Alert archive / South Carolina / Mesoscale Discussions in 2011

Mesoscale Discussion 722

May 11, 20118 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at May 11, 2011, 1:35 AM EDT for 8 counties in South Carolina. It was in force for 25 min.

The area

The outline as issued.

The facts

Issued: May 11, 2011, 1:35 AM EDT (05:35 UTC)
Expired: May 11, 2011, 2:00 AM EDT
In force: 25 min
Issued by: the Storm Prediction Center

Counties Berkeley County, SC, Charleston County, SC, Darlington County, SC, Dorchester County, SC, Florence County, SC, Georgetown County, SC, Marion County, SC, Williamsburg County, SC

The radar

The Columbia radar (KCAE), 120 km from the middle of the area, began a volume at 05:36 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

Severe Thunderstorm Watch 276May 11, 1:40 AM EDT

The nearest sounding before it

Charleston AFB, SC (KCHS), launched 00:00Z, 5.6 hours before the alert went out and 85 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: 2852 J/kg
Mixed-layer CIN: -45 J/kg
Mixed-layer LCL: 899 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: 110 m²/s²
0-3 km storm-relative helicity: 221 m²/s²
Significant tornado parameter: 3.0
Supercell composite: 14.5

Open this sounding in Storm Lab

The text

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

803 
ACUS11 KWNS 110535
SWOMCD
SPC MCD 110535 
SCZ000-110600-

MESOSCALE DISCUSSION 0722
NWS STORM PREDICTION CENTER NORMAN OK
1235 AM CDT WED MAY 11 2011

AREAS AFFECTED...PARTS OF ERN AND SERN SC

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 

VALID 110535Z - 110600Z

NEW WW WILL BE COORDINATED SOON FOR ERN AND SERN SC.

CURRENT SPEED OF A BOWING STRUCTURE IN UPSTATE SC AND ADJACENT NC IS
45-50 KT TOWARD THE SE...WITH THE NRN EXTENT OF THIS LINE PER RADAR
IMAGERY EXPECTED TO MOVE INTO DARLINGTON COUNTY SC BY 06Z AND THEN
FLORENCE COUNTY BEFORE 07Z.  GIVEN WELL ESTABLISHED MCS AND WITH THE
RECENT TRACK REMAINING ALONG THE BAROCLINIC ZONE WHICH EXTENDED TO
ERN SC...A NEW SEVERE TSTM WATCH WILL BE COORDINATED SOON FOR A
CONTINUED THREAT FOR DAMAGING WINDS DURING THE OVERNIGHT HOURS.

..PETERS.. 05/11/2011

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

ATTN...WFO...ILM...CHS...CAE...

LAT...LON   34617978 33787900 33217925 32847980 32628008 33108074
            33428014 34007993 34388023 34617978

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 10, 9:01 PM EDT	Mesoscale Discussion	SPC	Berkeley, Calhoun, Cherokee, Chester, Chesterfield, Clarendon and 19 more	59 min
May 10, 10:18 PM EDT	Mesoscale Discussion	SPC	Anderson, Cherokee, Greenville, Oconee, Pickens, Spartanburg and 1 more	27 min
May 10, 10:42 PM EDT	Severe Thunderstorm Watch	SPC	Cherokee, Chester, Greenville, Laurens, Spartanburg, Union and 1 more	4 hr
May 11, 12:14 AM EDT	Mesoscale Discussion	SPC	Anderson, Cherokee, Chester, Fairfield, Greenville, Lancaster and 5 more	61 min
May 11, 12:41 AM EDT	Severe Thunderstorm Watch	SPC	Aiken, Bamberg, Barnwell, Calhoun, Chesterfield, Clarendon and 11 more	3 hr
May 11, 1:41 AM EDT	Severe Thunderstorm Watch	SPC	Berkeley, Charleston, Darlington, Dillon, Dorchester, Florence and 5 more	3 hr
May 11, 2:37 AM EDT	Mesoscale Discussion	SPC	Cherokee, Chester, Greenville, Laurens, Spartanburg, Union and 1 more	23 min
May 11, 3:34 AM EDT	Mesoscale Discussion	SPC	Berkeley, Charleston, Chesterfield, Colleton, Darlington, Dillon and 7 more	56 min
May 11, 6:06 PM EDT	Mesoscale Discussion	SPC	Abbeville, Anderson, Greenville, Greenwood, McCormick, Oconee and 1 more	54 min

Nearby

Mesoscale Discussions in South Carolina, 2011 Every mesoscale discussion in 2011

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.