Alert archive / Tennessee / Severe Thunderstorm Watches in 2008

Severe Thunderstorm Watch 718

July 21, 200812 counties in North Carolina; 47 counties in Tennessee

The Storm Prediction Center issued this severe thunderstorm watch at Jul 21, 2008, 3:44 PM EDT for 12 counties in North Carolina; 47 counties in Tennessee. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Jul 21, 2008, 3:44 PM EDT (19:44 UTC)
Expired: Jul 21, 2008, 8:31 PM EDT
In force: 5 hr
Issued by: the Storm Prediction Center
Largest hail expected: 2 in
Strongest gust expected: 60 kt

All 59 counties

Avery County, NC, Buncombe County, NC, Cherokee County, NC, Clay County, NC, Graham County, NC, Haywood County, NC, Jackson County, NC, Macon County, NC, Madison County, NC, Mitchell County, NC, Swain County, NC, Yancey County, NC, Anderson County, TN, Bledsoe County, TN, Blount County, TN, Bradley County, TN, Campbell County, TN, Carter County, TN, Claiborne County, TN, Clay County, TN, Cocke County, TN, Cumberland County, TN, DeKalb County, TN, Fentress County, TN, Grainger County, TN, Greene County, TN, Grundy County, TN, Hamblen County, TN, Hamilton County, TN, Hancock County, TN, Hawkins County, TN, Jackson County, TN, Jefferson County, TN, Johnson County, TN, Knox County, TN, Loudon County, TN, Macon County, TN, Marion County, TN, McMinn County, TN, Meigs County, TN, Monroe County, TN, Morgan County, TN, Overton County, TN, Pickett County, TN, Polk County, TN, Putnam County, TN, Rhea County, TN, Roane County, TN, Scott County, TN, Sequatchie County, TN, Sevier County, TN, Smith County, TN, Sullivan County, TN, Unicoi County, TN, Union County, TN, Van Buren County, TN, Warren County, TN, Washington County, TN, White County, TN

The radar

The Knoxville radar (KMRX), 83 km from the middle of the area, began a volume at 19:46 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: 10%
One or more EF2 to EF5 tornadoes: 2%
Ten or more severe wind reports: 50%
One or more gusts of 65 knots or more: 30%
Ten or more severe hail reports: 30%
One or more hailstones of 2 inches or more: 20%
Six or more combined severe hail and wind reports: 70%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Jul 21, 3:49 PM EDT	Severe Thunderstorm Warning	OHX	Fentress, Pickett	27 min
Jul 21, 3:53 PM EDT	Severe Thunderstorm Warning	MRX	Loudon, McMinn, Meigs, Rhea, Roane	52 min
Jul 21, 4:00 PM EDT	Severe Thunderstorm Warning	OHX	Fentress, Pickett	17 min
Jul 21, 4:15 PM EDT	Severe Thunderstorm Warning	MRX	Cocke	30 min
Jul 21, 4:18 PM EDT	Severe Thunderstorm Warning	MRX	Carter, Johnson, Sullivan	57 min
Jul 21, 4:26 PM EDT	Severe Thunderstorm Warning	MRX	Anderson, Campbell, Claiborne, Grainger, Scott, Union	64 min
Jul 21, 4:33 PM EDT	Severe Thunderstorm Warning	OHX	Clay, Jackson	27 min
Jul 21, 4:45 PM EDT	Severe Thunderstorm Warning	MRX	Loudon, McMinn, Meigs, Monroe, Rhea, Roane	60 min
Jul 21, 4:53 PM EDT	Severe Thunderstorm Warning	MRX	Anderson, Morgan, Roane	67 min
Jul 21, 4:57 PM EDT	Severe Thunderstorm Warning	GSP	Madison	63 min
Jul 21, 5:01 PM EDT	Severe Thunderstorm Warning	MRX	Knox, Union	59 min
Jul 21, 5:04 PM EDT	Severe Thunderstorm Warning	OHX	Jackson, Macon, Smith	26 min
Jul 21, 5:07 PM EDT	Severe Thunderstorm Warning	GSP	Avery, Mitchell, Yancey	37 min
Jul 21, 5:11 PM EDT	Severe Thunderstorm Warning	MRX	Carter, Unicoi	20 min
Jul 21, 5:13 PM EDT	Flash Flood Warning	MRX	Meigs, Rhea, Roane	81 min
Jul 21, 5:13 PM EDT	Severe Thunderstorm Warning	MRX	Blount, Cocke, Jefferson, Loudon, Monroe, Sevier	62 min
Jul 21, 5:20 PM EDT	Severe Thunderstorm Warning	MRX	Grainger, Jefferson	40 min
Jul 21, 5:36 PM EDT	Severe Thunderstorm Warning	MRX	Grainger, Hamblen	54 min
Jul 21, 5:45 PM EDT	Severe Thunderstorm Warning	MRX	Bledsoe, Loudon, McMinn, Meigs, Monroe, Rhea and 1 more	60 min
Jul 21, 5:52 PM EDT	Severe Thunderstorm Warning	OHX	DeKalb	23 min
Jul 21, 5:53 PM EDT	Severe Thunderstorm Warning	MRX	Marion	52 min
Jul 21, 5:59 PM EDT	Severe Thunderstorm Warning	MRX	Knox	25 min
Jul 21, 6:03 PM EDT	Severe Thunderstorm Warning	MRX	Bradley, Hamilton, Polk	57 min
Jul 21, 6:09 PM EDT	Severe Thunderstorm Warning	MRX	Cocke, Jefferson	24 min
Jul 21, 6:15 PM EDT	Severe Thunderstorm Warning	MRX	Blount, Cocke, Jefferson, Loudon, Monroe, Sevier	60 min
Jul 21, 6:34 PM EDT	Severe Thunderstorm Warning	GSP	Graham, Swain	46 min
Jul 21, 6:41 PM EDT	Severe Thunderstorm Warning	MRX	Cherokee, Clay	54 min
Jul 21, 6:48 PM EDT	Severe Thunderstorm Warning	MRX	Polk	42 min
Jul 21, 6:57 PM EDT	Severe Thunderstorm Warning	MRX	Bradley, Hamilton, Polk	48 min
Jul 21, 7:14 PM EDT	Severe Thunderstorm Warning	MRX	Marion	46 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

Mesoscale Discussion 1843Jul 21, 6:28 PM EDT

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 21, 11:37 AM EDT	Severe Thunderstorm Watch	SPC	Boone, Bracken, Campbell, Carroll, Gallatin, Grant and 6 more	6 hr
Jul 21, 1:03 PM EDT	Severe Thunderstorm Watch	SPC	Adair, Allen, Anderson, Barren, Bath, Bell and 68 more	6 hr
Jul 21, 3:20 PM EDT	Mesoscale Discussion	SPC	Adair, Allen, Anderson, Barren, Bath, Bell and 59 more	55 min
Jul 21, 6:28 PM EDT	Mesoscale Discussion	SPC	Allen, Christian, Logan, Simpson, Todd, Trigg and 1 more	92 min

Nearby

Severe Thunderstorm Watches in Tennessee, 2008 Severe Thunderstorm Watches in North Carolina, 2008 Every severe thunderstorm 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; radar from the NEXRAD Level II archive.