Alert archive / Georgia / Mesoscale Discussions in 2011

Mesoscale Discussion 1915

August 9, 201134 counties in Alabama; 45 counties in Georgia; 15 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Aug 9, 2011, 1:20 PM CDT for 34 counties in Alabama; 45 counties in Georgia; 15 counties in Mississippi. It was in force for 115 min.

The area

The outline as issued.

The facts

Issued: Aug 9, 2011, 1:20 PM CDT (18:20 UTC)
Expired: Aug 9, 2011, 3:15 PM CDT
In force: 115 min
Issued by: the Storm Prediction Center

All 94 counties

Autauga County, AL, Barbour County, AL, Bibb County, AL, Bullock County, AL, Calhoun County, AL, Chambers County, AL, Chilton County, AL, Choctaw County, AL, Clay County, AL, Cleburne County, AL, Coosa County, AL, Crenshaw County, AL, Dallas County, AL, Elmore County, AL, Greene County, AL, Hale County, AL, Henry County, AL, Jefferson County, AL, Lee County, AL, Lowndes County, AL, Macon County, AL, Marengo County, AL, Montgomery County, AL, Perry County, AL, Pike County, AL, Randolph County, AL, Russell County, AL, Shelby County, AL, St. Clair County, AL, Sumter County, AL, Talladega County, AL, Tallapoosa County, AL, Tuscaloosa County, AL, Wilcox County, AL, Baker County, GA, Bibb County, GA, Bleckley County, GA, Calhoun County, GA, Carroll County, GA, Chattahoochee County, GA, Clay County, GA, Coweta County, GA, Crawford County, GA, Crisp County, GA, Dodge County, GA, Dooly County, GA, Dougherty County, GA, Douglas County, GA, Early County, GA, Fayette County, GA, Haralson County, GA, Harris County, GA, Heard County, GA, Houston County, GA, Lamar County, GA, Lee County, GA, Macon County, GA, Marion County, GA, Meriwether County, GA, Monroe County, GA, Muscogee County, GA, Peach County, GA, Pike County, GA, Pulaski County, GA, Quitman County, GA, Randolph County, GA, Schley County, GA, Spalding County, GA, Stewart County, GA, Sumter County, GA, Talbot County, GA, Taylor County, GA, Terrell County, GA, Troup County, GA, Turner County, GA, Upson County, GA, Webster County, GA, Wilcox County, GA, Worth County, GA, Clarke County, MS, Hinds County, MS, Jasper County, MS, Kemper County, MS, Lauderdale County, MS, Leake County, MS, Madison County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Rankin County, MS, Scott County, MS, Smith County, MS, Winston County, MS, Yazoo County, MS

The radar

The Birmingham radar (KBMX), 96 km from the middle of the area, began a volume at 18:22 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

Severe Thunderstorm Watch 756Aug 9, 4:45 PM CDT

The nearest sounding before it

Birmingham, AL (KBMX), launched 12:00Z, 6.3 hours before the alert went out and 96 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 2662 J/kg
Mixed-layer CIN: -32 J/kg
Mixed-layer LCL: 617 m above ground
0-6 km bulk shear: 7 kt
0-1 km storm-relative helicity: -135 m²/s²
0-3 km storm-relative helicity: -84 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.

Issued	Product	Office	Counties	Lasted
Aug 9, 4:46 PM CDT	Severe Thunderstorm Watch	SPC	Baldwin, Clarke, Coffee, Conecuh, Covington, Dale and 7 more	4 hr
Aug 9, 5:02 PM CDT	Mesoscale Discussion	SPC	Bryan, Bulloch, Effingham, Evans, Liberty, Long and 1 more	58 min
Aug 8, 8:39 PM CDT	Severe Thunderstorm Watch	SPC	Benton, Bolivar, Calhoun, Carroll, Coahoma, DeSoto and 12 more	6 hr
Aug 8, 11:27 PM CDT	Mesoscale Discussion	SPC	Bolivar, Coahoma, DeSoto, Grenada, Marshall, Panola and 5 more	93 min
Aug 9, 2:21 AM CDT	Mesoscale Discussion	SPC	Coahoma, DeSoto, Panola, Quitman, Tate, Tunica and 1 more	84 min

Nearby

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