Alert archive / Virginia / Mesoscale Discussions in 2004

Mesoscale Discussion 1664

July 14, 20044 states

The Storm Prediction Center issued this mesoscale discussion at Jul 14, 2004, 12:18 PM EDT for 4 states. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued: Jul 14, 2004, 12:18 PM EDT (16:18 UTC)
Expired: Jul 14, 2004, 2:15 PM EDT
In force: 117 min
Issued by: the Storm Prediction Center

All 83 counties

Washington County, MD, Alleghany County, NC, Caswell County, NC, Rockingham County, NC, Stokes County, NC, Surry County, NC, Albemarle County, VA, Amelia County, VA, Amherst County, VA, Appomattox 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, Chesterfield County, VA, City of Buena Vista, VA, City of Charlottesville, VA, City of Colonial Heights, VA, City of Danville, VA, City of Fairfax, VA, City of Fredericksburg, VA, City of Galax, 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 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, Fairfax County, VA, Fauquier County, VA, Floyd County, VA, Fluvanna County, VA, Franklin County, VA, Frederick County, VA, Goochland County, VA, Grayson County, VA, Greene County, VA, Halifax County, VA, Hanover County, VA, Henry County, VA, Loudoun County, VA, Louisa County, VA, Lunenburg County, VA, Madison County, VA, Montgomery County, VA, Nelson County, VA, Nottoway 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, Pulaski County, VA, Rappahannock County, VA, Roanoke County, VA, Rockbridge County, VA, Rockingham County, VA, Shenandoah County, VA, Spotsylvania County, VA, Stafford County, VA, Warren County, VA, Wythe County, VA, Berkeley County, WV, Hampshire County, WV, Jefferson County, WV, Morgan County, WV

The radar

The Roanoke radar (KFCX), 151 km from the middle of the area, began a volume at 16:20 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 watches that followed

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

Tornado Watch 630Jul 14, 12:50 PM EDT

The nearest sounding before it

Roanoke, VA (KRNK), launched 12:00Z, 4.3 hours before the alert went out and 91 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: 635 J/kg
Mixed-layer CIN: -84 J/kg
Mixed-layer LCL: 1181 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 92 m²/s²
0-3 km storm-relative helicity: 24 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

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
Jul 14, 12:50 PM EDT	Tornado Watch	SPC	Anne Arundel, Baltimore, Calvert, Caroline, Carroll, Cecil and 16 more	6 hr
Jul 14, 3:05 PM EDT	Mesoscale Discussion	SPC	Anne Arundel, Baltimore, Calvert, Caroline, Carroll, Cecil and 16 more	115 min
Jul 13, 9:20 PM EDT	Severe Thunderstorm Watch	SPC	Cherokee, Clay, Graham	6 hr
Jul 13, 11:21 PM EDT	Mesoscale Discussion	SPC	Cherokee, Graham	114 min
Jul 14, 8:35 AM EDT	Mesoscale Discussion	SPC	Avery, Buncombe, Burke, Cleveland, Graham, Haywood and 11 more	85 min
Jul 14, 10:40 AM EDT	Severe Thunderstorm Watch	SPC	Buncombe, Cleveland, Henderson, Jackson, McDowell, Mitchell and 4 more	6 hr
Jul 14, 1:03 PM EDT	Mesoscale Discussion	SPC	Cherokee, Clay, Graham, Macon, Swain	117 min
Jul 14, 6:10 PM EDT	Mesoscale Discussion	SPC	Bertie, Camden, Chowan, Edgecombe, Franklin, Gates and 11 more	65 min
Jul 14, 7:00 PM EDT	Severe Thunderstorm Watch	SPC	Alamance, Bertie, Camden, Chatham, Chowan, Currituck and 22 more	5 hr

Nearby

Mesoscale Discussions in Virginia, 2004 Mesoscale Discussions in North Carolina, 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.