Alert archive / Georgia / Mesoscale Discussions in 2012
Mesoscale Discussion 42
The Storm Prediction Center issued this mesoscale discussion at Jan 21, 2012, 10:01 AM CST for 4 states. It was in force for 59 min.
The area
The outline as issued.
The facts
- Issued
- Jan 21, 2012, 10:01 AM CST (16:01 UTC)
- Expired
- Jan 21, 2012, 11:00 AM CST
- In force
- 59 min
- Issued by
- the Storm Prediction Center
All 128 counties
Autauga County, AL, Barbour County, AL, Bibb County, AL, Bullock County, AL, Butler County, AL, Chambers County, AL, Chilton County, AL, Choctaw County, AL, Clarke County, AL, Clay County, AL, Cleburne County, AL, Coosa County, AL, Crenshaw County, AL, Dallas County, AL, Elmore County, AL, Greene County, AL, Hale County, AL, Lee County, AL, Lowndes County, AL, Macon County, AL, Marengo County, AL, Montgomery County, AL, Perry County, AL, Pike County, AL, Randolph County, AL, Russell County, AL, Shelby County, AL, Sumter County, AL, Talladega County, AL, Tallapoosa County, AL, Wilcox County, AL, Baldwin County, GA, Banks County, GA, Barrow County, GA, Bibb County, GA, Bleckley County, GA, Burke County, GA, Butts County, GA, Carroll County, GA, Chattahoochee County, GA, Clarke County, GA, Clayton County, GA, Cobb County, GA, Columbia County, GA, Coweta County, GA, Crawford County, GA, Crisp County, GA, DeKalb County, GA, Dooly County, GA, Douglas County, GA, Elbert County, GA, Fayette County, GA, Franklin County, GA, Fulton County, GA, Glascock County, GA, Greene County, GA, Gwinnett County, GA, Hancock County, GA, Haralson County, GA, Harris County, GA, Hart County, GA, Heard County, GA, Henry County, GA, Houston County, GA, Jackson County, GA, Jasper County, GA, Jefferson 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, Morgan County, GA, Muscogee County, GA, Newton County, GA, Oconee County, GA, Oglethorpe County, GA, Paulding 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, Spalding County, GA, Stewart County, GA, Sumter County, GA, Talbot County, GA, Taliaferro County, GA, Taylor County, GA, Terrell County, GA, Troup County, GA, Twiggs County, GA, Upson County, GA, Walton County, GA, Warren County, GA, Washington County, GA, Webster County, GA, Wilkes County, GA, Wilkinson County, GA, Kemper County, MS, Lauderdale County, MS, Abbeville County, SC, Aiken County, SC, Anderson County, SC, Barnwell County, SC, Calhoun County, SC, Chester County, SC, Edgefield County, SC, Fairfield County, SC, Greenwood County, SC, Laurens County, SC, Lexington County, SC, McCormick County, SC, Newberry County, SC, Richland County, SC, Saluda County, SC, Union County, SC
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, 4.0 hours before the alert went out and 94 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.
- 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
The text
As transmitted, in the capitals the NWS used until 2016.
064
ACUS11 KWNS 211602
SWOMCD
SPC MCD 211601
SCZ000-GAZ000-ALZ000-MSZ000-211700-
MESOSCALE DISCUSSION 0042
NWS STORM PREDICTION CENTER NORMAN OK
1001 AM CST SAT JAN 21 2012
AREAS AFFECTED...ECNTRL MS...AL...GA...SC
CONCERNING...TORNADO WATCH 3...
VALID 211601Z - 211700Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 3 CONTINUES.
BACK EDGE OF WELL DEFINED SHORTWAVE TROUGH HAS PROGRESSED INTO CNTRL
AL LATE THIS MORNING. THIS APPEARS TO BE LOOSELY CORRELATED WITH A
STRONGER CLUSTER OF STORMS ELONGATED IN A SW-NE FASHION JUST AHEAD
OF PRIMARY FRONTAL ZONE. GIVEN THAT THE UPPER TROUGH IS SHIFTING
EAST AT ROUGHLY 45KT IT WOULD SEEM THIS MORE FOCUSED TSTM ACTIVITY
SHOULD SPREAD/PROPAGATE DOWNSTREAM INTO CNTRL GA BY 17Z WITH
SUBSEQUENT DEVELOPMENT INTO SC DURING THE EARLY AFTERNOON HOURS.
THE AFFECTS OF INCREASING LARGE SCALE ASCENT ARE BEGINNING TO BE
NOTED ALONG NERN-MOST EDGE OF MOIST PLUME WHERE THUNDERSTORM
UPDRAFTS ARE GRADUALLY INTENSIFYING ACROSS NERN GA. GIVEN THESE
TRENDS IT APPEARS ATMOSPHERIC CONDITIONS WILL BECOME INCREASINGLY
FAVORABLE FOR SEVERE THUNDERSTORMS JUST DOWNSTREAM OF WW3 OVER THE
NEXT FEW HOURS AND A NEW WW WILL LIKELY BE WARRANTED BY 18Z.
OTHERWISE...TRAILING FRONTAL CONVECTION WILL GRADUALLY SAG SEWD AT
20-25KT IN THE WAKE OF SHORTWAVE TROUGH ACROSS THE REMAINDER OF AL
POSSIBLY APPROACHING THE NRN FL PANHANDLE LATE IN THE AFTERNOON.
..DARROW.. 01/21/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...CHS...CAE...GSP...FFC...TAE...BMX...MOB...JAN...
LAT...LON 32778913 33928522 34978128 33608063 31658425 31578833
32778913SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jan 20, 10:02 PM CST | Mesoscale Discussion | SPC | Colbert, Lauderdale, Limestone | 88 min |
| Jan 20, 10:35 PM CST | Tornado Watch | SPC | Colbert, Fayette, Franklin, Lamar, Lauderdale, Lawrence and 6 more | 8 hr |
| Jan 21, 1:52 AM CST | Mesoscale Discussion | SPC | Autauga, Bibb, Blount, Calhoun, Chambers, Cherokee and 31 more | 113 min |
| Jan 21, 4:20 AM CST | Mesoscale Discussion | SPC | Autauga, Bibb, Blount, Calhoun, Chambers, Cherokee and 35 more | 55 min |
| Jan 21, 4:55 AM CST | Tornado Watch | SPC | Autauga, Bibb, Blount, Calhoun, Chambers, Cherokee and 37 more | 7 hr |
| Jan 21, 7:22 AM CST | Mesoscale Discussion | SPC | Autauga, Bibb, Blount, Bullock, Calhoun, Chambers and 32 more | 83 min |
| Jan 21, 11:28 AM CST | Tornado Watch | SPC | Barbour, Bullock, Chambers, Clay, Henry, Lee and 4 more | 8 hr |
| Jan 21, 1:57 PM CST | Mesoscale Discussion | SPC | Barbour, Bullock, Chambers, Clay, Henry, Lee and 4 more | 63 min |
| Jan 21, 4:48 PM CST | Mesoscale Discussion | SPC | Henry | 57 min |
Nearby
Mesoscale Discussions in Georgia, 2012Mesoscale Discussions in Alabama, 2012Mesoscale Discussions in South Carolina, 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.