Alert archive / Virginia / Tornado Watches in 2009
Tornado Watch 793
The Storm Prediction Center issued this tornado watch at Dec 2, 2009, 9:01 PM EST for Worcester County, Maryland; 18 counties in North Carolina; 41 counties in Virginia. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Dec 2, 2009, 9:01 PM EST (02:01 UTC)
- Expired
- Dec 3, 2009, 2:34 AM EST
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 0.5 in
- Strongest gust expected
- 50 kt
All 60 counties
Worcester County, MD, Bertie County, NC, Camden County, NC, Chatham County, NC, Chowan County, NC, Currituck County, NC, Durham County, NC, Franklin County, NC, Gates County, NC, Granville County, NC, Hertford County, NC, Lee County, NC, Northampton County, NC, Orange County, NC, Pasquotank County, NC, Perquimans County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Accomack County, VA, Amelia County, VA, Brunswick County, VA, Charles City County, VA, Chesterfield County, VA, City of Chesapeake, VA, City of Emporia, VA, City of Franklin, VA, City of Hampton, VA, City of Hopewell, VA, City of Newport News, VA, City of Norfolk, VA, City of Petersburg, VA, City of Poquoson, VA, City of Portsmouth, VA, City of Richmond, VA, City of Suffolk, VA, City of Virginia Beach, VA, City of Williamsburg, VA, Dinwiddie County, VA, Gloucester 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 William County, VA, Lancaster County, VA, Lunenburg County, VA, Mathews County, VA, Mecklenburg County, VA, Middlesex County, VA, New Kent County, VA, Northampton County, VA, Nottoway County, VA, Prince George County, VA, Southampton County, VA, Surry County, VA, Sussex County, VA, York County, VA
The radar
The Norfolk radar (KAKQ), 70 km from the middle of the area, began a volume at 02:02 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
- 40%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 20%
- One or more gusts of 65 knots or more
- 5%
- 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
- 50%
Warnings issued inside it
3 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 2, 9:35 PM EST | Tornado Warning | AKQ | Greensville, Sussex | 25 min |
| Dec 2, 9:50 PM EST | Flash Flood Warning | RAH | Chatham, Durham, Orange, Wake | 3 hr |
| Dec 2, 11:30 PM EST | Flash Flood Warning | RAH | Franklin, Warren | 3 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
Roanoke, VA (KRNK), launched 00:00Z, 2.0 hours before the alert went out and 167 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
- 626 m above ground
- 0-6 km bulk shear
- 80 kt
- 0-1 km storm-relative helicity
- 345 m²/s²
- 0-3 km storm-relative helicity
- 392 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 3, 12:12 AM EST | Mesoscale Discussion | SPC | Calvert, Caroline, Dorchester, Saint Mary's, Somerset, Talbot and 2 more | 93 min |
| Dec 2, 8:31 PM EST | Mesoscale Discussion | SPC | Alamance, Beaufort, Bertie, Bladen, Brunswick, Camden and 53 more | 89 min |
Nearby
Tornado Watches in Virginia, 2009Tornado Watches in North Carolina, 2009Tornado Watches in Maryland, 2009Every tornado watch in 2009
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.