Alert archive / Virginia / Mesoscale Discussions in 2020

Mesoscale Discussion 1002

June 25, 202020 counties in Maryland; 59 counties in Virginia; Jefferson County, West Virginia

The Storm Prediction Center issued this mesoscale discussion at Jun 25, 2020, 6:09 PM EDT for 20 counties in Maryland; 59 counties in Virginia; Jefferson County, West Virginia. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued: Jun 25, 2020, 6:09 PM EDT (22:09 UTC)
Expired: Jun 25, 2020, 7:45 PM EDT
In force: 96 min
Issued by: the Storm Prediction Center
Concerning: Severe potential...watch unlikely
Chance of a watch: 20%

All 80 counties

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, Saint Mary's County, MD, Somerset County, MD, Talbot County, MD, Wicomico County, MD, Accomack County, VA, Amelia County, VA, Arlington County, VA, Caroline County, VA, Charles City County, VA, Chesterfield County, VA, City of Alexandria, VA, City of Colonial Heights, VA, City of Fairfax, VA, City of Falls Church, 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 Petersburg, VA, City of Poquoson, VA, City of Richmond, VA, City of Williamsburg, VA, City of Winchester, VA, Clarke County, VA, Culpeper County, VA, Dinwiddie County, VA, Essex County, VA, Fairfax County, VA, Fauquier County, VA, Fluvanna County, VA, Gloucester County, VA, Goochland 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, New Kent County, VA, Northampton County, VA, Northumberland County, VA, Orange County, VA, Page County, VA, Powhatan County, VA, Prince George County, VA, Prince William County, VA, Rappahannock County, VA, Richmond County, VA, Spotsylvania County, VA, Stafford County, VA, Surry County, VA, Sussex County, VA, Warren County, VA, Westmoreland County, VA, York County, VA, Jefferson County, WV

The radar

The Sterling radar (KLWX), 104 km from the middle of the area, began a volume at 22:09 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, 10.2 hours before the alert went out and 99 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: 2 J/kg
Mixed-layer CIN: -176 J/kg
Mixed-layer LCL: 1731 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 17 m²/s²
0-3 km storm-relative helicity: 68 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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
Jun 25, 1:48 PM EDT	Mesoscale Discussion	SPC	Anne Arundel, Baltimore, Carroll, Charles, Frederick, Harford and 5 more	117 min
Jun 25, 5:48 PM EDT	Mesoscale Discussion	SPC	Charlotte, Halifax, Henry, Lunenburg, Mecklenburg, Nottoway and 3 more	87 min

Nearby

Mesoscale Discussions in Virginia, 2020 Mesoscale Discussions in Maryland, 2020 Mesoscale Discussions in West Virginia, 2020 Every mesoscale discussion in 2020

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.