Alert archive / Tennessee / Mesoscale Discussions in 2009
Mesoscale Discussion 768
The Storm Prediction Center issued this mesoscale discussion at May 8, 2009, 7:30 PM CDT for 8 states. It was in force for 90 min.
The area
The outline as issued.
The facts
- Issued
- May 8, 2009, 7:30 PM CDT (00:30 UTC)
- Expired
- May 8, 2009, 9:00 PM CDT
- In force
- 90 min
- Issued by
- the Storm Prediction Center
All 156 counties
Clay County, AR, Craighead County, AR, Greene County, AR, Mississippi County, AR, Poinsett County, AR, Bell County, KY, Breathitt County, KY, Clay County, KY, Floyd County, KY, Harlan County, KY, Knott County, KY, Knox County, KY, Laurel County, KY, Leslie County, KY, Letcher County, KY, Magoffin County, KY, Martin County, KY, McCreary County, KY, Owsley County, KY, Perry County, KY, Pike County, KY, Whitley County, KY, Dunklin County, MO, Pemiscot County, MO, Alexander County, NC, Alleghany County, NC, Ashe County, NC, Avery County, NC, Buncombe County, NC, Burke County, NC, Caldwell County, NC, Catawba County, NC, Cleveland County, NC, Graham County, NC, Haywood County, NC, Henderson County, NC, Jackson County, NC, Macon County, NC, Madison County, NC, McDowell County, NC, Mitchell County, NC, Polk County, NC, Rutherford County, NC, Surry County, NC, Swain County, NC, Transylvania County, NC, Watauga County, NC, Wilkes County, NC, Yancey County, NC, Cherokee County, SC, Greenville County, SC, Pickens County, SC, Spartanburg County, SC, Anderson County, TN, Bedford County, TN, Benton County, TN, Bledsoe County, TN, Blount County, TN, Campbell County, TN, Cannon County, TN, Carroll County, TN, Carter County, TN, Cheatham County, TN, Claiborne County, TN, Clay County, TN, Cocke County, TN, Coffee County, TN, Crockett County, TN, Cumberland County, TN, Davidson County, TN, Decatur County, TN, DeKalb County, TN, Dickson County, TN, Dyer County, TN, Fentress County, TN, Gibson County, TN, Grainger County, TN, Greene County, TN, Grundy County, TN, Hamblen County, TN, Hancock County, TN, Hawkins County, TN, Haywood County, TN, Henderson County, TN, Henry County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Jackson County, TN, Jefferson County, TN, Johnson County, TN, Knox County, TN, Lake County, TN, Lauderdale County, TN, Lewis County, TN, Loudon County, TN, Macon County, TN, Madison County, TN, Marshall County, TN, Maury County, TN, McMinn County, TN, Meigs County, TN, Monroe County, TN, Montgomery County, TN, Morgan County, TN, Obion County, TN, Overton County, TN, Perry County, TN, Pickett County, TN, Putnam County, TN, Rhea County, TN, Roane County, TN, Robertson County, TN, Rutherford County, TN, Scott County, TN, Sequatchie County, TN, Sevier County, TN, Smith County, TN, Stewart County, TN, Sullivan County, TN, Sumner County, TN, Tipton County, TN, Trousdale County, TN, Unicoi County, TN, Union County, TN, Van Buren County, TN, Warren County, TN, Washington County, TN, Weakley County, TN, White County, TN, Williamson County, TN, Wilson County, TN, Bland County, VA, Buchanan County, VA, Carroll County, VA, City of Bristol, VA, City of Galax, VA, City of Norton, VA, City of Radford, VA, Dickenson County, VA, Giles County, VA, Grayson County, VA, Lee County, VA, Pulaski County, VA, Russell County, VA, Scott County, VA, Smyth County, VA, Tazewell County, VA, Washington County, VA, Wise County, VA, Wythe County, VA, Logan County, WV, McDowell County, WV, Mercer County, WV, Mingo County, WV, Wyoming County, WV
The radar
The Knoxville radar (KMRX), 112 km from the middle of the area, began a volume at 00:32 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.
The watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Nashville Metro, TN (KBNA), launched 00:00Z, 0.5 hours before the alert went out and 178 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
- 755 J/kg
- Mixed-layer CIN
- -212 J/kg
- Mixed-layer LCL
- 1403 m above ground
- 0-6 km bulk shear
- 53 kt
- 0-1 km storm-relative helicity
- 286 m²/s²
- 0-3 km storm-relative helicity
- 487 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.9
The text
As transmitted, in the capitals the NWS used until 2016.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 8, 9:31 PM CDT | Mesoscale Discussion | SPC | Cleburne, Conway, Crawford, Faulkner, Franklin, Izard and 15 more | 89 min |
| May 8, 10:04 PM CDT | Mesoscale Discussion | SPC | Clay, Greene | 86 min |
| May 8, 10:31 PM CDT | Severe Thunderstorm Watch | SPC | Clay, Greene, Lawrence, Randolph | 7 hr |
| May 8, 11:19 PM CDT | Mesoscale Discussion | SPC | Miller | 86 min |
| May 9, 2:22 AM CDT | Mesoscale Discussion | SPC | Craighead, Crittenden, Cross, Greene, Mississippi, Poinsett | 53 min |
| May 9, 12:33 PM CDT | Mesoscale Discussion | SPC | Arkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 13 more | 57 min |
| May 9, 12:51 PM CDT | Severe Thunderstorm Watch | SPC | Arkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 22 more | 7 hr |
| May 9, 3:25 PM CDT | Mesoscale Discussion | SPC | Arkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 13 more | 65 min |
| May 8, 9:01 PM CDT | Tornado Watch | SPC | Caswell, Rockingham, Stokes | 4 hr |
| May 8, 10:37 PM CDT | Mesoscale Discussion | SPC | Alleghany, Ashe, Forsyth, Rockingham, Stokes, Surry and 3 more | 53 min |
| May 8, 11:51 PM CDT | Mesoscale Discussion | SPC | Caswell, Edgecombe, Franklin, Gates, Granville, Halifax and 7 more | 84 min |
| May 9, 11:47 AM CDT | Mesoscale Discussion | SPC | Alamance, Alexander, Burke, Cabarrus, Caldwell, Caswell and 32 more | 118 min |
| May 9, 12:17 PM CDT | Severe Thunderstorm Watch | SPC | Alamance, Alexander, Anson, Burke, Cabarrus, Caldwell and 36 more | 8 hr |
| May 9, 3:30 PM CDT | Mesoscale Discussion | SPC | Alamance, Cabarrus, Caswell, Catawba, Chatham, Davidson and 19 more | 90 min |
| May 9, 4:58 PM CDT | Mesoscale Discussion | SPC | Bertie, Camden, Chatham, Chowan, Durham, Edgecombe and 20 more | 62 min |
| May 9, 5:25 PM CDT | Severe Thunderstorm Watch | SPC | Beaufort, Bertie, Camden, Carteret, Chowan, Craven and 31 more | 4 hr |
| May 9, 12:07 AM CDT | Tornado Watch | SPC | Amelia, Brunswick, Charles City, Chesterfield, Cumberland, Dinwiddie and 39 more | 4 hr |
Nearby
Mesoscale Discussions in Tennessee, 2009Mesoscale Discussions in North Carolina, 2009Mesoscale Discussions in Virginia, 2009Every mesoscale discussion 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.