Alert archive / Virginia / Mesoscale Discussions in 2017

Mesoscale Discussion 388

March 31, 20179 counties in North Carolina; 15 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Mar 31, 2017, 6:11 PM EDT for 9 counties in North Carolina; 15 counties in Virginia. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued: Mar 31, 2017, 6:11 PM EDT (22:11 UTC)
Expired: Mar 31, 2017, 7:45 PM EDT
In force: 94 min
Issued by: the Storm Prediction Center

All 24 counties

Bertie County, NC, Camden County, NC, Chowan County, NC, Currituck County, NC, Gates County, NC, Hertford County, NC, Northampton County, NC, Pasquotank County, NC, Perquimans 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 Portsmouth, VA, City of Suffolk, VA, City of Virginia Beach, VA, Dinwiddie 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), 70 km from the middle of the area, began a volume at 22:10 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, 10.2 hours before the alert went out and 187 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: 177 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 721 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 283 m²/s²
0-3 km storm-relative helicity: 335 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.3

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
Mar 31, 12:53 AM EDT	Mesoscale Discussion	SPC	Bladen, Brunswick, Columbus, New Hanover, Pender, Robeson and 1 more	2 hr
Mar 31, 9:57 AM EDT	Mesoscale Discussion	SPC	Beaufort, Bertie, Bladen, Brunswick, Camden, Carteret and 31 more	2 hr
Mar 31, 2:08 PM EDT	Mesoscale Discussion	SPC	Alamance, Caswell, Davidson, Davie, Durham, Forsyth and 13 more	67 min
Mar 31, 3:54 PM EDT	Tornado Watch	SPC	Bertie, Camden, Chowan, Currituck, Gates, Granville and 8 more	6 hr

Nearby

Mesoscale Discussions in Virginia, 2017 Mesoscale Discussions in North Carolina, 2017 Every 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.