Alert archive / North Carolina / Mesoscale Discussions in 2021
Mesoscale Discussion 1411
The Storm Prediction Center issued this mesoscale discussion at Aug 1, 2021, 10:54 AM EDT for 10 counties in North Carolina. It was in force for 96 min.
The area
The outline as issued.
The facts
- Issued
- Aug 1, 2021, 10:54 AM EDT (14:54 UTC)
- Expired
- Aug 1, 2021, 12:30 PM EDT
- In force
- 96 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 20%
Counties Bertie County, NC, Camden County, NC, Chowan County, NC, Currituck County, NC, Gates County, NC, Hertford County, NC, Northampton County, NC, Pasquotank County, NC, Perquimans County, NC, Tyrrell County, NC
The radar
The Norfolk radar (KAKQ), 86 km from the middle of the area, began a volume at 14:55 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
Newport, NC (KMHX), launched 12:00Z, 2.9 hours before the alert went out and 165 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
- 756 J/kg
- Mixed-layer CIN
- -48 J/kg
- Mixed-layer LCL
- 934 m above ground
- 0-6 km bulk shear
- 28 kt
- 0-1 km storm-relative helicity
- 54 m²/s²
- 0-3 km storm-relative helicity
- 99 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 2.4
The text
As transmitted.
283
ACUS11 KWNS 011454
SWOMCD
SPC MCD 011454
NCZ000-VAZ000-011630-
Mesoscale Discussion 1411
NWS Storm Prediction Center Norman OK
0954 AM CDT Sun Aug 01 2021
Areas affected...Far Northeastern NC
Concerning...Severe potential...Watch unlikely
Valid 011454Z - 011630Z
Probability of Watch Issuance...20 percent
SUMMARY...Isolated damaging wind gusts and even a tornado are
possible across far northeastern NC for the next hour or two.
DISCUSSION...Recent surface analysis places a low over central NC,
with a warm front extending northeastward to near the far eastern
NC/VA. This warm front is demarcated well by the 80 deg F isotherm.
The thunderstorms ongoing along the eastern NC/VA border are
occurring near this boundary, which should augment both mesoscale
lift and surface vorticity. Recent updraft intensification as well
as increased updraft rotation suggests this augmentation is
occurring now. As a result, a localized threat for damaging wind
gusts and even a brief tornado exists within this confined area of
far northeast NC. The threat will likely last for the next hour or
two, but the overall threat coverage is expected to remain too
isolated for watch issuance.
..Mosier/Grams.. 08/01/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...AKQ...MHX...RAH...
LAT...LON 36587684 36497608 36317579 35827590 35917643 36027715
36177760 36447751 36587684SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 1, 6:29 AM EDT | Mesoscale Discussion | SPC | Alamance, Caswell, Chatham, Davidson, Durham, Franklin and 9 more | 91 min |
| Aug 1, 11:51 AM EDT | Mesoscale Discussion | SPC | Beaufort, Bertie, Chowan, Cumberland, Duplin, Edgecombe and 14 more | 114 min |
| Aug 1, 12:37 PM EDT | Severe Thunderstorm Watch | SPC | Beaufort, Bladen, Brunswick, Carteret, Chatham, Columbus and 31 more | 7 hr |
| Aug 1, 2:53 PM EDT | Mesoscale Discussion | SPC | Anson, Beaufort, Bertie, Bladen, Chatham, Columbus and 31 more | 97 min |
Nearby
Mesoscale Discussions in North Carolina, 2021Every mesoscale discussion in 2021
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.