Alert archive / Georgia / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 841

September 5, 20115 counties in Alabama; 17 counties in Florida; 26 counties in Georgia

The Storm Prediction Center issued this severe thunderstorm watch at Sep 5, 2011, 3:04 PM CDT for 5 counties in Alabama; 17 counties in Florida; 26 counties in Georgia. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Sep 5, 2011, 3:04 PM CDT (20:04 UTC)
Expired
Sep 5, 2011, 9:00 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 48 counties

Coffee County, AL, Dale County, AL, Geneva County, AL, Henry County, AL, Houston County, AL, Bay County, FL, Calhoun County, FL, Dixie County, FL, Franklin County, FL, Gadsden County, FL, Gulf County, FL, Holmes County, FL, Jackson County, FL, Jefferson County, FL, Lafayette County, FL, Leon County, FL, Liberty County, FL, Madison County, FL, Taylor County, FL, Wakulla County, FL, Walton County, FL, Washington County, FL, Baker County, GA, Ben Hill County, GA, Berrien County, GA, Brooks County, GA, Calhoun County, GA, Clay County, GA, Colquitt County, GA, Cook County, GA, Decatur County, GA, Dougherty County, GA, Early County, GA, Grady County, GA, Irwin County, GA, Lanier County, GA, Lee County, GA, Lowndes County, GA, Miller County, GA, Mitchell County, GA, Quitman County, GA, Randolph County, GA, Seminole County, GA, Terrell County, GA, Thomas County, GA, Tift County, GA, Turner County, GA, Worth County, GA

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
20%
One or more EF2 to EF5 tornadoes
5%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
5%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

21 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Sep 5, 3:05 PM CDTSevere Thunderstorm WarningTAEWalton, Washington40 min
Sep 5, 3:10 PM CDTSevere Thunderstorm WarningTAELanier, Lowndes35 min
Sep 5, 3:12 PM CDTSevere Thunderstorm WarningTAEHenry, Houston48 min
Sep 5, 3:16 PM CDTSevere Thunderstorm WarningTAEDougherty, Lee, Worth44 min
Sep 5, 3:26 PM CDTSevere Thunderstorm WarningTAEColquitt, Tift, Worth49 min
Sep 5, 3:37 PM CDTSevere Thunderstorm WarningTAEGeneva53 min
Sep 5, 3:39 PM CDTSevere Thunderstorm WarningTAELeon, Wakulla11 min
Sep 5, 3:46 PM CDTSevere Thunderstorm WarningTAEDixie, Lafayette, Taylor29 min
Sep 5, 3:57 PM CDTSevere Thunderstorm WarningTAETurner, Worth33 min
Sep 5, 3:59 PM CDTSevere Thunderstorm WarningTAEJefferson, Taylor31 min
Sep 5, 4:03 PM CDTSevere Thunderstorm WarningTAEHouston42 min
Sep 5, 4:13 PM CDTSevere Thunderstorm WarningTAEBen Hill, Irwin, Tift, Turner47 min
Sep 5, 4:17 PM CDTSevere Thunderstorm WarningTAEDale, Houston43 min
Sep 5, 4:20 PM CDTSevere Thunderstorm WarningTAEJefferson, Madison, Taylor40 min
Sep 5, 4:24 PM CDTSevere Thunderstorm WarningTAEBay, Holmes, Walton, Washington51 min
Sep 5, 4:51 PM CDTSevere Thunderstorm WarningTAEBrooks, Cook, Lowndes39 min
Sep 5, 5:16 PM CDTSevere Thunderstorm WarningTAEMadison, Taylor29 min
Sep 5, 5:29 PM CDTSevere Thunderstorm WarningTAEBay, Calhoun, Holmes, Jackson, Washington46 min
Sep 5, 5:42 PM CDTSevere Thunderstorm WarningTAEGeneva, Houston48 min
Sep 5, 6:25 PM CDTSevere Thunderstorm WarningTAELafayette, Madison, Taylor50 min
Sep 5, 7:43 PM CDTSevere Thunderstorm WarningTAEColquitt, Grady, Mitchell, Worth47 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

Tallahassee Rgnl, FL (KTLH), launched 12:00Z, 8.1 hours before the alert went out and 135 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, Tallahassee Rgnl, FL at 12:00Z on 2011-09-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2763 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, Tallahassee Rgnl, FL at 12:00Z on 2011-09-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 223 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
2763 J/kg
Mixed-layer CIN
-7 J/kg
Mixed-layer LCL
465 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
223 m²/s²
0-3 km storm-relative helicity
266 m²/s²
Significant tornado parameter
2.6
Supercell composite
17.8

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 4, 9:42 PM CDTTornado WatchSPCAutauga, Baldwin, Butler, Choctaw, Clarke, Conecuh and 16 more9 hr
Sep 4, 11:35 PM CDTMesoscale DiscussionSPCBaldwin, Choctaw, Clarke, Conecuh, Covington, Escambia and 6 more115 min
Sep 5, 4:26 AM CDTMesoscale DiscussionSPCAutauga, Baldwin, Barbour, Bibb, Bullock, Butler and 41 more94 min
Sep 5, 5:35 AM CDTTornado WatchSPCAutauga, Baldwin, Barbour, Bibb, Blount, Bullock and 50 more10 hr
Sep 5, 7:24 AM CDTMesoscale DiscussionSPCAutauga, Barbour, Bibb, Bullock, Butler, Calhoun and 20 more66 min
Sep 5, 11:01 AM CDTMesoscale DiscussionSPCAutauga, Baldwin, Barbour, Bibb, Blount, Bullock and 41 more29 min
Sep 5, 3:15 PM CDTMesoscale DiscussionSPCBarbour, Bullock, Chambers, Coffee, Dale, Elmore and 9 more30 min
Sep 5, 3:49 PM CDTTornado WatchSPCAutauga, Barbour, Bullock, Calhoun, Chambers, Chilton and 16 more4 hr
Sep 5, 6:37 PM CDTMesoscale DiscussionSPCBarbour, Bullock, Calhoun, Chambers, Clay, Cleburne and 9 more113 min
Sep 5, 5:24 PM CDTMesoscale DiscussionSPCAlachua, Baker, Columbia, Gilchrist, Hamilton, Levy and 1 more66 min
Sep 5, 11:10 AM CDTTornado WatchSPCBartow, Bibb, Butts, Carroll, Chattahoochee, Chattooga and 46 more4 hr
Sep 5, 12:23 PM CDTMesoscale DiscussionSPCBaldwin, Burke, Columbia, Elbert, Emanuel, Glascock and 17 more67 min
Sep 5, 2:05 PM CDTMesoscale DiscussionSPCBaldwin, Banks, Barrow, Bartow, Bibb, Bleckley and 75 more55 min
Sep 5, 2:42 PM CDTTornado WatchSPCBaldwin, Banks, Barrow, Bartow, Bibb, Bleckley and 81 more7 hr
Sep 5, 4:48 PM CDTMesoscale DiscussionSPCAppling, Bacon, Brantley, Bryan, Bulloch, Camden and 19 more87 min
Sep 5, 5:12 PM CDTSevere Thunderstorm WatchSPCBurke, Richmond4 hr

Nearby

Severe Thunderstorm Watches in Georgia, 2011Severe Thunderstorm Watches in Florida, 2011Severe Thunderstorm Watches in Alabama, 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.