Alert archive / Georgia / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 66

March 26, 201145 counties in Georgia; 10 counties in South Carolina

The Storm Prediction Center issued this severe thunderstorm watch at Mar 26, 2011, 9:19 PM EDT for 45 counties in Georgia; 10 counties in South Carolina. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
Mar 26, 2011, 9:19 PM EDT (01:19 UTC)
Expired
Mar 27, 2011, 5:00 AM EDT
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 55 counties

Banks County, GA, Barrow County, GA, Bartow County, GA, Burke County, GA, Catoosa County, GA, Chattooga County, GA, Cherokee County, GA, Clarke County, GA, Columbia County, GA, Dade County, GA, Dawson County, GA, Elbert County, GA, Fannin County, GA, Floyd County, GA, Forsyth County, GA, Franklin County, GA, Gilmer County, GA, Gordon County, GA, Greene County, GA, Gwinnett County, GA, Habersham County, GA, Hall County, GA, Hart County, GA, Jackson County, GA, Lincoln County, GA, Lumpkin County, GA, Madison County, GA, McDuffie County, GA, Morgan County, GA, Murray County, GA, Oconee County, GA, Oglethorpe County, GA, Pickens County, GA, Rabun County, GA, Richmond County, GA, Stephens County, GA, Taliaferro County, GA, Towns County, GA, Union County, GA, Walker County, GA, Walton County, GA, Warren County, GA, White County, GA, Whitfield County, GA, Wilkes County, GA, Abbeville County, SC, Aiken County, SC, Anderson County, SC, Barnwell County, SC, Edgefield County, SC, Greenwood County, SC, McCormick County, SC, Oconee County, SC, Pickens County, SC, Saluda County, SC

The radar

The Atlanta radar (KFFC), 135 km from the middle of the area, began a volume at 01:21 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
20%
One or more EF2 to EF5 tornadoes
5%
Ten or more severe wind reports
5%
One or more gusts of 65 knots or more
5%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Mar 26, 9:28 PM EDTSevere Thunderstorm WarningFFCCherokee, Gilmer, Pickens47 min
Mar 26, 9:37 PM EDTSevere Thunderstorm WarningFFCBartow, Chattooga, Floyd38 min
Mar 26, 9:44 PM EDTSevere Thunderstorm WarningFFCHall, White46 min
Mar 26, 10:08 PM EDTSevere Thunderstorm WarningFFCBartow, Cherokee, Cobb, Paulding, Polk52 min
Mar 26, 10:18 PM EDTSevere Thunderstorm WarningGSPHabersham11 min
Mar 26, 10:22 PM EDTSevere Thunderstorm WarningFFCForsyth, Hall, Jackson38 min
Mar 26, 10:30 PM EDTSevere Thunderstorm WarningFFCCobb, DeKalb, Fulton, Gwinnett60 min
Mar 26, 11:13 PM EDTSevere Thunderstorm WarningFFCBarrow, DeKalb, Henry, Newton, Oconee, Rockdale and 1 more47 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, 1.3 hours before the alert went out and 130 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 00:00Z on 2011-03-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 120 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 00:00Z on 2011-03-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 343 square meters per square second.19395878Sfc1 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
120 J/kg
Mixed-layer CIN
-166 J/kg
Mixed-layer LCL
635 m above ground
0-6 km bulk shear
67 kt
0-1 km storm-relative helicity
343 m²/s²
0-3 km storm-relative helicity
404 m²/s²
Significant tornado parameter
0.0
Supercell composite
6.7

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 26, 8:47 PM EDTTornado WatchSPCBaldwin, Ben Hill, Bibb, Bleckley, Butts, Carroll and 61 more7 hr
Mar 26, 8:55 PM EDTMesoscale DiscussionSPCBanks, Barrow, Bartow, Catoosa, Chattooga, Cherokee and 36 more95 min
Mar 26, 11:10 PM EDTMesoscale DiscussionSPCBryan, Bulloch, Candler, Chatham, Effingham, Evans and 3 more65 min
Mar 27, 12:21 AM EDTMesoscale DiscussionSPCBaldwin, Bibb, Bleckley, Butts, Carroll, Chattahoochee and 55 more54 min
Mar 27, 12:43 AM EDTMesoscale DiscussionSPCBanks, Barrow, Bartow, Burke, Catoosa, Chattooga and 38 more62 min
Mar 27, 3:03 AM EDTMesoscale DiscussionSPCAppling, Atkinson, Bacon, Ben Hill, Bibb, Bleckley and 40 more57 min
Mar 27, 3:25 AM EDTTornado WatchSPCAppling, Baldwin, Bibb, Bleckley, Bryan, Bulloch and 46 more3 hr
Mar 27, 8:33 AM EDTMesoscale DiscussionSPCBaldwin, Bibb, Bleckley, Bulloch, Burke, Butts and 48 more117 min
Mar 27, 9:55 AM EDTSevere Thunderstorm WatchSPCAppling, Atkinson, Bacon, Baker, Baldwin, Ben Hill and 87 more7 hr
Mar 27, 11:51 AM EDTMesoscale DiscussionSPCAppling, Atkinson, Bacon, Baker, Ben Hill, Berrien and 64 more84 min
Mar 27, 3:49 PM EDTMesoscale DiscussionSPCAppling, Atkinson, Bacon, Baker, Ben Hill, Berrien and 44 more56 min
Mar 27, 4:27 PM EDTSevere Thunderstorm WatchSPCAppling, Atkinson, Bacon, Baker, Ben Hill, Berrien and 38 more5 hr
Mar 27, 7:24 PM EDTMesoscale DiscussionSPCAppling, Atkinson, Bacon, Baker, Ben Hill, Berrien and 34 more2 hr

Nearby

Severe Thunderstorm Watches in Georgia, 2011Severe Thunderstorm Watches in South 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.