Alert archive / Maryland / Severe Thunderstorm Watches in 2004
Severe Thunderstorm Watch 764
The Storm Prediction Center issued this severe thunderstorm watch at Aug 19, 2004, 6:10 PM EDT for 5 states. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 19, 2004, 6:10 PM EDT (22:10 UTC)
- Expired
- Aug 19, 2004, 10:00 PM EDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
All 34 counties
New Castle County, DE, Anne Arundel County, MD, Baltimore County, MD, Calvert County, MD, Carroll County, MD, Cecil County, MD, Charles County, MD, City of Baltimore, 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, Adams County, PA, Chester County, PA, Delaware County, PA, Lancaster County, PA, York County, PA, Arlington County, VA, City of Alexandria, VA, City of Fairfax, VA, City of Falls Church, VA, City of Manassas, VA, City of Manassas Park, VA, Clarke County, VA, Culpeper County, VA, Fairfax County, VA, Fauquier County, VA, Loudoun County, VA, Prince William County, VA, Rappahannock County, VA, Jefferson County, WV
The radar
The Sterling radar (KLWX), 28 km from the middle of the area, began a volume at 22:11 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
6 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 19, 6:30 PM EDT | Severe Thunderstorm Warning | LWX | Carroll | 75 min |
| Aug 19, 6:43 PM EDT | Severe Thunderstorm Warning | LWX | Frederick | 32 min |
| Aug 19, 6:45 PM EDT | Severe Thunderstorm Warning | CTP | Adams | 30 min |
| Aug 19, 6:50 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 40 min |
| Aug 19, 7:34 PM EDT | Severe Thunderstorm Warning | LWX | Culpeper | 41 min |
| Aug 19, 7:42 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore | 63 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
Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 10.2 hours before the alert went out and 104 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
- 204 J/kg
- Mixed-layer CIN
- -102 J/kg
- Mixed-layer LCL
- 1138 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- 96 m²/s²
- 0-3 km storm-relative helicity
- 123 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.5
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 19, 1:41 PM EDT | Mesoscale Discussion | SPC | Allegheny, Beaver, Fayette, Greene, Indiana, Washington and 1 more | 64 min |
| Aug 19, 2:30 PM EDT | Severe Thunderstorm Watch | SPC | Allegheny, Beaver, Bedford, Blair, Cambria, Fayette and 10 more | 6 hr |
| Aug 19, 5:02 PM EDT | Mesoscale Discussion | SPC | Adams, Allegheny, Armstrong, Beaver, Bedford, Blair and 16 more | 88 min |
| Aug 19, 7:26 PM EDT | Mesoscale Discussion | SPC | Allegheny, Washington, Westmoreland | 64 min |
Nearby
Severe Thunderstorm Watches in Maryland, 2004Severe Thunderstorm Watches in Virginia, 2004Severe Thunderstorm Watches in Pennsylvania, 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.