Alert archive / North Carolina / Mesoscale Discussions in 2011
Mesoscale Discussion 720
The Storm Prediction Center issued this mesoscale discussion at May 11, 2011, 12:14 AM EDT for 23 counties in North Carolina; 11 counties in South Carolina; 7 counties in Tennessee. It was in force for 61 min.
The area
The outline as issued.
The facts
- Issued
- May 11, 2011, 12:14 AM EDT (04:14 UTC)
- Expired
- May 11, 2011, 1:15 AM EDT
- In force
- 61 min
- Issued by
- the Storm Prediction Center
All 41 counties
Alexander County, NC, Alleghany 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, Henderson County, NC, Iredell County, NC, Lincoln County, NC, Madison County, NC, McDowell County, NC, Mecklenburg 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, Chester County, SC, Fairfield County, SC, Greenville County, SC, Lancaster County, SC, Laurens County, SC, Pickens County, SC, Spartanburg County, SC, Union County, SC, York County, SC, Carter County, TN, Greene County, TN, Hawkins County, TN, Johnson County, TN, Sullivan County, TN, Unicoi County, TN, Washington County, TN
The radar
The Greer radar (KGSP), 47 km from the middle of the area, began a volume at 04:14 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, 4.2 hours before the alert went out and 212 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.
- 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
The text
As transmitted, in the capitals the NWS used until 2016.
201 ACUS11 KWNS 110414 SWOMCD SPC MCD 110414 SCZ000-NCZ000-VAZ000-TNZ000-110515- MESOSCALE DISCUSSION 0720 NWS STORM PREDICTION CENTER NORMAN OK 1114 PM CDT TUE MAY 10 2011 AREAS AFFECTED...ERN TN...WRN NC...NRN SC CONCERNING...SEVERE THUNDERSTORM WATCH 273... VALID 110414Z - 110515Z THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 273 CONTINUES. WRN NC MCS HAS BECOME SLIGHTLY LESS ORGANIZED AS IT CROSSED THE SRN APPALACHIANS. EVEN SO LEADING EDGE OF STRONGEST ACTIVITY IS SURGING SWD AT ROUGHLY 40KT AND WILL APPROACH THE SRN PORTIONS OF WW273 BY 0530Z. IF CONTINUED WEAKENING OCCURS THEN A NEW WW MAY NOT BE NEEDED...OTHERWISE CURRENT SPEED OF CONVECTION WOULD IMPLY SEVERE WIND GUSTS ARE POSSIBLE AND A NEW WATCH MAY BE REQUIRED DOWNSTREAM ACROSS SC. ..DARROW.. 05/11/2011 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...RNK...CAE...GSP...MRX... LAT...LON 34388274 36608306 36618091 34378064 34388274
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 10, 9:01 PM EDT | Mesoscale Discussion | SPC | Alexander, Alleghany, Anson, Ashe, Avery, Bladen and 46 more | 59 min |
| May 10, 10:18 PM EDT | Mesoscale Discussion | SPC | Alexander, Ashe, Avery, Buncombe, Burke, Caldwell and 16 more | 27 min |
| May 10, 10:42 PM EDT | Severe Thunderstorm Watch | SPC | Alexander, Avery, Buncombe, Burke, Caldwell, Catawba and 13 more | 4 hr |
| May 11, 2:37 AM EDT | Mesoscale Discussion | SPC | Alexander, Ashe, Avery, Buncombe, Burke, Caldwell and 14 more | 23 min |
| May 11, 6:06 PM EDT | Mesoscale Discussion | SPC | Buncombe, Haywood, Henderson, Jackson, Polk, Transylvania | 54 min |
| May 11, 12:41 AM EDT | Severe Thunderstorm Watch | SPC | Aiken, Bamberg, Barnwell, Calhoun, Chesterfield, Clarendon and 11 more | 3 hr |
| May 11, 1:35 AM EDT | Mesoscale Discussion | SPC | Berkeley, Charleston, Darlington, Dorchester, Florence, Georgetown and 2 more | 25 min |
| May 11, 1:41 AM EDT | Severe Thunderstorm Watch | SPC | Berkeley, Charleston, Darlington, Dillon, Dorchester, Florence and 5 more | 3 hr |
| May 11, 3:34 AM EDT | Mesoscale Discussion | SPC | Berkeley, Charleston, Chesterfield, Colleton, Darlington, Dillon and 7 more | 56 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.