Alert archive / Illinois / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 21, NWS Chicago, IL
NWS Chicago, IL issued this severe thunderstorm warning at Jun 26, 2021, 12:34 PM CDT for Cook County, Will County, Illinois; Lake County, Indiana. It was in force for 41 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Jun 26, 2021, 12:34 PM CDT (17:34 UTC)
- Expired
- Jun 26, 2021, 1:15 PM CDT
- In force
- 41 min
- Issued by
- NWS Chicago, IL
- Area
- Storm-based polygon
- Tornado
- Possible
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Cook County, IL, Will County, IL, Lake County, IN
The radar
The Chicago radar (KLOT), 45 km from the middle of the area, began a volume at 17:33 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.
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jun 26, 12:05 PM CDT | Tornado Watch | SPC | 9 hr |
The nearest sounding before it
Lincoln, IL (KILX), launched 12:00Z, 5.6 hours before the alert went out and 188 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
- 683 J/kg
- Mixed-layer CIN
- -28 J/kg
- Mixed-layer LCL
- 684 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- 263 m²/s²
- 0-3 km storm-relative helicity
- 229 m²/s²
- Significant tornado parameter
- 0.5
- Supercell composite
- 3.1
The text
As transmitted.
066
WUUS53 KLOT 261734
SVRLOT
ILC031-197-INC089-261815-
/O.NEW.KLOT.SV.W.0021.210626T1734Z-210626T1815Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Chicago/Romeoville
1234 PM CDT Sat Jun 26 2021
The National Weather Service in Chicago has issued a
* Severe Thunderstorm Warning for...
Central Will County in northeastern Illinois...
Southeastern Cook County in northeastern Illinois...
Northwestern Lake County in northwestern Indiana...
* Until 115 PM CDT.
* At 1234 PM CDT, severe thunderstorms were located along a line
extending from near New Lenox to near Mokena, moving northeast at
45 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
* Locations impacted include...
Chicago, Hammond, Gary, Orland Park, Tinley Park, Calumet City,
Chicago Heights, Roseland, South Shore, East Chicago, Lansing, Oak
Forest, Harvey, Lockport, New Lenox, Homer Glen, Highland, Blue
Island, Munster and Dolton.
This includes... Purdue University Northwest Hammond, Windy City
Thunderbolts Baseball, Hollywood Casino Amphitheatre, Prairie State
College, South Shore Rail Cats Baseball, and South Suburban College.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A Tornado Watch remains in effect until 700 PM CDT for northeastern
Illinois...and northwestern Indiana.
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4141 8797 4158 8799 4176 8754 4174 8753
4174 8754 4173 8752 4171 8753 4167 8747
4168 8746 4167 8744 4168 8743 4167 8742
4165 8744 4164 8743 4163 8736 4162 8727
TIME...MOT...LOC 1734Z 243DEG 41KT 4155 8795 4148 8792
TORNADO...POSSIBLE
HAIL...<.75IN
WIND...60MPH
$$
Birk2 follow-up statements
307
WWUS53 KLOT 261749
SVSLOT
Severe Weather Statement
National Weather Service Chicago/Romeoville
1249 PM CDT Sat Jun 26 2021
ILC031-197-INC089-261815-
/O.CON.KLOT.SV.W.0021.000000T0000Z-210626T1815Z/
Will IL-Cook IL-Lake IN-
1249 PM CDT Sat Jun 26 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 115 PM CDT
FOR CENTRAL WILL...SOUTHEASTERN COOK AND NORTHWESTERN LAKE
COUNTIES...
At 1249 PM CDT, severe thunderstorms were located along a line
extending from Blue Island to Markham to Matteson, moving northeast
at 50 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
Locations impacted include...
Chicago, Hammond, Gary, Orland Park, Tinley Park, Calumet City,
Chicago Heights, Roseland, South Shore, East Chicago, Lansing, Oak
Forest, Harvey, Lockport, New Lenox, Homer Glen, Highland, Blue
Island, Munster and Dolton.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A Tornado Watch remains in effect until 700 PM CDT for northeastern
Illinois...and northwestern Indiana.
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4141 8797 4158 8799 4176 8754 4174 8753
4174 8754 4173 8752 4171 8753 4167 8747
4168 8746 4167 8744 4168 8743 4167 8742
4165 8744 4164 8743 4163 8736 4162 8727
TIME...MOT...LOC 1749Z 237DEG 41KT 4166 8770 4160 8770 4153 8773
TORNADO...POSSIBLE
HAIL...<.75IN
WIND...60MPH
OEMC zones...SEVERE THUNDERSTORM WARNING.
10...11...and 12.
$$
Birk632
WWUS53 KLOT 261812
SVSLOT
Severe Weather Statement
National Weather Service Chicago/Romeoville
112 PM CDT Sat Jun 26 2021
ILC031-197-INC089-261821-
/O.EXP.KLOT.SV.W.0021.000000T0000Z-210626T1815Z/
Will IL-Cook IL-Lake IN-
112 PM CDT Sat Jun 26 2021
...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL WILL...SOUTHEASTERN
COOK AND NORTHWESTERN LAKE COUNTIES WILL EXPIRE AT 115 PM CDT...
The storms which prompted the warning have weakened below severe
limits, and no longer pose an significant threat to life or property.
Therefore, the warning will be allowed to expire. However strong,
gusty winds and heavy rain are still possible with these
thunderstorms.
