Alert archive / Illinois / Tornado Warnings in 2020
Tornado Warning 10, NWS St. Louis, MO
NWS St. Louis, MO issued this tornado warning at Jul 21, 2020, 4:17 PM CDT for Montgomery County, Illinois. It was in force for 13 min. 1 report came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Jul 21, 2020, 4:17 PM CDT (21:17 UTC)
- Expired
- Jul 21, 2020, 4:30 PM CDT
- In force
- 13 min
- Issued by
- NWS St. Louis, MO
- Area
- Storm-based polygon
- Tornado
- Radar indicated
- Hail
- 0.75 in
County Montgomery County, IL
The radar
The Lincoln radar (KILX), 78 km from the middle of the area, began a volume at 21:21 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 was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jul 21, 4:18 PM CDT | TORNADO 0 | White Oak, IL | MONTGOMERY CO. EMERGENCY MANAGEMENT REPORTED A TORNADO ON THE GROUND NEAR WHITE OAK. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Lincoln, IL (KILX), launched 12:00Z, 9.3 hours before the alert went out and 115 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
- 474 J/kg
- Mixed-layer CIN
- -67 J/kg
- Mixed-layer LCL
- 804 m above ground
- 0-6 km bulk shear
- 21 kt
- 0-1 km storm-relative helicity
- 57 m²/s²
- 0-3 km storm-relative helicity
- 138 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.3
The text
As transmitted.
829
WFUS53 KLSX 212117
TORLSX
ILC135-212130-
/O.NEW.KLSX.TO.W.0010.200721T2117Z-200721T2130Z/
BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service St Louis MO
417 PM CDT Tue Jul 21 2020
The National Weather Service in St Louis has issued a
* Tornado Warning for...
Northwestern Montgomery County in south central Illinois...
* Until 430 PM CDT.
* At 416 PM CDT, a severe thunderstorm capable of producing a tornado
was located over White Oak, moving east at 45 mph.
HAZARD...Tornado.
SOURCE...Radar indicated rotation.
IMPACT...Flying debris will be dangerous to those caught without
shelter. Mobile homes will be damaged or destroyed.
Damage to roofs, windows, and vehicles will occur. Tree
damage is likely.
* This tornadic thunderstorm will remain over mainly rural areas of
northwestern Montgomery County.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.
&&
LAT...LON 3946 8969 3952 8969 3953 8966 3952 8953
3945 8953
TIME...MOT...LOC 2116Z 272DEG 37KT 3952 8958
TORNADO...RADAR INDICATED
HAIL...<.75IN
$$
MRM2 follow-up statements
282
WWUS53 KLSX 212122
SVSLSX
Severe Weather Statement
National Weather Service St Louis MO
422 PM CDT Tue Jul 21 2020
ILC135-212130-
/O.CON.KLSX.TO.W.0010.000000T0000Z-200721T2130Z/
Montgomery IL-
422 PM CDT Tue Jul 21 2020
...A TORNADO WARNING REMAINS IN EFFECT UNTIL 430 PM CDT FOR
NORTHWESTERN MONTGOMERY COUNTY...
At 421 PM CDT, a confirmed tornado was located near White Oak, moving
east at 45 mph.
HAZARD...Damaging tornado.
SOURCE...Emergency management confirmed tornado.
IMPACT...Flying debris will be dangerous to those caught without
shelter. Mobile homes will be damaged or destroyed. Damage
to roofs, windows, and vehicles will occur. Tree damage is
likely.
Locations impacted include...
White Oak.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
To repeat, a tornado is on the ground. TAKE COVER NOW! Move to a
basement or an interior room on the lowest floor of a sturdy
building. Avoid windows. If you are outdoors, in a mobile home, or in
a vehicle, move to the closest substantial shelter and protect
yourself from flying debris.
&&
LAT...LON 3946 8969 3952 8969 3953 8966 3952 8953
3945 8953
TIME...MOT...LOC 2121Z 272DEG 37KT 3952 8951
TORNADO...OBSERVED
HAIL...<.75IN
$$
MRM682
WWUS53 KLSX 212126
SVSLSX
Severe Weather Statement
National Weather Service St Louis MO
426 PM CDT Tue Jul 21 2020
ILC135-212135-
/O.EXP.KLSX.TO.W.0010.000000T0000Z-200721T2130Z/
Montgomery IL-
426 PM CDT Tue Jul 21 2020
...THE TORNADO WARNING FOR NORTHWESTERN MONTGOMERY COUNTY WILL EXPIRE
AT 430 PM CDT...
The storm which prompted the warning has moved east out of the area.
Therefore, the warning will be allowed to expire.
LAT...LON 3946 8969 3952 8969 3953 8966 3952 8953
3945 8953
TIME...MOT...LOC 2125Z 272DEG 37KT 3952 8951
$$
MRMThe office that day
Everything else NWS St. Louis, MO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 21, 1:36 PM CDT | Severe Thunderstorm Warning | LSX | Pike | 39 min |
| Jul 21, 2:07 PM CDT | Severe Thunderstorm Warning | LSX | Calhoun | 23 min |
| Jul 21, 2:12 PM CDT | Severe Thunderstorm Warning | LSX | Calhoun, Pike | 48 min |
| Jul 21, 2:28 PM CDT | Severe Thunderstorm Warning | LSX | Calhoun, Jersey | 47 min |
| Jul 21, 2:51 PM CDT | Severe Thunderstorm Warning | LSX | Calhoun, Greene, Jersey | 54 min |
| Jul 21, 2:57 PM CDT | Severe Thunderstorm Warning | LSX | Jersey, Macoupin, Madison | 48 min |
| Jul 21, 3:38 PM CDT | Severe Thunderstorm Warning | LSX | Macoupin, Madison | 30 min |
Nearby
Tornado Warnings in Illinois, 2020Every tornado warning in 2020Tornadoes 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.