Alert archive / Georgia / Mesoscale Discussions in 2011

Mesoscale Discussion 1889

August 7, 201118 counties in Alabama; 28 counties in Georgia; 9 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Aug 7, 2011, 6:10 PM CDT for 18 counties in Alabama; 28 counties in Georgia; 9 counties in Mississippi. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Aug 7, 2011, 6:10 PM CDT (23:10 UTC)
Expired
Aug 7, 2011, 8:15 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 55 counties

Blount County, AL, Cherokee County, AL, Colbert County, AL, Cullman County, AL, DeKalb County, AL, Etowah County, AL, Fayette County, AL, Franklin County, AL, Jackson County, AL, Lamar County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marion County, AL, Marshall County, AL, Morgan County, AL, Walker County, AL, Winston County, AL, Banks County, GA, Barrow County, GA, Bartow County, GA, Chattooga County, GA, Cherokee County, GA, Cobb County, GA, Dade County, GA, Dawson County, GA, Fannin County, GA, Floyd County, GA, Forsyth County, GA, Franklin County, GA, Gilmer County, GA, Gordon County, GA, Gwinnett County, GA, Habersham County, GA, Hall County, GA, Jackson County, GA, Lumpkin County, GA, Madison County, GA, Murray County, GA, Paulding County, GA, Pickens County, GA, Polk County, GA, Stephens County, GA, Walker County, GA, White County, GA, Whitfield County, GA, Chickasaw County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Monroe County, MS, Pontotoc County, MS, Prentiss County, MS, Tishomingo County, MS, Union County, MS

The radar

The Northeast Alabama radar (KHTX), 74 km from the middle of the area, began a volume at 23:10 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

Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 11.2 hours before the alert went out and 172 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, Peachtre/Fal Fld, GA at 12:00Z on 2011-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1453 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, Peachtre/Fal Fld, GA at 12:00Z on 2011-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -8 square meters per square second.1939Sfc1 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
1453 J/kg
Mixed-layer CIN
-76 J/kg
Mixed-layer LCL
854 m above ground
0-6 km bulk shear
2 kt
0-1 km storm-relative helicity
-8 m²/s²
0-3 km storm-relative helicity
93 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.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 7, 1:46 PM CDTMesoscale DiscussionSPCBolivar, Coahoma, DeSoto, Lafayette, Leflore, Marshall and 8 more119 min

Nearby

Mesoscale Discussions in Georgia, 2011Mesoscale Discussions in Alabama, 2011Mesoscale Discussions in Mississippi, 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.