Alert archive / Virginia / Mesoscale Discussions in 2012

Mesoscale Discussion 1316

June 29, 20124 states

The Storm Prediction Center issued this mesoscale discussion at Jun 29, 2012, 10:51 PM EDT for 4 states. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued: Jun 29, 2012, 10:51 PM EDT (02:51 UTC)
Expired: Jun 30, 2012, 12:15 AM EDT
In force: 84 min
Issued by: the Storm Prediction Center

All 89 counties

Kent County, DE, New Castle County, DE, Sussex County, DE, Anne Arundel County, MD, Baltimore County, MD, Calvert County, MD, Caroline County, MD, Carroll County, MD, Cecil County, MD, Charles County, MD, City of Baltimore, MD, Dorchester County, MD, Harford County, MD, Howard County, MD, Kent County, MD, Montgomery County, MD, Prince George's County, MD, Queen Anne's County, MD, Saint Mary's County, MD, Somerset County, MD, Talbot County, MD, Wicomico County, MD, Worcester County, MD, Atlantic County, NJ, Cape May County, NJ, Cumberland County, NJ, Gloucester County, NJ, Salem County, NJ, Accomack County, VA, Amelia County, VA, Arlington County, VA, Brunswick County, VA, Caroline County, VA, Charles City County, VA, Chesterfield County, VA, City of Alexandria, VA, City of Chesapeake, VA, City of Colonial Heights, VA, City of Emporia, VA, City of Fairfax, VA, City of Falls Church, VA, City of Franklin, VA, City of Fredericksburg, VA, City of Hampton, VA, City of Hopewell, VA, City of Manassas, VA, City of Manassas Park, VA, City of Newport News, VA, City of Norfolk, VA, City of Petersburg, VA, City of Poquoson, VA, City of Portsmouth, VA, City of Richmond, VA, City of Suffolk, VA, City of Virginia Beach, VA, City of Williamsburg, VA, Dinwiddie County, VA, Essex County, VA, Fairfax County, VA, Gloucester County, VA, Goochland County, VA, Greensville County, VA, Hanover County, VA, Henrico County, VA, Isle of Wight County, VA, James City County, VA, King and Queen County, VA, King George County, VA, King William County, VA, Lancaster County, VA, Lunenburg County, VA, Mathews County, VA, Mecklenburg County, VA, Middlesex County, VA, New Kent County, VA, Northampton County, VA, Northumberland County, VA, Nottoway County, VA, Powhatan County, VA, Prince George County, VA, Prince William County, VA, Richmond County, VA, Southampton County, VA, Spotsylvania County, VA, Stafford County, VA, Surry County, VA, Sussex County, VA, Westmoreland County, VA, York County, VA

The radar

The Dover AFB radar (KDOX), 106 km from the middle of the area, began a volume at 02:53 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, 2.9 hours before the alert went out and 75 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: 2642 J/kg
Mixed-layer CIN: -133 J/kg
Mixed-layer LCL: 1881 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 24 m²/s²
0-3 km storm-relative helicity: 56 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.5

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
Jun 29, 10:09 PM EDT	Severe Thunderstorm Watch	SPC	Kent, New Castle, Sussex	4 hr
Jun 30, 7:39 PM EDT	Mesoscale Discussion	SPC	Kent, Sussex	3 hr
Jun 30, 4:27 PM EDT	Mesoscale Discussion	SPC	Montgomery	3 hr

Nearby

Mesoscale Discussions in Virginia, 2012 Mesoscale Discussions in Maryland, 2012 Mesoscale Discussions in New Jersey, 2012 Every mesoscale discussion in 2012

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.