Alert archive / Georgia / Mesoscale Discussions in 2012

Mesoscale Discussion 221

March 2, 201242 counties in Alabama; 48 counties in Georgia; Bradley County, Polk County, Tennessee

The Storm Prediction Center issued this mesoscale discussion at Mar 2, 2012, 5:41 PM CST for 42 counties in Alabama; 48 counties in Georgia; Bradley County, Polk County, Tennessee. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Mar 2, 2012, 5:41 PM CST (23:41 UTC)
Expired
Mar 2, 2012, 7:45 PM CST
In force
2 hr
Issued by
the Storm Prediction Center
All 92 counties

Autauga County, AL, Barbour County, AL, Bibb County, AL, Blount County, AL, Bullock County, AL, Butler County, AL, Calhoun County, AL, Chambers County, AL, Cherokee County, AL, Chilton County, AL, Choctaw County, AL, Clarke County, AL, Clay County, AL, Cleburne County, AL, Coffee County, AL, Conecuh County, AL, Coosa County, AL, Covington County, AL, Crenshaw County, AL, Dale County, AL, Dallas County, AL, DeKalb County, AL, Elmore County, AL, Etowah County, AL, Hale County, AL, Jefferson County, AL, Lee County, AL, Lowndes County, AL, Macon County, AL, Marengo County, AL, Marshall County, AL, Monroe County, AL, Montgomery County, AL, Perry County, AL, Pike County, AL, Randolph County, AL, Russell County, AL, Shelby County, AL, St. Clair County, AL, Talladega County, AL, Tallapoosa County, AL, Wilcox County, AL, Barrow County, GA, Bartow County, GA, Butts County, GA, Carroll County, GA, Catoosa County, GA, Chattahoochee County, GA, Chattooga County, GA, Cherokee 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, Harris County, GA, Heard County, GA, Henry County, GA, Lamar County, GA, Lumpkin County, GA, Meriwether County, GA, Murray County, GA, Muscogee County, GA, Newton County, GA, Paulding County, GA, Pickens County, GA, Pike County, GA, Polk County, GA, Rockdale County, GA, Spalding County, GA, Talbot County, GA, Troup County, GA, Union County, GA, Upson County, GA, Walker County, GA, Walton County, GA, White County, GA, Whitfield County, GA, Bradley County, TN, Polk County, TN

The nearest sounding before it

Birmingham, AL (KBMX), launched 12:00Z, 11.7 hours before the alert went out and 77 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, Birmingham, AL at 12:00Z on 2012-03-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 544 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, Birmingham, AL at 12:00Z on 2012-03-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 180 square meters per square second.1939587897117Sfc1 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
544 J/kg
Mixed-layer CIN
-15 J/kg
Mixed-layer LCL
530 m above ground
0-6 km bulk shear
59 kt
0-1 km storm-relative helicity
180 m²/s²
0-3 km storm-relative helicity
204 m²/s²
Significant tornado parameter
0.6
Supercell composite
2.5

Open this sounding in Storm Lab

The text

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

872 
ACUS11 KWNS 022341
SWOMCD
SPC MCD 022341 
GAZ000-NCZ000-TNZ000-ALZ000-030145-

MESOSCALE DISCUSSION 0221
NWS STORM PREDICTION CENTER NORMAN OK
0541 PM CST FRI MAR 02 2012

AREAS AFFECTED...MUCH OF SRN-CNTRL-NERN AL / W-CNTRL AND NWRN GA /
FAR SERN TN

CONCERNING...TORNADO WATCH 59...61...63...

VALID 022341Z - 030145Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH
59...61...63...CONTINUES.

TORNADIC SUPERCELL POTENTIAL WILL CONTINUE TO INCREASE THIS EVENING
AND INTO THE EARLY OVERNIGHT HOURS ACROSS A LARGE PORTION OF AL AND
WRN-NWRN GA.  ASIDE FROM THE THREAT OF TORNADOES /POTENTIALLY
SIGNIFICANT/...SUPERCELLS WILL ALSO POSE AN ACCOMPANYING DMGG
STRAIGHT-LINE WINDS RISK.