A Tornado Watch remains in effect until 700 PM CDT for northeastern
Illinois...and northwestern Indiana.
To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Chicago.
LAT...LON 4141 8797 4158 8799 4176 8754 4174 8753
4174 8754 4173 8752 4171 8753 4167 8747
4168 8746 4167 8744 4168 8743 4167 8742
4165 8744 4164 8743 4163 8736 4162 8727
TIME...MOT...LOC 1811Z 243DEG 41KT 4177 8740 4171 8740 4164 8743
$$
RCThe office that day
Everything else NWS Chicago, IL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 25, 8:01 PM CDT | Tornado Warning | LOT | Iroquois | 31 min |
| Jun 25, 8:11 PM CDT | Tornado Warning | LOT | Iroquois | 22 min |
| Jun 25, 8:37 PM CDT | Areal Flood Advisory | LOT | Ford, Iroquois, Kankakee, Livingston | 5 hr |
| Jun 25, 9:11 PM CDT | Special Weather Statement | LOT | Ford | 64 min |
| Jun 25, 10:39 PM CDT | Special Weather Statement | LOT | Ford | 66 min |
| Jun 26, 11:27 AM CDT | Tornado Warning | LOT | Livingston | 18 min |
| Jun 26, 11:34 AM CDT | Tornado Warning | LOT | Will | 26 min |
| Jun 26, 11:44 AM CDT | Tornado Warning | LOT | Grundy, LaSalle, Livingston | 36 min |
| Jun 26, 11:49 AM CDT | Tornado Warning | LOT | Cook | 26 min |
| Jun 26, 11:55 AM CDT | Special Marine Warning | LOT | 2 hr | |
| Jun 26, 12:18 PM CDT | Flash Flood Warning | LOT | Cook, DuPage, Will | 6 hr |
| Jun 26, 12:33 PM CDT | Special Marine Warning | LOT | 117 min | |
| Jun 26, 12:59 PM CDT | Severe Thunderstorm Warning | LOT | Cook | 11 min |
| Jun 26, 1:26 PM CDT | Severe Thunderstorm Warning | LOT | Cook, Will | 34 min |
| Jun 26, 2:08 PM CDT | Tornado Warning | LOT | Cook, Will | 25 min |
| Jun 26, 2:24 PM CDT | Special Marine Warning | LOT | 2 hr | |
| Jun 26, 2:43 PM CDT | Areal Flood Advisory | LOT | Cook, Ford, Grundy, Iroquois, Kankakee, LaSalle and 2 more | 6 hr |
| Jun 26, 3:31 PM CDT | Special Marine Warning | LOT | 119 min | |
| Jun 26, 3:34 PM CDT | Tornado Warning | LOT | Livingston | 41 min |
| Jun 26, 3:50 PM CDT | Flash Flood Warning | LOT | Cook, Grundy, Kankakee, Will | 6 hr |
| Jun 26, 3:56 PM CDT | Tornado Warning | LOT | Kankakee, Will | 34 min |
| Jun 26, 3:57 PM CDT | Flash Flood Warning | LOT | Ford, Grundy, Iroquois, Kankakee, Livingston | 6 hr |
| Jun 26, 3:57 PM CDT | Tornado Warning | LOT | Grundy, Kankakee, Livingston | 33 min |
| Jun 26, 4:13 PM CDT | Severe Thunderstorm Warning | LOT | Ford, Iroquois, Livingston | 47 min |
| Jun 26, 4:23 PM CDT | Tornado Warning | LOT | Ford, Livingston | 36 min |
| Jun 26, 4:26 PM CDT | River Flood Warning | LOT | Cook | 28 hr |
| Jun 26, 4:26 PM CDT | Tornado Warning | LOT | Cook, Will | 34 min |
| Jun 26, 4:30 PM CDT | Special Marine Warning | LOT | 2 hr | |
| Jun 26, 4:41 PM CDT | Tornado Warning | LOT | Kankakee | 34 min |
| Jun 26, 4:49 PM CDT | Severe Thunderstorm Warning | LOT | Ford, Iroquois, Kankakee, Will | 56 min |
| Jun 26, 5:21 PM CDT | Severe Thunderstorm Warning | LOT | Will | 54 min |
| Jun 26, 5:44 PM CDT | Severe Thunderstorm Warning | LOT | Iroquois | 76 min |
| Jun 26, 5:54 PM CDT | Areal Flood Advisory | LOT | Ford, Iroquois, Livingston | 3 hr |
| Jun 26, 6:23 PM CDT | Areal Flood Advisory | LOT | Cook, DuPage, Will | 7 hr |
| Jun 26, 6:55 PM CDT | River Flood Warning | LOT | Livingston | 3 days |
| Jun 26, 1:56 PM CDT | Special Weather Statement | LOT | Porter | 34 min |
| Jun 26, 2:27 PM CDT | Severe Thunderstorm Warning | LOT | Jasper, Lake, Newton, Porter | 48 min |
| Jun 26, 5:19 PM CDT | Tornado Warning | LOT | Lake, Porter | 13 min |
| Jun 26, 6:14 PM CDT | Severe Thunderstorm Warning | LOT | Benton, Jasper, Newton | 76 min |
Nearby
Severe Thunderstorm Warnings in Illinois, 2021Severe Thunderstorm Warnings in Indiana, 2021Every severe thunderstorm warning 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.