Alert archive / Virginia / Mesoscale Discussions in 2018

Mesoscale Discussion 1141

July 23, 2018Sussex County, Delaware; 11 counties in Maryland; 75 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Jul 23, 2018, 2:57 AM EDT for Sussex County, Delaware; 11 counties in Maryland; 75 counties in Virginia. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Jul 23, 2018, 2:57 AM EDT (06:57 UTC)
Expired: Jul 23, 2018, 5:30 AM EDT
In force: 3 hr
Issued by: the Storm Prediction Center
Chance of a watch: 5%

All 87 counties

Sussex County, DE, Anne Arundel County, MD, Calvert County, MD, Caroline County, MD, Charles County, MD, Dorchester County, MD, Prince George'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, Appomattox County, VA, Arlington County, VA, Brunswick County, VA, Buckingham County, VA, Caroline County, VA, Charles City County, VA, Charlotte County, VA, Chesterfield County, VA, City of Alexandria, VA, City of Charlottesville, 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, Culpeper County, VA, Cumberland County, VA, Dinwiddie County, VA, Essex County, VA, Fairfax County, VA, Fauquier County, VA, Fluvanna County, VA, Gloucester County, VA, Goochland County, VA, Greensville County, VA, Halifax 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, Louisa County, VA, Lunenburg County, VA, Madison County, VA, Mathews County, VA, Mecklenburg County, VA, Middlesex County, VA, New Kent County, VA, Northampton County, VA, Northumberland County, VA, Nottoway County, VA, Orange County, VA, Powhatan County, VA, Prince Edward 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 Norfolk radar (KAKQ), 99 km from the middle of the area, began a volume at 06:57 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 00:00Z, 7.0 hours before the alert went out and 123 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: 1533 J/kg
Mixed-layer CIN: -2 J/kg
Mixed-layer LCL: 664 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 83 m²/s²
0-3 km storm-relative helicity: 147 m²/s²
Significant tornado parameter: 0.8
Supercell composite: 5.5

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
Jul 23, 2:40 PM EDT	Mesoscale Discussion	SPC	Kent, New Castle, Sussex	3 hr

Nearby

Mesoscale Discussions in Virginia, 2018 Mesoscale Discussions in Maryland, 2018 Mesoscale Discussions in Delaware, 2018 Every mesoscale discussion in 2018

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.