Alert archive / Virginia / Mesoscale Discussions in 2016

Mesoscale Discussion 1424

July 28, 20166 states

The Storm Prediction Center issued this mesoscale discussion at Jul 28, 2016, 4:10 PM EDT for 6 states. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued: Jul 28, 2016, 4:10 PM EDT (20:10 UTC)
Expired: Jul 28, 2016, 5:45 PM EDT
In force: 95 min
Issued by: the Storm Prediction Center

All 105 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, Frederick County, MD, Harford County, MD, Howard County, MD, Kent County, MD, Montgomery County, MD, Prince George's County, MD, Queen Anne's County, MD, Talbot County, MD, Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Cape May County, NJ, Cumberland County, NJ, Gloucester County, NJ, Mercer County, NJ, Middlesex County, NJ, Ocean County, NJ, Salem County, NJ, Bucks County, PA, Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA, Albemarle County, VA, Alleghany County, VA, Amherst County, VA, Arlington County, VA, Augusta County, VA, Bath County, VA, Bedford County, VA, Bland County, VA, Botetourt County, VA, City of Alexandria, VA, City of Buena Vista, VA, City of Charlottesville, VA, City of Covington, VA, City of Fairfax, VA, City of Falls Church, VA, City of Fredericksburg, VA, City of Harrisonburg, VA, City of Lexington, VA, City of Lynchburg, VA, City of Manassas, VA, City of Manassas Park, VA, City of Radford, VA, City of Roanoke, VA, City of Salem, VA, City of Staunton, VA, City of Waynesboro, VA, City of Winchester, VA, Clarke County, VA, Craig County, VA, Culpeper County, VA, Fairfax County, VA, Fauquier County, VA, Floyd County, VA, Franklin County, VA, Frederick County, VA, Giles County, VA, Greene County, VA, Highland County, VA, King George County, VA, Loudoun County, VA, Madison County, VA, Montgomery County, VA, Nelson County, VA, Orange County, VA, Page County, VA, Prince William County, VA, Pulaski County, VA, Rappahannock County, VA, Roanoke County, VA, Rockbridge County, VA, Rockingham County, VA, Shenandoah County, VA, Spotsylvania County, VA, Stafford County, VA, Warren County, VA, Wythe County, VA, Berkeley County, WV, Grant County, WV, Greenbrier County, WV, Hampshire County, WV, Hardy County, WV, Jefferson County, WV, Mercer County, WV, Monroe County, WV, Pendleton County, WV, Pocahontas County, WV, Raleigh County, WV, Randolph County, WV, Summers County, WV, Webster County, WV

The radar

The Sterling radar (KLWX), 10 km from the middle of the area, began a volume at 20:13 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

Washington/Dulle, VA (KIAD), launched 12:00Z, 8.2 hours before the alert went out and 8 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: 552 J/kg
Mixed-layer CIN: -98 J/kg
Mixed-layer LCL: 1083 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 13 m²/s²
0-3 km storm-relative helicity: 87 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.8

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
Jul 28, 12:58 PM EDT	Mesoscale Discussion	SPC	Kent, New Castle, Sussex	2 hr
Jul 28, 1:27 PM EDT	Severe Thunderstorm Watch	SPC	Kent, New Castle, Sussex	11 hr
Jul 28, 6:52 PM EDT	Mesoscale Discussion	SPC	Kent, New Castle, Sussex	83 min
Jul 28, 1:28 PM EDT	Mesoscale Discussion	SPC	Alleghany, Bedford, Bland, Botetourt, Craig, Floyd and 12 more	3 hr
Jul 28, 2:08 PM EDT	Severe Thunderstorm Watch	SPC	Alleghany, Amherst, Appomattox, Bath, Bedford, Bland and 29 more	10 hr
Jul 28, 2:57 PM EDT	Mesoscale Discussion	SPC	Accomack, Amelia, Brunswick, Charles City, Chesterfield, Dinwiddie and 36 more	3 hr

Nearby

Mesoscale Discussions in Virginia, 2016 Mesoscale Discussions in Maryland, 2016 Mesoscale Discussions in West Virginia, 2016 Every mesoscale discussion in 2016

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.