Alert archive / North Carolina / Mesoscale Discussions in 2017
Mesoscale Discussion 547
The Storm Prediction Center issued this mesoscale discussion at Apr 22, 2017, 4:12 PM EDT for 18 counties in North Carolina; 14 counties in Virginia. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 22, 2017, 4:12 PM EDT (20:12 UTC)
- Expired
- Apr 22, 2017, 6:15 PM EDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
All 32 counties
Alamance County, NC, Caswell County, NC, Durham County, NC, Edgecombe County, NC, Forsyth County, NC, Franklin County, NC, Granville County, NC, Guilford County, NC, Halifax County, NC, Hertford County, NC, Nash County, NC, Northampton County, NC, Orange County, NC, Person County, NC, Rockingham County, NC, Stokes County, NC, Vance County, NC, Warren County, NC, Brunswick County, VA, Charlotte County, VA, City of Danville, VA, City of Emporia, VA, City of Franklin, VA, City of Suffolk, VA, Dinwiddie County, VA, Greensville County, VA, Halifax County, VA, Lunenburg County, VA, Mecklenburg County, VA, Pittsylvania County, VA, Southampton County, VA, Sussex County, VA
The radar
The Raleigh/Durham radar (KRAX), 96 km from the middle of the area, began a volume at 20:12 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
Roanoke, VA (KRNK), launched 12:00Z, 8.2 hours before the alert went out and 136 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
- 28 J/kg
- Mixed-layer CIN
- -103 J/kg
- Mixed-layer LCL
- 755 m above ground
- 0-6 km bulk shear
- 47 kt
- 0-1 km storm-relative helicity
- 106 m²/s²
- 0-3 km storm-relative helicity
- 131 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
The text
As transmitted.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 22, 11:57 AM EDT | Mesoscale Discussion | SPC | Alleghany, Ashe, Caswell, Granville, Person, Rockingham and 6 more | 2 hr |
| Apr 22, 3:17 PM EDT | Severe Thunderstorm Watch | SPC | Alamance, Caswell, Durham, Edgecombe, Forsyth, Franklin and 12 more | 4 hr |
| Apr 22, 7:40 PM EDT | Mesoscale Discussion | SPC | Cherokee | 65 min |
Nearby
Mesoscale Discussions in North Carolina, 2017Mesoscale Discussions in Virginia, 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.