Alert archive / Kentucky / Severe Thunderstorm Watches in 2018
Severe Thunderstorm Watch 345
The Storm Prediction Center issued this severe thunderstorm watch at Aug 20, 2018, 4:45 PM CDT for 5 states. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 20, 2018, 4:45 PM CDT (21:45 UTC)
- Expired
- Aug 20, 2018, 10:58 PM CDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 60 kt
All 85 counties
Gallatin County, IL, Hardin County, IL, Massac County, IL, Pope County, IL, Crawford County, IN, Dubois County, IN, Gibson County, IN, Perry County, IN, Pike County, IN, Posey County, IN, Spencer County, IN, Vanderburgh County, IN, Warrick County, IN, Ballard County, KY, Butler County, KY, Caldwell County, KY, Calloway County, KY, Carlisle County, KY, Christian County, KY, Crittenden County, KY, Daviess County, KY, Fulton County, KY, Graves County, KY, Hancock County, KY, Henderson County, KY, Hickman County, KY, Hopkins County, KY, Livingston County, KY, Logan County, KY, Lyon County, KY, Marshall County, KY, McCracken County, KY, McLean County, KY, Muhlenberg County, KY, Ohio County, KY, Todd County, KY, Trigg County, KY, Union County, KY, Webster County, KY, Alcorn County, MS, Benton County, MS, Calhoun County, MS, Chickasaw County, MS, DeSoto County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Marshall County, MS, Monroe County, MS, Panola County, MS, Pontotoc County, MS, Prentiss County, MS, Quitman County, MS, Tallahatchie County, MS, Tate County, MS, Tippah County, MS, Tishomingo County, MS, Union County, MS, Yalobusha County, MS, Benton County, TN, Carroll County, TN, Chester County, TN, Crockett County, TN, Decatur County, TN, Dyer County, TN, Fayette County, TN, Gibson County, TN, Hardeman County, TN, Hardin County, TN, Haywood County, TN, Henderson County, TN, Henry County, TN, Houston County, TN, Humphreys County, TN, Lake County, TN, Lauderdale County, TN, Madison County, TN, McNairy County, TN, Montgomery County, TN, Obion County, TN, Perry County, TN, Shelby County, TN, Stewart County, TN, Tipton County, TN, Weakley County, TN
The radar
The Memphis radar (KNQA), 112 km from the middle of the area, began a volume at 21:44 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
- 10%
- Ten or more severe wind reports
- 50%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 20%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
15 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 20, 4:57 PM CDT | Severe Thunderstorm Warning | MEG | Shelby | 48 min |
| Aug 20, 5:13 PM CDT | Tornado Warning | MEG | Panola, Quitman | 47 min |
| Aug 20, 5:39 PM CDT | Severe Thunderstorm Warning | MEG | Fayette, Shelby, Tipton | 51 min |
| Aug 20, 5:41 PM CDT | Severe Thunderstorm Warning | MEG | DeSoto, Tunica | 49 min |
| Aug 20, 5:51 PM CDT | Severe Thunderstorm Warning | MEG | Panola, Quitman, Tallahatchie | 39 min |
| Aug 20, 5:59 PM CDT | Severe Thunderstorm Warning | MEG | Lafayette, Panola | 46 min |
| Aug 20, 6:27 PM CDT | Severe Thunderstorm Warning | MEG | Lafayette, Panola, Quitman, Tallahatchie, Yalobusha | 48 min |
| Aug 20, 6:30 PM CDT | Severe Thunderstorm Warning | MEG | Benton, Marshall | 28 min |
| Aug 20, 6:49 PM CDT | Severe Thunderstorm Warning | MEG | Calhoun, Lafayette, Pontotoc | 41 min |
| Aug 20, 7:01 PM CDT | Severe Thunderstorm Warning | MEG | Calhoun, Chickasaw | 44 min |
| Aug 20, 7:02 PM CDT | Severe Thunderstorm Warning | PAH | Massac, Pope | 28 min |
| Aug 20, 7:08 PM CDT | Tornado Warning | MEG | Dyer | 37 min |
| Aug 20, 7:31 PM CDT | Tornado Warning | MEG | Lafayette, Pontotoc | 24 min |
| Aug 20, 7:37 PM CDT | Severe Thunderstorm Warning | MEG | Chickasaw, Monroe | 53 min |
| Aug 20, 8:31 PM CDT | Severe Thunderstorm Warning | MEG | Monroe | 21 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
Little Rock, AR (KBYH), launched 12:00Z, 9.8 hours before the alert went out and 149 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
- 904 J/kg
- Mixed-layer CIN
- -46 J/kg
- Mixed-layer LCL
- 737 m above ground
- 0-6 km bulk shear
- 39 kt
- 0-1 km storm-relative helicity
- 81 m²/s²
- 0-3 km storm-relative helicity
- 133 m²/s²
- Significant tornado parameter
- 0.5
- Supercell composite
- 3.7
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 20, 11:46 AM CDT | Mesoscale Discussion | SPC | Alexander, Bond, Clay, Clinton, Franklin, Hamilton and 17 more | 119 min |
| Aug 20, 12:46 PM CDT | Severe Thunderstorm Watch | SPC | Alexander, Clinton, Edwards, Franklin, Hamilton, Jackson and 16 more | 7 hr |
| Aug 20, 4:00 PM CDT | Mesoscale Discussion | SPC | Alexander, Clinton, Edwards, Franklin, Gallatin, Hamilton and 14 more | 2 hr |
| Aug 20, 4:46 PM CDT | Mesoscale Discussion | SPC | Boone, Carroll, Cook, DeKalb, DuPage, Grundy and 11 more | 119 min |
| Aug 20, 1:27 PM CDT | Mesoscale Discussion | SPC | Blackford, Boone, Carroll, Cass, Clinton, Delaware and 21 more | 2 hr |
| Aug 20, 3:14 PM CDT | Mesoscale Discussion | SPC | Holmes, Humphreys, Issaquena, Leflore, Sharkey, Sunflower and 3 more | 3 hr |
| Aug 20, 5:57 PM CDT | Mesoscale Discussion | SPC | Alcorn, Attala, Benton, Bolivar, Calhoun, Carroll and 33 more | 63 min |
Nearby
Severe Thunderstorm Watches in Kentucky, 2018Severe Thunderstorm Watches in Tennessee, 2018Severe Thunderstorm Watches in Mississippi, 2018Every severe thunderstorm watch in 2018
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.