Alert archive / Georgia / Mesoscale Discussions in 2015

Mesoscale Discussion 1659

August 10, 20158 counties in Alabama; 22 counties in Georgia; 6 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Aug 10, 2015, 1:21 PM CDT for 8 counties in Alabama; 22 counties in Georgia; 6 counties in Tennessee. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Aug 10, 2015, 1:21 PM CDT (18:21 UTC)
Expired: Aug 10, 2015, 3:45 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 20%

All 36 counties

Blount County, AL, Calhoun County, AL, Cherokee County, AL, Cleburne County, AL, DeKalb County, AL, Etowah County, AL, Jackson County, AL, Marshall County, AL, Bartow County, GA, Catoosa County, GA, Chattooga County, GA, Cherokee County, GA, Cobb County, GA, Dade County, GA, Dawson County, GA, Douglas County, GA, Fannin County, GA, Floyd County, GA, Forsyth County, GA, Fulton County, GA, Gilmer County, GA, Gordon County, GA, Haralson County, GA, Lumpkin County, GA, Murray County, GA, Paulding County, GA, Pickens County, GA, Polk County, GA, Walker County, GA, Whitfield County, GA, Bradley County, TN, Grundy County, TN, Hamilton County, TN, Marion County, TN, Polk County, TN, Sequatchie County, TN

The radar

The Northeast Alabama radar (KHTX), 87 km from the middle of the area, began a volume at 18:24 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, 6.4 hours before the alert went out and 144 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: 374 J/kg
Mixed-layer CIN: -92 J/kg
Mixed-layer LCL: 1079 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 67 m²/s²
0-3 km storm-relative helicity: 98 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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Nearby

Mesoscale Discussions in Georgia, 2015 Mesoscale Discussions in Alabama, 2015 Mesoscale Discussions in Tennessee, 2015 Every mesoscale discussion in 2015

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.