Alert archive / Georgia / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 167
The Storm Prediction Center issued this severe thunderstorm watch at Apr 20, 2011, 7:55 AM EDT for 56 counties in Georgia; 4 counties in North Carolina; 5 counties in South Carolina. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 20, 2011, 7:55 AM EDT (11:55 UTC)
- Expired
- Apr 20, 2011, 10:48 AM EDT
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 60 kt
All 65 counties
Banks County, GA, Barrow County, GA, Bartow County, GA, Butts County, GA, Carroll County, GA, Catoosa County, GA, Chattooga County, GA, Cherokee County, GA, Clarke County, GA, Clayton County, GA, Cobb County, GA, Coweta County, GA, Dade 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, Hart County, GA, Heard County, GA, Henry County, GA, Jackson County, GA, Jasper County, GA, Lumpkin County, GA, Madison 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, Putnam County, GA, Rabun County, GA, Rockdale County, GA, Spalding County, GA, Stephens County, GA, Towns County, GA, Union County, GA, Walker County, GA, Walton County, GA, White County, GA, Whitfield County, GA, Henderson County, NC, Jackson County, NC, Macon County, NC, Transylvania County, NC, Abbeville County, SC, Anderson County, SC, Greenville County, SC, Oconee County, SC, Pickens County, SC
The radar
The Atlanta radar (KFFC), 119 km from the middle of the area, began a volume at 11:57 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.
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 10%
- One or more EF2 to EF5 tornadoes
- 2%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 20%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
3 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 20, 8:15 AM EDT | Severe Thunderstorm Warning | FFC | Fannin, Gilmer, Gordon, Murray, Pickens, Whitfield | 45 min |
| Apr 20, 8:18 AM EDT | Flash Flood Warning | FFC | Whitfield | 116 min |
| Apr 20, 8:57 AM EDT | Severe Thunderstorm Warning | GSP | Habersham, Rabun, Stephens | 50 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Peachtre/Fal Fld, GA (KFFC), launched 00:00Z, 11.9 hours before the alert went out and 118 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 3375 m above ground
- 0-6 km bulk shear
- 27 kt
- 0-1 km storm-relative helicity
- 52 m²/s²
- 0-3 km storm-relative helicity
- 97 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 19, 10:39 PM EDT | Mesoscale Discussion | SPC | Colbert, Franklin, Lauderdale | 66 min |
| Apr 20, 12:56 AM EDT | Mesoscale Discussion | SPC | Colbert, Franklin, Lamar, Lauderdale, Lawrence, Limestone and 4 more | 94 min |
| Apr 20, 4:19 AM EDT | Mesoscale Discussion | SPC | Blount, Calhoun, Cherokee, Cullman, DeKalb, Etowah and 16 more | 86 min |
| Apr 20, 4:37 AM EDT | Severe Thunderstorm Watch | SPC | Bibb, Blount, Calhoun, Chambers, Cherokee, Chilton and 33 more | 8 hr |
| Apr 20, 6:39 AM EDT | Mesoscale Discussion | SPC | Calhoun, Cherokee, Cleburne, St. Clair | 66 min |
| Apr 20, 9:42 AM EDT | Mesoscale Discussion | SPC | Autauga, Bibb, Chilton, Clay, Coosa, Elmore and 11 more | 63 min |
| Apr 20, 2:16 PM EDT | Mesoscale Discussion | SPC | Autauga, Barbour, Bibb, Blount, Bullock, Chambers and 28 more | 89 min |
| Apr 20, 2:33 PM EDT | Severe Thunderstorm Watch | SPC | Autauga, Barbour, Bibb, Bullock, Butler, Chambers and 33 more | 6 hr |
| Apr 20, 6:24 PM EDT | Mesoscale Discussion | SPC | Autauga, Bibb, Chilton, Coosa, Elmore, Fayette and 10 more | 96 min |
| Apr 20, 7:51 PM EDT | Mesoscale Discussion | SPC | Fayette, Greene, Lamar, Marion, Pickens, Tuscaloosa and 2 more | 84 min |
| Apr 19, 9:07 PM EDT | Mesoscale Discussion | SPC | Dyer, Lake, Lauderdale, Obion, Tipton | 83 min |
| Apr 19, 11:14 PM EDT | Tornado Watch | SPC | Bedford, Benton, Carroll, Cheatham, Chester, Clay and 31 more | 7 hr |
| Apr 20, 2:42 AM EDT | Tornado Watch | SPC | Anderson, Bledsoe, Blount, Bradley, Campbell, Cannon and 42 more | 5 hr |
| Apr 20, 3:20 AM EDT | Mesoscale Discussion | SPC | Anderson, Bledsoe, Campbell, Claiborne, Clay, Cumberland and 23 more | 85 min |
Nearby
Severe Thunderstorm Watches in Georgia, 2011Severe Thunderstorm Watches in South Carolina, 2011Severe Thunderstorm Watches in North Carolina, 2011Every severe thunderstorm watch 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.