Alert archive / Virginia / Mesoscale Discussions in 2017

Mesoscale Discussion 1527

August 18, 20174 states

The Storm Prediction Center issued this mesoscale discussion at Aug 18, 2017, 8:03 PM EDT for 4 states. It was in force for 57 min.

The area

The outline as issued.

The facts

Issued: Aug 18, 2017, 8:03 PM EDT (00:03 UTC)
Expired: Aug 18, 2017, 9:00 PM EDT
In force: 57 min
Issued by: the Storm Prediction Center

All 33 counties

Kent County, DE, 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, Atlantic County, NJ, Burlington County, NJ, Cape May County, NJ, Cumberland County, NJ, Monmouth County, NJ, Ocean County, NJ, Accomack County, VA, Charles City County, VA, City of Richmond, VA, City of Williamsburg, VA, Essex County, VA, Gloucester County, VA, Henrico 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, Northumberland County, VA, Richmond County, VA, Westmoreland County, VA

The radar

The Dover AFB radar (KDOX), 41 km from the middle of the area, began a volume at 00:05 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

Wallops Is Stn, VA (KWAL), launched 00:00Z, 0.1 hours before the alert went out and 79 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: 394 J/kg
Mixed-layer CIN: -110 J/kg
Mixed-layer LCL: 1406 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 33 m²/s²
0-3 km storm-relative helicity: 52 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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Nearby

Mesoscale Discussions in Virginia, 2017 Mesoscale Discussions in Maryland, 2017 Mesoscale Discussions in New Jersey, 2017 Every mesoscale discussion in 2017

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.