Alert archive / North Carolina / Mesoscale Discussions in 2011
Mesoscale Discussion 2144
The Storm Prediction Center issued this mesoscale discussion at Sep 6, 2011, 12:41 PM EDT for 61 counties in North Carolina; 8 counties in South Carolina; 21 counties in Virginia. It was in force for 64 min.
The area
The outline as issued.
The facts
- Issued
- Sep 6, 2011, 12:41 PM EDT (16:41 UTC)
- Expired
- Sep 6, 2011, 1:45 PM EDT
- In force
- 64 min
- Issued by
- the Storm Prediction Center
All 90 counties
Alamance County, NC, Alleghany County, NC, Anson County, NC, Beaufort County, NC, Bertie County, NC, Bladen County, NC, Brunswick County, NC, Camden County, NC, Caswell County, NC, Chatham County, NC, Chowan County, NC, Columbus County, NC, Craven County, NC, Cumberland County, NC, Currituck County, NC, Davidson County, NC, Duplin County, NC, Durham County, NC, Edgecombe County, NC, Forsyth County, NC, Franklin County, NC, Gates County, NC, Granville County, NC, Greene County, NC, Guilford County, NC, Halifax County, NC, Harnett County, NC, Hertford County, NC, Hoke County, NC, Johnston County, NC, Jones County, NC, Lee County, NC, Lenoir County, NC, Martin County, NC, Montgomery County, NC, Moore County, NC, Nash County, NC, New Hanover County, NC, Northampton County, NC, Orange County, NC, Pasquotank County, NC, Pender County, NC, Perquimans County, NC, Person County, NC, Pitt County, NC, Randolph County, NC, Richmond County, NC, Robeson County, NC, Rockingham County, NC, Sampson County, NC, Scotland County, NC, Stokes County, NC, Surry County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Washington County, NC, Wayne County, NC, Wilkes County, NC, Wilson County, NC, Yadkin County, NC, Darlington County, SC, Dillon County, SC, Florence County, SC, Georgetown County, SC, Horry County, SC, Marion County, SC, Marlboro County, SC, Williamsburg County, SC, Brunswick County, VA, Charlotte County, VA, City of Chesapeake, VA, City of Danville, VA, City of Emporia, VA, City of Franklin, VA, City of Martinsville, VA, City of Norfolk, VA, City of Portsmouth, VA, City of Suffolk, VA, City of Virginia Beach, VA, Greensville County, VA, Halifax County, VA, Henry County, VA, Isle of Wight County, VA, Lunenburg County, VA, Mecklenburg County, VA, Patrick County, VA, Pittsylvania County, VA, Southampton County, VA, Sussex County, VA
The radar
The Raleigh/Durham radar (KRAX), 28 km from the middle of the area, began a volume at 16:44 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 12:00Z, 4.7 hours before the alert went out and 153 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
- 1434 J/kg
- Mixed-layer CIN
- 0 J/kg
- Mixed-layer LCL
- 515 m above ground
- 0-6 km bulk shear
- 40 kt
- 0-1 km storm-relative helicity
- 246 m²/s²
- 0-3 km storm-relative helicity
- 274 m²/s²
- Significant tornado parameter
- 1.9
- Supercell composite
- 11.1
The text
As transmitted, in the capitals the NWS used until 2016.
323
ACUS11 KWNS 061642
SWOMCD
SPC MCD 061641
NCZ000-VAZ000-SCZ000-061745-
MESOSCALE DISCUSSION 2144
NWS STORM PREDICTION CENTER NORMAN OK
1141 AM CDT TUE SEP 06 2011
AREAS AFFECTED...NERN SC/NWRN-CENTRAL AND ERN NC/FAR SRN VA
CONCERNING...TORNADO WATCH 845...846...847...
VALID 061641Z - 061745Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH
845...846...847...CONTINUES.
A NEW WW WILL BE NEEDED BY 18Z TO REPLACE MUCH OF WW 845 WHICH IS
SCHEDULED TO EXPIRE AT THAT TIME.
THREAT FOR TORNADOES AND DAMAGING WINDS IS EXPECTED TO PERSIST
THROUGH THE AFTERNOON ACROSS MUCH OF CENTRAL AND ERN CAROLINAS INTO
PARTS OF FAR SRN VA.
