Alert archive / Georgia / Mesoscale Discussions in 2011

Mesoscale Discussion 2133

September 5, 201181 counties in Georgia

The Storm Prediction Center issued this mesoscale discussion at Sep 5, 2011, 3:05 PM EDT for 81 counties in Georgia. It was in force for 55 min.

The area

The outline as issued.

The facts

Issued
Sep 5, 2011, 3:05 PM EDT (19:05 UTC)
Expired
Sep 5, 2011, 4:00 PM EDT
In force
55 min
Issued by
the Storm Prediction Center
All 81 counties

Baldwin County, GA, Banks County, GA, Barrow County, GA, Bartow County, GA, Bibb County, GA, Bleckley County, GA, Butts County, GA, Carroll County, GA, Chattahoochee County, GA, Chattooga County, GA, Cherokee County, GA, Clarke County, GA, Clayton County, GA, Cobb County, GA, Coweta County, GA, Crawford County, GA, Dawson County, GA, DeKalb County, GA, Dodge County, GA, Dooly County, GA, Douglas County, GA, Fayette County, GA, Floyd County, GA, Forsyth County, GA, Franklin County, GA, Fulton County, GA, Glascock County, GA, Gordon County, GA, Greene County, GA, Gwinnett County, GA, Hall County, GA, Hancock County, GA, Haralson County, GA, Harris County, GA, Heard County, GA, Henry County, GA, Houston County, GA, Jackson County, GA, Jasper County, GA, Johnson County, GA, Jones County, GA, Lamar County, GA, Laurens County, GA, Macon County, GA, Madison County, GA, Marion County, GA, Meriwether County, GA, Monroe County, GA, Montgomery County, GA, Morgan County, GA, Muscogee County, GA, Newton County, GA, Oconee County, GA, Oglethorpe County, GA, Paulding County, GA, Peach County, GA, Pickens County, GA, Pike County, GA, Polk County, GA, Pulaski County, GA, Putnam County, GA, Rockdale County, GA, Schley County, GA, Spalding County, GA, Stewart County, GA, Sumter County, GA, Talbot County, GA, Taliaferro County, GA, Taylor County, GA, Treutlen County, GA, Troup County, GA, Twiggs County, GA, Upson County, GA, Walton County, GA, Warren County, GA, Washington County, GA, Webster County, GA, Wheeler County, GA, Wilcox County, GA, Wilkes County, GA, Wilkinson County, GA

The radar

The Robins AFB radar (KJGX), 63 km from the middle of the area, began a volume at 19:06 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 12:00Z, 7.1 hours before the alert went out and 71 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 12:00Z on 2011-09-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 279 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 12:00Z on 2011-09-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 167 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
279 J/kg
Mixed-layer CIN
-5 J/kg
Mixed-layer LCL
471 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
167 m²/s²
0-3 km storm-relative helicity
228 m²/s²
Significant tornado parameter
0.3
Supercell composite
3.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

917 
ACUS11 KWNS 051906
SWOMCD
SPC MCD 051905
GAZ000-ALZ000-052000-

MESOSCALE DISCUSSION 2133
NWS STORM PREDICTION CENTER NORMAN OK
0205 PM CDT MON SEP 05 2011

AREAS AFFECTED...GA

CONCERNING...TORNADO WATCH 839...

VALID 051905Z - 052000Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 839 CONTINUES.

CONCERN EXISTS FOR AN INCREASE IN A TORNADO POTENTIAL WITH STORMS
MOVING NWD INTO CENTRAL/ERN GA THIS AFTERNOON.  LOCAL AREAL
EXTENSION OF WW 839 MAY BE NEEDED SOON.

TRENDS IN REGIONAL RADAR IMAGERY DURING THE EARLY-MID AFTERNOON AND
LIGHTNING DATA INDICATED AN INCREASE IN TSTM DEVELOPMENT ACROSS NRN
FL AND SRN GA WITH ACTIVITY TRACKING GENERALLY NWD.  THIS INCREASE
IN COVERAGE APPEARS TO BE ASSOCIATED WITH AN INLAND FLUX OF HIGHER
THETAE THROUGH SRN TO CENTRAL GA.  THE INCREASE IN MOISTURE COMBINED
WITH ADDITIONAL SURFACE HEATING THIS AFTERNOON HAS RESULTED IN A
MODERATELY UNSTABLE AIR MASS /MLCAPE 1000-2000 J/KG/.  EFFECTIVE
BULK SHEAR IS ALSO INCREASING ACROSS CENTRAL AND NRN GA WITH VALUES
OF 35-50 KT SUFFICIENT FOR STORM ORGANIZATION.

ANALYSIS OF AREA WSR-88D VADS SHOWED GREATER HODOGRAPH CURVATURE
WITH NWD EXTENT INTO CENTRAL/NRN GA.  THIS SUPPORTS THE POTENTIAL
FOR TORNADOES BEING GREATER WITHIN AND EAST OF WW 839.

..PETERS.. 09/05/2011

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...CAE...GSP...FFC...TAE...BMX...HUN...

LAT...LON   31968496 33398521 34638557 34598417 34418303 33308249
            32548235 32118244 31968303 31968496

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 5, 5:26 AM EDTMesoscale DiscussionSPCClay, Early, Quitman, Seminole94 min
Sep 5, 6:35 AM EDTTornado WatchSPCBaker, Calhoun, Clay, Decatur, Dougherty, Early and 9 more10 hr
Sep 5, 8:24 AM EDTMesoscale DiscussionSPCBaldwin, Barrow, Bibb, Butts, Carroll, Chattahoochee and 42 more66 min
Sep 5, 12:01 PM EDTMesoscale DiscussionSPCBaker, Baldwin, Barrow, Bartow, Ben Hill, Berrien and 85 more29 min
Sep 5, 12:10 PM EDTTornado WatchSPCBartow, Bibb, Butts, Carroll, Chattahoochee, Chattooga and 46 more4 hr
Sep 5, 1:23 PM EDTMesoscale DiscussionSPCBaldwin, Burke, Columbia, Elbert, Emanuel, Glascock and 17 more67 min
Sep 5, 3:42 PM EDTTornado WatchSPCBaldwin, Banks, Barrow, Bartow, Bibb, Bleckley and 81 more7 hr
Sep 5, 4:04 PM EDTSevere Thunderstorm WatchSPCBaker, Ben Hill, Berrien, Brooks, Calhoun, Clay and 20 more6 hr
Sep 5, 4:15 PM EDTMesoscale DiscussionSPCBaker, Ben Hill, Berrien, Brooks, Calhoun, Clay and 20 more30 min
Sep 5, 5:48 PM EDTMesoscale DiscussionSPCAppling, Bacon, Brantley, Bryan, Bulloch, Camden and 19 more87 min
Sep 5, 6:12 PM EDTSevere Thunderstorm WatchSPCBurke, Richmond4 hr
Sep 5, 7:37 PM EDTMesoscale DiscussionSPCBaldwin, Banks, Barrow, Bartow, Bibb, Bleckley and 77 more113 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.