Alert archive / Missouri / Severe Thunderstorm Watches in 2020
Severe Thunderstorm Watch 66
The Storm Prediction Center issued this severe thunderstorm watch at Mar 27, 2020, 10:16 PM CDT for 15 counties in Illinois; 17 counties in Missouri. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Mar 27, 2020, 10:16 PM CDT (03:16 UTC)
- Expired
- Mar 28, 2020, 4:00 AM CDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2.5 in
- Strongest gust expected
- 50 kt
All 32 counties
Bond County, IL, Calhoun County, IL, Christian County, IL, Effingham County, IL, Fayette County, IL, Greene County, IL, Jersey County, IL, Macoupin County, IL, Madison County, IL, Montgomery County, IL, Morgan County, IL, Pike County, IL, Sangamon County, IL, Scott County, IL, Shelby County, IL, Audrain County, MO, Boone County, MO, Callaway County, MO, City of Saint Louis, MO, Cole County, MO, Franklin County, MO, Gasconade County, MO, Lincoln County, MO, Moniteau County, MO, Monroe County, MO, Montgomery County, MO, Osage County, MO, Pike County, MO, Ralls County, MO, Saint Charles County, MO, Saint Louis County, MO, Warren County, MO
The radar
The St Louis radar (KLSX), 57 km from the middle of the area, began a volume at 03:19 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
- 10%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 20%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 40%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 60%
Warnings issued inside it
4 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 27, 10:21 PM CDT | Severe Thunderstorm Warning | LSX | Boone, Callaway, Cole, Osage | 39 min |
| Mar 27, 10:53 PM CDT | Severe Thunderstorm Warning | LSX | Callaway, Franklin, Gasconade, Montgomery, Osage, Warren | 41 min |
| Mar 27, 11:20 PM CDT | Severe Thunderstorm Warning | LSX | Calhoun | 40 min |
| Mar 27, 11:43 PM CDT | Severe Thunderstorm Warning | LSX | Calhoun, Jersey, Macoupin, Madison | 47 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
Lincoln, IL (KILX), launched 00:00Z, 3.3 hours before the alert went out and 237 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 626 m above ground
- 0-6 km bulk shear
- 85 kt
- 0-1 km storm-relative helicity
- 371 m²/s²
- 0-3 km storm-relative helicity
- 383 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 27, 8:02 PM CDT | Mesoscale Discussion | SPC | Edwards, Franklin, Hamilton, Jackson, Jefferson, Lawrence and 10 more | 88 min |
| Mar 27, 8:33 PM CDT | Mesoscale Discussion | SPC | Calhoun | 87 min |
| Mar 27, 11:46 PM CDT | Mesoscale Discussion | SPC | Bond, Calhoun, Christian, Fayette, Greene, Jersey and 8 more | 89 min |
| Mar 28, 1:34 AM CDT | Mesoscale Discussion | SPC | Carroll, Henry, Jo Daviess, Mercer, Rock Island, Whiteside | 56 min |
| Mar 28, 10:18 AM CDT | Mesoscale Discussion | SPC | Champaign, Christian, DeWitt, Douglas, Ford, Iroquois and 8 more | 2 hr |
| Mar 28, 1:17 PM CDT | Mesoscale Discussion | SPC | Alexander, Bond, Clark, Clay, Clinton, Crawford and 34 more | 88 min |
| Mar 28, 1:33 PM CDT | Mesoscale Discussion | SPC | Adams, Hancock, Henderson | 117 min |
| Mar 28, 2:45 PM CDT | Tornado Watch | SPC | Adams, Brown, Bureau, Calhoun, Cass, Champaign and 44 more | 6 hr |
| Mar 28, 3:53 PM CDT | Tornado Watch | SPC | Alexander, Bond, Clark, Clay, Clinton, Crawford and 30 more | 5 hr |
| Mar 28, 4:59 PM CDT | Mesoscale Discussion | SPC | Gallatin, Hamilton, Hardin, Johnson, Massac, Pope and 2 more | 61 min |
| Mar 28, 5:21 PM CDT | Mesoscale Discussion | SPC | Brown, Fulton, Hancock, Henderson, Henry, Knox and 7 more | 84 min |
| Mar 28, 6:42 PM CDT | Mesoscale Discussion | SPC | Carroll, Jo Daviess, Stephenson | 93 min |
| Mar 28, 7:05 AM CDT | Mesoscale Discussion | SPC | Barry, Barton, Bates, Benton, Boone, Camden and 27 more | 85 min |
| Mar 28, 2:10 PM CDT | Tornado Watch | SPC | Dunklin, Pemiscot | 5 hr |
| Mar 28, 2:56 PM CDT | Mesoscale Discussion | SPC | Dunklin, Pemiscot | 94 min |
| Mar 28, 6:34 PM CDT | Tornado Watch | SPC | Dunklin, Pemiscot | 7 hr |
Nearby
Severe Thunderstorm Watches in Missouri, 2020Severe Thunderstorm Watches in Illinois, 2020Every severe thunderstorm watch in 2020
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.