Alert archive / South Carolina / Mesoscale Discussions in 2012

Mesoscale Discussion 610

April 27, 20126 counties in Georgia; 32 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at Apr 27, 2012, 8:54 PM EDT for 6 counties in Georgia; 32 counties in South Carolina. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued
Apr 27, 2012, 8:54 PM EDT (00:54 UTC)
Expired
Apr 27, 2012, 10:30 PM EDT
In force
96 min
Issued by
the Storm Prediction Center
All 38 counties

Columbia County, GA, Elbert County, GA, Hart County, GA, Lincoln County, GA, Oglethorpe County, GA, Wilkes County, GA, Abbeville County, SC, Aiken County, SC, Anderson County, SC, Berkeley County, SC, Calhoun County, SC, Chester County, SC, Clarendon County, SC, Darlington County, SC, Dillon County, SC, Edgefield County, SC, Fairfield County, SC, Florence County, SC, Georgetown County, SC, Greenville County, SC, Greenwood County, SC, Horry County, SC, Kershaw County, SC, Lancaster County, SC, Laurens County, SC, Lee County, SC, Lexington County, SC, Marion County, SC, McCormick County, SC, Newberry County, SC, Oconee County, SC, Orangeburg County, SC, Pickens County, SC, Richland County, SC, Saluda County, SC, Sumter County, SC, Union County, SC, Williamsburg County, SC

The radar

The Columbia radar (KCAE), 41 km from the middle of the area, began a volume at 00:54 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 00:00Z, 0.9 hours before the alert went out and 197 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, Charleston AFB, SC at 00:00Z on 2012-04-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 10 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, Charleston AFB, SC at 00:00Z on 2012-04-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 99 square meters per square second.193958Sfc1 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
10 J/kg
Mixed-layer CIN
-276 J/kg
Mixed-layer LCL
1877 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
99 m²/s²
0-3 km storm-relative helicity
126 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.

950 
ACUS11 KWNS 280054
SWOMCD
SPC MCD 280054 
NCZ000-SCZ000-GAZ000-280230-

MESOSCALE DISCUSSION 0610
NWS STORM PREDICTION CENTER NORMAN OK
0754 PM CDT FRI APR 27 2012

AREAS AFFECTED...PORTIONS OF ERN GA...NRN AND CNTRL SC...SRN NC

CONCERNING...SEVERE THUNDERSTORM WATCH 195...

VALID 280054Z - 280230Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 195
CONTINUES.

AT 0045Z...MULTICELL CLUSTERS CONTINUE TO PERSIST ALONG A FRONTAL
ZONE FROM ROUGHLY 10 N OF AHN IN ERN GA EWD ACROSS CNTRL/NRN SC INTO
SRN NC. SURFACE OBSERVATIONS ALONG AND S OF THE FRONT INDICATE THAT
THE BOUNDARY LAYER IS COOLING/STABILIZING WITH LOSS OF DAYTIME
HEATING...RESULTING IN RAPIDLY WEAKENING LOW-LEVEL LAPSE RATES AND
MLCAPE VALUES FALLING TO AROUND 500 J/KG BASED ON OBJECTIVE ANALYSIS
GUIDANCE. GIVEN THESE TRENDS...AS WELL AS A LACK OF LARGE-SCALE
FORCING FOR ASCENT OVER THE REGION...STORM CLUSTERS WILL LIKELY
DECREASE IN INTENSITY DURING THE NIGHT AS THEY DRIFT EWD ACROSS WW
195...WHICH WILL RESULT IN AN INCREASINGLY MORE ISOLATED SVR WEATHER
THREAT.

..GARNER.. 04/28/2012

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

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

LAT...LON   35068311 34437884 32987884 33628311 35068311

Nearby

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