Alert archive / Georgia / Mesoscale Discussions in 2009

Mesoscale Discussion 1213

June 18, 20094 states

The Storm Prediction Center issued this mesoscale discussion at Jun 18, 2009, 4:54 PM EDT for 4 states. It was in force for 66 min.

The area

The outline as issued.

The facts

Issued
Jun 18, 2009, 4:54 PM EDT (20:54 UTC)
Expired
Jun 18, 2009, 6:00 PM EDT
In force
66 min
Issued by
the Storm Prediction Center
All 65 counties

Banks County, GA, Barrow County, GA, Bartow County, GA, Carroll County, GA, Catoosa County, GA, Chattooga County, GA, Cherokee County, GA, Clarke County, GA, Clayton County, GA, Cobb County, GA, Columbia County, GA, Dade County, GA, Dawson County, GA, DeKalb County, GA, Douglas County, GA, Elbert County, GA, Fannin 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, Hart County, GA, Henry County, GA, Jackson County, GA, Lincoln County, GA, Lumpkin County, GA, Madison County, GA, McDuffie County, GA, Morgan County, GA, Murray County, GA, Newton County, GA, Oconee County, GA, Oglethorpe County, GA, Paulding County, GA, Pickens County, GA, Polk County, GA, Rabun County, GA, Rockdale County, GA, Stephens County, GA, Taliaferro County, GA, Towns County, GA, Union County, GA, Walker County, GA, Walton County, GA, White County, GA, Whitfield County, GA, Wilkes County, GA, Cherokee County, NC, Clay County, NC, Jackson County, NC, Macon County, NC, Abbeville County, SC, Anderson County, SC, McCormick County, SC, Oconee County, SC, Bradley County, TN, Hamilton County, TN, Marion County, TN, Polk County, TN

The radar

The Atlanta radar (KFFC), 150 km from the middle of the area, began a volume at 20:55 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 12:00Z, 8.9 hours before the alert went out and 148 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 12:00Z on 2009-06-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2883 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 12:00Z on 2009-06-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 64 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
2883 J/kg
Mixed-layer CIN
-24 J/kg
Mixed-layer LCL
758 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
64 m²/s²
0-3 km storm-relative helicity
158 m²/s²
Significant tornado parameter
0.9
Supercell composite
5.7

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
Jun 17, 8:11 PM EDTMesoscale DiscussionSPCCharlton64 min
Jun 17, 10:32 PM EDTMesoscale DiscussionSPCBaldwin, Banks, Barrow, Burke, Butts, Cherokee and 43 more28 min
Jun 17, 10:52 PM EDTSevere Thunderstorm WatchSPCBanks, Barrow, Burke, Clarke, Columbia, Dawson and 30 more4 hr
Jun 18, 1:21 AM EDTMesoscale DiscussionSPCAppling, Bacon, Baldwin, Brantley, Bryan, Bulloch and 32 more24 min
Jun 18, 1:39 AM EDTSevere Thunderstorm WatchSPCAppling, Bacon, Baldwin, Bartow, Bibb, Bleckley and 67 more5 hr
Jun 18, 3:45 AM EDTMesoscale DiscussionSPCAppling, Bacon, Ben Hill, Bleckley, Brantley, Bryan and 31 more2 hr
Jun 18, 10:15 AM EDTMesoscale DiscussionSPCBanks, Barrow, Bartow, Catoosa, Chattooga, Cherokee and 20 more90 min
Jun 18, 10:39 AM EDTSevere Thunderstorm Watch PDSSPCBanks, Barrow, Bartow, Carroll, Catoosa, Chattooga and 40 more7 hr
Jun 18, 1:48 PM EDTMesoscale DiscussionSPCBanks, Barrow, Bartow, Carroll, Catoosa, Chattooga and 46 more57 min
Jun 18, 3:13 PM EDTSevere Thunderstorm WatchSPCBurke, Columbia, Lincoln, McDuffie, Richmond6 hr
Jun 18, 6:02 PM EDTMesoscale DiscussionSPCAppling, Atkinson, Bacon, Baldwin, Ben Hill, Berrien and 63 more28 min
Jun 18, 6:22 PM EDTSevere Thunderstorm WatchSPCAppling, Atkinson, Bacon, Baldwin, Ben Hill, Berrien and 66 more6 hr
Jun 18, 6:34 PM EDTMesoscale DiscussionSPCBrooks, Clinch, Colquitt, Cook, Echols, Grady and 4 more86 min
Jun 18, 2:21 PM EDTSevere Thunderstorm WatchSPCCamden, Chowan, Currituck, Gates, Pasquotank, Perquimans9 hr
Jun 18, 3:31 PM EDTMesoscale DiscussionSPCWarren59 min
Jun 18, 4:25 PM EDTMesoscale DiscussionSPCAlexander, Alleghany, Ashe, Avery, Buncombe, Burke and 17 more65 min
Jun 17, 8:37 PM EDTMesoscale DiscussionSPCCheatham, Davidson, Montgomery, Robertson, Rutherford, Sumner and 1 more53 min

Nearby

Mesoscale Discussions in Georgia, 2009Mesoscale Discussions in North Carolina, 2009Mesoscale Discussions in South Carolina, 2009Every mesoscale discussion in 2009

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.