Alert archive / Virginia / Mesoscale Discussions in 2005

Mesoscale Discussion 678

April 23, 20055 states

The Storm Prediction Center issued this mesoscale discussion at Apr 23, 2005, 3:17 PM EDT for 5 states. It was in force for 88 min.

The area

The outline as issued.

The facts

Issued: Apr 23, 2005, 3:17 PM EDT (19:17 UTC)
Expired: Apr 23, 2005, 4:45 PM EDT
In force: 88 min
Issued by: the Storm Prediction Center

All 89 counties

Calvert County, MD, Carroll County, MD, Charles County, MD, Frederick County, MD, Howard County, MD, Montgomery County, MD, Prince George's County, MD, Saint Mary's County, MD, Washington County, MD, Bertie County, NC, Camden County, NC, Chowan County, NC, Franklin County, NC, Gates County, NC, Halifax County, NC, Hertford County, NC, Northampton County, NC, Pasquotank County, NC, Perquimans County, NC, Vance County, NC, Warren County, NC, Adams County, PA, Franklin County, PA, Fulton County, PA, Huntingdon County, PA, Amelia County, VA, Arlington County, VA, Brunswick County, VA, Caroline County, VA, Charles City County, VA, Chesterfield County, VA, City of Alexandria, VA, City of Chesapeake, VA, City of Colonial Heights, VA, City of Emporia, VA, City of Fairfax, VA, City of Falls Church, VA, City of Franklin, VA, City of Fredericksburg, VA, City of Hampton, VA, City of Hopewell, VA, City of Manassas, VA, City of Manassas Park, 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 Suffolk, VA, City of Williamsburg, VA, Clarke County, VA, Culpeper County, VA, Dinwiddie County, VA, Essex County, VA, Fairfax County, VA, Fauquier County, VA, Gloucester County, VA, Goochland County, VA, Greensville County, VA, Hanover County, VA, Henrico County, VA, Isle of Wight County, VA, James City County, VA, King and Queen County, VA, King George County, VA, King William County, VA, Lancaster County, VA, Loudoun County, VA, Lunenburg County, VA, Mathews County, VA, Mecklenburg County, VA, Middlesex County, VA, New Kent County, VA, Northumberland County, VA, Nottoway County, VA, Powhatan County, VA, Prince George County, VA, Prince William County, VA, Richmond County, VA, Southampton County, VA, Spotsylvania County, VA, Stafford County, VA, Surry County, VA, Sussex County, VA, Westmoreland County, VA, York County, VA, Berkeley County, WV, Jefferson County, WV

The radar

The Sterling radar (KLWX), 108 km from the middle of the area, began a volume at 19:20 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 nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 7.3 hours before the alert went out and 107 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: 7 J/kg
Mixed-layer CIN: -138 J/kg
Mixed-layer LCL: 485 m above ground
0-6 km bulk shear: 51 kt
0-1 km storm-relative helicity: 122 m²/s²
0-3 km storm-relative helicity: 166 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 23, 12:35 PM EDT	Mesoscale Discussion	SPC	Carroll, Charles, Frederick, Howard, Montgomery, Washington	115 min
Apr 23, 1:10 PM EDT	Severe Thunderstorm Watch	SPC	Anne Arundel, Baltimore, Calvert, Carroll, Charles, Frederick and 7 more	7 hr
Apr 23, 4:26 PM EDT	Mesoscale Discussion	SPC	Caroline, Cecil, Dorchester, Kent, Queen Anne's, Saint Mary's and 4 more	94 min
Apr 23, 7:16 PM EDT	Mesoscale Discussion	SPC	Calvert, Caroline, Cecil, Dorchester, Harford, Kent and 6 more	59 min
Apr 22, 9:05 PM EDT	Severe Thunderstorm Watch	SPC	Swain	4 hr
Apr 22, 8:59 PM EDT	Mesoscale Discussion	SPC	Scott, City of Bristol, City of Norton	31 min
Apr 22, 11:18 PM EDT	Mesoscale Discussion	SPC	Scott, City of Bristol	57 min
Apr 22, 10:25 PM EDT	Mesoscale Discussion	SPC	Boone, Cabell, Calhoun, Clay, Doddridge, Gilmer and 15 more	95 min

Nearby

Mesoscale Discussions in Virginia, 2005 Mesoscale Discussions in North Carolina, 2005 Mesoscale Discussions in Maryland, 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.