Alert archive / Virginia / Mesoscale Discussions in 2004

Mesoscale Discussion 583

May 7, 20045 states

The Storm Prediction Center issued this mesoscale discussion at May 7, 2004, 6:17 PM EDT for 5 states. It was in force for 118 min.

The area

The outline as issued.

The facts

Issued: May 7, 2004, 6:17 PM EDT (22:17 UTC)
Expired: May 7, 2004, 8:15 PM EDT
In force: 118 min
Issued by: the Storm Prediction Center

All 53 counties

Kent County, DE, Sussex County, DE, Anne Arundel County, MD, Baltimore County, MD, Calvert County, MD, Caroline County, MD, Charles County, MD, City of Baltimore, MD, Dorchester County, MD, Frederick County, MD, Howard County, MD, Kent County, MD, Montgomery County, MD, Prince George's County, MD, Queen Anne's County, MD, Saint Mary's County, MD, Somerset County, MD, Talbot County, MD, Washington County, MD, Wicomico County, MD, Worcester County, MD, Cumberland County, NJ, Arlington County, VA, City of Alexandria, 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, King George County, VA, Loudoun County, VA, Madison County, VA, Orange County, VA, Page County, VA, Prince William County, VA, Rappahannock County, VA, Rockingham County, VA, Shenandoah County, VA, Stafford County, VA, Warren County, VA, Berkeley County, WV, Hampshire County, WV, Hardy County, WV, Jefferson County, WV, Morgan County, WV

The radar

The Sterling radar (KLWX), 34 km from the middle of the area, began a volume at 22:20 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, 10.3 hours before the alert went out and 36 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: -314 J/kg
Mixed-layer LCL: 1566 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 184 m²/s²
0-3 km storm-relative helicity: 167 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

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 7, 10:29 AM EDT	Mesoscale Discussion	SPC	New Castle	91 min
May 7, 1:24 PM EDT	Mesoscale Discussion	SPC	Kent, New Castle	96 min
May 7, 1:40 PM EDT	Severe Thunderstorm Watch	SPC	Kent, New Castle, Sussex	3 hr
May 7, 4:35 PM EDT	Severe Thunderstorm Watch	SPC	Kent, Sussex	5 hr
May 7, 11:00 AM EDT	Severe Thunderstorm Watch	SPC	Allegany, Anne Arundel, Baltimore, Carroll, Frederick, Garrett and 5 more	6 hr
May 7, 1:49 PM EDT	Mesoscale Discussion	SPC	Allegany, Garrett, Washington	86 min
May 7, 7:02 PM EDT	Mesoscale Discussion	SPC	Caroline, Essex, Fluvanna, Gloucester, Goochland, Hanover and 13 more	2 hr
May 7, 7:20 PM EDT	Severe Thunderstorm Watch	SPC	Accomack, Caroline, Essex, Gloucester, Hanover, King and Queen and 10 more	4 hr

Nearby

Mesoscale Discussions in Virginia, 2004 Mesoscale Discussions in Maryland, 2004 Mesoscale Discussions in West Virginia, 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.