Alert archive / Virginia / Severe Thunderstorm Watches in 2004

Severe Thunderstorm Watch 233

May 21, 20046 counties in North Carolina; 74 counties in Virginia

The Storm Prediction Center issued this severe thunderstorm watch at May 21, 2004, 1:00 PM EDT for 6 counties in North Carolina; 74 counties in Virginia. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: May 21, 2004, 1:00 PM EDT (17:00 UTC)
Expired: May 21, 2004, 8:00 PM EDT
In force: 7 hr
Issued by: the Storm Prediction Center

All 80 counties

Camden County, NC, Currituck County, NC, Gates County, NC, Hertford County, NC, Northampton County, NC, Pasquotank County, NC, Accomack County, VA, Albemarle County, VA, Amelia County, VA, Amherst County, VA, Appomattox County, VA, Augusta County, VA, Bath County, VA, Bedford County, VA, Botetourt County, VA, Brunswick County, VA, Buckingham County, VA, Campbell County, VA, Caroline County, VA, Charles City County, VA, Charlotte County, VA, Chesterfield County, VA, City of Buena Vista, VA, City of Charlottesville, VA, City of Chesapeake, VA, City of Colonial Heights, VA, City of Emporia, VA, City of Franklin, VA, City of Hampton, VA, City of Hopewell, VA, City of Lexington, VA, City of Lynchburg, VA, City of Newport News, VA, City of Norfolk, VA, City of Petersburg, VA, City of Poquoson, VA, City of Portsmouth, VA, City of Richmond, VA, City of Staunton, VA, City of Suffolk, VA, City of Virginia Beach, VA, City of Waynesboro, VA, City of Williamsburg, VA, Cumberland County, VA, Dinwiddie County, VA, Essex County, VA, Fluvanna County, VA, Franklin County, VA, Gloucester County, VA, Goochland County, VA, Greensville County, VA, Halifax County, VA, Hanover County, VA, Henrico County, VA, Highland County, VA, Isle of Wight County, VA, James City County, VA, King and Queen County, VA, King William County, VA, Lancaster County, VA, Louisa County, VA, Lunenburg County, VA, Mathews County, VA, Mecklenburg County, VA, Middlesex County, VA, Nelson County, VA, New Kent County, VA, Northampton County, VA, Northumberland County, VA, Nottoway County, VA, Pittsylvania County, VA, Powhatan County, VA, Prince Edward County, VA, Prince George County, VA, Richmond County, VA, Rockbridge County, VA, Southampton County, VA, Surry County, VA, Sussex County, VA, York County, VA

The radar

The Norfolk radar (KAKQ), 122 km from the middle of the area, began a volume at 17:04 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.

Warnings issued inside it

11 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

Issued	Product	Office	Counties	Lasted
May 21, 2:04 PM EDT	Severe Thunderstorm Warning	RNK	Bath	41 min
May 21, 2:41 PM EDT	Severe Thunderstorm Warning	RNK	Rockbridge	64 min
May 21, 3:03 PM EDT	Severe Thunderstorm Warning	RNK	Alleghany, Botetourt	57 min
May 21, 3:32 PM EDT	Severe Thunderstorm Warning	RNK	Amherst	58 min
May 21, 3:48 PM EDT	Severe Thunderstorm Warning	RNK	Botetourt	57 min
May 21, 3:49 PM EDT	Severe Thunderstorm Warning	RNK	Amherst, Bedford, City of Lynchburg	26 min
May 21, 3:54 PM EDT	Severe Thunderstorm Warning	RNK	Bedford, City of Lynchburg	21 min
May 21, 4:16 PM EDT	Severe Thunderstorm Warning	RNK	Campbell, City of Lynchburg	44 min
May 21, 4:27 PM EDT	Severe Thunderstorm Warning	RNK	Bedford	63 min
May 21, 4:50 PM EDT	Severe Thunderstorm Warning	RNK	Pittsylvania	55 min
May 21, 5:11 PM EDT	Severe Thunderstorm Warning	RNK	Charlotte	64 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Roanoke, VA (KRNK), launched 12:00Z, 5.0 hours before the alert went out and 120 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: 532 J/kg
Mixed-layer CIN: -66 J/kg
Mixed-layer LCL: 845 m above ground
0-6 km bulk shear: 8 kt
0-1 km storm-relative helicity: -50 m²/s²
0-3 km storm-relative helicity: 11 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 21, 12:28 PM EDT	Mesoscale Discussion	SPC	Bertie, Camden, Chowan, Currituck, Gates, Halifax and 6 more	2 hr
May 21, 4:30 PM EDT	Mesoscale Discussion	SPC	Camden, Chowan, Currituck, Gates, Hertford, Pasquotank and 1 more	2 hr
May 21, 8:34 AM EDT	Mesoscale Discussion	SPC	Albemarle, Arlington, Caroline, Clarke, Culpeper, Fairfax and 29 more	86 min
May 21, 5:31 PM EDT	Mesoscale Discussion	SPC	Albemarle, Alleghany, Augusta, Bath, Clarke, Culpeper and 24 more	89 min
May 21, 6:35 PM EDT	Severe Thunderstorm Watch	SPC	Arlington, Augusta, Bath, Clarke, Culpeper, Fairfax and 21 more	4 hr

Nearby

Severe Thunderstorm Watches in Virginia, 2004 Severe Thunderstorm Watches in North Carolina, 2004 Every severe thunderstorm watch 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.