LATE MORNING SURFACE ANALYSES SHOWED THE PRIMARY SYNOPTIC LOW
REMAINING GENERALLY STATIONARY OVER FAR NWRN GA...WHILE A
SECONDARY...SUB-SYNOPTIC LOW WAS LOCATED OVER FAR NERN TN /JUST S OF
TRI/. COLD FRONTS TRAILED SWD FROM EACH OF THESE AREAS OF LOW
PRESSURE...WITH THE ERN COLD FRONT MARKING THE WRN EXTENT OF THE
SEVERE WEATHER THREAT. AT 16Z...THIS BOUNDARY EXTENDED...INITIALLY
SSEWD FROM NERN TN THROUGH FAR WRN NC INTO CENTRAL SC /INVOF
CAE/...AND THEN SWD ALONG THE GA COAST THROUGH NRN FL TO OFF THE WRN
FL COAST. COUNTIES CAN CONTINUE TO BE CLEARED FROM THE WRN TWO
TORNADO WATCHES /846 AND 847/ WITH THE FRONTAL PASSAGE.
MEANWHILE...ISENTROPIC ASCENT ATOP A BAROCLINIC ZONE EXTENDING WSWWD
FROM THE FAR SRN EXTENT OF THE DELMARVA PENINSULA /S OF WAL/ THROUGH
FAR SERN VA TO NORTH CENTRAL NC...AND THEN WNWWD INTO FAR SWRN VA IS
CONTINUING TO REINFORCE A RAIN-COOLED AIR MASS N OF THIS BOUNDARY
WHICH IS ACTING A NRN DELIMITER TO SEVERE WEATHER. SLOW SWD
MOVEMENT HAS BEEN NOTED...WHILE THE SERN VA PORTION OF THIS FRONT
APPEARS TO BE BECOMING QUASI-STATIONARY GIVEN THE LACK OF SHOWER
ACTIVITY N OF THIS AREA.
GIVEN THE NWD TRACK OF THE UPPER LOW...DEEP LAYER MERIDIONAL FLOW
WILL LIMIT THE ERN EXPANSION OF THE SEVERE WEATHER THREAT INTO FAR
ERN NC. SUFFICIENT DEEP LAYER AND LOW LEVEL SHEAR COMBINED WITH
MODERATE INSTABILITY FROM ERN SC INTO CENTRAL NC AND SERN VA WILL
SUSTAIN THE ONGOING SEVERE WEATHER THREAT AND THE NEED FOR A NEW WW
BY 18Z.
..PETERS.. 09/06/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...AKQ...MHX...RAH...ILM...RNK...CAE...GSP...
LAT...LON 33667762 32987891 33517996 34408004 35588019 36038043
36108136 36518130 36878028 37147868 36947755 37047696
36897588 36537586 35837621 35257687 34717758 34477755
34307735 33667762SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 5, 8:36 PM EDT | Mesoscale Discussion | SPC | Anson, Cumberland, Hoke, Montgomery, Moore, Richmond and 3 more | 84 min |
| Sep 5, 11:47 PM EDT | Mesoscale Discussion | SPC | Stokes, Surry | 88 min |
| Sep 6, 3:30 AM EDT | Mesoscale Discussion | SPC | Rockingham, Stokes | 60 min |
| Sep 6, 4:36 AM EDT | Mesoscale Discussion | SPC | Alamance, Anson, Cabarrus, Caswell, Chatham, Davidson and 22 more | 84 min |
| Sep 6, 5:17 AM EDT | Tornado Watch | SPC | Alamance, Alleghany, Anson, Bladen, Brunswick, Caswell and 43 more | 9 hr |
| Sep 6, 8:35 AM EDT | Mesoscale Discussion | SPC | Alamance, Anson, Bladen, Brunswick, Cabarrus, Catawba and 42 more | 85 min |
| Sep 6, 9:51 AM EDT | Tornado Watch | SPC | Alexander, Avery, Burke, Cabarrus, Caldwell, Catawba and 13 more | 6 hr |
| Sep 6, 1:32 PM EDT | Tornado Watch | SPC | Alamance, Anson, Beaufort, Bertie, Bladen, Brunswick and 48 more | 7 hr |
| Sep 6, 4:41 PM EDT | Mesoscale Discussion | SPC | Alamance, Anson, Beaufort, Bertie, Bladen, Brunswick and 46 more | 64 min |
| Sep 6, 7:33 PM EDT | Mesoscale Discussion | SPC | Beaufort, Bertie, Bladen, Brunswick, Camden, Carteret and 38 more | 117 min |
| Sep 6, 10:11 AM EDT | Tornado Watch | SPC | Allendale, Bamberg, Barnwell, Beaufort, Berkeley, Calhoun and 15 more | 7 hr |
Nearby
Mesoscale Discussions in North Carolina, 2011Mesoscale Discussions in Virginia, 2011Mesoscale Discussions in South Carolina, 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.