Alert archive / Kentucky / Severe Thunderstorm Watches in 2017
Severe Thunderstorm Watch 254
The Storm Prediction Center issued this severe thunderstorm watch at May 20, 2017, 4:23 PM EDT for 9 counties in Indiana; 49 counties in Kentucky; 17 counties in Tennessee. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- May 20, 2017, 4:23 PM EDT (20:23 UTC)
- Expired
- May 20, 2017, 11:00 PM EDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 55 kt
All 75 counties
Clark County, IN, Crawford County, IN, Floyd County, IN, Harrison County, IN, Jefferson County, IN, Orange County, IN, Perry County, IN, Scott County, IN, Washington County, IN, Adair County, KY, Allen County, KY, Anderson County, KY, Barren County, KY, Bourbon County, KY, Boyle County, KY, Breckinridge County, KY, Bullitt County, KY, Butler County, KY, Casey County, KY, Clark County, KY, Clinton County, KY, Cumberland County, KY, Edmonson County, KY, Fayette County, KY, Franklin County, KY, Garrard County, KY, Grayson County, KY, Green County, KY, Hancock County, KY, Hardin County, KY, Harrison County, KY, Hart County, KY, Henry County, KY, Jefferson County, KY, Jessamine County, KY, Larue County, KY, Lincoln County, KY, Logan County, KY, Madison County, KY, Marion County, KY, Meade County, KY, Mercer County, KY, Metcalfe County, KY, Monroe County, KY, Nelson County, KY, Nicholas County, KY, Ohio County, KY, Oldham County, KY, Russell County, KY, Scott County, KY, Shelby County, KY, Simpson County, KY, Spencer County, KY, Taylor County, KY, Trimble County, KY, Warren County, KY, Washington County, KY, Woodford County, KY, Bedford County, TN, Cannon County, TN, Cheatham County, TN, Coffee County, TN, Davidson County, TN, DeKalb County, TN, Giles County, TN, Macon County, TN, Marshall County, TN, Maury County, TN, Robertson County, TN, Rutherford County, TN, Smith County, TN, Sumner County, TN, Trousdale County, TN, Williamson County, TN, Wilson County, TN
The radar
The Louisville radar (KLVX), 84 km from the middle of the area, began a volume at 20:25 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
- 20%
- One or more EF2 to EF5 tornadoes
- 2%
- Ten or more severe wind reports
- 50%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
20 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 20, 4:24 PM EDT | Severe Thunderstorm Warning | LMK | Perry | 36 min |
| May 20, 4:35 PM EDT | Severe Thunderstorm Warning | LMK | Logan | 40 min |
| May 20, 4:41 PM EDT | Severe Thunderstorm Warning | OHX | Cheatham, Davidson, Robertson | 34 min |
| May 20, 4:43 PM EDT | Tornado Warning | LMK | Crawford, Perry | 17 min |
| May 20, 4:44 PM EDT | Severe Thunderstorm Warning | OHX | Cheatham, Davidson, Dickson, Hickman, Williamson | 31 min |
| May 20, 4:58 PM EDT | Severe Thunderstorm Warning | LMK | Crawford, Harrison | 32 min |
| May 20, 5:06 PM EDT | Severe Thunderstorm Warning | LMK | Butler, Logan, Warren | 39 min |
| May 20, 5:07 PM EDT | Severe Thunderstorm Warning | OHX | Davidson, Williamson | 23 min |
| May 20, 5:11 PM EDT | Severe Thunderstorm Warning | LMK | Crawford, Harrison | 22 min |
| May 20, 5:14 PM EDT | Severe Thunderstorm Warning | OHX | Robertson | 31 min |
| May 20, 5:17 PM EDT | Severe Thunderstorm Warning | OHX | Williamson | 28 min |
| May 20, 5:28 PM EDT | Severe Thunderstorm Warning | LMK | Crawford, Floyd, Harrison, Washington | 32 min |
| May 20, 5:44 PM EDT | Severe Thunderstorm Warning | LMK | Butler, Edmonson, Grayson | 31 min |
| May 20, 5:52 PM EDT | Severe Thunderstorm Warning | LMK | Allen, Barren, Simpson, Warren | 38 min |
| May 20, 6:08 PM EDT | Severe Thunderstorm Warning | LMK | Clark, Floyd | 37 min |
| May 20, 6:33 PM EDT | Severe Thunderstorm Warning | LMK | Clark | 16 min |
| May 20, 7:00 PM EDT | Severe Thunderstorm Warning | LMK | Jefferson | 30 min |
| May 20, 7:05 PM EDT | Severe Thunderstorm Warning | LMK | Jefferson | 25 min |
| May 20, 7:09 PM EDT | Tornado Warning | LMK | Jefferson | 21 min |
| May 20, 7:31 PM EDT | Severe Thunderstorm Warning | LMK | Anderson, Franklin, Shelby, Spencer | 44 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Nashville Metro, TN (KBNA), launched 12:00Z, 8.4 hours before the alert went out and 133 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
- 268 J/kg
- Mixed-layer CIN
- -127 J/kg
- Mixed-layer LCL
- 1494 m above ground
- 0-6 km bulk shear
- 25 kt
- 0-1 km storm-relative helicity
- 23 m²/s²
- 0-3 km storm-relative helicity
- 18 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 20, 12:13 PM EDT | Mesoscale Discussion | SPC | Bartholomew, Brown, Clark, Crawford, Dearborn, Decatur and 22 more | 92 min |
| May 20, 6:42 PM EDT | Mesoscale Discussion | SPC | Bartholomew, Brown, Clark, Crawford, Dearborn, Decatur and 22 more | 2 hr |
| May 20, 7:07 PM EDT | Mesoscale Discussion | SPC | Adams, Benton, Blackford, Boone, Carroll, Cass and 31 more | 2 hr |
| May 19, 10:18 PM EDT | Mesoscale Discussion | SPC | Breathitt, Clay, Floyd, Jackson, Johnson, Knott and 16 more | 87 min |
| May 20, 2:45 AM EDT | Mesoscale Discussion | SPC | Ballard | 90 min |
Nearby
Severe Thunderstorm Watches in Kentucky, 2017Severe Thunderstorm Watches in Tennessee, 2017Severe Thunderstorm Watches in Indiana, 2017Every severe thunderstorm watch 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.