Alert archive / Virginia / Tornado Watches in 2010

Tornado Watch 69

April 8, 201018 counties in North Carolina; 24 counties in Virginia

The Storm Prediction Center issued this tornado watch at Apr 8, 2010, 7:12 PM EDT for 18 counties in North Carolina; 24 counties in Virginia. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Apr 8, 2010, 7:12 PM EDT (23:12 UTC)
Expired
Apr 8, 2010, 10:31 PM EDT
In force
3 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 42 counties

Alamance County, NC, Anson County, NC, Caswell County, NC, Chatham County, NC, Davidson County, NC, Forsyth County, NC, Guilford County, NC, Montgomery County, NC, Moore County, NC, Orange County, NC, Person County, NC, Randolph County, NC, Richmond County, NC, Rockingham County, NC, Stanly County, NC, Stokes County, NC, Surry County, NC, Yadkin County, NC, Amelia County, VA, Amherst County, VA, Appomattox County, VA, Bedford County, VA, Buckingham County, VA, Campbell County, VA, Charlotte County, VA, City of Danville, VA, City of Lynchburg, VA, City of Martinsville, VA, Cumberland County, VA, Fluvanna County, VA, Franklin County, VA, Goochland County, VA, Halifax County, VA, Henry County, VA, Louisa County, VA, Lunenburg County, VA, Mecklenburg County, VA, Nottoway County, VA, Patrick County, VA, Pittsylvania County, VA, Powhatan County, VA, Prince Edward County, VA

The radar

The Roanoke radar (KFCX), 108 km from the middle of the area, began a volume at 23:13 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
5%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 8, 7:15 PM EDTSevere Thunderstorm WarningRAHDavidson, Forsyth35 min
Apr 8, 7:27 PM EDTTornado WarningRNKAppomattox, Campbell, Charlotte, Pittsylvania33 min
Apr 8, 7:44 PM EDTTornado WarningRNKCharlotte, Halifax, Pittsylvania46 min
Apr 8, 7:58 PM EDTSevere Thunderstorm WarningRNKAppomattox, Buckingham, Charlotte19 min
Apr 8, 8:04 PM EDTSevere Thunderstorm WarningRNKCaswell, Rockingham46 min
Apr 8, 8:15 PM EDTSevere Thunderstorm WarningRAHAlamance, Guilford45 min
Apr 8, 8:17 PM EDTSevere Thunderstorm WarningRNKCharlotte, Halifax29 min
Apr 8, 8:25 PM EDTSevere Thunderstorm WarningRAHDurham, Orange, Person50 min
Apr 8, 8:45 PM EDTSevere Thunderstorm WarningRNKCharlotte, Halifax43 min
Apr 8, 9:31 PM EDTTornado WarningAKQBrunswick, Lunenburg, Mecklenburg29 min
Apr 8, 9:45 PM EDTSevere Thunderstorm WarningAKQAmelia, Chesterfield, Dinwiddie, Lunenburg, Nottoway, Prince Edward and 1 more45 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

Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 11.2 hours before the alert went out and 4 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-pSkew-T log-p diagram, Greensboro/Hi Pt, NC at 12:00Z on 2010-04-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 7 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Greensboro/Hi Pt, NC at 12:00Z on 2010-04-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 97 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
7 J/kg
Mixed-layer CIN
-59 J/kg
Mixed-layer LCL
1006 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
97 m²/s²
0-3 km storm-relative helicity
72 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 8, 4:28 PM EDTTornado WatchSPCCabarrus, Davie, Gaston, Iredell, Mecklenburg, Rowan and 1 more7 hr
Apr 8, 6:37 PM EDTMesoscale DiscussionSPCAlamance, Anson, Cabarrus, Caswell, Catawba, Chatham and 23 more53 min

Nearby

Tornado Watches in Virginia, 2010Tornado Watches in North Carolina, 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.