Alert archive / Georgia / Mesoscale Discussions in 2012

Mesoscale Discussion 1953

September 17, 20124 states

The Storm Prediction Center issued this mesoscale discussion at Sep 17, 2012, 8:14 PM EDT for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Sep 17, 2012, 8:14 PM EDT (00:14 UTC)
Expired
Sep 17, 2012, 10:15 PM EDT
In force
2 hr
Issued by
the Storm Prediction Center
All 121 counties

Baldwin County, GA, Banks County, GA, Barrow County, GA, Bartow County, GA, Bibb County, GA, Bleckley County, GA, Butts County, GA, Carroll County, GA, Catoosa County, GA, Chattahoochee County, GA, Chattooga County, GA, Cherokee County, GA, Clarke County, GA, Clayton County, GA, Cobb County, GA, Coweta County, GA, Crawford County, GA, Crisp County, GA, Dade County, GA, Dawson County, GA, DeKalb County, GA, Dodge County, GA, Dooly 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, Hancock County, GA, Haralson County, GA, Harris County, GA, Hart County, GA, Heard County, GA, Henry County, GA, Houston County, GA, Jackson County, GA, Jasper County, GA, Jones County, GA, Lamar County, GA, Lincoln County, GA, Lumpkin County, GA, Macon 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, Peach County, GA, Pickens County, GA, Pike County, GA, Polk County, GA, Pulaski County, GA, Putnam County, GA, Rabun County, GA, Rockdale County, GA, Schley County, GA, Spalding County, GA, Stephens County, GA, Stewart County, GA, Sumter County, GA, Talbot County, GA, Taliaferro County, GA, Taylor County, GA, Towns County, GA, Troup County, GA, Twiggs County, GA, Union County, GA, Upson County, GA, Walker County, GA, Walton County, GA, Webster County, GA, White County, GA, Whitfield County, GA, Wilcox County, GA, Wilkes County, GA, Wilkinson County, GA, Cherokee County, NC, Clay County, NC, Graham County, NC, Haywood County, NC, Henderson County, NC, Jackson County, NC, Macon County, NC, Polk County, NC, Swain County, NC, Transylvania County, NC, Abbeville County, SC, Anderson County, SC, Greenville County, SC, Greenwood County, SC, Laurens County, SC, McCormick County, SC, Oconee County, SC, Pickens County, SC, Spartanburg County, SC, Blount County, TN, Bradley County, TN, Hamilton County, TN, Knox County, TN, Loudon County, TN, McMinn County, TN, Meigs County, TN, Monroe County, TN, Polk County, TN, Roane County, TN, Sevier County, TN

The radar

The Atlanta radar (KFFC), 109 km from the middle of the area, began a volume at 00:15 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 00:00Z, 0.2 hours before the alert went out and 104 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 2012-09-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 405 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 2012-09-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 220 square meters per square second.193958Sfc1 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
405 J/kg
Mixed-layer CIN
-25 J/kg
Mixed-layer LCL
706 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
220 m²/s²
0-3 km storm-relative helicity
203 m²/s²
Significant tornado parameter
0.3
Supercell composite
3.2

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
Sep 17, 10:21 PM EDTMesoscale DiscussionSPCBaldwin, Banks, Barrow, Clarke, Elbert, Franklin and 21 more84 min
Sep 18, 12:23 AM EDTMesoscale DiscussionSPCBurke, Candler, Columbia, Elbert, Emanuel, Glascock and 17 more97 min
Sep 18, 3:44 AM EDTMesoscale DiscussionSPCBaker, Calhoun, Clay, Decatur, Dougherty, Early and 7 more2 hr
Sep 18, 9:39 AM EDTMesoscale DiscussionSPCAppling, Atkinson, Bacon, Ben Hill, Berrien, Brantley and 39 more66 min
Sep 18, 11:35 AM EDTMesoscale DiscussionSPCEffingham, Screven85 min
Sep 18, 8:49 AM EDTMesoscale DiscussionSPCAlamance, Anson, Caswell, Chatham, Cumberland, Davidson and 31 more116 min
Sep 18, 9:45 AM EDTTornado WatchSPCAlamance, Anson, Chatham, Cumberland, Davidson, Durham and 25 more8 hr
Sep 18, 10:54 AM EDTTornado WatchSPCBertie, Camden, Caswell, Chowan, Currituck, Gates and 4 more9 hr
Sep 18, 11:19 AM EDTMesoscale DiscussionSPCAlamance, Caswell, Chatham, Cumberland, Durham, Edgecombe and 27 more86 min
Sep 18, 1:00 PM EDTTornado WatchSPCBeaufort, Carteret, Craven, Dare, Duplin, Greene and 9 more5 hr
Sep 18, 1:21 PM EDTMesoscale DiscussionSPCAlamance, Anson, Chatham, Cumberland, Davidson, Durham and 25 more84 min
Sep 18, 1:27 PM EDTMesoscale DiscussionSPCCamden, Chowan, Currituck, Gates, Hertford, Northampton and 2 more63 min
Sep 18, 3:52 PM EDTMesoscale DiscussionSPCBertie, Camden, Chowan, Gates, Hertford, Northampton and 2 more113 min
Sep 18, 4:11 PM EDTMesoscale DiscussionSPCAlamance, Anson, Beaufort, Carteret, Chatham, Craven and 40 more94 min
Sep 18, 6:15 PM EDTMesoscale DiscussionSPCCamden, Carteret, Chowan, Currituck, Dare, Gates and 5 more30 min

Nearby

Mesoscale Discussions in Georgia, 2012Mesoscale Discussions in Tennessee, 2012Mesoscale Discussions in North Carolina, 2012Every mesoscale discussion in 2012

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.