Alert archive / Virginia / Tornado Watches in 2010
Tornado Watch 736
The Storm Prediction Center issued this tornado watch at Oct 27, 2010, 7:46 PM EDT for 7 counties in Maryland; 54 counties in Virginia. It was in force for 8 hr.
The area
The outline as issued.
The facts
- Issued
- Oct 27, 2010, 7:46 PM EDT (23:46 UTC)
- Expired
- Oct 28, 2010, 4:00 AM EDT
- In force
- 8 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 60 kt
All 61 counties
Calvert County, MD, Charles County, MD, Dorchester County, MD, Saint Mary's County, MD, Somerset County, MD, Wicomico County, MD, Worcester County, MD, Accomack County, VA, Amelia County, VA, Brunswick County, VA, Caroline County, VA, Charles City County, VA, Charlotte County, VA, Chesterfield County, VA, City of Chesapeake, VA, City of Colonial Heights, VA, City of Danville, 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, Essex County, VA, Gloucester County, VA, Goochland County, VA, Greensville County, VA, Halifax 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, Northumberland County, VA, Nottoway County, VA, Pittsylvania County, VA, Powhatan County, VA, Prince Edward County, VA, Prince George County, VA, Richmond County, VA, Southampton County, VA, Surry County, VA, Sussex County, VA, Westmoreland County, VA, York County, VA
The radar
The Norfolk radar (KAKQ), 59 km from the middle of the area, began a volume at 23:50 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
- 40%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 40%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 10%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
8 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Oct 27, 7:51 PM EDT | Tornado Warning | RNK | Henry, Pittsylvania, City of Danville | 54 min |
| Oct 27, 8:15 PM EDT | Tornado Warning | RNK | Charlotte, Halifax, Pittsylvania | 60 min |
| Oct 27, 8:22 PM EDT | Flash Flood Warning | RNK | Charlotte, Halifax, Henry, Pittsylvania, City of Danville | 5 hr |
| Oct 27, 8:38 PM EDT | Tornado Warning | RNK | Henry, Pittsylvania, City of Danville | 49 min |
| Oct 27, 8:52 PM EDT | Tornado Warning | RNK | Charlotte, Halifax | 53 min |
| Oct 27, 9:18 PM EDT | Tornado Warning | RNK | Halifax | 26 min |
| Oct 27, 9:39 PM EDT | Tornado Warning | AKQ | Isle of Wight, York, City of Hampton, City of Newport News, City of Poquoson | 51 min |
| Oct 27, 10:31 PM EDT | Tornado Warning | AKQ | Northampton | 44 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
Roanoke, VA (KRNK), launched 12:00Z, 11.8 hours before the alert went out and 170 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
- 52 J/kg
- Mixed-layer CIN
- -30 J/kg
- Mixed-layer LCL
- 521 m above ground
- 0-6 km bulk shear
- 56 kt
- 0-1 km storm-relative helicity
- 199 m²/s²
- 0-3 km storm-relative helicity
- 210 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Oct 26, 11:05 PM EDT | Mesoscale Discussion | SPC | Allegany, Baltimore, Carroll, Frederick, Howard, Montgomery and 1 more | 55 min |
| Oct 27, 12:24 AM EDT | Mesoscale Discussion | SPC | Allegany, Baltimore, Carroll, Frederick, Howard, Montgomery and 1 more | 66 min |
| Oct 27, 5:28 AM EDT | Mesoscale Discussion | SPC | Anne Arundel, Calvert, Caroline, Charles, Dorchester, Prince George's and 6 more | 2 hr |
| Oct 27, 11:54 AM EDT | Mesoscale Discussion | SPC | Anne Arundel, Baltimore, Calvert, Caroline, Cecil, Charles and 9 more | 66 min |
| Oct 27, 12:13 PM EDT | Tornado Watch | SPC | Anne Arundel, Baltimore, Calvert, Caroline, Cecil, Charles and 13 more | 8 hr |
| Oct 27, 3:21 PM EDT | Mesoscale Discussion | SPC | Calvert, Caroline, Charles, Dorchester, Queen Anne's, Saint Mary's and 3 more | 54 min |
| Oct 27, 4:48 PM EDT | Mesoscale Discussion | SPC | Calvert, Caroline, Charles, Dorchester, Queen Anne's, Saint Mary's and 3 more | 57 min |
| Oct 27, 7:16 PM EDT | Mesoscale Discussion | SPC | Calvert, Charles, Dorchester, Saint Mary's, Somerset, Wicomico and 1 more | 59 min |
| Oct 27, 2:44 AM EDT | Tornado Watch | SPC | Amelia, Appomattox, Brunswick, Buckingham, Campbell, Charles City and 34 more | 7 hr |
| Oct 27, 4:03 PM EDT | Mesoscale Discussion | SPC | Mecklenburg | 87 min |
Nearby
Tornado Watches in Virginia, 2010Tornado Watches in Maryland, 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.