Alert archive / Virginia / Mesoscale Discussions in 2003

Mesoscale Discussion 860

May 8, 20034 states

The Storm Prediction Center issued this mesoscale discussion at May 8, 2003, 4:46 PM EDT for 4 states. It was in force for 59 min.

The area

The outline as issued.

The facts

Issued: May 8, 2003, 4:46 PM EDT (20:46 UTC)
Expired: May 8, 2003, 5:45 PM EDT
In force: 59 min
Issued by: the Storm Prediction Center

All 38 counties

Allegany County, MD, Charles County, MD, Garrett County, MD, Saint Mary's County, MD, Fayette County, PA, Somerset County, PA, Washington County, PA, Caroline County, VA, City of Fairfax, VA, City of Fredericksburg, 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, King George County, VA, Loudoun County, VA, Madison County, VA, Orange County, VA, Page County, VA, Prince William County, VA, Rappahannock County, VA, Shenandoah County, VA, Spotsylvania County, VA, Stafford County, VA, Warren County, VA, Westmoreland County, VA, Berkeley County, WV, Grant County, WV, Hampshire County, WV, Hardy County, WV, Jefferson County, WV, Mineral County, WV, Morgan County, WV, Preston County, WV

The radar

The Sterling radar (KLWX), 69 km from the middle of the area, began a volume at 20:49 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, 8.8 hours before the alert went out and 76 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: 203 J/kg
Mixed-layer CIN: -52 J/kg
Mixed-layer LCL: 820 m above ground
0-6 km bulk shear: 56 kt
0-1 km storm-relative helicity: 29 m²/s²
0-3 km storm-relative helicity: 88 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 8, 12:55 PM EDT	Severe Thunderstorm Watch	SPC	Allegany, Anne Arundel, Baltimore, Calvert, Caroline, Carroll and 16 more	5 hr
May 8, 2:48 PM EDT	Mesoscale Discussion	SPC	Allegany, Anne Arundel, Baltimore, Calvert, Caroline, Carroll and 16 more	117 min

Nearby

Mesoscale Discussions in Virginia, 2003 Mesoscale Discussions in West Virginia, 2003 Mesoscale Discussions in Maryland, 2003 Every mesoscale discussion in 2003

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.