Alert archive / Virginia / Tornado Watches in 2007
Tornado Watch 483
The Storm Prediction Center issued this tornado watch at Jul 4, 2007, 2:06 PM EDT for 6 states. It was in force for 8 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 4, 2007, 2:06 PM EDT (18:06 UTC)
- Expired
- Jul 4, 2007, 10:00 PM EDT
- In force
- 8 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 60 kt
All 88 counties
Kent County, DE, New Castle County, DE, Allegany County, MD, 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, 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, Talbot County, MD, Washington County, MD, Burlington County, NJ, Camden County, NJ, Cumberland County, NJ, Gloucester County, NJ, Hunterdon County, NJ, Mercer County, NJ, Salem County, NJ, Warren County, NJ, Adams County, PA, Bedford County, PA, Berks County, PA, Bucks County, PA, Carbon County, PA, Chester County, PA, Cumberland County, PA, Dauphin County, PA, Delaware County, PA, Franklin County, PA, Fulton County, PA, Juniata County, PA, Lancaster County, PA, Lebanon County, PA, Lehigh County, PA, Monroe County, PA, Montgomery County, PA, Northampton County, PA, Perry County, PA, Philadelphia County, PA, Schuylkill County, PA, Somerset County, PA, York County, PA, Arlington County, VA, Augusta County, VA, City of Alexandria, VA, City of Fairfax, VA, City of Falls Church, VA, City of Harrisonburg, VA, City of Manassas, VA, City of Manassas Park, VA, City of Staunton, VA, City of Waynesboro, VA, City of Winchester, VA, Clarke County, VA, Culpeper County, VA, Fairfax County, VA, Fauquier County, VA, Frederick County, VA, Greene County, VA, Highland County, VA, King George County, VA, Loudoun County, VA, Madison County, VA, Page County, VA, Prince William County, VA, Rappahannock County, VA, Rockingham County, VA, Shenandoah County, VA, Stafford County, VA, Warren County, VA, Berkeley County, WV, Grant County, WV, Hampshire County, WV, Hardy County, WV, Jefferson County, WV, Mineral County, WV, Morgan County, WV, Pendleton County, WV
The radar
The Sterling radar (KLWX), 127 km from the middle of the area, began a volume at 18:09 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.
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 50%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 40%
- One or more gusts of 65 knots or more
- 5%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 80%
Warnings issued inside it
27 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 4, 3:34 PM EDT | Severe Thunderstorm Warning | LWX | Frederick | 41 min |
| Jul 4, 3:51 PM EDT | Severe Thunderstorm Warning | LWX | Fauquier | 39 min |
| Jul 4, 3:55 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery | 50 min |
| Jul 4, 3:56 PM EDT | Severe Thunderstorm Warning | LWX | Clarke | 19 min |
| Jul 4, 4:16 PM EDT | Tornado Warning | LWX | Montgomery | 29 min |
| Jul 4, 4:22 PM EDT | Severe Thunderstorm Warning | LWX | Fauquier, Loudoun | 38 min |
| Jul 4, 4:29 PM EDT | Severe Thunderstorm Warning | LWX | Howard | 46 min |
| Jul 4, 4:41 PM EDT | Tornado Warning | LWX | Montgomery | 14 min |
| Jul 4, 4:41 PM EDT | Tornado Warning | LWX | Fauquier, Loudoun, Prince William | 34 min |
| Jul 4, 5:11 PM EDT | Tornado Warning | LWX | Howard | 27 min |
| Jul 4, 5:15 PM EDT | Severe Thunderstorm Warning | LWX | Fairfax, Loudoun, Prince William, City of Fairfax, City of Manassas, City of Manassas Park | 45 min |
| Jul 4, 5:26 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, City of Baltimore | 22 min |
| Jul 4, 5:28 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel | 19 min |
| Jul 4, 5:32 PM EDT | Severe Thunderstorm Warning | LWX | Culpeper, Orange | 31 min |
| Jul 4, 5:32 PM EDT | Tornado Warning | LWX | Fairfax, City of Fairfax, City of Falls Church | 43 min |
| Jul 4, 5:51 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery | 39 min |
| Jul 4, 5:58 PM EDT | Severe Thunderstorm Warning | CTP | Perry | 32 min |
| Jul 4, 6:01 PM EDT | Severe Thunderstorm Warning | LWX | Arlington, City of Alexandria | 53 min |
| Jul 4, 6:27 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery | 63 min |
| Jul 4, 6:48 PM EDT | Severe Thunderstorm Warning | LWX | Prince George's | 42 min |
| Jul 4, 6:52 PM EDT | Tornado Warning | CTP | Dauphin | 23 min |
| Jul 4, 7:27 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery | 31 min |
| Jul 4, 7:32 PM EDT | Severe Thunderstorm Warning | LWX | Howard, Prince George's | 40 min |
| Jul 4, 7:47 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel | 51 min |
| Jul 4, 7:52 PM EDT | Severe Thunderstorm Warning | LWX | Loudoun | 26 min |
| Jul 4, 8:22 PM EDT | Severe Thunderstorm Warning | CTP | Lancaster | 38 min |
| Jul 4, 8:47 PM EDT | Severe Thunderstorm Warning | PHI | Chester | 58 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
Washington/Dulle, VA (KIAD), launched 12:00Z, 6.1 hours before the alert went out and 126 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
- 139 J/kg
- Mixed-layer CIN
- -185 J/kg
- Mixed-layer LCL
- 759 m above ground
- 0-6 km bulk shear
- 30 kt
- 0-1 km storm-relative helicity
- 150 m²/s²
- 0-3 km storm-relative helicity
- 128 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 |
|---|---|---|---|---|
| Jul 4, 12:39 PM EDT | Mesoscale Discussion | SPC | Kent, Sussex | 66 min |
| Jul 4, 4:13 PM EDT | Mesoscale Discussion | SPC | Kent, New Castle | 62 min |
| Jul 4, 1:41 PM EDT | Tornado Watch | SPC | Garrett | 7 hr |
| Jul 4, 1:27 PM EDT | Mesoscale Discussion | SPC | Greene | 63 min |
| Jul 4, 4:27 PM EDT | Mesoscale Discussion | SPC | Albemarle, Alleghany, Amelia, Amherst, Appomattox, Bath and 82 more | 63 min |
| Jul 4, 5:01 PM EDT | Severe Thunderstorm Watch | SPC | Albemarle, Alleghany, Amelia, Amherst, Appomattox, Bath and 46 more | 4 hr |
Nearby
Tornado Watches in Virginia, 2007Tornado Watches in Pennsylvania, 2007Tornado Watches in Maryland, 2007Every tornado watch in 2007
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.