Alert archive / Tennessee / Mesoscale Discussions in 2009
Mesoscale Discussion 654
The Storm Prediction Center issued this mesoscale discussion at May 1, 2009, 1:18 PM CDT for 4 states. It was in force for 87 min.
The area
The outline as issued.
The facts
- Issued
- May 1, 2009, 1:18 PM CDT (18:18 UTC)
- Expired
- May 1, 2009, 2:45 PM CDT
- In force
- 87 min
- Issued by
- the Storm Prediction Center
All 60 counties
Blount County, AL, Colbert County, AL, Cullman County, AL, DeKalb County, AL, Franklin County, AL, Jackson County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marion County, AL, Marshall County, AL, Morgan County, AL, Walker County, AL, Winston County, AL, Dade County, GA, Alcorn County, MS, Itawamba County, MS, Prentiss County, MS, Tishomingo County, MS, Bedford County, TN, Benton County, TN, Bledsoe County, TN, Cannon County, TN, Carroll County, TN, Chester County, TN, Coffee County, TN, Cumberland County, TN, Davidson County, TN, Decatur County, TN, DeKalb County, TN, Franklin County, TN, Giles County, TN, Grundy County, TN, Hardin County, TN, Henderson County, TN, Hickman County, TN, Humphreys County, TN, Lawrence County, TN, Lewis County, TN, Lincoln County, TN, Marion County, TN, Marshall County, TN, Maury County, TN, McNairy County, TN, Moore County, TN, Perry County, TN, Putnam County, TN, Rhea County, TN, Rutherford County, TN, Sequatchie County, TN, Smith County, TN, Trousdale County, TN, Van Buren County, TN, Warren County, TN, Wayne County, TN, Weakley County, TN, White County, TN, Williamson County, TN, Wilson County, TN
The radar
The Nashville radar (KOHX), 102 km from the middle of the area, began a volume at 18:17 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, 6.3 hours before the alert went out and 90 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
- 470 J/kg
- Mixed-layer CIN
- -13 J/kg
- Mixed-layer LCL
- 460 m above ground
- 0-6 km bulk shear
- 38 kt
- 0-1 km storm-relative helicity
- 110 m²/s²
- 0-3 km storm-relative helicity
- 132 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.2
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 1, 2:23 PM CDT | Severe Thunderstorm Watch | SPC | Colbert, Cullman, DeKalb, Franklin, Jackson, Lauderdale and 5 more | 5 hr |
| May 1, 3:48 PM CDT | Mesoscale Discussion | SPC | Blount, Colbert, Cullman, DeKalb, Etowah, Franklin and 10 more | 87 min |
| May 1, 6:41 PM CDT | Mesoscale Discussion | SPC | Colbert, DeKalb, Franklin, Jackson, Lauderdale, Lawrence and 6 more | 64 min |
| May 1, 3:21 PM CDT | Mesoscale Discussion | SPC | Carroll, Chester, Crockett, Dyer, Fayette, Gibson and 10 more | 54 min |
| May 1, 3:36 PM CDT | Severe Thunderstorm Watch | SPC | Carroll, Chester, Crockett, Decatur, Dyer, Fayette and 14 more | 6 hr |
| May 1, 6:11 PM CDT | Mesoscale Discussion | SPC | Carroll, Chester, Crockett, Dyer, Fayette, Gibson and 11 more | 64 min |
Nearby
Mesoscale Discussions in Tennessee, 2009Mesoscale Discussions in Alabama, 2009Mesoscale Discussions in Mississippi, 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.