Alert archive / South Carolina / Mesoscale Discussions in 2012

Mesoscale Discussion 356

March 24, 20126 counties in Georgia; Brunswick County, Columbus County, Robeson County, North Carolina; 25 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at Mar 24, 2012, 10:20 PM EDT for 6 counties in Georgia; Brunswick County, Columbus County, Robeson County, North Carolina; 25 counties in South Carolina. It was in force for 115 min.

The area

The outline as issued.

The facts

Issued: Mar 24, 2012, 10:20 PM EDT (02:20 UTC)
Expired: Mar 25, 2012, 12:15 AM EDT
In force: 115 min
Issued by: the Storm Prediction Center

All 34 counties

Bulloch County, GA, Burke County, GA, Candler County, GA, Effingham County, GA, Jenkins County, GA, Screven County, GA, Brunswick County, NC, Columbus County, NC, Robeson County, NC, 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, Darlington County, SC, Dillon County, SC, Dorchester County, SC, Florence County, SC, Georgetown County, SC, Hampton County, SC, Horry County, SC, Jasper County, SC, Lee County, SC, Marion County, SC, Marlboro County, SC, Orangeburg County, SC, Richland County, SC, Sumter County, SC, Williamsburg County, SC

The radar

The Columbia radar (KCAE), 107 km from the middle of the area, began a volume at 02:20 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, 2.3 hours before the alert went out and 84 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: 218 J/kg
Mixed-layer CIN: -86 J/kg
Mixed-layer LCL: 911 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: 205 m²/s²
0-3 km storm-relative helicity: 213 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.6

Open this sounding in Storm Lab

The text

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

635 
ACUS11 KWNS 250220
SWOMCD
SPC MCD 250220 
NCZ000-SCZ000-GAZ000-250415-

MESOSCALE DISCUSSION 0356
NWS STORM PREDICTION CENTER NORMAN OK
0920 PM CDT SAT MAR 24 2012

AREAS AFFECTED...SERN GA...SERN NC...CNTRL/ERN SC

CONCERNING...SEVERE THUNDERSTORM WATCH 110...

VALID 250220Z - 250415Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 110
CONTINUES.

CLUSTERS OF STRONG TO SVR TSTMS WILL CONTINUE AFFECTING THE WW AREA
INTO THE OVERNIGHT HOURS. DESPITE THE DEVELOPMENT OF A STABLE
NOCTURNAL BOUNDARY LAYER...ELEVATED INSTABILITY CONTINUES TO BE
MAINTAINED OVER THE PIEDMONT AND COASTAL PLAIN AS THE UPSTREAM
MIXED-LAYER EXTENDING TO 700 MB /REF. 00Z PEACHTREE CITY GA RAOB/ IS
ADVECTED ATOP A PLUME OF RICHER LOW-LEVEL MOISTURE FEATURING SFC
DEWPOINTS IN THE UPPER 50S TO LOWER 60S. ASCENT OWING TO DCVA EAST
OF AN UPSTREAM...EWD-MOVING CLOSED LOW /PRECEDED BY 500-MB HEIGHT
FALLS IN EXCESS OF 60 GEOPOTENTIAL METERS IN 12 HOURS PER 00Z UPPER
AIR DATA/ WILL ALSO AID IN REDUCING CINH SUCH THAT ORGANIZED
CONVECTION WILL BE MAINTAINED EWD TOWARD THE COAST AMIDST A BROAD
AREA OF LOW-LEVEL CONFLUENCE EVIDENT IN REGIONAL VWP DATA. AS A ZONE
OF MODERATE MID-LEVEL FLOW AROUND THE LOW OVERLAYS THE
AREA...EFFECTIVE BULK SHEAR MAGNITUDES OF 35-50 KT WILL SUPPORT
ORGANIZED LINE SEGMENTS...THOUGH OCCASIONAL SUPERCELL STRUCTURES
WILL BE POSSIBLE OVER SRN PORTIONS OF THE WW AREA WITH SEMI-DISCRETE
CONVECTION. SVR HAIL WILL BE THE PRIMARY CONCERN WITH THIS ACTIVITY.
HOWEVER...THE THREAT FOR DMGG WIND GUSTS WILL ALSO
EXIST...PARTICULARLY WITH MERGING COLD POOLS...AND WILL BE AIDED BY
THE INTRUSION OF A MID-LEVEL DRY SLOT INTO THE AREA.

..COHEN.. 03/25/2012

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

ATTN...WFO...RAH...ILM...CHS...CAE...FFC...

LAT...LON   34707964 34707863 33837806 33077883 31898064 32318218
            33348200 34338054 34707964

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Mar 24, 8:43 PM EDT	Severe Thunderstorm Watch	SPC	Bulloch, Burke, Candler, Effingham, Jenkins, Screven	5 hr
Mar 25, 12:33 AM EDT	Mesoscale Discussion	SPC	Brantley, Bryan, Camden, Charlton, Chatham, Effingham and 7 more	57 min
Mar 24, 10:23 PM EDT	Mesoscale Discussion	SPC	Bertie, Edgecombe, Franklin, Greene, Halifax, Hertford and 8 more	97 min
Mar 25, 12:31 PM EDT	Mesoscale Discussion	SPC	Beaufort, Bertie, Bladen, Brunswick, Carteret, Chowan and 26 more	2 hr
Mar 25, 5:56 PM EDT	Mesoscale Discussion	SPC	Bladen, Brunswick, Carteret, Columbus, Craven, Dare and 7 more	94 min

Nearby

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