Alert archive / North Carolina / Mesoscale Discussions in 2009

Mesoscale Discussion 697

May 4, 200942 counties in North Carolina; 4 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at May 4, 2009, 1:15 PM EDT for 42 counties in North Carolina; 4 counties in South Carolina. It was in force for 60 min.

The area

The outline as issued.

The facts

Issued: May 4, 2009, 1:15 PM EDT (17:15 UTC)
Expired: May 4, 2009, 2:15 PM EDT
In force: 60 min
Issued by: the Storm Prediction Center

All 46 counties

Beaufort County, NC, Bertie County, NC, Bladen County, NC, Brunswick County, NC, Camden County, NC, Chowan County, NC, Columbus County, NC, Craven County, NC, Cumberland County, NC, Currituck County, NC, Duplin County, NC, Edgecombe County, NC, Franklin County, NC, Gates County, NC, Greene County, NC, Halifax County, NC, Harnett County, NC, Hertford County, NC, Hoke County, NC, Hyde County, NC, Johnston County, NC, Jones County, NC, Lee County, NC, Lenoir County, NC, Martin County, NC, Nash County, NC, New Hanover County, NC, Northampton County, NC, Onslow County, NC, Pamlico County, NC, Pasquotank County, NC, Pender County, NC, Perquimans County, NC, Pitt County, NC, Robeson County, NC, Sampson County, NC, Scotland County, NC, Tyrrell County, NC, Wake County, NC, Washington County, NC, Wayne County, NC, Wilson County, NC, Dillon County, SC, Horry County, SC, Marion County, SC, Marlboro County, SC

The radar

The Raleigh/Durham radar (KRAX), 93 km from the middle of the area, began a volume at 17:16 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, 5.3 hours before the alert went out and 123 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: 1097 J/kg
Mixed-layer CIN: -5 J/kg
Mixed-layer LCL: 518 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 219 m²/s²
0-3 km storm-relative helicity: 197 m²/s²
Significant tornado parameter: 0.7
Supercell composite: 5.7

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
May 4, 12:03 PM EDT	Mesoscale Discussion	SPC	Camden, Currituck, Gates, Hertford, Northampton, Pasquotank	57 min
May 4, 1:30 PM EDT	Severe Thunderstorm Watch	SPC	Alamance, Beaufort, Bertie, Camden, Carteret, Caswell and 42 more	9 hr
May 4, 2:39 PM EDT	Severe Thunderstorm Watch	SPC	Bladen, Brunswick, Columbus, New Hanover, Pender, Robeson and 1 more	5 hr
May 4, 4:33 PM EDT	Mesoscale Discussion	SPC	Carteret, Craven, Dare, Hyde, Onslow, Pamlico and 1 more	57 min
May 4, 6:15 PM EDT	Mesoscale Discussion	SPC	Beaufort, Bertie, Bladen, Brunswick, Camden, Carteret and 39 more	60 min
May 4, 7:39 PM EDT	Severe Thunderstorm Watch	SPC	Bladen, Brunswick, Columbus, Craven, Cumberland, Duplin and 12 more	3 hr
May 4, 1:02 PM EDT	Severe Thunderstorm Watch	SPC	Beaufort, Jasper	7 hr
May 4, 2:23 PM EDT	Mesoscale Discussion	SPC	Aiken, Allendale, Bamberg, Barnwell, Calhoun, Colleton and 7 more	67 min

Nearby

Mesoscale Discussions in North Carolina, 2009 Mesoscale Discussions in South Carolina, 2009 Every mesoscale discussion in 2009

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.