Alert archive / North Carolina / Mesoscale Discussions in 2013

Mesoscale Discussion 968

June 5, 20134 states

The Storm Prediction Center issued this mesoscale discussion at Jun 5, 2013, 6:23 PM EDT for 4 states. It was in force for 97 min.

The area

The outline as issued.

The facts

Issued
Jun 5, 2013, 6:23 PM EDT (22:23 UTC)
Expired
Jun 5, 2013, 8:00 PM EDT
In force
97 min
Issued by
the Storm Prediction Center
Chance of a watch
5%
All 34 counties

Dawson County, GA, Fannin County, GA, Gilmer County, GA, Habersham County, GA, Lumpkin County, GA, Pickens County, GA, Rabun County, GA, Towns County, GA, Union County, GA, White County, GA, Buncombe County, NC, Cherokee County, NC, Clay County, NC, Graham County, NC, Haywood County, NC, Jackson County, NC, Macon County, NC, Madison County, NC, Mitchell County, NC, Swain County, NC, Transylvania County, NC, Yancey County, NC, Carter County, TN, Cocke County, TN, Greene County, TN, Hamblen County, TN, Hawkins County, TN, Jefferson County, TN, Sevier County, TN, Sullivan County, TN, Unicoi County, TN, Washington County, TN, City of Bristol, VA, Scott County, VA

The radar

The Knoxville radar (KMRX), 71 km from the middle of the area, began a volume at 22:22 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

Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 10.4 hours before the alert went out and 272 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, Peachtre/Fal Fld, GA at 12:00Z on 2013-06-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1227 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, Peachtre/Fal Fld, GA at 12:00Z on 2013-06-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 3 square meters per square second.193958Sfc1 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
1227 J/kg
Mixed-layer CIN
-51 J/kg
Mixed-layer LCL
558 m above ground
0-6 km bulk shear
3 kt
0-1 km storm-relative helicity
3 m²/s²
0-3 km storm-relative helicity
-34 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

987 
ACUS11 KWNS 052224
SWOMCD
SPC MCD 052223 
NCZ000-VAZ000-TNZ000-SCZ000-GAZ000-060000-

MESOSCALE DISCUSSION 0968
NWS STORM PREDICTION CENTER NORMAN OK
0523 PM CDT WED JUN 05 2013

AREAS AFFECTED...ERN TN...WRN NC...FAR SWRN VA...FAR WRN SC...NRN GA

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 052223Z - 060000Z

PROBABILITY OF WATCH ISSUANCE...5 PERCENT

SUMMARY...A FEW STORMS MAY PRODUCE GUSTY WINDS THROUGH EARLY
EVENING...BUT A WW IS NOT NEEDED.

DISCUSSION...CONVECTIVE CLUSTERS HAVE BECOME LOOSELY ORGANIZED INTO
NNE/SSW-ORIENTED CONVECTIVE SEGMENTS OVER PARTS OF THE CNTRL/SRN
APPALACHIANS...AS OROGRAPHIC EFFECTS HAVE BOOSTED ASCENT AT THE
LEADING EDGE OF A DISORGANIZED CONVECTIVE COMPLEX THAT EARLIER
CROSSED PARTS OF THE TN VALLEY. DIURNAL DIABATIC HEATING HAS
CONTRIBUTED TO ONLY MARGINAL DESTABILIZATION N OF AN ILL-DEFINED
STATIONARY FRONT OVER THE COASTAL PLAIN/PIEDMONT REGION OF SC AND
GA. MLCAPE VALUES ONLY REACH AROUND 500-800 J/KG N OF THIS BOUNDARY
PER MODIFIED 12Z RAOBS...WITH MORE SUBSTANTIAL MOISTENING/BUOYANCY
RELEGATED TO LOCATIONS FARTHER S. REGARDLESS...ENOUGH INSTABILITY
EXISTS DOWNSTREAM/E OF THE AFOREMENTIONED ACTIVITY FOR ITS
SUSTENANCE UNTIL AROUND DUSK. THEREAFTER...NOCTURNAL COOLING OF THE
BOUNDARY LAYER SHOULD CONTRIBUTE TO A WEAKENING TREND OF ONGOING
ACTIVITY. UNTIL THEN...A FEW STRONG WIND GUSTS MAY OCCUR...THOUGH
THE WEAK INSTABILITY...AND ONLY AROUND 15 KT OF 0-6-KM BULK SHEAR
SAMPLED BY MRX VWP...SUGGEST THAT THE SVR POTENTIAL WILL BE VERY
LOW.

..COHEN/MEAD.. 06/05/2013

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

ATTN...WFO...RNK...GSP...MRX...FFC...

LAT...LON   36388329 36798254 36648189 36178188 35448237 34618339
            34338395 34268445 34618467 36388329

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 5, 12:53 PM EDTMesoscale DiscussionSPCChattooga, Dade97 min
Jun 5, 7:12 PM EDTMesoscale DiscussionSPCLauderdale, Shelby, Tipton93 min

Nearby

Mesoscale Discussions in North Carolina, 2013Mesoscale Discussions in Georgia, 2013Mesoscale Discussions in Tennessee, 2013Every mesoscale discussion in 2013

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.