Alert archive / Illinois / Tornado Watches in 2021
Tornado Watch 313
The Storm Prediction Center issued this tornado watch at Jun 24, 2021, 11:47 PM CDT for 24 counties in Illinois; Des Moines County, Henry County, Lee County, Iowa; 10 counties in Missouri. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 24, 2021, 11:47 PM CDT (04:47 UTC)
- Expired
- Jun 25, 2021, 4:00 AM CDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 65 kt
All 37 counties
Des Moines County, IA, Henry County, IA, Lee County, IA, Adams County, IL, Bond County, IL, Brown County, IL, Calhoun County, IL, Cass County, IL, Christian County, IL, Fulton County, IL, Greene County, IL, Hancock County, IL, Henderson County, IL, Jersey County, IL, Knox County, IL, Macoupin County, IL, Madison County, IL, Mason County, IL, McDonough County, IL, Menard County, IL, Montgomery County, IL, Morgan County, IL, Pike County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Warren County, IL, Audrain County, MO, Callaway County, MO, City of Saint Louis, MO, Lincoln County, MO, Montgomery 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), 110 km from the middle of the area, began a volume at 04:46 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
- 30%
- One or more EF2 to EF5 tornadoes
- 10%
- Ten or more severe wind reports
- 50%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 10%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 60%
Warnings issued inside it
7 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 25, 12:03 AM CDT | Tornado Warning | LSX | Adams, Pike | 42 min |
| Jun 25, 12:09 AM CDT | Tornado Warning | LSX | Audrain, Pike, Ralls | 51 min |
| Jun 25, 12:17 AM CDT | Severe Thunderstorm Warning | LSX | Adams, Brown, Calhoun, Pike | 43 min |
| Jun 25, 12:33 AM CDT | Severe Thunderstorm Warning | ILX | Cass, Morgan, Schuyler, Scott | 72 min |
| Jun 25, 12:57 AM CDT | Severe Thunderstorm Warning | LSX | Brown, Calhoun, Greene, Jersey, Pike | 48 min |
| Jun 25, 1:21 AM CDT | Severe Thunderstorm Warning | ILX | Cass, Mason, Menard, Morgan, Sangamon | 42 min |
| Jun 25, 1:42 AM CDT | Flash Flood Warning | ILX | Knox, Marshall, Stark | 6 hr |
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, 4.8 hours before the alert went out and 219 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
- 263 J/kg
- Mixed-layer CIN
- -103 J/kg
- Mixed-layer LCL
- 875 m above ground
- 0-6 km bulk shear
- 34 kt
- 0-1 km storm-relative helicity
- 245 m²/s²
- 0-3 km storm-relative helicity
- 444 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 3.5
The text
As transmitted.
687
WWUS20 KWNS 250444
SEL3
SPC WW 250444
IAZ000-ILZ000-MOZ000-250900-
URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 313
NWS Storm Prediction Center Norman OK
1145 PM CDT Thu Jun 24 2021
The NWS Storm Prediction Center has issued a
* Tornado Watch for portions of
Far southeast Iowa
Western Illinois
East-central Missouri
* Effective this Thursday night and Friday morning from 1145 PM
until 400 AM CDT.
* Primary threats include...
A couple tornadoes possible
Scattered damaging winds and isolated significant gusts to 75
mph possible
SUMMARY...Well-organized QLCS should spread east across the
Mississippi Valley into Illinois through the pre-dawn hours. Brief
tornado risk will be most concentrated along the Mississippi Valley
before the line wanes in intensity.
The tornado watch area is approximately along and 65 statute miles
east and west of a line from 40 miles west of Saint Louis MO to 40
miles east northeast of Burlington IA. For a complete depiction of
the watch see the associated watch outline update (WOUS64 KWNS
WOU3).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Tornado Watch means conditions are favorable for
tornadoes and 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.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 312...
AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 1 inch. Extreme turbulence and surface wind
gusts to 65 knots. A few cumulonimbi with maximum tops to 550. Mean
storm motion vector 26035.
...GramsSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 24, 8:57 PM CDT | Severe Thunderstorm Watch | SPC | Adams, Brown, Hancock, Pike | 6 hr |
| Jun 24, 11:23 PM CDT | Mesoscale Discussion | SPC | Adams, Brown, Calhoun, Cass, Greene, Hancock and 9 more | 2 hr |
| Jun 25, 12:57 PM CDT | Mesoscale Discussion | SPC | Alexander, Clay, Crawford, Edwards, Franklin, Gallatin and 15 more | 2 hr |
| Jun 25, 4:46 PM CDT | Mesoscale Discussion | SPC | Bond, Brown, Calhoun, Cass, Champaign, Christian and 23 more | 59 min |
| Jun 25, 5:06 PM CDT | Severe Thunderstorm Watch | SPC | Adams, Brown, Calhoun, Cass, Champaign, Christian and 30 more | 6 hr |
| Jun 25, 6:47 PM CDT | Severe Thunderstorm Watch | SPC | Kankakee | 4 hr |
| Jun 24, 7:29 PM CDT | Mesoscale Discussion | SPC | Fremont, Page, Ringgold, Taylor | 61 min |
| Jun 25, 1:00 PM CDT | Mesoscale Discussion | SPC | Benton, Black Hawk, Boone, Buchanan, Buena Vista, Butler and 29 more | 2 hr |
| Jun 24, 8:33 PM CDT | Mesoscale Discussion | SPC | Adair, Andrew, Audrain, Bates, Benton, Boone and 49 more | 87 min |
| Jun 25, 11:56 AM CDT | Mesoscale Discussion | SPC | Bates, Benton, Cass, Cedar, Dade, Dallas and 8 more | 3 hr |
| Jun 25, 1:43 PM CDT | Severe Thunderstorm Watch | SPC | Barton, Bates, Benton, Carroll, Cass, Cedar and 14 more | 9 hr |
| Jun 25, 3:13 PM CDT | Mesoscale Discussion | SPC | Bates, Benton, Camden, Cass, Henry, Hickory and 7 more | 2 hr |
| Jun 25, 6:21 PM CDT | Mesoscale Discussion | SPC | Bates, Henry, Hickory, St. Clair, Vernon | 84 min |
Nearby
Tornado Watches in Illinois, 2021Tornado Watches in Missouri, 2021Tornado Watches in Iowa, 2021Every tornado 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.