Alert archive / Virginia / Mesoscale Discussions in 2011

Mesoscale Discussion 2065

August 27, 20114 states

The Storm Prediction Center issued this mesoscale discussion at Aug 27, 2011, 7:52 AM EDT for 4 states. It was in force for 113 min.

The area

The outline as issued.

The facts

Issued: Aug 27, 2011, 7:52 AM EDT (11:52 UTC)
Expired: Aug 27, 2011, 9:45 AM EDT
In force: 113 min
Issued by: the Storm Prediction Center

All 23 counties

Sussex County, DE, Somerset County, MD, Wicomico County, MD, Worcester County, MD, Camden County, NC, Currituck County, NC, Gates County, NC, Pasquotank County, NC, Accomack County, VA, City of Chesapeake, 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, Gloucester County, VA, Isle of Wight County, VA, Lancaster County, VA, Mathews County, VA, Northampton County, VA, York County, VA

The radar

The Norfolk radar (KAKQ), 129 km from the middle of the area, began a volume at 11:55 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.

Tornado Watch 811Aug 27, 10:40 AM EDT

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 00:00Z, 11.9 hours before the alert went out and 54 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: 901 J/kg
Mixed-layer CIN: -12 J/kg
Mixed-layer LCL: 737 m above ground
0-6 km bulk shear: 6 kt
0-1 km storm-relative helicity: -14 m²/s²
0-3 km storm-relative helicity: 8 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
Aug 27, 10:31 AM EDT	Mesoscale Discussion	SPC	Sussex	29 min
Aug 27, 10:41 AM EDT	Tornado Watch	SPC	Kent, New Castle, Sussex	9 hr
Aug 27, 1:01 PM EDT	Mesoscale Discussion	SPC	Kent, New Castle, Sussex	119 min
Aug 27, 4:44 PM EDT	Mesoscale Discussion	SPC	Sussex	2 hr
Aug 27, 7:31 PM EDT	Mesoscale Discussion	SPC	New Castle	89 min
Aug 27, 7:56 PM EDT	Tornado Watch	SPC	Kent, New Castle, Sussex	9 hr
Aug 27, 12:32 AM EDT	Tornado Watch	SPC	Somerset, Wicomico, Worcester	10 hr
Aug 27, 3:06 AM EDT	Mesoscale Discussion	SPC	Somerset, Wicomico, Worcester	114 min
Aug 26, 8:11 PM EDT	Tornado Watch	SPC	Beaufort, Brunswick, Carteret, Craven, Dare, Hyde and 6 more	9 hr
Aug 26, 11:06 PM EDT	Mesoscale Discussion	SPC	Beaufort, Bertie, Bladen, Brunswick, Camden, Carteret and 36 more	84 min

Nearby

Mesoscale Discussions in Virginia, 2011 Mesoscale Discussions in North Carolina, 2011 Mesoscale Discussions in Maryland, 2011 Every mesoscale discussion in 2011

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.