Alert archive / Virginia / Tornado Watches in 2010
Tornado Watch 762
The Storm Prediction Center issued this tornado watch at Dec 1, 2010, 3:48 AM EST for 13 counties in Maryland; 20 counties in Virginia; Berkeley County, Jefferson County, West Virginia. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Dec 1, 2010, 3:48 AM EST (08:48 UTC)
- Expired
- Dec 1, 2010, 11:13 AM EST
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 0.5 in
- Strongest gust expected
- 60 kt
All 35 counties
Anne Arundel County, MD, Baltimore County, MD, Calvert County, MD, Carroll County, MD, Charles County, MD, City of Baltimore, MD, Frederick County, MD, Harford County, MD, Howard County, MD, Montgomery County, MD, Prince George's County, MD, Saint Mary's County, MD, Washington County, MD, Arlington County, VA, City of Alexandria, 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 Winchester, VA, Clarke County, VA, Culpeper County, VA, Fairfax County, VA, Fauquier County, VA, Frederick County, VA, Greene County, VA, Loudoun County, VA, Madison County, VA, Page County, VA, Prince William County, VA, Rappahannock County, VA, Warren County, VA, Berkeley County, WV, Jefferson County, WV
The radar
The Sterling radar (KLWX), 13 km from the middle of the area, began a volume at 08:50 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
- 30%
- One or more EF2 to EF5 tornadoes
- 10%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 5%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 30%
Warnings issued inside it
12 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 1, 4:06 AM EST | Severe Thunderstorm Warning | LWX | Albemarle, Culpeper, Greene, Madison, Orange, Rappahannock and 1 more | 54 min |
| Dec 1, 4:18 AM EST | Flash Flood Warning | LWX | Allegany, Washington | 6 hr |
| Dec 1, 4:22 AM EST | Severe Thunderstorm Warning | LWX | Allegany, Washington | 22 min |
| Dec 1, 4:29 AM EST | Flash Flood Warning | LWX | Washington | 6 hr |
| Dec 1, 4:34 AM EST | Flash Flood Warning | LWX | Culpeper, Fauquier, Greene, Madison, Orange, Rappahannock | 6 hr |
| Dec 1, 4:58 AM EST | Severe Thunderstorm Warning | LWX | Culpeper, Fairfax, Fauquier, Loudoun, Orange, Prince William and 6 more | 47 min |
| Dec 1, 5:44 AM EST | Severe Thunderstorm Warning | LWX | Frederick, Montgomery | 26 min |
| Dec 1, 6:37 AM EST | Severe Thunderstorm Warning | LWX | Calvert, Charles, Saint Mary's | 53 min |
| Dec 1, 7:25 AM EST | Severe Thunderstorm Warning | LWX | Frederick, Montgomery, Washington | 35 min |
| Dec 1, 8:03 AM EST | Severe Thunderstorm Warning | LWX | Baltimore, Carroll, Frederick, Howard, Montgomery | 42 min |
| Dec 1, 9:00 AM EST | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Carroll, Harford, Howard, City of Baltimore | 75 min |
| Dec 1, 9:28 AM EST | Tornado Warning | LWX | Charles, Prince George's | 17 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 00:00Z, 8.8 hours before the alert went out and 15 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 671 m above ground
- 0-6 km bulk shear
- 45 kt
- 0-1 km storm-relative helicity
- 416 m²/s²
- 0-3 km storm-relative helicity
- 505 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 1, 5:18 AM EST | Mesoscale Discussion | SPC | Saint Mary's, Somerset, Wicomico, Worcester | 117 min |
| Dec 1, 6:12 AM EST | Tornado Watch | SPC | Dorchester, Somerset, Wicomico, Worcester | 4 hr |
| Dec 1, 7:51 AM EST | Mesoscale Discussion | SPC | Anne Arundel, Baltimore, Calvert, Caroline, Carroll, Cecil and 15 more | 84 min |
| Nov 30, 9:29 PM EST | Mesoscale Discussion | SPC | Franklin, Halifax, Henry, Patrick, Pittsylvania, City of Danville and 1 more | 91 min |
| Nov 30, 9:56 PM EST | Tornado Watch | SPC | Amherst, Appomattox, Bedford, Buckingham, Campbell, Charlotte and 8 more | 6 hr |
| Dec 1, 12:48 AM EST | Mesoscale Discussion | SPC | Albemarle, Amelia, Amherst, Appomattox, Augusta, Bath and 31 more | 117 min |
| Dec 1, 2:13 AM EST | Tornado Watch | SPC | Albemarle, Amelia, Brunswick, Caroline, Charles City, Chesterfield and 43 more | 8 hr |
| Dec 1, 4:25 AM EST | Mesoscale Discussion | SPC | Amelia, Brunswick, Buckingham, Caroline, Charles City, Charlotte and 55 more | 2 hr |
Nearby
Tornado Watches in Virginia, 2010Tornado Watches in Maryland, 2010Tornado Watches in West Virginia, 2010Every tornado watch in 2010
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.