Alert archive / Virginia / Mesoscale Discussions in 2016

Mesoscale Discussion 1554

August 17, 2016Kent County, Sussex County, Delaware; 19 counties in Maryland; 55 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Aug 17, 2016, 4:26 PM EDT for Kent County, Sussex County, Delaware; 19 counties in Maryland; 55 counties in Virginia. It was in force for 64 min.

The area

The outline as issued.

The facts

Issued: Aug 17, 2016, 4:26 PM EDT (20:26 UTC)
Expired: Aug 17, 2016, 5:30 PM EDT
In force: 64 min
Issued by: the Storm Prediction Center
Chance of a watch: 60%

All 76 counties

Kent County, DE, Sussex County, DE, Anne Arundel County, MD, Baltimore County, MD, Calvert County, MD, Caroline County, MD, Carroll County, MD, Charles County, MD, City of Baltimore, MD, Dorchester County, MD, Frederick 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, Accomack County, VA, Albemarle County, VA, Amelia County, VA, Amherst County, VA, Appomattox County, VA, Arlington County, VA, Buckingham County, VA, Caroline County, VA, Charles City County, VA, Chesterfield County, VA, City of Alexandria, VA, City of Charlottesville, VA, City of Fairfax, VA, City of Falls Church, VA, City of Fredericksburg, VA, City of Hopewell, VA, City of Lynchburg, VA, City of Manassas, VA, City of Manassas Park, VA, City of Richmond, VA, City of Waynesboro, VA, City of Williamsburg, VA, Culpeper County, VA, Cumberland County, VA, Essex County, VA, Fairfax County, VA, Fauquier County, VA, Fluvanna County, VA, Gloucester County, VA, Goochland County, VA, Greene County, VA, Hanover County, VA, Henrico County, VA, James City County, VA, King and Queen County, VA, King George County, VA, King William County, VA, Lancaster County, VA, Loudoun County, VA, Louisa County, VA, Madison County, VA, Mathews County, VA, Middlesex County, VA, Nelson County, VA, New Kent County, VA, Northampton County, VA, Northumberland County, VA, Orange County, VA, Powhatan County, VA, Prince William County, VA, Rappahannock County, VA, Richmond County, VA, Spotsylvania County, VA, Stafford County, VA, Westmoreland County, VA

The radar

The Sterling radar (KLWX), 101 km from the middle of the area, began a volume at 20:27 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, 8.4 hours before the alert went out and 94 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: -83 J/kg
Mixed-layer LCL: 1193 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 28 m²/s²
0-3 km storm-relative helicity: 27 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.5

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
Aug 17, 1:25 PM EDT	Mesoscale Discussion	SPC	Garrett	95 min
Aug 17, 2:02 PM EDT	Severe Thunderstorm Watch	SPC	Allegany, Garrett, Washington	5 hr

Nearby

Mesoscale Discussions in Virginia, 2016 Mesoscale Discussions in Maryland, 2016 Mesoscale Discussions in Delaware, 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.