Alert archive / Tennessee / Mesoscale Discussions in 2009
Mesoscale Discussion 1776
The Storm Prediction Center issued this mesoscale discussion at Aug 4, 2009, 6:45 PM EDT for 7 states. It was in force for 90 min.
The area
The outline as issued.
The facts
- Issued
- Aug 4, 2009, 6:45 PM EDT (22:45 UTC)
- Expired
- Aug 4, 2009, 8:15 PM EDT
- In force
- 90 min
- Issued by
- the Storm Prediction Center
All 106 counties
Catoosa County, GA, Dade County, GA, Fannin County, GA, Gilmer County, GA, Habersham County, GA, Lumpkin County, GA, Murray County, GA, Rabun County, GA, Towns County, GA, Union County, GA, Walker County, GA, White County, GA, Whitfield County, GA, Perry County, IN, Spencer County, IN, Allen County, KY, Barren County, KY, Breckinridge County, KY, Butler County, KY, Daviess County, KY, Edmonson County, KY, Grayson County, KY, Hancock County, KY, Logan County, KY, McLean County, KY, Monroe County, KY, Muhlenberg County, KY, Ohio County, KY, Simpson County, KY, Warren County, KY, Ashe County, NC, Avery County, NC, Buncombe County, NC, Burke County, NC, Caldwell County, NC, Cherokee County, NC, Clay 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, Swain County, NC, Transylvania County, NC, Watauga County, NC, Yancey County, NC, Greenville County, SC, Oconee County, SC, Pickens County, SC, Anderson County, TN, Bedford County, TN, Bledsoe County, TN, Blount County, TN, Bradley County, TN, Cannon County, TN, Carter County, TN, Clay County, TN, Cocke County, TN, Coffee County, TN, Cumberland County, TN, Davidson County, TN, DeKalb County, TN, Fentress County, TN, Franklin County, TN, Greene County, TN, Grundy County, TN, Hamblen County, TN, Hamilton 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, Moore County, TN, Morgan County, TN, Overton County, TN, Polk County, TN, Putnam County, TN, Rhea County, TN, Roane County, TN, Robertson County, TN, Rutherford County, TN, Sequatchie County, TN, Sevier County, TN, Smith County, TN, Sullivan County, TN, Sumner County, TN, Trousdale County, TN, Unicoi County, TN, Van Buren County, TN, Warren County, TN, Washington County, TN, White County, TN, Wilson County, TN, City of Bristol, VA, Washington County, VA
The radar
The Knoxville radar (KMRX), 93 km from the middle of the area, began a volume at 22:47 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 12:00Z, 10.8 hours before the alert went out and 195 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
- 3443 J/kg
- Mixed-layer CIN
- -21 J/kg
- Mixed-layer LCL
- 680 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- 80 m²/s²
- 0-3 km storm-relative helicity
- 42 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.8
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 |
|---|---|---|---|---|
| Aug 4, 5:37 AM EDT | Mesoscale Discussion | SPC | Adams, Bartholomew, Blackford, Brown, Dearborn, Decatur and 24 more | 53 min |
| Aug 4, 8:39 AM EDT | Severe Thunderstorm Watch | SPC | Benton | 4 hr |
| Aug 4, 9:24 AM EDT | Mesoscale Discussion | SPC | Bartholomew, Boone, Brown, Clay, Clinton, Dearborn and 33 more | 36 min |
| Aug 4, 9:41 AM EDT | Severe Thunderstorm Watch | SPC | Bartholomew, Boone, Brown, Carroll, Clark, Clay and 51 more | 6 hr |
| Aug 4, 9:47 AM EDT | Mesoscale Discussion | SPC | Bartholomew, Boone, Clark, Dearborn, Decatur, Fayette and 20 more | 58 min |
| Aug 4, 12:41 PM EDT | Mesoscale Discussion | SPC | Clark, Crawford, Dubois, Floyd, Harrison, Jackson and 10 more | 94 min |
| Aug 4, 1:21 PM EDT | Severe Thunderstorm Watch | SPC | Spencer, Vanderburgh, Warrick | 7 hr |
| Aug 4, 3:36 PM EDT | Mesoscale Discussion | SPC | Adair, Allen, Ballard, Barren, Boyle, Butler and 44 more | 84 min |
| Aug 4, 4:09 PM EDT | Severe Thunderstorm Watch | SPC | Ballard, Caldwell, Calloway, Carlisle, Christian, Crittenden and 13 more | 7 hr |
| Aug 4, 4:29 PM EDT | Severe Thunderstorm Watch | SPC | Harlan, Knott, Leslie, Letcher, Perry | 6 hr |
| Aug 4, 7:21 PM EDT | Mesoscale Discussion | SPC | Ballard, Caldwell, Calloway, Carlisle, Christian, Crittenden and 11 more | 114 min |
| Aug 4, 7:34 PM EDT | Severe Thunderstorm Watch | SPC | Bedford, Benton, Cannon, Carroll, Cheatham, Chester and 35 more | 4 hr |
Nearby
Mesoscale Discussions in Tennessee, 2009Mesoscale Discussions in North Carolina, 2009Mesoscale Discussions in Kentucky, 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.