Alert archive / Georgia / Mesoscale Discussions in 2011

Mesoscale Discussion 648

April 27, 20115 states

The Storm Prediction Center issued this mesoscale discussion at Apr 27, 2011, 11:09 PM CDT for 5 states. It was in force for 36 min.

The area

The outline as issued.

The facts

Issued
Apr 27, 2011, 11:09 PM CDT (04:09 UTC)
Expired
Apr 27, 2011, 11:45 PM CDT
In force
36 min
Issued by
the Storm Prediction Center
All 137 counties

Barbour County, AL, Bullock County, AL, Chambers County, AL, Clay County, AL, Cleburne County, AL, Elmore County, AL, Lee County, AL, Macon County, AL, Montgomery County, AL, Pike County, AL, Randolph County, AL, Russell County, AL, Tallapoosa County, AL, Banks County, GA, Barrow County, GA, Bartow County, GA, Bibb County, GA, Butts County, GA, Carroll County, GA, Chattahoochee County, GA, Cherokee County, GA, Clarke County, GA, Clayton County, GA, Cobb County, GA, Coweta County, GA, Crawford County, GA, Dawson County, GA, DeKalb County, GA, Douglas County, GA, Elbert County, GA, Fannin County, GA, Fayette County, GA, Floyd County, GA, Forsyth County, GA, Franklin County, GA, Fulton County, GA, Gilmer County, GA, Gordon County, GA, Greene County, GA, Gwinnett County, GA, Habersham County, GA, Hall County, GA, Haralson County, GA, Harris County, GA, Hart County, GA, Heard County, GA, Henry County, GA, Jackson County, GA, Jasper County, GA, Jones County, GA, Lamar County, GA, Lumpkin County, GA, Madison County, GA, Marion County, GA, Meriwether County, GA, Monroe County, GA, Morgan County, GA, Murray County, GA, Muscogee County, GA, Newton County, GA, Oconee County, GA, Oglethorpe County, GA, Paulding County, GA, Pickens County, GA, Pike County, GA, Polk County, GA, Putnam County, GA, Quitman County, GA, Rabun County, GA, Rockdale County, GA, Schley County, GA, Spalding County, GA, Stephens County, GA, Stewart County, GA, Talbot County, GA, Taylor County, GA, Towns County, GA, Troup County, GA, Union County, GA, Upson County, GA, Walton County, GA, Webster County, GA, White County, GA, Wilkes County, GA, Alexander County, NC, Alleghany County, NC, Ashe County, NC, Avery County, NC, Buncombe County, NC, Burke County, NC, Caldwell County, NC, Catawba County, NC, Cherokee County, NC, Clay County, NC, Cleveland County, NC, Davie County, NC, Gaston County, NC, Graham County, NC, Haywood County, NC, Henderson County, NC, Iredell County, NC, Jackson County, NC, Lincoln County, NC, Macon County, NC, Madison County, NC, McDowell County, NC, Mitchell County, NC, Polk County, NC, Rutherford County, NC, Swain County, NC, Transylvania County, NC, Watauga County, NC, Wilkes County, NC, Yadkin County, NC, Yancey County, NC, Abbeville County, SC, Anderson County, SC, Cherokee County, SC, Greenville County, SC, Laurens County, SC, Oconee County, SC, Pickens County, SC, Spartanburg County, SC, Blount County, TN, Carter County, TN, Cocke County, TN, Grainger County, TN, Greene County, TN, Hamblen County, TN, Hancock County, TN, Hawkins County, TN, Jefferson County, TN, Johnson County, TN, Sevier County, TN, Sullivan County, TN, Unicoi County, TN, Washington County, TN

The radar

The Atlanta radar (KFFC), 75 km from the middle of the area, began a volume at 04:12 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

Peachtre/Fal Fld, GA (KFFC), launched 00:00Z, 4.2 hours before the alert went out and 71 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 00:00Z on 2011-04-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1215 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 00:00Z on 2011-04-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 244 square meters per square second.19395878Sfc1 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
1215 J/kg
Mixed-layer CIN
-15 J/kg
Mixed-layer LCL
1433 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
244 m²/s²
0-3 km storm-relative helicity
408 m²/s²
Significant tornado parameter
1.6
Supercell composite
15.2

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
Apr 27, 7:55 PM CDTMesoscale DiscussionSPCAutauga, Bibb, Blount, Butler, Calhoun, Cherokee and 27 more65 min
Apr 27, 9:20 PM CDTMesoscale DiscussionSPCAutauga, Bibb, Blount, Butler, Calhoun, Cherokee and 29 more25 min
Apr 27, 9:42 PM CDTTornado WatchSPCAutauga, Bibb, Butler, Calhoun, Cherokee, Chilton and 19 more4 hr
Apr 28, 1:22 AM CDTMesoscale DiscussionSPCDale, Geneva, Henry, Houston83 min
Apr 27, 11:56 PM CDTTornado WatchSPCBaldwin, Banks, Barrow, Bibb, Bleckley, Burke and 80 more4 hr
Apr 28, 2:30 AM CDTMesoscale DiscussionSPCBaldwin, Bibb, Bleckley, Burke, Chattahoochee, Columbia and 30 more90 min
Apr 28, 3:30 AM CDTTornado WatchSPCBaldwin, Bibb, Bleckley, Bulloch, Burke, Candler and 37 more10 hr
Apr 28, 7:05 AM CDTMesoscale DiscussionSPCBurke, Candler, Dodge, Emanuel, Jefferson, Jenkins and 5 more85 min
Apr 28, 7:48 AM CDTTornado WatchSPCBryan, Bulloch, Candler, Chatham, Effingham, Evans and 6 more7 hr
Apr 28, 8:47 AM CDTSevere Thunderstorm WatchSPCAppling, Atkinson, Bacon, Brantley, Camden, Charlton and 8 more9 hr
Apr 28, 10:22 AM CDTMesoscale DiscussionSPCBulloch, Burke, Candler, Chatham, Effingham, Emanuel and 2 more53 min
Apr 28, 11:19 AM CDTMesoscale DiscussionSPCAppling, Bacon, Brantley, Camden, Charlton, Clinch and 10 more56 min
Apr 27, 9:12 PM CDTMesoscale DiscussionSPCAlleghany, Ashe, Forsyth, Rockingham, Stokes, Surry and 3 more63 min
Apr 27, 11:27 PM CDTMesoscale DiscussionSPCAlamance, Alleghany, Ashe, Caswell, Davidson, Davie and 11 more63 min
Apr 27, 11:41 PM CDTTornado WatchSPCAlamance, Alleghany, Ashe, Caswell, Davidson, Forsyth and 10 more7 hr
Apr 28, 6:38 AM CDTTornado WatchSPCBertie, Camden, Caswell, Chowan, Currituck, Gates and 9 more7 hr
Apr 28, 1:41 PM CDTTornado WatchSPCBeaufort, Bertie, Camden, Carteret, Chowan, Craven and 21 more6 hr
Apr 28, 2:19 PM CDTTornado WatchSPCBladen, Brunswick, Columbus, New Hanover, Pender4 hr
Apr 28, 5:33 PM CDTMesoscale DiscussionSPCBeaufort, Bertie, Camden, Carteret, Chowan, Craven and 20 more57 min

Nearby

Mesoscale Discussions in Georgia, 2011Mesoscale Discussions in North Carolina, 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.