Alert archive / Georgia / Mesoscale Discussions in 2012
Mesoscale Discussion 1683
The Storm Prediction Center issued this mesoscale discussion at Aug 2, 2012, 12:11 PM CDT for 5 counties in Alabama; 97 counties in Georgia; 5 counties in South Carolina. It was in force for 64 min.
The area
The outline as issued.
The facts
- Issued
- Aug 2, 2012, 12:11 PM CDT (17:11 UTC)
- Expired
- Aug 2, 2012, 1:15 PM CDT
- In force
- 64 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 40%
All 107 counties
Barbour County, AL, Bullock County, AL, Henry County, AL, Lee County, AL, Russell County, AL, Appling County, GA, Atkinson County, GA, Bacon County, GA, Baker County, GA, Baldwin County, GA, Ben Hill County, GA, Berrien County, GA, Bibb County, GA, Bleckley County, GA, Brantley County, GA, Brooks County, GA, Bryan County, GA, Bulloch County, GA, Burke County, GA, Butts County, GA, Calhoun County, GA, Candler County, GA, Charlton County, GA, Chattahoochee County, GA, Clay County, GA, Clinch County, GA, Coffee County, GA, Colquitt County, GA, Cook County, GA, Crawford County, GA, Crisp County, GA, Decatur County, GA, Dodge County, GA, Dooly County, GA, Dougherty County, GA, Early County, GA, Echols County, GA, Effingham County, GA, Emanuel County, GA, Evans County, GA, Glascock County, GA, Glynn County, GA, Grady County, GA, Hancock County, GA, Harris County, GA, Houston County, GA, Irwin County, GA, Jasper County, GA, Jeff Davis County, GA, Jefferson County, GA, Jenkins County, GA, Johnson County, GA, Jones County, GA, Lamar County, GA, Lanier County, GA, Laurens County, GA, Lee County, GA, Liberty County, GA, Long County, GA, Lowndes County, GA, Macon County, GA, Marion County, GA, McDuffie County, GA, Meriwether County, GA, Miller County, GA, Mitchell County, GA, Monroe County, GA, Montgomery County, GA, Muscogee County, GA, Peach County, GA, Pierce County, GA, Pike County, GA, Pulaski County, GA, Putnam County, GA, Quitman County, GA, Randolph County, GA, Richmond County, GA, Schley County, GA, Screven County, GA, Stewart County, GA, Sumter County, GA, Talbot County, GA, Tattnall County, GA, Taylor County, GA, Telfair County, GA, Terrell County, GA, Thomas County, GA, Tift County, GA, Toombs County, GA, Treutlen County, GA, Turner County, GA, Twiggs County, GA, Upson County, GA, Ware County, GA, Warren County, GA, Washington County, GA, Wayne County, GA, Webster County, GA, Wheeler County, GA, Wilcox County, GA, Wilkinson County, GA, Worth County, GA, Allendale County, SC, Bamberg County, SC, Barnwell County, SC, Hampton County, SC, Orangeburg County, SC
The radar
The Robins AFB radar (KJGX), 88 km from the middle of the area, began a volume at 17:15 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
Jacksonville, FL (KJAX), launched 12:00Z, 5.2 hours before the alert went out and 209 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
- 3176 J/kg
- Mixed-layer CIN
- -14 J/kg
- Mixed-layer LCL
- 572 m above ground
- 0-6 km bulk shear
- 13 kt
- 0-1 km storm-relative helicity
- -5 m²/s²
- 0-3 km storm-relative helicity
- 14 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
766
ACUS11 KWNS 021711
SWOMCD
SPC MCD 021711
SCZ000-GAZ000-FLZ000-ALZ000-021815-
MESOSCALE DISCUSSION 1683
NWS STORM PREDICTION CENTER NORMAN OK
1211 PM CDT THU AUG 02 2012
AREAS AFFECTED...SERN AL...CNTRL/SRN GA...SWRN SC
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 021711Z - 021815Z
PROBABILITY OF WATCH ISSUANCE...40 PERCENT
SUMMARY...TSTMS ARE DEVELOPING WITHIN A VERY UNSTABLE AIR MASS OVER
CNTRL/SRN GA AND PARTS OF SWRN SC. ALTHOUGH DEEP-LAYER FLOW IS
RATHER WEAK...THESE SLOW-MOVING STORMS WILL HAVE THE POTENTIAL TO
PRODUCE ISOLATED STRONG-SVR WIND GUSTS AND SOME HAIL. IF CONVECTIVE
TRENDS SHOW THE POTENTIAL FOR SOME ORGANIZATION INTO MULTICELL
CLUSTERS...THEN A WATCH MAY BE NEEDED.
DISCUSSION...VISIBLE SATELLITE IMAGERY SHOWS DEVELOPING TOWERING
CU/CB FIELDS ALONG WEAKLY CONFLUENT DIFFERENTIAL HEATING BOUNDARIES.
12Z FFC/JAX SOUNDINGS MODIFIED WITH 17Z SFC OBS SHOWS EXTREME
READINGS OF POTENTIAL INSTABILITY...WITH MLCAPE VALUES APPROACHING
4000 J/KG. ADDITIONALLY...DRY MIDLEVEL /EVIDENT ON BOTH MORNING
SOUNDINGS AND WATER VAPOR IMAGERY/ WILL LIKELY CONTRIBUTE TO
DOWNDRAFT INTENSITY...AND ALONG WITH STRONG BOUNDARY LAYER HEATING
AND STEEPENING LOW-LEVEL LAPSE RATES...WILL SUPPORT DCAPE VALUES AOA
1000 J/KG. THE PRIMARY LIMITING FACTORS FOR A MORE ORGANIZED SVR
THREAT APPEAR TO BE A WEAKNESS IN LOW/MID-LEVEL FLOW...AND LACK OF
DISCERNABLE MESOSCALE FORCING MECHANISMS. THUS...STORM MODE MAY TEND
TO FAVOR PULSE CONVECTION...BUT SOME LOOSELY ORGANIZED MULTICELL
CLUSTERS MAY EVOLVE VIA CELL MERGERS AND COOL POOL INTERACTIONS.
NONETHELESS...THE STRONGEST STORMS WILL BE CAPABLE OF PRODUCING DMGG
WINDS AND HAIL.
..ROGERS/WEISS.. 08/02/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...CHS...CAE...JAX...FFC...TAE...BMX...
LAT...LON 31238147 30748204 30578322 30818472 31768584 32858549
33498355 33488177 33598137 33498081 33328062 32338112
31238147SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 1, 7:54 PM CDT | Mesoscale Discussion | SPC | DeKalb, Jackson, Limestone, Madison | 66 min |
| Aug 2, 1:33 PM CDT | Severe Thunderstorm Watch | SPC | Appling, Atkinson, Bacon, Bleckley, Brantley, Bryan and 35 more | 5 hr |
| Aug 2, 3:24 PM CDT | Mesoscale Discussion | SPC | Appling, Atkinson, Bacon, Baker, Baldwin, Ben Hill and 75 more | 66 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; radar from the NEXRAD Level II archive.