Alert archive / Tennessee / Mesoscale Discussions in 2017
Mesoscale Discussion 537
The Storm Prediction Center issued this mesoscale discussion at Apr 21, 2017, 1:13 PM CDT for 7 states. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 21, 2017, 1:13 PM CDT (18:13 UTC)
- Expired
- Apr 21, 2017, 3:15 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 20%
All 118 counties
Colbert County, AL, Jackson County, AL, Lauderdale County, AL, Limestone County, AL, Madison County, AL, Catoosa County, GA, Dade County, GA, Bell County, KY, Harlan County, KY, Knox County, KY, Leslie County, KY, Letcher County, KY, McCreary County, KY, Whitley County, KY, Prentiss County, MS, Tishomingo County, MS, Alexander County, NC, Alleghany County, NC, 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, Rutherford County, NC, Surry County, NC, Swain County, NC, Transylvania County, NC, Watauga County, NC, Wilkes County, NC, Yadkin County, NC, Yancey County, NC, Anderson County, TN, Bedford County, TN, Bledsoe County, TN, Blount County, TN, Bradley County, TN, Campbell County, TN, Cannon County, TN, Carter County, TN, Claiborne County, TN, Cocke County, TN, Coffee County, TN, Cumberland County, TN, DeKalb County, TN, Fentress County, TN, Franklin County, TN, Giles County, TN, Grainger County, TN, Greene County, TN, Grundy County, TN, Hamblen County, TN, Hamilton County, TN, Hancock County, TN, Hardin County, TN, Hawkins County, TN, Jackson County, TN, Jefferson County, TN, Johnson County, TN, Knox County, TN, Lawrence County, TN, Lewis County, TN, Lincoln County, TN, Loudon County, TN, Marion County, TN, Marshall County, TN, Maury County, TN, McMinn County, TN, Meigs County, TN, Monroe County, TN, Moore County, TN, Morgan County, TN, Overton County, TN, Pickett County, TN, Polk County, TN, Putnam County, TN, Rhea County, TN, Roane County, TN, Rutherford 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, Wayne 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, Dickenson County, VA, Grayson County, VA, Lee County, VA, Russell County, VA, Scott County, VA, Smyth County, VA, Tazewell County, VA, Washington County, VA, Wise County, VA, Wythe County, VA
The radar
The Knoxville radar (KMRX), 129 km from the middle of the area, began a volume at 18:11 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 nearest sounding before it
Nashville Metro, TN (KBNA), launched 12:00Z, 6.2 hours before the alert went out and 169 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
- 68 J/kg
- Mixed-layer CIN
- -110 J/kg
- Mixed-layer LCL
- 813 m above ground
- 0-6 km bulk shear
- 40 kt
- 0-1 km storm-relative helicity
- 26 m²/s²
- 0-3 km storm-relative helicity
- 8 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 21, 1:12 PM CDT | Mesoscale Discussion | SPC | Alcorn, Benton, Coahoma, DeSoto, Lafayette, Marshall and 7 more | 93 min |
| Apr 21, 3:19 PM CDT | Mesoscale Discussion | SPC | Alamance, Alexander, Alleghany, Ashe, Avery, Buncombe and 38 more | 56 min |
Nearby
Mesoscale Discussions in Tennessee, 2017Mesoscale Discussions in North Carolina, 2017Mesoscale Discussions in Virginia, 2017Every mesoscale discussion in 2017
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.