Alert archive / Virginia / Mesoscale Discussions in 2009

Mesoscale Discussion 940

June 3, 20095 states

The Storm Prediction Center issued this mesoscale discussion at Jun 3, 2009, 4:34 PM EDT for 5 states. It was in force for 86 min.

The area

The outline as issued.

The facts

Issued: Jun 3, 2009, 4:34 PM EDT (20:34 UTC)
Expired: Jun 3, 2009, 6:00 PM EDT
In force: 86 min
Issued by: the Storm Prediction Center

All 115 counties

Kent County, DE, New Castle County, DE, Sussex County, DE, Anne Arundel County, MD, Calvert County, MD, Caroline County, MD, Charles County, MD, City of Baltimore, MD, Dorchester 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, Wicomico County, MD, Worcester County, MD, Cumberland County, NJ, Salem County, NJ, Accomack County, VA, Albemarle County, VA, Alleghany County, VA, Amherst County, VA, Appomattox County, VA, Arlington County, VA, Augusta County, VA, Bath County, VA, Bedford County, VA, Bland County, VA, Botetourt County, VA, Buckingham County, VA, Campbell County, VA, Caroline County, VA, City of Alexandria, VA, City of Buena Vista, VA, City of Charlottesville, VA, City of Covington, VA, City of Fairfax, VA, City of Falls Church, VA, City of Fredericksburg, VA, City of Harrisonburg, VA, City of Lexington, VA, City of Lynchburg, VA, City of Manassas, VA, City of Manassas Park, VA, City of Radford, VA, City of Richmond, VA, City of Roanoke, VA, City of Salem, VA, City of Staunton, VA, City of Waynesboro, VA, City of Winchester, VA, Clarke County, VA, Craig County, VA, Culpeper County, VA, Cumberland County, VA, Essex County, VA, Fairfax County, VA, Fauquier County, VA, Fluvanna County, VA, Giles County, VA, Goochland County, VA, Greene County, VA, Hanover County, VA, Highland County, VA, King and Queen County, VA, King George County, VA, King William County, VA, Lancaster County, VA, Loudoun County, VA, Louisa County, VA, Madison County, VA, Middlesex County, VA, Montgomery County, VA, Nelson County, VA, New Kent County, VA, Northumberland County, VA, Orange County, VA, Page County, VA, Powhatan County, VA, Prince William County, VA, Pulaski County, VA, Rappahannock County, VA, Richmond County, VA, Roanoke County, VA, Rockbridge County, VA, Rockingham County, VA, Shenandoah County, VA, Spotsylvania County, VA, Stafford County, VA, Tazewell County, VA, Warren County, VA, Westmoreland County, VA, Boone County, WV, Braxton County, WV, Clay County, WV, Fayette County, WV, Greenbrier County, WV, Hardy County, WV, Kanawha County, WV, McDowell County, WV, Mercer County, WV, Monroe County, WV, Nicholas County, WV, Pendleton County, WV, Pocahontas County, WV, Raleigh County, WV, Randolph County, WV, Roane County, WV, Summers County, WV, Upshur County, WV, Webster County, WV, Wyoming County, WV

The radar

The Sterling radar (KLWX), 160 km from the middle of the area, began a volume at 20:37 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

Roanoke, VA (KRNK), launched 12:00Z, 8.6 hours before the alert went out and 129 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: 451 J/kg
Mixed-layer CIN: -97 J/kg
Mixed-layer LCL: 1134 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 41 m²/s²
0-3 km storm-relative helicity: 34 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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
Jun 3, 1:06 PM EDT	Severe Thunderstorm Watch	SPC	Kent, New Castle, Sussex	9 hr
Jun 3, 7:10 PM EDT	Mesoscale Discussion	SPC	Kent, New Castle, Sussex	95 min
Jun 3, 12:41 PM EDT	Mesoscale Discussion	SPC	Anne Arundel, Calvert, Charles, Howard, Montgomery, Prince George's and 2 more	64 min
Jun 2, 9:19 PM EDT	Mesoscale Discussion	SPC	Cabell, Calhoun, Doddridge, Gilmer, Harrison, Jackson and 10 more	56 min
Jun 3, 12:12 PM EDT	Mesoscale Discussion	SPC	Barbour, Boone, Braxton, Cabell, Calhoun, Clay and 24 more	93 min

Nearby

Mesoscale Discussions in Virginia, 2009 Mesoscale Discussions in West Virginia, 2009 Mesoscale Discussions in Maryland, 2009 Every mesoscale discussion in 2009

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.