Alert archive / North Carolina / Mesoscale Discussions in 2011

Mesoscale Discussion 718

May 10, 201122 counties in North Carolina; 7 counties in South Carolina; 6 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at May 10, 2011, 10:18 PM EDT for 22 counties in North Carolina; 7 counties in South Carolina; 6 counties in Tennessee. It was in force for 27 min.

The area

The outline as issued.

The facts

Issued
May 10, 2011, 10:18 PM EDT (02:18 UTC)
Expired
May 10, 2011, 10:45 PM EDT
In force
27 min
Issued by
the Storm Prediction Center
All 35 counties

Alexander County, NC, Ashe County, NC, Avery County, NC, Buncombe County, NC, Burke County, NC, Caldwell County, NC, Catawba County, NC, Cleveland County, NC, Gaston County, NC, Haywood County, NC, Henderson County, NC, Jackson County, NC, Lincoln County, NC, Madison County, NC, McDowell County, NC, Mitchell County, NC, Polk County, NC, Rutherford County, NC, Transylvania County, NC, Watauga County, NC, Wilkes County, NC, Yancey County, NC, Anderson County, SC, Cherokee County, SC, Greenville County, SC, Oconee County, SC, Pickens County, SC, Spartanburg County, SC, York County, SC, Carter County, TN, Cocke County, TN, Greene County, TN, Johnson County, TN, Unicoi County, TN, Washington County, TN

The radar

The Greer radar (KGSP), 97 km from the middle of the area, began a volume at 02:19 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

Greensboro/Hi Pt, NC (KGSO), launched 00:00Z, 2.3 hours before the alert went out and 223 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 00:00Z on 2011-05-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 694 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 00:00Z on 2011-05-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 109 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
694 J/kg
Mixed-layer CIN
-146 J/kg
Mixed-layer LCL
1286 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
109 m²/s²
0-3 km storm-relative helicity
420 m²/s²
Significant tornado parameter
0.3
Supercell composite
11.6

Open this sounding in Storm Lab

The text

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

796 
ACUS11 KWNS 110218
SWOMCD
SPC MCD 110218 
NCZ000-SCZ000-TNZ000-GAZ000-110245-

MESOSCALE DISCUSSION 0718
NWS STORM PREDICTION CENTER NORMAN OK
0918 PM CDT TUE MAY 10 2011

AREAS AFFECTED...ERN TN...WRN NC...NRN SC

CONCERNING...SEVERE THUNDERSTORM WATCH 269...

VALID 110218Z - 110245Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 269
CONTINUES.

...NEW WW WILL BE ISSUED SOON FOR PORTIONS OF THE SRN
APPALACHIANS...

WELL DEFINED MCS IS SURGING SSEWD AT 40-45KT INTO NERN PORTIONS OF
TN AT 0215Z.  DAMAGING WINDS AND LARGE HAIL WILL LIKELY ACCOMPANY
THIS ACTIVITY AS IT SPREADS ACROSS THE MOUNTAINS OF ERN TN/NC INTO
NRN SC.  NEW WW WILL BE ISSUED SOON.

..DARROW.. 05/11/2011

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

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

LAT...LON   36478283 36458097 34818091 34468299 35858352 36478283

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 10, 9:01 PM EDTMesoscale DiscussionSPCAlexander, Alleghany, Anson, Ashe, Avery, Bladen and 46 more59 min
May 10, 10:42 PM EDTSevere Thunderstorm WatchSPCAlexander, Avery, Buncombe, Burke, Caldwell, Catawba and 13 more4 hr
May 11, 12:14 AM EDTMesoscale DiscussionSPCAlexander, Alleghany, Ashe, Avery, Buncombe, Burke and 17 more61 min
May 11, 2:37 AM EDTMesoscale DiscussionSPCAlexander, Ashe, Avery, Buncombe, Burke, Caldwell and 14 more23 min
May 11, 6:06 PM EDTMesoscale DiscussionSPCBuncombe, Haywood, Henderson, Jackson, Polk, Transylvania54 min
May 11, 12:41 AM EDTSevere Thunderstorm WatchSPCAiken, Bamberg, Barnwell, Calhoun, Chesterfield, Clarendon and 11 more3 hr
May 11, 1:35 AM EDTMesoscale DiscussionSPCBerkeley, Charleston, Darlington, Dorchester, Florence, Georgetown and 2 more25 min
May 11, 1:41 AM EDTSevere Thunderstorm WatchSPCBerkeley, Charleston, Darlington, Dillon, Dorchester, Florence and 5 more3 hr
May 11, 3:34 AM EDTMesoscale DiscussionSPCBerkeley, Charleston, Chesterfield, Colleton, Darlington, Dillon and 7 more56 min

Nearby

Mesoscale Discussions in North Carolina, 2011Mesoscale Discussions in South Carolina, 2011Mesoscale Discussions in Tennessee, 2011Every 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.