Alert archive / Kentucky / Severe Thunderstorm Watches in 2021
Severe Thunderstorm Watch 118
The Storm Prediction Center issued this severe thunderstorm watch at Apr 28, 2021, 12:40 PM CDT for 7 counties in Illinois; 19 counties in Kentucky; 10 counties in Missouri. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 28, 2021, 12:40 PM CDT (17:40 UTC)
- Expired
- Apr 28, 2021, 8:00 PM CDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 36 counties
Alexander County, IL, Hardin County, IL, Johnson County, IL, Massac County, IL, Pope County, IL, Pulaski County, IL, Union County, IL, Ballard County, KY, Caldwell County, KY, Calloway County, KY, Carlisle County, KY, Christian County, KY, Crittenden County, KY, Fulton County, KY, Graves County, KY, Hickman County, KY, Hopkins County, KY, Livingston County, KY, Lyon County, KY, Marshall County, KY, McCracken County, KY, McLean County, KY, Muhlenberg County, KY, Todd County, KY, Trigg County, KY, Webster County, KY, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Carter County, MO, Mississippi County, MO, New Madrid County, MO, Ripley County, MO, Scott County, MO, Stoddard County, MO, Wayne County, MO
The radar
The Paducah radar (KPAH), 70 km from the middle of the area, began a volume at 17:40 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
- 5%
- Ten or more severe wind reports
- 50%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 50%
- One or more hailstones of 2 inches or more
- 20%
- Six or more combined severe hail and wind reports
- 80%
Warnings issued inside it
10 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 28, 1:14 PM CDT | Severe Thunderstorm Warning | PAH | Carter, Ripley | 28 min |
| Apr 28, 1:32 PM CDT | Severe Thunderstorm Warning | PAH | Wayne | 43 min |
| Apr 28, 2:04 PM CDT | Flash Flood Warning | PAH | Wayne | 107 min |
| Apr 28, 2:15 PM CDT | Severe Thunderstorm Warning | PAH | Bollinger | 45 min |
| Apr 28, 2:38 PM CDT | Flash Flood Warning | PAH | Butler, Ripley | 117 min |
| Apr 28, 3:47 PM CDT | Severe Thunderstorm Warning | PAH | Cape Girardeau, Scott, Stoddard | 28 min |
| Apr 28, 3:56 PM CDT | Severe Thunderstorm Warning | PAH | Fulton | 49 min |
| Apr 28, 4:10 PM CDT | Severe Thunderstorm Warning | PAH | Alexander, Pulaski | 30 min |
| Apr 28, 4:33 PM CDT | Flash Flood Warning | PAH | Fulton, Hickman | 95 min |
| Apr 28, 6:24 PM CDT | Severe Thunderstorm Warning | PAH | Calloway, Marshall | 36 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 (KLZK), launched 12:00Z, 5.7 hours before the alert went out and 268 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
- 845 J/kg
- Mixed-layer CIN
- -8 J/kg
- Mixed-layer LCL
- 593 m above ground
- 0-6 km bulk shear
- 48 kt
- 0-1 km storm-relative helicity
- 78 m²/s²
- 0-3 km storm-relative helicity
- 122 m²/s²
- Significant tornado parameter
- 0.4
- Supercell composite
- 1.7
The text
As transmitted.
339 WWUS20 KWNS 281734 SEL8 SPC WW 281734 ILZ000-KYZ000-MOZ000-290100- URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 118 NWS Storm Prediction Center Norman OK 1235 PM CDT Wed Apr 28 2021 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southern Illinois Western Kentucky Southeast Missouri * Effective this Wednesday afternoon and evening from 1235 PM until 800 PM CDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible Scattered large hail events to 1.5 inches in diameter possible A tornado or two possible SUMMARY...A long-lived cluster of thunderstorms over south-central Missouri will track eastward across the watch area, while new storms intensify ahead of it. Damaging winds and hail are the primary threats, although a tornado or two cannot be ruled out. The severe thunderstorm watch area is approximately along and 40 statute miles north and south of a line from 50 miles west northwest of Poplar Bluff MO to 40 miles south southeast of Owensboro KY. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU8). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 117... AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 26030. ...Hart
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 28, 12:33 PM CDT | Mesoscale Discussion | SPC | Alexander, Johnson, Massac, Pulaski, Union, Williamson | 57 min |
| Apr 28, 3:29 PM CDT | Mesoscale Discussion | SPC | Alexander, Hardin, Johnson, Massac, Pope, Pulaski and 1 more | 91 min |
| Apr 28, 5:25 PM CDT | Mesoscale Discussion | SPC | Hardin, Massac, Pope | 2 hr |
| Apr 28, 8:52 AM CDT | Mesoscale Discussion | SPC | Butler, Dunklin, Howell, Oregon, Ozark, Ripley and 1 more | 113 min |
| Apr 28, 9:33 AM CDT | Tornado Watch | SPC | Christian, Douglas, Howell, Oregon, Ozark, Shannon and 4 more | 4 hr |
| Apr 28, 10:56 AM CDT | Mesoscale Discussion | SPC | Douglas, Howell, Oregon, Ozark, Shannon, Texas and 1 more | 64 min |
Nearby
Severe Thunderstorm Watches in Kentucky, 2021Severe Thunderstorm Watches in Missouri, 2021Severe Thunderstorm Watches in Illinois, 2021Every severe thunderstorm watch in 2021
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.