Alert archive / Georgia / Mesoscale Discussions in 2012

Mesoscale Discussion 1685

August 2, 201281 counties in Georgia; 10 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at Aug 2, 2012, 4:24 PM EDT for 81 counties in Georgia; 10 counties in South Carolina. It was in force for 66 min.

The area

The outline as issued.

The facts

Issued
Aug 2, 2012, 4:24 PM EDT (20:24 UTC)
Expired
Aug 2, 2012, 5:30 PM EDT
In force
66 min
Issued by
the Storm Prediction Center
All 91 counties

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, Calhoun County, GA, Camden County, GA, Candler County, GA, Charlton County, GA, Chatham County, GA, Chattahoochee County, GA, Clinch County, GA, Coffee County, GA, Colquitt County, GA, Cook County, GA, Crawford County, GA, Crisp County, GA, Dodge County, GA, Dooly County, GA, Dougherty County, GA, Echols County, GA, Effingham County, GA, Emanuel County, GA, Evans County, GA, Glascock County, GA, Glynn County, GA, Grady County, GA, Houston County, GA, Irwin County, GA, Jeff Davis County, GA, Jefferson County, GA, Jenkins County, GA, Johnson 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, McIntosh County, GA, Miller County, GA, Mitchell County, GA, Montgomery County, GA, Peach County, GA, Pierce County, GA, Pulaski County, GA, Randolph County, GA, Richmond County, GA, Schley County, GA, Screven County, GA, Stewart County, GA, Sumter 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, Ware 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, Beaufort County, SC, Calhoun County, SC, Colleton County, SC, Dorchester County, SC, Hampton County, SC, Jasper County, SC, Orangeburg County, SC

The nearest sounding before it

Jacksonville, FL (KJAX), launched 12:00Z, 8.4 hours before the alert went out and 134 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, Jacksonville, FL at 12:00Z on 2012-08-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3176 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, Jacksonville, FL at 12:00Z on 2012-08-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -5 square meters per square second.1939Sfc1 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
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

Open this sounding in Storm Lab

The text

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

366 
ACUS11 KWNS 022024
SWOMCD
SPC MCD 022024 
SCZ000-GAZ000-FLZ000-ALZ000-022130-

MESOSCALE DISCUSSION 1685
NWS STORM PREDICTION CENTER NORMAN OK
0324 PM CDT THU AUG 02 2012

AREAS AFFECTED...SWRN SC...CNTRL/SRN GA

CONCERNING...SEVERE THUNDERSTORM WATCH 550...

VALID 022024Z - 022130Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 550
CONTINUES.

SUMMARY...DMGG WIND GUST AND HAIL POTENTIAL WILL CONTINUE ACROSS
PARTS OF CNTRL/SRN GA AND SWRN SC...ESPECIALLY ACROSS AREAS THAT
HAVE NOT BEEN CONVECTIVELY OVERTURNED.

DISCUSSION...WIDELY SCT TSTMS ARE ONGOING ACROSS CNTRL/SRN GA AND
SWRN SC...WITH INDIVIDUAL CELLS GENERALLY SHORT-LIVED AND PULSE-LIKE
IN NATURE...ALTHOUGH LOOSELY ORGANIZED MULTICELL STRUCTURES HAVE
BEEN OBSERVED ON OCCASION. SIGNIFICANT CONVECTIVE OVERTURNING HAS
LIKELY OCCURRED ACROSS MUCH OF THE WATCH AREA...WITH MANY
OBSERVATION SITES REPORTING TEMPERATURES IN THE 70S/80S F AS OF 20Z.
HOWEVER...POCKETS OF GREATER INSTABILITY AND WARMER BOUNDARY LAYER
TEMPERATURES STILL EXIST...PARTICULARLY OVER SRN GA...AND WILL HAVE
THE GREATEST POTENTIAL FOR NEW CONVECTION TO PRODUCE DMGG WIND GUSTS
AND MARGINALLY SVR HAIL. TSTM COVERAGE IS ALSO BEGINNING TO INCREASE
TO THE W OF THE WATCH AREA ACROSS SWRN GA...BUT SO FAR THIS THREAT
HAS REMAINED MORE ISOLATED/LOCALIZED.

..ROGERS/WEISS.. 08/02/2012

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

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

LAT...LON   32568023 31968092 30828143 30678141 30738174 30778194
            30338204 30378220 30548225 30578254 30738405 30998487
            32238496 32808422 33528170 33818078 33388006 32628014
            32568023

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 1, 8:54 PM EDTMesoscale DiscussionSPCBartow, Catoosa, Chattooga, Cherokee, Dade, Dawson and 11 more66 min
Aug 2, 1:11 PM EDTMesoscale DiscussionSPCAppling, Atkinson, Bacon, Baker, Baldwin, Ben Hill and 91 more64 min
Aug 2, 2:33 PM EDTSevere Thunderstorm WatchSPCAppling, Atkinson, Bacon, Bleckley, Brantley, Bryan and 35 more5 hr

Nearby

Mesoscale Discussions in Georgia, 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.