Alert archive / North Carolina / Mesoscale Discussions in 2020

Mesoscale Discussion 1880

December 24, 202017 counties in North Carolina; 15 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Dec 24, 2020, 10:46 PM EST for 17 counties in North Carolina; 15 counties in Virginia. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Dec 24, 2020, 10:46 PM EST (03:46 UTC)
Expired: Dec 25, 2020, 1:45 AM EST
In force: 3 hr
Issued by: the Storm Prediction Center
Concerning: Tornado watch 519

All 32 counties

Beaufort County, NC, Bertie County, NC, Camden County, NC, Carteret County, NC, Chowan County, NC, Craven County, NC, Currituck County, NC, Dare County, NC, Gates County, NC, Hertford County, NC, Hyde County, NC, Martin County, NC, Pamlico County, NC, Pasquotank County, NC, Perquimans County, NC, Tyrrell County, NC, Washington County, NC, City of Chesapeake, VA, City of Franklin, VA, City of Hampton, VA, City of Newport News, VA, City of Norfolk, VA, City of Poquoson, VA, City of Portsmouth, VA, City of Suffolk, VA, City of Virginia Beach, VA, City of Williamsburg, VA, Isle of Wight County, VA, James City County, VA, Southampton County, VA, Surry County, VA, York County, VA

The radar

The Morehead City radar (KMHX), 130 km from the middle of the area, began a volume at 03:46 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, 3.8 hours before the alert went out and 129 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: 507 J/kg
Mixed-layer CIN: -22 J/kg
Mixed-layer LCL: 647 m above ground
0-6 km bulk shear: 55 kt
0-1 km storm-relative helicity: 498 m²/s²
0-3 km storm-relative helicity: 533 m²/s²
Significant tornado parameter: 1.8
Supercell composite: 11.5

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 24, 7:13 PM EST	Mesoscale Discussion	SPC	Beaufort, Bertie, Bladen, Brunswick, Camden, Carteret and 38 more	2 hr
Dec 24, 9:38 PM EST	Tornado Watch	SPC	Beaufort, Bertie, Camden, Carteret, Chowan, Craven and 18 more	3 hr

Nearby

Mesoscale Discussions in North Carolina, 2020 Mesoscale Discussions in Virginia, 2020 Every mesoscale discussion in 2020

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.