Alert archive / North Carolina / Mesoscale Discussions in 2014

Mesoscale Discussion 1576

August 18, 201423 counties in North Carolina

The Storm Prediction Center issued this mesoscale discussion at Aug 18, 2014, 5:49 PM EDT for 23 counties in North Carolina. It was in force for 56 min.

The area

The outline as issued.

The facts

Issued: Aug 18, 2014, 5:49 PM EDT (21:49 UTC)
Expired: Aug 18, 2014, 6:45 PM EDT
In force: 56 min
Issued by: the Storm Prediction Center

All 23 counties

Alamance County, NC, Bertie County, NC, Chatham County, NC, Davidson County, NC, Durham County, NC, Edgecombe County, NC, Franklin County, NC, Greene County, NC, Harnett County, NC, Johnston County, NC, Lee County, NC, Lenoir County, NC, Martin County, NC, Montgomery County, NC, Moore County, NC, Nash County, NC, Orange County, NC, Pitt County, NC, Randolph County, NC, Rowan County, NC, Wake County, NC, Wayne County, NC, Wilson County, NC

The radar

The Raleigh/Durham radar (KRAX), 33 km from the middle of the area, began a volume at 21:53 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

Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 9.8 hours before the alert went out and 107 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 429 J/kg
Mixed-layer CIN: -73 J/kg
Mixed-layer LCL: 1211 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 93 m²/s²
0-3 km storm-relative helicity: 124 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.5

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 18, 12:59 PM EDT	Mesoscale Discussion	SPC	Bertie, Camden, Chowan, Currituck, Gates, Halifax and 6 more	91 min
Aug 18, 2:35 PM EDT	Severe Thunderstorm Watch	SPC	Bertie, Camden, Chowan, Currituck, Gates, Hertford and 3 more	4 hr
Aug 18, 4:19 PM EDT	Mesoscale Discussion	SPC	Bertie, Camden, Chowan, Currituck, Gates, Halifax and 4 more	56 min

Nearby

Mesoscale Discussions in North Carolina, 2014 Every mesoscale discussion in 2014

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.