Alert archive / Virginia / Mesoscale Discussions in 2020

Mesoscale Discussion 769

May 30, 202014 counties in North Carolina; 16 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at May 30, 2020, 6:33 PM EDT for 14 counties in North Carolina; 16 counties in Virginia. It was in force for 87 min.

The area

The outline as issued.

The facts

Issued: May 30, 2020, 6:33 PM EDT (22:33 UTC)
Expired: May 30, 2020, 8:00 PM EDT
In force: 87 min
Issued by: the Storm Prediction Center
Concerning: Severe potential...watch unlikely
Chance of a watch: 5%

All 30 counties

Bertie County, NC, Camden County, NC, Chowan County, NC, Currituck County, NC, Dare County, NC, Gates County, NC, Halifax County, NC, Hertford County, NC, Martin County, NC, Northampton County, NC, Pasquotank County, NC, Perquimans County, NC, Tyrrell County, NC, Washington County, NC, City of Chesapeake, VA, City of Emporia, VA, City of Franklin, VA, City of Hampton, VA, City of Newport News, VA, City of Norfolk, VA, City of Petersburg, VA, City of Portsmouth, VA, City of Suffolk, VA, City of Virginia Beach, VA, Greensville County, VA, Isle of Wight County, VA, Prince George County, VA, Southampton County, VA, Surry County, VA, Sussex County, VA

The radar

The Norfolk radar (KAKQ), 94 km from the middle of the area, began a volume at 22:34 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 12:00Z, 10.6 hours before the alert went out and 162 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: 664 J/kg
Mixed-layer CIN: -22 J/kg
Mixed-layer LCL: 821 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 47 m²/s²
0-3 km storm-relative helicity: 11 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.0

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
May 30, 2:25 PM EDT	Mesoscale Discussion	SPC	Camden, Chowan, Gates, Halifax, Hertford, Northampton and 2 more	95 min

Nearby

Mesoscale Discussions in Virginia, 2020 Mesoscale Discussions in North Carolina, 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.