Alert archive / South Carolina / Mesoscale Discussions in 2012

Mesoscale Discussion 2005

September 29, 20128 counties in North Carolina; 14 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at Sep 29, 2012, 5:49 PM EDT for 8 counties in North Carolina; 14 counties in South Carolina. It was in force for 56 min.

The area

The outline as issued.

The facts

Issued
Sep 29, 2012, 5:49 PM EDT (21:49 UTC)
Expired
Sep 29, 2012, 6:45 PM EDT
In force
56 min
Issued by
the Storm Prediction Center
Chance of a watch
20%
All 22 counties

Anson County, NC, Cumberland County, NC, Hoke County, NC, Moore County, NC, Richmond County, NC, Robeson County, NC, Scotland County, NC, Union County, NC, Chester County, SC, Chesterfield County, SC, Darlington County, SC, Dillon County, SC, Fairfield County, SC, Kershaw County, SC, Lancaster County, SC, Lee County, SC, Lexington County, SC, Marlboro County, SC, Newberry County, SC, Richland County, SC, Saluda County, SC, Union County, SC

The radar

The Columbia radar (KCAE), 103 km from the middle of the area, began a volume at 21:49 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

Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 9.8 hours before the alert went out and 171 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, Greensboro/Hi Pt, NC at 12:00Z on 2012-09-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 365 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, Greensboro/Hi Pt, NC at 12:00Z on 2012-09-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 14 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
365 J/kg
Mixed-layer CIN
-26 J/kg
Mixed-layer LCL
795 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
14 m²/s²
0-3 km storm-relative helicity
34 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.4

Open this sounding in Storm Lab

The text

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

796 
ACUS11 KWNS 292150
SWOMCD
SPC MCD 292149
NCZ000-SCZ000-292245-

MESOSCALE DISCUSSION 2005
NWS STORM PREDICTION CENTER NORMAN OK
0449 PM CDT SAT SEP 29 2012

AREAS AFFECTED...UPSTATE SC...CNTRL NC

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 292149Z - 292245Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...BRIEF SUPERCELLS CAPABLE OF AN ISOLD TORNADO AND/OR HAIL
AND DMGG WINDS. DUE TO THE BRIEF/ISOLD NATURE...A WW IS NOT
CURRENTLY ANTICIPATED.

DISCUSSION...A FEW WEAK SUPERCELLS HAVE BEEN NOTED INVOF A SURFACE
LOW LOCATED ACROSS N CNTRL SC EXTENDING NEWD INTO S CNTRL NC...AND
ALONG AN APPARENT AREA OF SURFACE CONFLUENCE THAT IS SAGGING ESEWD.
AREA VAD WIND PROFILE DATA IS SHOWING APPROXIMATELY 43 KT 0-6 KM
SHEAR...AND WITH BACKED LOW LEVEL WINDS INVOF THE AFOREMENTIONED
SURFACE LOW /ALBEIT LIGHT/...AT LEAST BRIEF ROTATION HAS BEEN
OBSERVED WITH STORMS THAT HAVE BECOME SUSTAINED. CLOUD COVER APPEARS
TO HAVE LIMITED STRONGER SURFACE-BASED DESTABILIZATION...THOUGH THE
ONGOING STORMS ARE PROGRESSING INTO A RELATIVE MAXIMUM WHERE BREAKS
IN THE CLOUDS HAVE ALLOWED FOR TEMPERATURES TO RISE INTO THE MID-70S
TO LOWER 80S. AS SUCH...A NARROW TEMPORAL THREAT MAY EXIST FOR A
COUPLE OF SEVERE STORMS PRIOR TO NOCTURNAL COOLING AND SUBSEQUENT
BOUNDARY LAYER STABILIZATION.

..HURLBUT/CARBIN.. 09/29/2012

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

ATTN...WFO...RAH...ILM...CAE...GSP...

LAT...LON   34598192 35168038 35397923 35217860 34757856 34277919
            34028017 33858102 33958190 34598192

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.