Alert archive / South Carolina / Mesoscale Discussions in 2012

Mesoscale Discussion 154

February 24, 20127 counties in North Carolina; 17 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at Feb 24, 2012, 11:10 AM EST for 7 counties in North Carolina; 17 counties in South Carolina. It was in force for 65 min.

The area

The outline as issued.

The facts

Issued
Feb 24, 2012, 11:10 AM EST (16:10 UTC)
Expired
Feb 24, 2012, 12:15 PM EST
In force
65 min
Issued by
the Storm Prediction Center
All 24 counties

Bladen County, NC, Brunswick County, NC, Columbus County, NC, New Hanover County, NC, Onslow County, NC, Pender County, NC, Robeson County, NC, Bamberg County, SC, Barnwell County, SC, Calhoun County, SC, Clarendon County, SC, Darlington County, SC, Dillon County, SC, Florence County, SC, Horry County, SC, Kershaw County, SC, Lee County, SC, Lexington 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), 114 km from the middle of the area, began a volume at 16:11 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 watches that followed

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

The nearest sounding before it

Charleston AFB, SC (KCHS), launched 12:00Z, 4.2 hours before the alert went out and 140 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 12:00Z on 2012-02-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 817 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 12:00Z on 2012-02-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 350 square meters per square second.1939587897Sfc1 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
817 J/kg
Mixed-layer CIN
-120 J/kg
Mixed-layer LCL
606 m above ground
0-6 km bulk shear
70 kt
0-1 km storm-relative helicity
350 m²/s²
0-3 km storm-relative helicity
365 m²/s²
Significant tornado parameter
0.0
Supercell composite
9.4

Open this sounding in Storm Lab

The text

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

031 
ACUS11 KWNS 241610
SWOMCD
SPC MCD 241610 
NCZ000-SCZ000-241715-

MESOSCALE DISCUSSION 0154
NWS STORM PREDICTION CENTER NORMAN OK
1010 AM CST FRI FEB 24 2012

AREAS AFFECTED...SC...SRN NC

CONCERNING...TORNADO WATCH 35...

VALID 241610Z - 241715Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 35 CONTINUES.

NEWD EXTENSION OF PRE-FRONTAL TSTM BAND IS EXPANDING ACROSS SC
TOWARD SRN NC.  ALONG THIS BAND INDIVIDUAL CELLS ARE INTENSIFYING
WITHIN STRONGLY SHEARED ENVIRONMENT.  OVER THE LAST HOUR OR SO A FEW
NE-SW LINE SEGMENTS HAVE EVOLVED AND THESE SEGMENTS MAY BECOME MORE
EFFICIENT WIND PRODUCERS IF THEY CAN MAINTAIN A MORE PERPENDICULAR
ORIENTATION TO MEAN FLOW.  GIVEN THEIR FAST MOVEMENT THE LEADING
ACTIVITY WILL SPREAD EAST OF WW35 INTO PORTIONS OF SERN SC/NC WITHIN
THE HOUR.  WILL CONTINUE TO MONITOR THIS REGION FOR A POSSIBLE WW.

..DARROW.. 02/24/2012

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

ATTN...WFO...MHX...RAH...ILM...CHS...CAE...

LAT...LON   34238175 34787925 34867746 33717772 33128150 34238175

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 24, 6:56 AM ESTMesoscale DiscussionSPCCherokee, Clay, Cleveland, Haywood, Henderson, Jackson and 4 more94 min
Feb 24, 9:05 AM ESTMesoscale DiscussionSPCAlexander, Alleghany, Ashe, Avery, Buncombe, Burke and 29 more25 min
Feb 24, 9:17 AM ESTTornado WatchSPCAlexander, Avery, Buncombe, Burke, Cabarrus, Caldwell and 22 more7 hr
Feb 24, 12:00 PM ESTMesoscale DiscussionSPCAlexander, Alleghany, Ashe, Avery, Buncombe, Burke and 27 more60 min
Feb 24, 12:43 PM ESTMesoscale DiscussionSPCAlamance, Anson, Beaufort, Bertie, Bladen, Brunswick and 51 more92 min
Feb 24, 1:19 PM ESTTornado WatchSPCAlamance, Anson, Beaufort, Bertie, Bladen, Brunswick and 55 more7 hr
Feb 24, 1:50 PM ESTMesoscale DiscussionSPCBladen, Brunswick, Columbus, Robeson85 min
Feb 24, 3:24 PM ESTMesoscale DiscussionSPCAlexander, Alleghany, Ashe, Avery, Buncombe, Burke and 27 more66 min
Feb 24, 4:45 PM ESTMesoscale DiscussionSPCAlamance, Beaufort, Bertie, Bladen, Brunswick, Camden and 51 more90 min
Feb 24, 8:48 AM ESTTornado WatchSPCAbbeville, Aiken, Bamberg, Barnwell, Calhoun, Chester and 17 more7 hr
Feb 24, 10:49 AM ESTMesoscale DiscussionSPCAiken56 min
Feb 24, 12:04 PM ESTTornado WatchSPCAllendale, Beaufort, Berkeley, Charleston, Colleton, Dorchester and 2 more7 hr
Feb 24, 4:11 PM ESTMesoscale DiscussionSPCAllendale, Beaufort, Berkeley, Charleston, Colleton, Dorchester and 2 more64 min

Nearby

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