Alert archive / Virginia / Mesoscale Discussions in 2005

Mesoscale Discussion 628

April 21, 20055 states

The Storm Prediction Center issued this mesoscale discussion at Apr 21, 2005, 2:46 PM EDT for 5 states. It was in force for 119 min.

The area

The outline as issued.

The facts

Issued: Apr 21, 2005, 2:46 PM EDT (18:46 UTC)
Expired: Apr 21, 2005, 4:45 PM EDT
In force: 119 min
Issued by: the Storm Prediction Center

All 96 counties

Pike County, KY, Alamance County, NC, Alleghany County, NC, Ashe County, NC, Caswell County, NC, Forsyth County, NC, Granville County, NC, Guilford County, NC, Halifax County, NC, Northampton County, NC, Orange County, NC, Person County, NC, Rockingham County, NC, Stokes County, NC, Surry County, NC, Vance County, NC, Warren County, NC, Wilkes County, NC, Yadkin County, NC, Johnson County, TN, Alleghany County, VA, Amelia County, VA, Amherst County, VA, Appomattox County, VA, Bath County, VA, Bedford County, VA, Bland County, VA, Botetourt County, VA, Brunswick County, VA, Buchanan County, VA, Buckingham County, VA, Campbell County, VA, Carroll County, VA, Charlotte County, VA, Chesterfield County, VA, City of Bristol, VA, City of Buena Vista, VA, City of Colonial Heights, VA, City of Covington, VA, City of Danville, VA, City of Emporia, VA, City of Galax, VA, City of Hopewell, VA, City of Lexington, VA, City of Lynchburg, VA, City of Martinsville, VA, City of Petersburg, VA, City of Radford, VA, City of Richmond, VA, City of Roanoke, VA, City of Salem, VA, Craig County, VA, Cumberland County, VA, Dickenson County, VA, Dinwiddie County, VA, Floyd County, VA, Fluvanna County, VA, Franklin County, VA, Giles County, VA, Goochland County, VA, Grayson County, VA, Greensville County, VA, Halifax County, VA, Henrico County, VA, Henry County, VA, Lunenburg County, VA, Mecklenburg County, VA, Montgomery County, VA, Nelson County, VA, Nottoway County, VA, Patrick County, VA, Pittsylvania County, VA, Powhatan County, VA, Prince Edward County, VA, Prince George County, VA, Pulaski County, VA, Roanoke County, VA, Rockbridge County, VA, Russell County, VA, Smyth County, VA, Sussex County, VA, Tazewell County, VA, Washington County, VA, Wythe County, VA, Boone County, WV, Fayette County, WV, Greenbrier County, WV, Lincoln County, WV, Logan County, WV, McDowell County, WV, Mercer County, WV, Mingo County, WV, Monroe County, WV, Raleigh County, WV, Summers County, WV, Wyoming County, WV

The radar

The Roanoke radar (KFCX), 67 km from the middle of the area, began a volume at 18:45 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, 6.8 hours before the alert went out and 277 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1134 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: -50 m²/s²
0-3 km storm-relative helicity: -76 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
Apr 21, 6:22 PM EDT	Mesoscale Discussion	SPC	Ballard, Caldwell, Carlisle, Crittenden, Fulton, Graves and 6 more	53 min
Apr 21, 6:35 PM EDT	Severe Thunderstorm Watch	SPC	Ballard, Carlisle, Fulton, Hickman, McCracken	7 hr

Nearby

Mesoscale Discussions in Virginia, 2005 Mesoscale Discussions in North Carolina, 2005 Mesoscale Discussions in West Virginia, 2005 Every mesoscale discussion in 2005

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.