Alert archive / Georgia / Mesoscale Discussions in 2011
Mesoscale Discussion 615
The Storm Prediction Center issued this mesoscale discussion at Apr 27, 2011, 7:19 AM EDT for 28 counties in Georgia. It was in force for 56 min.
The area
The outline as issued.
The facts
- Issued
- Apr 27, 2011, 7:19 AM EDT (11:19 UTC)
- Expired
- Apr 27, 2011, 8:15 AM EDT
- In force
- 56 min
- Issued by
- the Storm Prediction Center
All 28 counties
Bartow County, GA, Carroll County, GA, Chattooga County, GA, Cherokee County, GA, Clayton County, GA, Cobb County, GA, Coweta County, GA, DeKalb County, GA, Douglas County, GA, Fayette County, GA, Floyd County, GA, Fulton County, GA, Gilmer County, GA, Gordon County, GA, Haralson County, GA, Harris County, GA, Heard County, GA, Henry County, GA, Lamar County, GA, Meriwether County, GA, Paulding County, GA, Pickens County, GA, Pike County, GA, Polk County, GA, Spalding County, GA, Troup County, GA, Upson County, GA, Walker County, GA
The radar
The Atlanta radar (KFFC), 25 km from the middle of the area, began a volume at 11:18 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, 11.3 hours before the alert went out and 27 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.
- Mixed-layer CAPE
- 528 J/kg
- Mixed-layer CIN
- -28 J/kg
- Mixed-layer LCL
- 1385 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- 88 m²/s²
- 0-3 km storm-relative helicity
- 134 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.3
The text
As transmitted, in the capitals the NWS used until 2016.
869 ACUS11 KWNS 271120 SWOMCD SPC MCD 271119 GAZ000-271215- MESOSCALE DISCUSSION 0615 NWS STORM PREDICTION CENTER NORMAN OK 0619 AM CDT WED APR 27 2011 AREAS AFFECTED...WRN THROUGH CNTRL GA CONCERNING...SEVERE POTENTIAL...WATCH LIKELY VALID 271119Z - 271215Z LINE OF STRONG TO SEVERE STORMS WILL LIKELY PERSIST NEXT FEW HOURS AND CONTINUE INTO WRN GA. PRIMARY THREAT APPEARS TO BE DAMAGING WIND...BUT ISOLATED TORNADOES CANNOT BE RULED OUT. LINE OF STORMS WITH LEWP AND SUPERCELL STRUCTURES EXTENDS FROM CNTRL KY SWD THROUGH CNTRL AL AND IS MOVING EAST AT 45-55 KT. INSTABILITY DOWNSTREAM IS MARGINAL WITH MUCAPE AOB 1000 J/KG BUT REMAINS SUFFICIENT FOR STORMS TO CONTINUE DEVELOPING EWD GIVEN STRONG STORM RELATIVE INFLOW AND CONVERGENCE ALONG LEADING GUST FRONT. PRIMARY THREAT APPEARS TO BE DAMAGING WIND...BUT ACTIVITY REMAINS EMBEDDED WITHIN STRONG VERTICAL SHEAR WITH LARGE HODOGRAPHS /400+ 0-1 KM STORM RELATIVE HELICITY/ SUPPORTIVE OF EMBEDDED LOW LEVEL MESOCYCLONES AND POSSIBLY ISOLATED TORNADOES. ..DIAL.. 04/27/2011 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...FFC... LAT...LON 32918402 32708493 33368524 34788542 34778436 32918402
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 27, 7:48 AM EDT | Tornado Watch | SPC | Bartow, Butts, Carroll, Catoosa, Chattooga, Cherokee and 36 more | 2 hr |
| Apr 27, 12:39 PM EDT | Mesoscale Discussion | SPC | Catoosa, Dade, Murray, Walker, Whitfield | 66 min |
| Apr 27, 2:05 PM EDT | Mesoscale Discussion | SPC | Chattooga, Dade, Walker | 85 min |
| Apr 27, 2:42 PM EDT | Tornado Watch | SPC | Catoosa, Chattooga, Dade, Floyd, Haralson, Polk and 2 more | 8 hr |
| Apr 27, 3:56 PM EDT | Mesoscale Discussion | SPC | Dade | 2 hr |
| Apr 27, 6:01 PM EDT | Mesoscale Discussion | SPC | Bartow, Floyd, Haralson, Polk | 89 min |
| Apr 27, 6:41 PM EDT | Mesoscale Discussion | SPC | Baldwin, Banks, Barrow, Bartow, Bibb, Bleckley and 86 more | 34 min |
| Apr 27, 6:52 PM EDT | Tornado Watch | SPC | Banks, Barrow, Bartow, Butts, Carroll, Catoosa and 66 more | 9 hr |
| Apr 27, 7:39 PM EDT | Mesoscale Discussion | SPC | Bartow, Chattooga, Floyd, Gordon, Haralson, Pickens and 1 more | 66 min |
Nearby
Mesoscale Discussions in Georgia, 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.