Alert archive / Virginia / Mesoscale Discussions in 2004

Mesoscale Discussion 2190

September 8, 20049 counties in Maryland; 14 counties in North Carolina; 67 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Sep 8, 2004, 3:39 PM EDT for 9 counties in Maryland; 14 counties in North Carolina; 67 counties in Virginia. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Sep 8, 2004, 3:39 PM EDT (19:39 UTC)
Expired
Sep 8, 2004, 5:45 PM EDT
In force
2 hr
Issued by
the Storm Prediction Center
All 90 counties

Anne Arundel County, MD, Baltimore County, MD, Calvert County, MD, Charles County, MD, City of Baltimore, MD, Howard County, MD, Montgomery County, MD, Prince George's County, MD, Saint Mary's County, MD, Bertie County, NC, Edgecombe County, NC, Franklin County, NC, Gates County, NC, Greene County, NC, Halifax County, NC, Hertford County, NC, Martin County, NC, Nash County, NC, Northampton County, NC, Vance County, NC, Warren County, NC, Wayne County, NC, Wilson County, NC, Albemarle County, VA, 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 Charlottesville, 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 Petersburg, VA, City of Poquoson, VA, City of Richmond, VA, City of Suffolk, VA, City of Williamsburg, VA, Culpeper County, VA, Cumberland County, VA, Dinwiddie County, VA, Essex County, VA, Fairfax County, VA, Fauquier County, VA, Fluvanna County, VA, Gloucester County, VA, Goochland County, VA, Greene 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, Louisa County, VA, Lunenburg County, VA, Madison County, VA, Mathews County, VA, Mecklenburg County, VA, Middlesex County, VA, New Kent County, VA, Northumberland County, VA, Nottoway County, VA, Orange County, VA, Powhatan County, VA, Prince Edward County, VA, Prince George County, VA, Prince William County, VA, Rappahannock 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

The radar

The Norfolk radar (KAKQ), 93 km from the middle of the area, began a volume at 19:42 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.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 7.7 hours before the alert went out and 153 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-pSkew-T log-p diagram, Washington/Dulle, VA at 12:00Z on 2004-09-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 188 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 12:00Z on 2004-09-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 57 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
188 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
490 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
57 m²/s²
0-3 km storm-relative helicity
106 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.

IssuedProductOfficeCountiesLasted
Sep 8, 12:00 PM EDTMesoscale DiscussionSPCCharles2 hr
Sep 8, 12:50 PM EDTTornado WatchSPCCharles, Prince George's6 hr
Sep 8, 6:40 PM EDTTornado WatchSPCAllegany, Anne Arundel, Calvert, Carroll, Charles, Frederick and 6 more5 hr
Sep 7, 10:09 PM EDTMesoscale DiscussionSPCAnson, Bladen, Cabarrus, Cleveland, Columbus, Cumberland and 14 more96 min
Sep 8, 12:30 AM EDTTornado WatchSPCAlexander, Anson, Avery, Bladen, Brunswick, Burke and 31 more7 hr
Sep 8, 3:38 AM EDTMesoscale DiscussionSPCAlexander, Anson, Avery, Bladen, Brunswick, Burke and 31 more3 hr
Sep 8, 6:50 AM EDTTornado WatchSPCAlamance, Anson, Bladen, Cabarrus, Caswell, Chatham and 42 more7 hr
Sep 8, 8:41 AM EDTMesoscale DiscussionSPCAlamance, Anson, Bladen, Cabarrus, Caswell, Chatham and 44 more2 hr

Nearby

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