Alert archive / Virginia / Mesoscale Discussions in 2004

Mesoscale Discussion 756

May 19, 20046 states

The Storm Prediction Center issued this mesoscale discussion at May 19, 2004, 2:52 AM EDT for 6 states. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: May 19, 2004, 2:52 AM EDT (06:52 UTC)
Expired: May 19, 2004, 5:45 AM EDT
In force: 3 hr
Issued by: the Storm Prediction Center

All 46 counties

Kent County, DE, New Castle County, DE, Anne Arundel County, MD, Baltimore County, MD, Caroline County, MD, Carroll County, MD, Cecil County, MD, City of Baltimore, 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, Washington County, MD, Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Cumberland County, NJ, Gloucester County, NJ, Salem County, NJ, Chester County, PA, Delaware County, PA, Lancaster County, PA, Montgomery County, PA, Philadelphia County, PA, York County, PA, Arlington County, VA, City of Alexandria, VA, City of Fairfax, VA, City of Falls Church, VA, City of Manassas, VA, City of Manassas Park, VA, City of Winchester, VA, Clarke County, VA, Fairfax County, VA, Fauquier County, VA, Frederick County, VA, Loudoun County, VA, Prince William County, VA, Rappahannock County, VA, Shenandoah County, VA, Warren County, VA, Berkeley County, WV, Jefferson County, WV

The radar

The Sterling radar (KLWX), 93 km from the middle of the area, began a volume at 06:52 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, 6.9 hours before the alert went out and 88 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: 136 J/kg
Mixed-layer CIN: -136 J/kg
Mixed-layer LCL: 1253 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 85 m²/s²
0-3 km storm-relative helicity: 134 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 19, 3:01 PM EDT	Mesoscale Discussion	SPC	Calvert, Charles, Dorchester, Saint Mary's, Somerset, Wicomico and 1 more	119 min
May 19, 1:18 PM EDT	Mesoscale Discussion	SPC	Brunswick, Charlotte, Dinwiddie, Greensville, Halifax, Isle of Wight and 15 more	117 min

Nearby

Mesoscale Discussions in Virginia, 2004 Mesoscale Discussions in Maryland, 2004 Mesoscale Discussions in New Jersey, 2004 Every mesoscale discussion in 2004

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.