Alert archive / Georgia / Mesoscale Discussions in 2012

Mesoscale Discussion 1544

July 22, 201249 counties in Georgia; 20 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at Jul 22, 2012, 4:39 PM EDT for 49 counties in Georgia; 20 counties in South Carolina. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Jul 22, 2012, 4:39 PM EDT (20:39 UTC)
Expired: Jul 22, 2012, 6:45 PM EDT
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 5%

All 69 counties

Appling County, GA, Atkinson County, GA, Bacon County, GA, Ben Hill County, GA, Berrien County, GA, Bleckley County, GA, Bryan County, GA, Bulloch County, GA, Burke County, GA, Candler County, GA, Clinch County, GA, Coffee County, GA, Colquitt County, GA, Columbia County, GA, Cook County, GA, Dodge County, GA, Echols County, GA, Effingham County, GA, Emanuel County, GA, Evans County, GA, Glascock County, GA, Irwin County, GA, Jeff Davis County, GA, Jefferson County, GA, Jenkins County, GA, Johnson County, GA, Lanier County, GA, Laurens County, GA, Long County, GA, Lowndes County, GA, McDuffie County, GA, Montgomery County, GA, Pierce County, GA, Pulaski County, GA, Richmond County, GA, Screven County, GA, Tattnall County, GA, Telfair County, GA, Tift County, GA, Toombs County, GA, Treutlen County, GA, Turner County, GA, Ware County, GA, Warren County, GA, Washington County, GA, Wayne County, GA, Wheeler County, GA, Wilcox County, GA, Worth County, GA, Aiken County, SC, Allendale County, SC, Bamberg County, SC, Barnwell County, SC, Berkeley County, SC, Calhoun County, SC, Clarendon County, SC, Colleton County, SC, Dorchester County, SC, Edgefield County, SC, Hampton County, SC, Jasper County, SC, Kershaw County, SC, Lee County, SC, Lexington County, SC, Orangeburg County, SC, Richland County, SC, Saluda County, SC, Sumter County, SC, Williamsburg County, SC

The radar

The Charleston,SC radar (KCLX), 94 km from the middle of the area, began a volume at 20:40 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

Charleston AFB, SC (KCHS), launched 12:00Z, 8.7 hours before the alert went out and 195 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 3219 J/kg
Mixed-layer CIN: -11 J/kg
Mixed-layer LCL: 688 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: 16 m²/s²
0-3 km storm-relative helicity: 47 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.

348 
ACUS11 KWNS 222039
SWOMCD
SPC MCD 222039 
SCZ000-GAZ000-222245-

MESOSCALE DISCUSSION 1544
NWS STORM PREDICTION CENTER NORMAN OK
0339 PM CDT SUN JUL 22 2012

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

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 222039Z - 222245Z

PROBABILITY OF WATCH ISSUANCE...5 PERCENT

SUMMARY...STRONG STORMS WILL BE POSSIBLE THROUGH THE LATE AFTERNOON.
WHILE AN ISOLATED MARGINALLY SVR STORM CANNOT BE RULED OUT...WW
ISSUANCE IS NOT NEEDED.

DISCUSSION...WITH WEAK LOW-LEVEL ASCENT ALONG SUBTLE SFC
BOUNDARIES/SEA-BREEZE CONVERGENCE ZONES AMIDST ENHANCED MID-LEVEL
MOISTURE PER WATER VAPOR IMAGERY...ISOLATED TO WIDELY SCATTERED
THUNDERSTORMS HAVE DEVELOPED. THIS ACTIVITY WILL CONTINUE INTO THE
LATE AFTERNOON HOURS...AS SFC TEMPERATURES HAVE CLIMBED INTO THE
LOWER/MIDDLE 90S. AND...WITH SFC DEWPOINTS IN THE LOWER 70S...MLCAPE
VALUES OF 1500-3000 J/KG ARE IN PLACE PER MODIFICATIONS TO 12Z RAOBS
AND FORECAST SOUNDINGS. THIS DEGREE OF BUOYANCY WILL SUPPORT INTENSE
UPDRAFTS/DOWNDRAFTS...WITH STRONG WIND GUSTS ATTENDANT TO
MICROBURSTS POSSIBLE. STEEP LOW-LEVEL LAPSE RATES SUPPORTING DCAPE
VALUES IN EXCESS OF 1000 J/KG IN MANY AREAS COULD SUPPORT AN
ISOLATED MARGINALLY SVR WIND GUST. HOWEVER...WEAK LOW/MID-LEVEL FLOW
PER VWP DATA AND WEAK MID-LEVEL LAPSE RATES WILL GREATLY LIMIT THE
SVR THREAT. STORMS ARE EXPECTED TO DECREASE IN NUMBER AND INTENSITY
THROUGH THE EVENING AS NOCTURNAL STABILIZATION OCCURS.

..COHEN/HART.. 07/22/2012

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

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

LAT...LON   30898378 31508397 33428274 34228158 34418052 33727956
            33047976 32478080 31618172 30858235 30698294 30898378

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 22, 3:38 PM EDT	Mesoscale Discussion	SPC	Brooks, Decatur, Grady, Seminole, Thomas	3 hr
Jul 22, 2:20 PM EDT	Mesoscale Discussion	SPC	Cherokee, Chesterfield, Dillon, Lancaster, Marlboro, York	2 hr

Nearby

Mesoscale Discussions in Georgia, 2012 Mesoscale Discussions in South Carolina, 2012 Every 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.