oconee County, GA, Paulding County, GA, Pickens County, GA, Pike County, GA, Polk County, GA, Putnam County, GA, Rockdale County, GA, Spalding County, GA, Talbot County, GA, Troup County, GA, Upson County, GA, Walker County, GA, Walton County, GA, Whitfield County, GA, Bedford County, TN, Cannon County, TN, Cheatham County, TN, Coffee County, TN, Davidson County, TN, Franklin County, TN, Giles County, TN, Grundy County, TN, Lincoln County, TN, Marion County, TN, Marshall County, TN, Maury County, TN, Moore County, TN, Robertson County, TN, Rutherford County, TN, Sumner County, TN, Trousdale County, TN, Williamson County, TN, Wilson County, TN

The radar

The Northeast Alabama radar (KHTX), 41 km from the middle of the area, began a volume at 23:23 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, 11.3 hours before the alert went out and 179 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 2012-07-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1407 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 2012-07-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 22 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
1407 J/kg
Mixed-layer CIN
-126 J/kg
Mixed-layer LCL
1485 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
22 m²/s²
0-3 km storm-relative helicity
33 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.

325 
ACUS11 KWNS 052320
SWOMCD
SPC MCD 052320 
GAZ000-TNZ000-ALZ000-KYZ000-060115-

MESOSCALE DISCUSSION 1413
NWS STORM PREDICTION CENTER NORMAN OK
0620 PM CDT THU JUL 05 2012

AREAS AFFECTED...MIDDLE TN...NRN GA...NRN/ERN AL

CONCERNING...SEVERE THUNDERSTORM WATCH 470...471...

VALID 052320Z - 060115Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
470...471...CONTINUES.

SUMMARY...THE ORIGINAL MCS APPEARS TO BE DWINDLING ACROSS ERN
TN...BUT SOME INCREASE IN STORMS MAY CONTINUE ACROSS MIDDLE TN INTO
NERN AL AND NRN GA. HAIL AND WIND ALL POSSIBLE.

DISCUSSION...THE TN MCS CONTINUES TO EXHIBIT WARMING CLOUD TOPS AS
WELL AS A POOR RADAR PRESENTATION...ALTHOUGH A FEW STRONGER CELLS
REMAIN ALONG THE LEADING GUST FRONT. OF NOTE HAS BEEN THE INCREASE
IN STRONG TO SEVERE CORES TO THE W...IN AN AXIS FROM MIDDLE TN INTO
NERN AL AND NRN GA. THIS GENERAL ZONE APPEARS TO BE MORE UNSTABLE
WITH SEVERAL SEVERE HAIL CORES NOTED.

AS THE DYING MCS INTERACTS WITH THESE AREAS...THERE MAY BE AN
INCREASE IN STRONG TO SEVERE CONVECTION OVER THE NEXT FEW HOURS.
WEAK WIND CONVERGENCE WAS ALSO NOTED ACROSS NRN GA WHICH MAY FORCE
MORE STRONG TO SEVERE PULSE STORMS.

..JEWELL.. 07/05/2012

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

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

LAT...LON   34998487 33948335 33068328 32458505 32478651 32698674
            34038698 35578740 36368725 36728668 36598604 36078600
            35418570 34998487

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 5, 12:11 PM CDTMesoscale DiscussionSPCCalhoun, Chambers, Cherokee, Clay, Cleburne, DeKalb and 6 more94 min
Jul 5, 12:37 PM CDTSevere Thunderstorm WatchSPCElbert, Franklin, Habersham, Hart, Rabun, Stephens8 hr
Jul 5, 10:14 AM CDTMesoscale DiscussionSPCCarter, Greene, Hancock, Hawkins, Johnson, Sullivan and 2 more91 min
Jul 5, 10:37 AM CDTSevere Thunderstorm WatchSPCCarter, Greene, Hancock, Hawkins, Johnson, Sullivan and 2 more7 hr
Jul 5, 1:57 PM CDTMesoscale DiscussionSPCCarter, Claiborne, Grainger, Greene, Hamblen, Hancock and 6 more2 hr
Jul 5, 2:19 PM CDTSevere Thunderstorm WatchSPCAnderson, Bledsoe, Blount, Bradley, Campbell, Cannon and 34 more6 hr

Nearby

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