Alert archive / North Carolina / Mesoscale Discussions in 2011
Mesoscale Discussion 931
The Storm Prediction Center issued this mesoscale discussion at May 24, 2011, 3:33 PM EDT for 4 states. It was in force for 87 min.
The area
The outline as issued.
The facts
- Issued
- May 24, 2011, 3:33 PM EDT (19:33 UTC)
- Expired
- May 24, 2011, 5:00 PM EDT
- In force
- 87 min
- Issued by
- the Storm Prediction Center
All 75 counties
Harlan County, KY, Alamance County, NC, Alexander County, NC, Alleghany County, NC, Ashe County, NC, Avery County, NC, Bertie County, NC, Caldwell County, NC, Caswell County, NC, Chatham County, NC, Davidson County, NC, Davie County, NC, Durham County, NC, Edgecombe County, NC, Forsyth County, NC, Franklin County, NC, Gates County, NC, Granville County, NC, Guilford County, NC, Halifax County, NC, Hertford County, NC, Iredell County, NC, Mitchell County, NC, Nash County, NC, Northampton County, NC, Orange County, NC, Person County, NC, Randolph County, NC, Rockingham County, NC, Stokes County, NC, Surry County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Watauga County, NC, Wilkes County, NC, Yadkin County, NC, Carter County, TN, Greene County, TN, Hancock County, TN, Hawkins County, TN, Johnson County, TN, Sullivan County, TN, Unicoi County, TN, Washington County, TN, Brunswick County, VA, Carroll County, VA, City of Bristol, VA, City of Chesapeake, VA, City of Danville, VA, City of Emporia, VA, City of Franklin, VA, City of Galax, VA, City of Martinsville, VA, City of Norton, VA, City of Portsmouth, VA, City of Suffolk, VA, Floyd County, VA, Grayson County, VA, Greensville County, VA, Halifax County, VA, Henry County, VA, Isle of Wight County, VA, Lee County, VA, Mecklenburg County, VA, Patrick County, VA, Pittsylvania County, VA, Russell County, VA, Scott County, VA, Smyth County, VA, Southampton County, VA, Sussex County, VA, Washington County, VA, Wise County, VA, Wythe County, VA
The radar
The Roanoke radar (KFCX), 84 km from the middle of the area, began a volume at 19:35 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, 7.6 hours before the alert went out and 27 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
- 451 J/kg
- Mixed-layer CIN
- -124 J/kg
- Mixed-layer LCL
- 1350 m above ground
- 0-6 km bulk shear
- 35 kt
- 0-1 km storm-relative helicity
- 4 m²/s²
- 0-3 km storm-relative helicity
- 99 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.2
The text
As transmitted, in the capitals the NWS used until 2016.
070
ACUS11 KWNS 241934
SWOMCD
SPC MCD 241933
NCZ000-VAZ000-TNZ000-KYZ000-242100-
MESOSCALE DISCUSSION 0931
NWS STORM PREDICTION CENTER NORMAN OK
0233 PM CDT TUE MAY 24 2011
AREAS AFFECTED...SRN VA...NRN NC
CONCERNING...SEVERE THUNDERSTORM WATCH 354...355...357...
VALID 241933Z - 242100Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
354...355...357...CONTINUES.
WW 354 IS SCHEDULED TO EXPIRE AT 21Z. COORDINATION WITH WFO RNK AND
ADJACENT WFOS WILL OCCUR BETWEEN 20-21Z TO DISCUSS THE NEED FOR WW
REPLACEMENT OR TEMPORAL EXTENSION OF THE EXISTING WW.
WELL-DEFINED OUTFLOW BOUNDARY REMAINS REFLECTED IN VISIBLE SATELLITE
AND SURFACE OBSERVATIONS TRAILING WEST TO EAST IN THE WAKE OF AN
INITIAL MCS PROGRESSING ACROSS SERN VA/FAR NERN NC. ROBUST TSTM
DEVELOPMENT HAS RECENTLY OCCURRED JUST N OF THIS BOUNDARY WHERE
LOW-LEVEL CONVERGENCE/UPSLOPE IS MAXIMIZED IN FAR NWRN NC. THIS
ACTIVITY ALONG WITH NUMEROUS UPSTREAM CLUSTERS WITHIN WW 357 WILL
LIKELY POSE A CONTINUED RISK FOR PRIMARILY SEVERE WIND/HAIL GIVEN
THE DEGREE OF HEATING /TEMPERATURES IN THE MIDDLE 80S TO LOWER 90S/
THAT HAS TAKEN PLACE TO THE S OF THE OUTFLOW BOUNDARY.
..GRAMS.. 05/24/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...AKQ...MHX...RAH...RNK...RLX...GSP...MRX...JKL...
LAT...LON 36638378 36948344 37038213 36857823 36987672 36877626
36597614 36317628 35867711 35747795 35657897 35658012
35738073 35818156 36018232 36278315 36638378SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 23, 8:31 PM EDT | Severe Thunderstorm Watch | SPC | Bath, Boyd, Carter, Elliott, Fleming, Greenup and 6 more | 3 hr |
| May 23, 8:47 PM EDT | Mesoscale Discussion | SPC | Adair, Allen, Barren, Butler, Caldwell, Christian and 21 more | 58 min |
| May 24, 6:24 AM EDT | Mesoscale Discussion | SPC | Adair, Allen, Barren, Bell, Casey, Clay and 18 more | 96 min |
| May 24, 7:01 AM EDT | Severe Thunderstorm Watch | SPC | Adair, Allen, Barren, Bell, Breathitt, Casey and 38 more | 8 hr |
| May 24, 8:34 AM EDT | Mesoscale Discussion | SPC | Bell, Breathitt, Clay, Floyd, Harlan, Jackson and 13 more | 116 min |
| May 24, 12:55 PM EDT | Mesoscale Discussion | SPC | Adair, Allen, Barren, Bell, Clay, Clinton and 15 more | 65 min |
| May 24, 1:57 PM EDT | Severe Thunderstorm Watch | SPC | Adair, Allen, Barren, Bell, Clay, Clinton and 14 more | 6 hr |
| May 24, 4:27 PM EDT | Mesoscale Discussion | SPC | Bell, Harlan, Letcher, Whitley | 63 min |
| May 24, 10:00 AM EDT | Severe Thunderstorm Watch | SPC | Alleghany, Ashe, Caswell, Rockingham, Stokes, Surry and 3 more | 7 hr |
| May 24, 12:15 PM EDT | Mesoscale Discussion | SPC | Alamance, Bertie, Camden, Caswell, Chowan, Durham and 24 more | 90 min |
| May 24, 12:42 PM EDT | Severe Thunderstorm Watch | SPC | Alamance, Bertie, Camden, Chowan, Currituck, Durham and 20 more | 5 hr |
| May 24, 4:43 PM EDT | Tornado Watch | SPC | Alamance, Alleghany, Ashe, Caswell, Forsyth, Guilford and 8 more | 5 hr |
| May 24, 7:33 PM EDT | Mesoscale Discussion | SPC | Alamance, Alleghany, Ashe, Caswell, Durham, Forsyth and 11 more | 57 min |
| May 24, 7:46 PM EDT | Mesoscale Discussion | SPC | Anderson, Bledsoe, Blount, Campbell, Carter, Claiborne and 26 more | 59 min |
Nearby
Mesoscale Discussions in North Carolina, 2011Mesoscale Discussions in Virginia, 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.