Alert archive / Georgia / Mesoscale Discussions in 2011

Mesoscale Discussion 1848

August 4, 20114 states

The Storm Prediction Center issued this mesoscale discussion at Aug 4, 2011, 1:25 AM CDT for 4 states. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
Aug 4, 2011, 1:25 AM CDT (06:25 UTC)
Expired
Aug 4, 2011, 3:00 AM CDT
In force
95 min
Issued by
the Storm Prediction Center
All 72 counties

Blount County, AL, Calhoun County, AL, Cherokee County, AL, Cleburne County, AL, Colbert County, AL, Cullman County, AL, DeKalb County, AL, Etowah County, AL, Fayette County, AL, Franklin County, AL, Jackson County, AL, Jefferson County, AL, Lamar County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marion County, AL, Marshall County, AL, Morgan County, AL, St. Clair County, AL, Talladega County, AL, Walker County, AL, Winston County, AL, Banks County, GA, Barrow County, GA, Bartow County, GA, Carroll County, GA, Chattooga County, GA, Cherokee County, GA, Clayton County, GA, Cobb County, GA, Dawson County, GA, DeKalb County, GA, Douglas County, GA, Floyd County, GA, Forsyth County, GA, Fulton County, GA, Gordon County, GA, Gwinnett County, GA, Hall County, GA, Haralson County, GA, Jackson County, GA, Lumpkin County, GA, Paulding County, GA, Pickens County, GA, Polk County, GA, Rockdale County, GA, Walker County, GA, Walton County, GA, Alcorn County, MS, Benton County, MS, Itawamba County, MS, Lee County, MS, Marshall County, MS, Prentiss County, MS, Tippah County, MS, Tishomingo County, MS, Union County, MS, Chester County, TN, Crockett County, TN, Decatur County, TN, Fayette County, TN, Giles County, TN, Hardeman County, TN, Hardin County, TN, Haywood County, TN, Henderson County, TN, Lawrence County, TN, Madison County, TN, McNairy County, TN, Wayne County, TN

The radar

The Northeast Alabama radar (KHTX), 85 km from the middle of the area, began a volume at 06:27 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.

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 00:00Z, 6.4 hours before the alert went out and 159 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 00:00Z on 2011-08-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 5553 joules per kilogram.LCLEL10008507005003002001001 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 00:00Z on 2011-08-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 28 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
5553 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
1715 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
28 m²/s²
0-3 km storm-relative helicity
130 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 3, 10:52 PM CDTMesoscale DiscussionSPCBibb, Blount, Calhoun, Cherokee, Cleburne, Colbert and 23 more83 min
Aug 3, 11:59 PM CDTSevere Thunderstorm WatchSPCBibb, Blount, Calhoun, Cherokee, Clay, Cleburne and 24 more7 hr
Aug 4, 12:09 PM CDTMesoscale DiscussionSPCButler, Choctaw, Clarke, Coffee, Conecuh, Covington and 8 more66 min
Aug 4, 3:06 PM CDTMesoscale DiscussionSPCColbert, Fayette, Franklin, Lamar, Marion, Pickens54 min
Aug 4, 3:41 PM CDTSevere Thunderstorm WatchSPCFayette, Greene, Lamar, Marion, Pickens, Sumter5 hr
Aug 4, 6:06 PM CDTMesoscale DiscussionSPCColbert, Fayette, Franklin, Greene, Lamar, Lauderdale and 3 more54 min
Aug 4, 1:41 AM CDTSevere Thunderstorm WatchSPCBaldwin, Banks, Barrow, Bartow, Bibb, Butts and 47 more3 hr
Aug 4, 8:06 AM CDTSevere Thunderstorm WatchSPCAlcorn, Benton, DeSoto, Itawamba, Lee, Marshall and 5 more4 hr
Aug 4, 10:21 AM CDTMesoscale DiscussionSPCCarroll, Chester, Crockett, Dyer, Fayette, Gibson and 10 more84 min

Nearby

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