Alert archive / North Carolina / Mesoscale Discussions in 2012

Mesoscale Discussion 2018

October 2, 20127 counties in North Carolina; 5 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at Oct 2, 2012, 9:41 AM EDT for 7 counties in North Carolina; 5 counties in South Carolina. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued
Oct 2, 2012, 9:41 AM EDT (13:41 UTC)
Expired
Oct 2, 2012, 11:15 AM EDT
In force
94 min
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Cabarrus County, NC, Cleveland County, NC, Gaston County, NC, Lincoln County, NC, Mecklenburg County, NC, Stanly County, NC, Union County, NC, Cherokee County, SC, Chester County, SC, Lancaster County, SC, Union County, SC, York County, SC

The radar

The Greer radar (KGSP), 108 km from the middle of the area, began a volume at 13:42 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, 1.7 hours before the alert went out and 148 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 2012-10-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 415 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 2012-10-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 158 square meters per square second.19395878Sfc1 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
415 J/kg
Mixed-layer CIN
-29 J/kg
Mixed-layer LCL
468 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
158 m²/s²
0-3 km storm-relative helicity
205 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.6

Open this sounding in Storm Lab

The text

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

865 
ACUS11 KWNS 021341
SWOMCD
SPC MCD 021341 
NCZ000-SCZ000-021515-

MESOSCALE DISCUSSION 2018
NWS STORM PREDICTION CENTER NORMAN OK
0841 AM CDT TUE OCT 02 2012

AREAS AFFECTED...PARTS OF N CENTRAL SC AND ADJACENT AREAS OF NC

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 021341Z - 021515Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...LOCALIZED THREAT FOR AN ISOLATED/BRIEF TORNADO OR TWO
EXISTS ACROSS THE DISCUSSION AREA...BUT WW NOT ANTICIPATED.

DISCUSSION...LATEST RADAR LOOP SHOWS A BROKEN LINE OF CONVECTION
ACROSS PORTIONS OF WRN NC AND N CENTRAL/NWRN SC ATTM...WITH ONE
EMBEDDED STORM OVER CHEROKEE CO SC WHICH HAS ACQUIRED LOW-LEVEL
ROTATION OVER THE PAST HALF HOUR OR SO.  THIS PARTICULAR STORM
APPEARS TO BE OCCURRING IN THE IMMEDIATE VICINITY OF THE SURFACE
WARM FRONT -- WHERE BACKED LOW-LEVEL FLOW IS PROVIDING ENHANCED
SHEAR/VORTICITY.  ALONG THE FRONT...ISOLATED/BRIEF TORNADO POTENTIAL
SHOULD PERSIST OVER THE NEXT COUPLE OF HOURS.

OVERALL HOWEVER...DESPITE A VERY MOIST BOUNDARY LAYER...LARGER-SCALE
CONDITIONS APPEAR UNSUPPORTIVE OF A MORE SUBSTANTIAL TORNADO RISK. 
WITH THE UPPER TROUGH PROGGED TO REMAIN IN PLACE WELL W OF THIS AREA
AND MID-LEVEL HEIGHTS FORECAST TO RISE DOWNSTREAM -- I.E. ACROSS VA
AND THE CAROLINAS AND INTO GA...STORMS SHOULD REMAIN GENERALLY
ISOLATED AND DISORGANIZED THROUGH THE DAY.  FURTHER...WITH SHEAR
PROGGED TO WEAKEN WITH TIME THROUGH MIDDAY/EARLY
AFTERNOON...POTENTIAL FOR AN INCREASE IN THREAT APPEARS UNLIKELY.

THUS -- DESPITE THE LOCALIZED/ISOLATED TORNADO POTENTIAL IN THE
IMMEDIATE VICINITY OF THE FRONT...WW IS NOT ANTICIPATED.

..GOSS/HART.. 10/02/2012

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

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

LAT...LON   35548169 35718064 35298001 34558031 34458165 35058163
            35548169

Nearby

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