Alert archive / Virginia / Tornado Watches in 2008

Tornado Watch 286

May 9, 2008Calvert County, Saint Mary's County, Maryland; 40 counties in North Carolina; 51 counties in Virginia

The Storm Prediction Center issued this tornado watch at May 9, 2008, 3:00 AM EDT for Calvert County, Saint Mary's County, Maryland; 40 counties in North Carolina; 51 counties in Virginia. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued: May 9, 2008, 3:00 AM EDT (07:00 UTC)
Expired: May 9, 2008, 11:00 AM EDT
In force: 8 hr
Issued by: the Storm Prediction Center
Largest hail expected: 2 in
Strongest gust expected: 60 kt

All 93 counties

Calvert County, MD, Saint Mary's County, MD, Alamance County, NC, Beaufort County, NC, Bertie County, NC, Camden County, NC, Caswell County, NC, Chatham County, NC, Chowan County, NC, Currituck County, NC, Dare County, NC, Davidson County, NC, Durham County, NC, Edgecombe County, NC, Forsyth County, NC, Franklin County, NC, Gates County, NC, Granville County, NC, Greene County, NC, Guilford County, NC, Halifax County, NC, Hertford County, NC, Hyde County, NC, Johnston County, NC, Lee County, NC, Martin County, NC, Nash County, NC, Northampton County, NC, Orange County, NC, Pasquotank County, NC, Perquimans County, NC, Person County, NC, Pitt County, NC, Randolph County, NC, Rockingham County, NC, Stokes County, NC, Tyrrell County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Washington County, NC, Wilson County, NC, Accomack County, VA, Amelia County, VA, Brunswick 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 Martinsville, 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, Greensville County, VA, Halifax County, VA, Henrico County, VA, Henry 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, 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 Raleigh/Durham radar (KRAX), 121 km from the middle of the area, began a volume at 07:02 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: 30%
One or more gusts of 65 knots or more: 30%
Ten or more severe hail reports: 20%
One or more hailstones of 2 inches or more: 20%
Six or more combined severe hail and wind reports: 80%

Warnings issued inside it

18 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

Issued	Product	Office	Counties	Lasted
May 9, 3:11 AM EDT	Severe Thunderstorm Warning	AKQ	Lunenburg, Mecklenburg	34 min
May 9, 3:31 AM EDT	Tornado Warning	AKQ	Brunswick, Lunenburg, Mecklenburg, Nottoway	33 min
May 9, 3:55 AM EDT	Flash Flood Warning	RNK	Henry, City of Martinsville	6 hr
May 9, 5:11 AM EDT	Tornado Warning	AKQ	Gloucester, Lancaster, Middlesex	34 min
May 9, 5:24 AM EDT	Tornado Warning	AKQ	King and Queen, King William, New Kent	36 min
May 9, 5:36 AM EDT	Severe Thunderstorm Warning	AKQ	Charles City, Henrico, James City, King William, New Kent, Prince George	24 min
May 9, 6:01 AM EDT	Severe Thunderstorm Warning	AKQ	Gloucester, James City, King and Queen, Lancaster, Mathews, Middlesex and 1 more	29 min
May 9, 6:31 AM EDT	Severe Thunderstorm Warning	AKQ	Lancaster, Mathews, Middlesex	14 min
May 9, 7:05 AM EDT	Severe Thunderstorm Warning	RAH	Edgecombe, Halifax, Nash	40 min
May 9, 7:10 AM EDT	Flash Flood Warning	RNK	Henry, Pittsylvania, City of Danville	6 hr
May 9, 7:27 AM EDT	Tornado Warning	RAH	Halifax	18 min
May 9, 7:37 AM EDT	Severe Thunderstorm Warning	AKQ	Accomack	28 min
May 9, 7:41 AM EDT	Severe Thunderstorm Warning	AKQ	Bertie, Hertford, Northampton	49 min
May 9, 8:14 AM EDT	Tornado Warning	AKQ	Bertie, Chowan, Gates, Hertford	31 min
May 9, 8:46 AM EDT	Tornado Warning	AKQ	Chowan, Gates, Pasquotank, Perquimans	44 min
May 9, 8:46 AM EDT	Tornado Warning	MHX	Beaufort, Hyde	44 min
May 9, 9:27 AM EDT	Severe Thunderstorm Warning	AKQ	Camden, Currituck, Pasquotank	48 min
May 9, 10:47 AM EDT	Tornado Warning	MHX	Dare	28 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 00:00Z, 7.0 hours before the alert went out and 112 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 196 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 1306 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 98 m²/s²
0-3 km storm-relative helicity: 288 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 1.6

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 8, 8:38 PM EDT	Tornado Watch	SPC	Calvert, Charles, Saint Mary's	6 hr
May 8, 9:47 PM EDT	Mesoscale Discussion	SPC	Calvert, Charles, Prince George's, Saint Mary's	58 min
May 9, 2:32 AM EDT	Mesoscale Discussion	SPC	Calvert, Charles, Saint Mary's, Somerset	88 min
May 9, 6:37 AM EDT	Mesoscale Discussion	SPC	Dorchester, Somerset, Wicomico, Worcester	53 min
May 9, 12:06 AM EDT	Mesoscale Discussion	SPC	Alamance, Caswell, Durham, Granville, Guilford, Orange and 2 more	54 min
May 9, 5:04 AM EDT	Mesoscale Discussion	SPC	Bertie, Camden, Chatham, Chowan, Currituck, Durham and 25 more	56 min
May 9, 5:56 AM EDT	Mesoscale Discussion	SPC	Brunswick, Columbus	2 hr
May 9, 8:29 AM EDT	Mesoscale Discussion	SPC	Beaufort, Bertie, Camden, Carteret, Chowan, Craven and 18 more	61 min
May 9, 7:18 PM EDT	Mesoscale Discussion	SPC	Dickenson, Lee, Scott, Wise, City of Norton	57 min

Nearby

Tornado Watches in Virginia, 2008 Tornado Watches in North Carolina, 2008 Tornado Watches in Maryland, 2008 Every tornado watch in 2008

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.