Alert archive / Indiana / Severe Thunderstorm Warnings in 2020
Severe Thunderstorm Warning 69, NWS Chicago, IL
NWS Chicago, IL issued this severe thunderstorm warning at Jul 11, 2020, 1:44 PM CDT for Iroquois County, Illinois; Benton County, Jasper County, Newton County, Indiana. It was in force for 61 min. No storm report in the archive falls inside the area while it was in force.
The area
The counties it named.
The facts
- Issued
- Jul 11, 2020, 1:44 PM CDT (18:44 UTC)
- Expired
- Jul 11, 2020, 2:45 PM CDT
- In force
- 61 min
- Issued by
- NWS Chicago, IL
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 60.0 mph
Counties Iroquois County, IL, Benton County, IN, Jasper County, IN, Newton County, IN
The radar
The Chicago radar (KLOT), 103 km from the middle of the area, began a volume at 18:47 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 nearest sounding before it
Lincoln, IL (KILX), launched 12:00Z, 6.7 hours before the alert went out and 126 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
- 12 J/kg
- Mixed-layer CIN
- -285 J/kg
- Mixed-layer LCL
- 1580 m above ground
- 0-6 km bulk shear
- 37 kt
- 0-1 km storm-relative helicity
- 36 m²/s²
- 0-3 km storm-relative helicity
- 105 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
What forecasters said that day
The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Chicago, IL wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 11, 12:58 PM CDT, 46 minutes earlier.
Area forecast discussion, Jul 11, 12:58 PM CDT, 46 minutes before
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</html>Hazardous weather outlook, Jul 11, 12:17 PM CDT, 1 hour 27 minutes before
Hazardous Weather Outlook
National Weather Service Chicago/Romeoville IL
1217 PM CDT Sat Jul 11 2020
ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-
010-011-019-121730-
Winnebago-Boone-McHenry-Lake IL-Ogle-Lee-De Kalb-Kane-DuPage-
La Salle-Kendall-Grundy-Kankakee-Livingston-Iroquois-Ford-
Northern Cook-Central Cook-Southern Cook-Northern Will-
Southern Will-Eastern Will-Lake IN-Porter-Newton-Jasper-Benton-
1217 PM CDT Sat Jul 11 2020 /117 PM EDT Sat Jul 11 2020/
This Hazardous Weather Outlook is for portions of North Central
Illinois...Northeast Illinois and Northwest Indiana.
.DAY ONE...This Afternoon and Tonight.
Weather hazards expected...
Elevated Thunderstorm Risk...with an associated:
Elevated hail risk...up to quarter size.
Elevated damaging wind risk...to 65 mph.
Limited Flooding Risk.
DISCUSSION...
Scattered thunderstorms are ongoing near the Interstate 80
corridor as of the noon hour. These storms will continue to shift
southeast during the early afternoon hours. The main threats from
these storms will be gusty winds up to 50 mph and frequent cloud
to ground lightning.
Another round of scattered thunderstorms is likely this evening
in association with the approach of a mid level disturbance.
Some of these storms may be severe, with damaging wind gusts
likely to be the main severe threat. However, large hail will
also be possible with the strongest storms. Storms may also
produce locally heavy rainfall, which could lead to minor
localized flooding. The most likely time for strong to severe
storms is roughly 7 pm to 11 pm.
.DAYS TWO THROUGH SEVEN...Sunday through Friday.
Sunday...
Limited Thunderstorm Risk.
High Swim Risk.
Tuesday...
Elevated Thunderstorm Risk.
Wednesday and Thursday...
Limited Thunderstorm Risk.
Friday...
Limited Thunderstorm Risk.
Limited Excessive Heat Risk.
.SPOTTER INFORMATION STATEMENT...
Spotters may be needed this evening.
GENERAL STORM MOTION OF THE DAY:
Moving toward the southeast at 35 mph.
LMZ740>745-121730-
Winthrop Harbor to Wilmette Harbor IL-
Wilmette Harbor to Northerly Island IL-
Northerly Island to Calumet Harbor IL-
Calumet Harbor IL to Gary IN-Gary to Burns Harbor IN-
Burns Harbor to Michigan City IN-
1217 PM CDT Sat Jul 11 2020
This Hazardous Weather Outlook is for portions of the Illinois
nearshore waters of Lake Michigan and the Indiana nearshore
waters of Lake Michigan.
.DAY ONE...This Afternoon and Tonight.
Weather hazards expected...
Elevated Thunderstorm Risk...with an associated:
Limited hail risk...up to quarter size.
Limited thunderstorm wind gust risk...up to 55 knots.
.DAYS TWO THROUGH SEVEN...Sunday through Friday.
Sunday...
Hazardous conditions for small craft are likely.
Limited Thunderstorm Risk.
Tuesday...
Elevated Thunderstorm Risk.
Wednesday through Friday...
Limited Thunderstorm Risk.
KJB
Visit us at http://weather.gov/chicago
Follow us on Facebook, Twitter, and Youtube at:
www.facebook.com/nwschicago
www.twitter.com/nwschicago
www.youtube.com/nwschicagoIn the hours before
Special weather statement, Jul 11, 12:39 PM CDT, 1 hour 5 minutes before
Special Weather Statement
National Weather Service Chicago/Romeoville
1239 PM CDT Sat Jul 11 2020
ILZ021-023-107-111800-
Grundy IL-Southern Will IL-Kankakee IL-
1239 PM CDT Sat Jul 11 2020
...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN WILL...SOUTHEASTERN
GRUNDY AND NORTHWESTERN KANKAKEE COUNTIES UNTIL 100 PM CDT...
At 1239 PM CDT, Doppler radar was tracking a strong thunderstorm near
Lakewood Shores, or near Braidwood, moving southeast at 40 mph.
Wind gusts up to 50 mph will be possible with this storm.
Locations impacted include...
Braidwood, Wilmington, Gardner, Lakewood Shores, Braceville, Essex,
South Wilmington, Godley, Bonfield, Reddick, East Brooklyn, Symerton
and Union Hill.
Including the following interstate...
I-55 between mile markers 228 and 233.
This includes... Kankakee River State Park.
LAT...LON 4104 8823 4108 8825 4111 8825 4111 8827
4121 8833 4136 8807 4122 8788
TIME...MOT...LOC 1739Z 312DEG 33KT 4120 8815
BirkThe office that day
Everything else NWS Chicago, IL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 11, 12:39 PM CDT | Special Weather Statement | LOT | Kankakee | 21 min |
| Jul 11, 12:54 PM CDT | Severe Thunderstorm Warning | LOT | Iroquois, Kankakee | 66 min |
| Jul 11, 2:55 PM CDT | Severe Thunderstorm Warning | LOT | Ford, Iroquois, Livingston | 50 min |
| Jul 11, 3:50 PM CDT | Small Craft Advisory | LOT | 39 hr | |
| Jul 11, 3:58 PM CDT | Beach Hazards Statement | LOT | Cook, Lake | 39 hr |
| Jul 11, 4:06 PM CDT | Special Weather Statement | LOT | Livingston | 39 min |
| Jul 11, 4:17 PM CDT | Special Weather Statement | LOT | Ford | 43 min |
| Jul 11, 4:19 PM CDT | Severe Thunderstorm Warning | LOT | Ford, Livingston | 26 min |
Nearby
Severe Thunderstorm Warnings in Indiana, 2020Severe Thunderstorm Warnings in Illinois, 2020Every severe thunderstorm warning 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.