Alert archive / Virginia / Mesoscale Discussions in 2014

Mesoscale Discussion 1273

July 4, 2014Currituck County, North Carolina; 7 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Jul 4, 2014, 3:58 AM EDT for Currituck County, North Carolina; 7 counties in Virginia. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Jul 4, 2014, 3:58 AM EDT (07:58 UTC)
Expired: Jul 4, 2014, 6:00 AM EDT
In force: 2 hr
Issued by: the Storm Prediction Center

Counties Currituck County, NC, City of Hampton, VA, City of Norfolk, VA, City of Poquoson, VA, City of Portsmouth, VA, City of Virginia Beach, VA, Mathews County, VA, Northampton County, VA

The radar

The Norfolk radar (KAKQ), 91 km from the middle of the area, began a volume at 07:59 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

Wallops Is Stn, VA (KWAL), launched 00:00Z, 8.0 hours before the alert went out and 130 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: 1466 J/kg
Mixed-layer CIN: -41 J/kg
Mixed-layer LCL: 907 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 3 m²/s²
0-3 km storm-relative helicity: 12 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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
Jul 3, 9:23 PM EDT	Mesoscale Discussion	SPC	Beaufort, Bertie, Brunswick, Camden, Carteret, Chowan and 26 more	67 min
Jul 3, 9:49 PM EDT	Tornado Watch	SPC	Beaufort, Bertie, Camden, Carteret, Chowan, Craven and 20 more	6 hr
Jul 4, 1:01 AM EDT	Mesoscale Discussion	SPC	Beaufort, Bertie, Camden, Carteret, Chowan, Currituck and 10 more	119 min
Jul 3, 8:13 PM EDT	Mesoscale Discussion	SPC	Alleghany, Amherst, Bedford, Botetourt, Franklin, Nelson and 8 more	32 min

Nearby

Mesoscale Discussions in Virginia, 2014 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.