Alert archive / Virginia / Mesoscale Discussions in 2009

Mesoscale Discussion 936

June 3, 20098 counties in Maryland; 15 counties in North Carolina; 63 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Jun 3, 2009, 12:41 PM EDT for 8 counties in Maryland; 15 counties in North Carolina; 63 counties in Virginia. It was in force for 64 min.

The area

The outline as issued.

The facts

Issued: Jun 3, 2009, 12:41 PM EDT (16:41 UTC)
Expired: Jun 3, 2009, 1:45 PM EDT
In force: 64 min
Issued by: the Storm Prediction Center

All 86 counties

Anne Arundel County, MD, Calvert County, MD, Charles County, MD, Howard County, MD, Montgomery County, MD, Prince George's County, MD, Saint Mary's County, MD, Talbot County, MD, Alexander County, NC, Burke County, NC, Caldwell County, NC, Catawba County, NC, Cleveland County, NC, Davie County, NC, Forsyth County, NC, Gaston County, NC, Iredell County, NC, Lincoln County, NC, Rockingham County, NC, Stokes County, NC, Surry County, NC, Wilkes County, NC, Yadkin County, NC, Albemarle County, VA, Amelia County, VA, Amherst County, VA, Appomattox County, VA, Arlington County, VA, Augusta County, VA, Bedford County, VA, Botetourt County, VA, Buckingham County, VA, Campbell County, VA, Caroline County, VA, Carroll County, VA, Charlotte County, VA, City of Alexandria, VA, City of Buena Vista, VA, City of Charlottesville, VA, City of Danville, 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 Martinsville, VA, City of Roanoke, VA, City of Salem, VA, City of Staunton, VA, City of Waynesboro, VA, Clarke County, VA, Culpeper County, VA, Cumberland County, VA, Essex County, VA, Fairfax County, VA, Fauquier County, VA, Floyd County, VA, Fluvanna County, VA, Franklin County, VA, Goochland County, VA, Greene County, VA, Halifax County, VA, Hanover County, VA, Henry County, VA, King George County, VA, Loudoun County, VA, Louisa County, VA, Madison County, VA, Nelson County, VA, Orange County, VA, Page County, VA, Patrick County, VA, Pittsylvania County, VA, Powhatan County, VA, Prince Edward County, VA, Prince William County, VA, Rappahannock County, VA, Richmond County, VA, Rockbridge County, VA, Spotsylvania County, VA, Stafford County, VA, Warren County, VA, Westmoreland County, VA

The radar

The Roanoke radar (KFCX), 144 km from the middle of the area, began a volume at 16:42 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

Severe Thunderstorm Watch 325Jun 3, 1:05 PM EDT

The nearest sounding before it

Roanoke, VA (KRNK), launched 12:00Z, 4.7 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: 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	Allegany, Anne Arundel, Baltimore, Calvert, Caroline, Carroll and 17 more	9 hr
Jun 3, 4:34 PM EDT	Mesoscale Discussion	SPC	Anne Arundel, Calvert, Caroline, Charles, Dorchester, Howard and 10 more	86 min
Jun 3, 7:10 PM EDT	Mesoscale Discussion	SPC	Allegany, Anne Arundel, Baltimore, Calvert, Caroline, Carroll and 17 more	95 min

Nearby

Mesoscale Discussions in Virginia, 2009 Mesoscale Discussions in North Carolina, 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.