Alert archive / Georgia / Mesoscale Discussions in 2012

Mesoscale Discussion 43

January 21, 201210 counties in Alabama; 84 counties in Georgia; 19 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at Jan 21, 2012, 1:57 PM CST for 10 counties in Alabama; 84 counties in Georgia; 19 counties in South Carolina. It was in force for 63 min.

The area

The outline as issued.

The facts

Issued
Jan 21, 2012, 1:57 PM CST (19:57 UTC)
Expired
Jan 21, 2012, 3:00 PM CST
In force
63 min
Issued by
the Storm Prediction Center
All 113 counties

Barbour County, AL, Bullock County, AL, Chambers County, AL, Clay County, AL, Henry County, AL, Lee County, AL, Macon County, AL, Randolph County, AL, Russell County, AL, Tallapoosa County, AL, Baldwin County, GA, Barrow County, GA, Bibb County, GA, Bleckley County, GA, Bulloch County, GA, Burke County, GA, Butts County, GA, Calhoun County, GA, Candler County, GA, Carroll County, GA, Chattahoochee County, GA, Clarke County, GA, Clay County, GA, Clayton County, GA, Columbia County, GA, Coweta County, GA, Crawford County, GA, Crisp County, GA, DeKalb County, GA, Dodge County, GA, Dooly County, GA, Douglas County, GA, Elbert County, GA, Emanuel County, GA, Fayette County, GA, Fulton County, GA, Glascock County, GA, Greene County, GA, Gwinnett County, GA, Hancock County, GA, Harris County, GA, Heard County, GA, Henry County, GA, Houston County, GA, Jasper County, GA, Jefferson County, GA, Jenkins County, GA, Johnson County, GA, Jones County, GA, Lamar County, GA, Laurens County, GA, Lee County, GA, Lincoln County, GA, Macon County, GA, Madison County, GA, Marion County, GA, McDuffie 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, Peach County, GA, Pike County, GA, Pulaski County, GA, Putnam County, GA, Quitman County, GA, Randolph County, GA, Richmond County, GA, Rockdale County, GA, Schley County, GA, Screven County, GA, Spalding County, GA, Stewart County, GA, Sumter County, GA, Talbot County, GA, Taliaferro County, GA, Taylor County, GA, Terrell 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, Abbeville County, SC, Aiken County, SC, Allendale County, SC, Bamberg County, SC, Barnwell County, SC, Calhoun County, SC, Chester County, SC, Colleton County, SC, Edgefield County, SC, Fairfield County, SC, Greenwood County, SC, Hampton County, SC, Laurens County, SC, Lexington County, SC, McCormick County, SC, Newberry County, SC, Orangeburg County, SC, Richland County, SC, Saluda County, SC

The radar

The Robins AFB radar (KJGX), 64 km from the middle of the area, began a volume at 19:57 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.

The nearest sounding before it

Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 8.0 hours before the alert went out and 70 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 2012-01-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 238 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 2012-01-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 265 square meters per square second.1939587897Sfc1 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
238 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
505 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
265 m²/s²
0-3 km storm-relative helicity
291 m²/s²
Significant tornado parameter
0.4
Supercell composite
2.4

Open this sounding in Storm Lab

The text

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

242 
ACUS11 KWNS 211958
SWOMCD
SPC MCD 211957
SCZ000-GAZ000-ALZ000-212100-

MESOSCALE DISCUSSION 0043
NWS STORM PREDICTION CENTER NORMAN OK
0157 PM CST SAT JAN 21 2012

AREAS AFFECTED...SERN AL...GA...SC

CONCERNING...TORNADO WATCH 4...

VALID 211957Z - 212100Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 4 CONTINUES.

UPPER SHORTWAVE TROUGH IS PROGRESSING STEADILY EWD ACROSS THE TN
VALLEY/GULF STATES AT ROUGHLY 45KT...CURRENTLY EXTENDING FROM A VORT
MAX JUST E OF CHA...SWD THROUGH CNTRL GA.  A LONGER LIVED COMPLEX OF
STORMS THAT EVOLVED OVER CNTRL AL HAS PROPAGATED INTO ECNTRL
GA...HANCOCK/WASHINGTON COUNTY...WHERE IT HAS MERGED WITH
SEWD-MOVING FRONTAL CONVECTION.  THIS LEADING...SOMEWHAT MORE
ORGANIZED...COMPLEX IS APPROACHING THE ERN LIMITS OF MORE BUOYANT
AIRMASS AS SFC DEW POINTS HAVE STRUGGLED TO RISE THROUGH THE UPPER
50S ACROSS SC.  EVEN SO...PRE-FRONTAL BOUNDARY LAYER HAS HEATED
ACROSS SRN GA/AL WHERE SFC-3KM LAPSE RATES ARE NOW ON THE ORDER OF 7
C/KM AND THIS MAY ENHANCE THE PROSPECT FOR HAIL/DAMAGING WINDS AS
FRONTAL SQUALL LINE SAGS SEWD.  IN THE WAKE OF AFOREMENTIONED
SHORTWAVE TROUGH IT APPEARS LARGE SCALE SUBSIDENCE WILL GRADUALLY
PROVE DETRIMENTAL TO TSTMS AS THEY TRAIL SWWD ALONG WIND SHIFT.

..DARROW.. 01/21/2012

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

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

LAT...LON   33338615 34848105 32758031 31258544 33338615

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 20, 10:02 PM CSTMesoscale DiscussionSPCColbert, Lauderdale, Limestone88 min
Jan 20, 10:35 PM CSTTornado WatchSPCColbert, Fayette, Franklin, Lamar, Lauderdale, Lawrence and 6 more8 hr
Jan 21, 1:52 AM CSTMesoscale DiscussionSPCAutauga, Bibb, Blount, Calhoun, Chambers, Cherokee and 31 more113 min
Jan 21, 4:20 AM CSTMesoscale DiscussionSPCAutauga, Bibb, Blount, Calhoun, Chambers, Cherokee and 35 more55 min
Jan 21, 4:55 AM CSTTornado WatchSPCAutauga, Bibb, Blount, Calhoun, Chambers, Cherokee and 37 more7 hr
Jan 21, 7:22 AM CSTMesoscale DiscussionSPCAutauga, Bibb, Blount, Bullock, Calhoun, Chambers and 32 more83 min
Jan 21, 10:01 AM CSTMesoscale DiscussionSPCAutauga, Barbour, Bibb, Bullock, Butler, Chambers and 25 more59 min
Jan 21, 11:28 AM CSTTornado WatchSPCBarbour, Bullock, Chambers, Clay, Henry, Lee and 4 more8 hr
Jan 21, 4:48 PM CSTMesoscale DiscussionSPCHenry57 min

Nearby

Mesoscale Discussions in Georgia, 2012Mesoscale Discussions in South Carolina, 2012Mesoscale Discussions in Alabama, 2012Every mesoscale discussion in 2012

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.