Alert archive / Virginia / Mesoscale Discussions in 2018

Mesoscale Discussion 1628

November 6, 2018Sussex County, Delaware; 8 counties in Maryland; 30 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Nov 6, 2018, 12:11 PM EST for Sussex County, Delaware; 8 counties in Maryland; 30 counties in Virginia. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued: Nov 6, 2018, 12:11 PM EST (17:11 UTC)
Expired: Nov 6, 2018, 1:45 PM EST
In force: 94 min
Issued by: the Storm Prediction Center
Chance of a watch: 40%

All 39 counties

Sussex County, DE, Calvert County, MD, Caroline County, MD, Dorchester County, MD, Saint Mary's County, MD, Somerset County, MD, Talbot County, MD, Wicomico County, MD, Worcester County, MD, Accomack County, VA, Charles City County, VA, City of Colonial Heights, VA, City of Hampton, VA, City of Hopewell, VA, City of Newport News, VA, City of Norfolk, VA, City of Petersburg, VA, City of Poquoson, VA, City of Portsmouth, VA, City of Williamsburg, VA, Essex County, VA, Gloucester County, VA, Henrico County, VA, Isle of Wight County, VA, James City County, VA, King and Queen County, VA, King William County, VA, Lancaster County, VA, Mathews County, VA, Middlesex County, VA, New Kent County, VA, Northampton County, VA, Northumberland County, VA, Prince George County, VA, Richmond County, VA, Surry County, VA, Sussex County, VA, Westmoreland County, VA, York County, VA

The radar

The Norfolk radar (KAKQ), 105 km from the middle of the area, began a volume at 17:12 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, 5.2 hours before the alert went out and 146 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 502 m above ground
0-6 km bulk shear: 75 kt
0-1 km storm-relative helicity: 375 m²/s²
0-3 km storm-relative helicity: 468 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
Nov 6, 12:44 AM EST	Mesoscale Discussion	SPC	Buchanan, Dickenson, Wise, City of Norton	2 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.