23Z SURFACE ANALYSIS SHOWS A LARGE UNIMPEDED WARM/MOIST SECTOR
ACROSS AL AND MOVING INTO WRN PARTS OF GA --AHEAD OF A DRYLINE OVER
NWRN MS.  3 HR CHANGE IN SURFACE TEMP/DEWPOINT SHOW A DECREASE OF
2-7 DEG F AND A 2 DEG F INCREASE...RESPECTIVELY.  THE FORECAST
CONTINUED TREND IN LOWERING SURFACE SPREADS AND LESS SUBSTANTIAL
BOUNDARY LAYER MIXING WILL SEEMINGLY PROVE MORE FAVORABLE FOR LOW
LEVEL MESOCYCLONES.  SLIGHT IMPROVEMENTS IN THE LOW LEVEL
THERMODYNAMIC PROFILE WILL ACCOMPANY A STRENGTHENING IN THE LLJ
/40-55 KTS/ FROM SWRN AND W-CNTRL AL NEWD INTO NRN GA IN THE NEXT
FEW HOURS.  THIS WILL SET THE STAGE FOR A POSSIBLE NOCTURNAL TORNADO
EPISODE FROM CNTRL AND E-CNTRL AL NEWD INTO N-CNTRL GA.  THIS
SCENARIO IS AT LEAST SUPPORTED TO A CERTAIN EXTENT BY THE LATEST
STORM-SCALE MODEL ENSEMBLE /SSEO/.  AS SUCH...SCATTERED DISCRETE
SUPERCELLS WILL POSE AN ATTENDANT ISOLD TORNADO THREAT --WITH
PERHAPS A FEW STRONG TORNADOES WITH THE MORE INTENSE SUPERCELLS.

..SMITH.. 03/02/2012

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

ATTN...WFO...GSP...MRX...FFC...TAE...BMX...HUN...MOB...

LAT...LON   32598809 34718606 35228482 34928377 34058355 33468366
            31108573 31158740 31898840 32598809

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 2, 9:07 AM CSTMesoscale DiscussionSPCDeKalb, Jackson, Lawrence, Limestone, Madison, Marshall and 1 more53 min
Mar 2, 9:25 AM CSTTornado WatchSPCDeKalb, Jackson, Lawrence, Limestone, Madison, Marshall and 1 more5 hr
Mar 2, 11:46 AM CSTMesoscale DiscussionSPCDeKalb, Jackson, Madison, Marshall, Morgan29 min
Mar 2, 12:57 PM CSTMesoscale DiscussionSPCColbert, Fayette, Franklin, Lamar, Lauderdale, Lawrence and 2 more63 min
Mar 2, 1:20 PM CSTTornado WatchSPCBlount, Colbert, Cullman, DeKalb, Fayette, Franklin and 14 more9 hr
Mar 2, 2:42 PM CSTMesoscale DiscussionSPCAutauga, Baldwin, Bullock, Butler, Choctaw, Clarke and 18 more63 min
Mar 2, 3:25 PM CSTMesoscale DiscussionSPCColbert, Cullman, Fayette, Franklin, Lamar, Lauderdale and 9 more65 min
Mar 2, 4:37 PM CSTTornado WatchSPCAutauga, Baldwin, Barbour, Bibb, Blount, Bullock and 50 more7 hr
Mar 2, 2:30 AM CSTMesoscale DiscussionSPCBanks, Dawson, Fannin, Franklin, Gilmer, Habersham and 8 more90 min
Mar 2, 1:58 PM CSTMesoscale DiscussionSPCBartow, Catoosa, Cherokee, Dawson, Fannin, Forsyth and 14 more62 min
Mar 2, 2:19 PM CSTTornado WatchSPCBanks, Bartow, Catoosa, Chattooga, Cherokee, Dade and 23 more8 hr
Mar 2, 3:40 AM CSTMesoscale DiscussionSPCClay, Fentress, Overton, Pickett, Scott65 min
Mar 2, 9:22 AM CSTMesoscale DiscussionSPCBenton, Carroll, Cheatham, Chester, Crockett, Davidson and 28 more113 min
Mar 2, 10:28 AM CSTMesoscale DiscussionSPCCrockett, Dyer, Fayette, Gibson, Haywood, Lake and 5 more62 min
Mar 2, 12:05 PM CSTMesoscale DiscussionSPCBenton, Carroll, Cheatham, Chester, Crockett, Davidson and 28 more85 min
Mar 2, 2:35 PM CSTMesoscale DiscussionSPCClay, Macon, Pickett, Sumner85 min

Nearby

Mesoscale Discussions in Georgia, 2012Mesoscale Discussions in Alabama, 2012Mesoscale Discussions in Tennessee, 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.