Alert archive / Georgia / Tornado Watches in 2011
Tornado Watch 228
The Storm Prediction Center issued this tornado watch at Apr 27, 2011, 7:48 AM EDT for 42 counties in Georgia. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 27, 2011, 7:48 AM EDT (11:48 UTC)
- Expired
- Apr 27, 2011, 9:56 AM EDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 60 kt
All 42 counties
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, Fannin County, GA, Fayette County, GA, Floyd County, GA, Forsyth County, GA, Fulton County, GA, Gilmer County, GA, Gordon County, GA, Gwinnett County, GA, Hall County, GA, Haralson County, GA, Heard County, GA, Henry County, GA, Lamar County, GA, Lumpkin County, GA, Meriwether County, GA, Murray County, GA, Paulding County, GA, Pickens County, GA, Pike County, GA, Polk County, GA, Rockdale County, GA, Spalding County, GA, Towns County, GA, Troup County, GA, Union County, GA, Walker County, GA, White County, GA, Whitfield County, GA
The radar
The Atlanta radar (KFFC), 83 km from the middle of the area, began a volume at 11:47 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
- 30%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 20%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 60%
Warnings issued inside it
10 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 27, 8:04 AM EDT | Severe Thunderstorm Warning | FFC | Bartow, Chattooga, Floyd, Haralson, Polk | 56 min |
| Apr 27, 8:16 AM EDT | Tornado Warning | FFC | Catoosa, Chattooga, Dade, Walker, Whitfield | 44 min |
| Apr 27, 8:25 AM EDT | Tornado Warning | FFC | Dade, Walker | 35 min |
| Apr 27, 8:28 AM EDT | Severe Thunderstorm Warning | FFC | Carroll, Haralson, Heard | 32 min |
| Apr 27, 8:35 AM EDT | Severe Thunderstorm Warning | FFC | Bartow, Cherokee, Cobb, Gilmer, Gordon, Murray and 5 more | 55 min |
| Apr 27, 8:42 AM EDT | Severe Thunderstorm Warning | FFC | Catoosa, Murray, Whitfield | 48 min |
| Apr 27, 8:51 AM EDT | Severe Thunderstorm Warning | FFC | Clayton, Coweta, Douglas, Fayette, Fulton | 29 min |
| Apr 27, 8:54 AM EDT | Tornado Warning | FFC | Gilmer, Gordon, Murray, Whitfield | 51 min |
| Apr 27, 9:02 AM EDT | Severe Thunderstorm Warning | FFC | Catoosa, Dade, Walker | 16 min |
| Apr 27, 9:26 AM EDT | Severe Thunderstorm Warning | FFC | Fannin, Gilmer, Murray | 39 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, 11.8 hours before the alert went out and 84 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.
233
WWUS20 KWNS 271141
SEL8
SPC WW 271141
GAZ000-271600-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 228
NWS STORM PREDICTION CENTER NORMAN OK
740 AM EDT WED APR 27 2011
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
CENTRAL THROUGH NORTHERN GEORGIA
EFFECTIVE THIS WEDNESDAY MORNING FROM 740 AM UNTIL NOON EDT.
TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.
THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 65 STATUTE
MILES EAST AND WEST OF A LINE FROM 50 MILES NORTH NORTHEAST OF
ROME GEORGIA TO 25 MILES WEST OF MACON GEORGIA. FOR A COMPLETE
DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE
(WOUS64 KWNS WOU8).
REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.
OTHER WATCH INFORMATION...CONTINUE...WW 225...WW 226...WW 227...
DISCUSSION...LINE OF STORMS WITH EMBEDDED MESOCYCLONES AND LEWP
STRUCTURES WILL CONTINUE EWD THROUGH CNTRL AND NRN GA. INSTABILITY
DOWNSTREAM IS MARGINAL...BUT WILL REMAIN SUFFICIENT TO MAINTAIN LINE
NEXT FEW HOURS GIVEN STRONG STORM RELATIVE INFLOW. THREAT WILL EXIST
FOR DAMAGING WIND AND ISOLATED TORNADOES.
AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.
MEAN STORM MOTION VECTOR 26050.
...DIALSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 26, 8:59 PM EDT | Mesoscale Discussion | SPC | Colbert, Franklin, Lamar, Lauderdale, Lawrence, Limestone and 1 more | 2 hr |
| Apr 26, 10:33 PM EDT | Tornado Watch | SPC | Colbert, Franklin, Lauderdale | 7 hr |
| Apr 27, 12:33 AM EDT | Mesoscale Discussion | SPC | Colbert, Franklin, Lamar, Lauderdale, Marion | 117 min |
| Apr 27, 2:56 AM EDT | Mesoscale Discussion | SPC | Bibb, Blount, Cullman, Fayette, Greene, Hale and 12 more | 64 min |
| Apr 27, 3:26 AM EDT | Tornado Watch | SPC | Bibb, Blount, Calhoun, Cherokee, Chilton, Clay and 29 more | 6 hr |
| Apr 27, 9:08 AM EDT | Tornado Watch | SPC | Colbert, Cullman, DeKalb, Fayette, Franklin, Jackson and 10 more | 6 hr |
| Apr 27, 11:45 AM EDT | Mesoscale Discussion | SPC | Greene, Lamar, Marion, Pickens, Sumter | 90 min |
| Apr 27, 12:39 PM EDT | Mesoscale Discussion | SPC | Cullman, DeKalb, Jackson, Madison, Marshall, Morgan | 66 min |
| Apr 27, 2:05 PM EDT | Mesoscale Discussion | SPC | Bibb, Blount, Calhoun, Cherokee, Chilton, Choctaw and 27 more | 85 min |
| Apr 27, 2:42 PM EDT | Tornado Watch | SPC | Autauga, Bibb, Blount, Butler, Calhoun, Cherokee and 41 more | 8 hr |
| Apr 27, 3:56 PM EDT | Mesoscale Discussion | SPC | Bibb, Blount, Calhoun, Cherokee, Chilton, Choctaw and 33 more | 2 hr |
| Apr 27, 6:01 PM EDT | Mesoscale Discussion | SPC | Autauga, Bibb, Blount, Butler, Calhoun, Cherokee and 38 more | 89 min |
| Apr 27, 6:41 PM EDT | Mesoscale Discussion | SPC | Barbour, Bullock, Chambers, Crenshaw, Elmore, Lee and 6 more | 34 min |
| Apr 27, 6:52 PM EDT | Tornado Watch | SPC | Barbour, Bullock, Chambers, Elmore, Lee, Macon and 5 more | 9 hr |
| Apr 27, 7:39 PM EDT | Mesoscale Discussion | SPC | Autauga, Bibb, Blount, Calhoun, Cherokee, Chilton and 26 more | 66 min |
| Apr 27, 7:19 AM EDT | Mesoscale Discussion | SPC | Bartow, Carroll, Chattooga, Cherokee, Clayton, Cobb and 22 more | 56 min |
Nearby
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.