Alert archive / North Carolina / Mesoscale Discussions in 2017
Mesoscale Discussion 702
The Storm Prediction Center issued this mesoscale discussion at May 11, 2017, 10:12 PM EDT for 12 counties in North Carolina. It was in force for 63 min.
The area
The outline as issued.
The facts
- Issued
- May 11, 2017, 10:12 PM EDT (02:12 UTC)
- Expired
- May 11, 2017, 11:15 PM EDT
- In force
- 63 min
- Issued by
- the Storm Prediction Center
Counties Beaufort County, NC, Edgecombe County, NC, Franklin County, NC, Greene County, NC, Johnston County, NC, Lenoir County, NC, Martin County, NC, Nash County, NC, Pitt County, NC, Wake County, NC, Wayne County, NC, Wilson County, NC
The radar
The Raleigh/Durham radar (KRAX), 38 km from the middle of the area, began a volume at 02:14 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 nearest sounding before it
Newport, NC (KMHX), launched 00:00Z, 2.2 hours before the alert went out and 151 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
- 769 J/kg
- Mixed-layer CIN
- -32 J/kg
- Mixed-layer LCL
- 1520 m above ground
- 0-6 km bulk shear
- 45 kt
- 0-1 km storm-relative helicity
- 87 m²/s²
- 0-3 km storm-relative helicity
- 124 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 2.6
The text
As transmitted.
419
ACUS11 KWNS 120213
SWOMCD
SPC MCD 120212
NCZ000-120315-
Mesoscale Discussion 0702
NWS Storm Prediction Center Norman OK
0912 PM CDT Thu May 11 2017
Areas affected...Central and eastern North Carolina
Concerning...Severe Thunderstorm Watch 211...
Valid 120212Z - 120315Z
The severe weather threat for Severe Thunderstorm Watch 211
continues.
SUMMARY...The severe threat continues in WW 211, and cannot be
completely ruled out southeast of the watch area after about 03Z.
DISCUSSION...Scattered thunderstorms capable of a hail and wind
damage are ongoing in portions of the watch. These storms are along
and just north of a nearly stationary surface boundary oriented from
near RDU to near EWN. Despite residing just on the cool side of
this boundary, storms have been able to remain near-surface-based
owing to mid-60s dewpoints, while a more southeasterly component to
the surface winds have enhanced low-level shear to foster some storm
organization/occasional supercell structures. A linear segment has
organized and propagated across the Raleigh/Durham area, producing
several reports of wind damage. Other isolated storms east of this
complex may foster a marginally severe hail threat. These storms
will continue to migrate southeastward toward the NC coast and may
maintain a localized severe threat in these areas as storms
propagate into a moderately unstable downstream airmass. Convective
trends will be monitored, and local extensions of WW 211 may be
needed to address the threat toward 03Z.
..Cook/Hart.. 05/12/2017
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...AKQ...MHX...RAH...
LAT...LON 36137860 36227794 36137730 35797679 35437679 35167730
35127775 35267844 35567902 35827921 35907921 36137860SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 12, 2:06 PM EDT | Mesoscale Discussion | SPC | Buncombe, Burke, Cherokee, Clay, Cleveland, Graham and 12 more | 2 hr |
Nearby
Mesoscale Discussions in North Carolina, 2017Every mesoscale discussion in 2017
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.