Alert archive / Virginia / Mesoscale Discussions in 2018

Mesoscale Discussion 402

May 13, 20185 states

The Storm Prediction Center issued this mesoscale discussion at May 13, 2018, 7:00 PM EDT for 5 states. It was in force for 60 min.

The area

The outline as issued.

The facts

Issued: May 13, 2018, 7:00 PM EDT (23:00 UTC)
Expired: May 13, 2018, 8:00 PM EDT
In force: 60 min
Issued by: the Storm Prediction Center

All 69 counties

Charles County, MD, Garrett County, MD, Belmont County, OH, Carroll County, OH, Guernsey County, OH, Harrison County, OH, Jefferson County, OH, Monroe County, OH, Morgan County, OH, Noble County, OH, Tuscarawas County, OH, Washington County, OH, Fayette County, PA, Greene County, PA, Washington County, PA, Arlington County, VA, Caroline 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 Harrisonburg, VA, City of Manassas, VA, City of Manassas Park, VA, City of Winchester, VA, Clarke County, VA, Culpeper County, VA, Fairfax County, VA, Fauquier County, VA, Frederick County, VA, Greene County, VA, Hanover County, VA, King George County, VA, Loudoun County, VA, Louisa County, VA, Madison County, VA, Orange County, VA, Page County, VA, Prince William County, VA, Rappahannock County, VA, Rockingham County, VA, Shenandoah County, VA, Spotsylvania County, VA, Stafford County, VA, Warren County, VA, Barbour County, WV, Brooke County, WV, Doddridge County, WV, Grant County, WV, Hampshire County, WV, Hardy County, WV, Harrison County, WV, Lewis County, WV, Marion County, WV, Marshall County, WV, Mineral County, WV, Monongalia County, WV, Ohio County, WV, Pendleton County, WV, Pleasants County, WV, Preston County, WV, Randolph County, WV, Ritchie County, WV, Taylor County, WV, Tucker County, WV, Tyler County, WV, Upshur County, WV, Wetzel County, WV

The radar

The Pittsburgh radar (KPBZ), 125 km from the middle of the area, began a volume at 23:02 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

Pittsburgh, PA (KAGC), launched 12:00Z, 11.0 hours before the alert went out and 110 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: 28 J/kg
Mixed-layer CIN: -201 J/kg
Mixed-layer LCL: 485 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: 267 m²/s²
0-3 km storm-relative helicity: 366 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.1

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
May 12, 9:14 PM EDT	Mesoscale Discussion	SPC	Caroline, Talbot	61 min
May 13, 1:56 PM EDT	Mesoscale Discussion	SPC	Allegany, Garrett	2 hr
May 13, 4:28 PM EDT	Severe Thunderstorm Watch	SPC	Allegany, Garrett, Washington	7 hr

Nearby

Mesoscale Discussions in Virginia, 2018 Mesoscale Discussions in West Virginia, 2018 Mesoscale Discussions in Ohio, 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.