Alert archive / South Carolina / Mesoscale Discussions in 2005

Mesoscale Discussion 2004

August 17, 200528 counties in Georgia; 29 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at Aug 17, 2005, 1:12 PM EDT for 28 counties in Georgia; 29 counties in South Carolina. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Aug 17, 2005, 1:12 PM EDT (17:12 UTC)
Expired: Aug 17, 2005, 3:15 PM EDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 57 counties

Appling County, GA, Bryan County, GA, Bulloch County, GA, Burke County, GA, Candler County, GA, Chatham County, GA, Columbia County, GA, Effingham County, GA, Emanuel County, GA, Evans County, GA, Glascock County, GA, Jefferson County, GA, Jenkins County, GA, Johnson County, GA, Liberty County, GA, Lincoln County, GA, Long County, GA, McDuffie County, GA, McIntosh County, GA, Montgomery County, GA, Richmond County, GA, Screven County, GA, Tattnall County, GA, Toombs County, GA, Treutlen County, GA, Warren County, GA, Wayne County, GA, Wilkes County, GA, Aiken County, SC, Allendale County, SC, Bamberg County, SC, Barnwell County, SC, Beaufort County, SC, Berkeley County, SC, Calhoun County, SC, Charleston County, SC, Clarendon County, SC, Colleton County, SC, Dorchester County, SC, Edgefield County, SC, Florence County, SC, Georgetown County, SC, Greenwood County, SC, Hampton County, SC, Horry County, SC, Jasper County, SC, Kershaw County, SC, Lee County, SC, Lexington County, SC, Marion County, SC, McCormick County, SC, Newberry County, SC, Orangeburg County, SC, Richland County, SC, Saluda County, SC, Sumter County, SC, Williamsburg County, SC

The radar

The Charleston,SC radar (KCLX), 63 km from the middle of the area, began a volume at 17:11 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, 5.2 hours before the alert went out and 62 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: 2451 J/kg
Mixed-layer CIN: -29 J/kg
Mixed-layer LCL: 847 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 32 m²/s²
0-3 km storm-relative helicity: 53 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.

000 
ACUS11 KWNS 171712
SWOMCD
SPC MCD 171712 
SCZ000-GAZ000-171915-

MESOSCALE DISCUSSION 2004
NWS STORM PREDICTION CENTER NORMAN OK
1212 PM CDT WED AUG 17 2005

AREAS AFFECTED...CENTRAL/ERN SC...ERN GA

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 171712Z - 171915Z

ISOLATED SVR STORMS ARE POSSIBLE BY 19Z OVER CENTRAL/ERN SC AHEAD OF
A SLOW MOVING WEAK COLD FRONT. CONVECTION MAY DEVELOP INTO A SMALL
CLUSTER LATER THIS AFTERNOON WITH SOME INCREASE IN DMGG WIND THREAT
POSSIBLE INTO ERN GA. WE WILL CONTINUE TO MONITOR TRENDS FOR A
POSSIBLE OUTLOOK UPGRADE AND WW. 

VERY WARM AND UNSTABLE AIRMASS WAS IN PLACE ACROSS SC...WITH MLCAPES
FROM 2500-3000 J/KG. AT MID LEVELS...DRY AIR WAS EVIDENT PER WV
IMAGERY OVER SRN SC INTO ERN/SRN GA. INCIPIENT TSTMS DEVELOPING
ALONG A THE LEADING EDGE OF A WEAK COLD FRONTAL BOUNDARY EXTENDING
FROM NW OF CAE TO MYR WILL CONTINUE TO INTENSIFY OVER THE NEXT FEW
HOURS...AS THEY MOVE SWD AROUND 10-15 KTS. DESPITE WEAK AMBIENT
VERTICAL SHEAR...THE COMBINATION OF MODERATE INSTABILITY...STEEP LOW
LEVEL LAPSE RATES AND AMBIENT MID LEVEL DRY AIR WILL FAVOR ISOLATED
WET MICROBURSTS. GIVEN A FOCUSING MECHANISM WITH THE FRONTAL
BOUNDARY...IT IS POSSIBLE THAT AN SEMI-ORGANIZED CONVECTIVE LINE MAY
DEVELOP BY THE 20-22Z TIME FRAME AS CONVECTION MOVES INTO SRN SC AND
EVENTUALLY ERN GA. IF THIS BECOMES APPARENT BEFORE THEN...AREA MAY
NEED TO BE UPGRADED TO A SLIGHT RISK AND WW ISSUANCE WOULD BE
CONSIDERED.

..CROSBIE.. 08/17/2005

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

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

33867868 34237943 34378028 34378191 33738289 31938258
31438194 31358122 32028087 32867978 33167916

Nearby

Mesoscale Discussions in South Carolina, 2005 Mesoscale Discussions in Georgia, 2005 Every mesoscale discussion in 2005

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.