Alert archive / Virginia / Severe Thunderstorm Watches in 2004
Severe Thunderstorm Watch 739
The Storm Prediction Center issued this severe thunderstorm watch at Aug 11, 2004, 2:35 PM EDT for 4 states. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 11, 2004, 2:35 PM EDT (18:35 UTC)
- Expired
- Aug 11, 2004, 8:00 PM EDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
All 76 counties
Kent County, DE, New Castle County, DE, Sussex County, DE, Anne Arundel County, MD, Baltimore County, MD, Calvert County, MD, Caroline County, MD, Carroll County, MD, Cecil County, MD, Charles County, MD, City of Baltimore, MD, Dorchester County, MD, Frederick County, MD, Harford County, MD, Howard County, MD, Kent County, MD, Montgomery County, MD, Prince George's County, MD, Queen Anne's County, MD, Saint Mary's County, MD, Somerset County, MD, Talbot County, MD, Wicomico County, MD, Worcester County, MD, Atlantic County, NJ, Cape May County, NJ, Cumberland County, NJ, Gloucester County, NJ, Salem County, NJ, Accomack County, VA, Albemarle County, VA, Amelia County, VA, Appomattox County, VA, Arlington County, VA, Buckingham County, VA, Caroline County, VA, Charles City County, VA, Chesterfield County, VA, City of Alexandria, VA, City of Charlottesville, VA, City of Fairfax, VA, City of Falls Church, VA, City of Fredericksburg, VA, City of Manassas, VA, City of Manassas Park, VA, City of Richmond, VA, Culpeper County, VA, Cumberland County, VA, Essex County, VA, Fairfax County, VA, Fauquier County, VA, Fluvanna County, VA, Gloucester County, VA, Goochland County, VA, Hanover County, VA, Henrico 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, Louisa County, VA, Madison County, VA, Mathews County, VA, Middlesex County, VA, New Kent County, VA, Northampton County, VA, Northumberland County, VA, Orange County, VA, Powhatan County, VA, Prince William County, VA, Richmond County, VA, Spotsylvania County, VA, Stafford County, VA, Westmoreland County, VA
The radar
The Sterling radar (KLWX), 85 km from the middle of the area, began a volume at 18:36 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
13 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 11, 2:46 PM EDT | Severe Thunderstorm Warning | LWX | Fauquier, Prince William | 29 min |
| Aug 11, 3:16 PM EDT | Severe Thunderstorm Warning | LWX | Fairfax, City of Fairfax | 44 min |
| Aug 11, 3:42 PM EDT | Severe Thunderstorm Warning | LWX | Howard, Montgomery | 48 min |
| Aug 11, 3:44 PM EDT | Severe Thunderstorm Warning | LWX | Arlington, City of Alexandria, City of Falls Church | 61 min |
| Aug 11, 3:58 PM EDT | Severe Thunderstorm Warning | LWX | Fairfax, City of Fairfax | 47 min |
| Aug 11, 4:30 PM EDT | Severe Thunderstorm Warning | LWX | Harford | 45 min |
| Aug 11, 4:35 PM EDT | Severe Thunderstorm Warning | LWX | Prince George's | 40 min |
| Aug 11, 5:03 PM EDT | Severe Thunderstorm Warning | PHI | Kent, Queen Anne's | 57 min |
| Aug 11, 5:16 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel | 59 min |
| Aug 11, 5:36 PM EDT | Severe Thunderstorm Warning | PHI | Talbot | 54 min |
| Aug 11, 6:37 PM EDT | Severe Thunderstorm Warning | PHI | Talbot | 53 min |
| Aug 11, 7:27 PM EDT | Severe Thunderstorm Warning | PHI | Talbot | 63 min |
| Aug 11, 7:28 PM EDT | Flash Flood Warning | PHI | Talbot | 2 hr |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 12:00Z, 6.6 hours before the alert went out and 79 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.
- Mixed-layer CAPE
- 253 J/kg
- Mixed-layer CIN
- -107 J/kg
- Mixed-layer LCL
- 1194 m above ground
- 0-6 km bulk shear
- 26 kt
- 0-1 km storm-relative helicity
- 51 m²/s²
- 0-3 km storm-relative helicity
- 95 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 11, 11:59 AM EDT | Mesoscale Discussion | SPC | New Castle | 91 min |
| Aug 11, 7:26 PM EDT | Mesoscale Discussion | SPC | Kent, New Castle, Sussex | 64 min |
| Aug 11, 12:31 PM EDT | Mesoscale Discussion | SPC | Anne Arundel, Calvert, Charles, Howard, Kent, Montgomery and 4 more | 89 min |
| Aug 11, 12:55 PM EDT | Severe Thunderstorm Watch | SPC | Bergen, Burlington, Camden, Essex, Gloucester, Hudson and 11 more | 7 hr |
| Aug 11, 7:00 PM EDT | Mesoscale Discussion | SPC | Bergen, Burlington, Camden, Essex, Gloucester, Hudson and 11 more | 90 min |
Nearby
Severe Thunderstorm Watches in Virginia, 2004Severe Thunderstorm Watches in Maryland, 2004Severe Thunderstorm Watches in New Jersey, 2004Every 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.