Alert archive / Illinois / Tornado Warnings in 2026

Tornado Warning 10, NWS Chicago, IL

April 2, 2026Lake County, McHenry County, Illinois

NWS Chicago, IL issued this tornado warning at Apr 2, 2026, 7:40 PM CDT for Lake County, McHenry County, Illinois. It was in force for 35 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: Apr 2, 2026, 7:40 PM CDT (00:40 UTC)
Expired: Apr 2, 2026, 8:15 PM CDT
In force: 35 min
Issued by: NWS Chicago, IL
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.0 in

Counties Lake County, IL, McHenry County, IL

The radar

The Milwaukee radar (KMKX), 77 km from the middle of the area, began a volume at 00:39 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
Apr 2, 1:43 PM CDT	Tornado Watch	SPC	8 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 0.7 hours before the alert went out and 209 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 21 J/kg
Mixed-layer CIN: -76 J/kg
Mixed-layer LCL: 1092 m above ground
0-6 km bulk shear: 48 kt
0-1 km storm-relative helicity: -14 m²/s²
0-3 km storm-relative helicity: 40 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this tornado 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 tornado warning went out at Apr 2, 7:06 PM CDT, 34 minutes earlier.

Area forecast discussion, Apr 2, 7:06 PM CDT, 34 minutes before

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Hazardous weather outlook, Apr 2, 2:49 PM CDT, 4 hours 51 minutes before

Hazardous Weather Outlook
National Weather Service Chicago/Romeoville IL
249 PM CDT Thu Apr 2 2026

ILZ003>006-008-010>013-019>021-023-032-033-039-103>108-INZ001-002-
010-011-019-032000-
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-
249 PM CDT Thu Apr 2 2026 /349 PM EDT Thu Apr 2 2026/

This Hazardous Weather Outlook is for portions of north central
Illinois...northeast Illinois and northwest Indiana.

.DAY ONE...Tonight.

Weather hazards expected...

  Elevated Thunderstorm Risk...with an associated:
     Level 3 of 5 Tornado Risk.
     Level 3 of 5 Damaging Wind Risk...up to 70 mph.
     Level 2 of 5 Large Hail Risk...up to quarter size.
  Limited Flooding Risk.
  Elevated Non Thunderstorm Wind Risk.

DISCUSSION...

Scattered thunderstorms are expected this afternoon and continue
into this evening. Some of these thunderstorms may be severe.
Damaging winds in excess of 70 mph and possible tornadoes will be
the primary severe threats. The greatest threat of tornadoes will
be across northwest Illinois, along and west of the Fox Valley.

Locally heavy rainfall will accompany these thunderstorms, and
this may result in some instances of flooding, particularly in low
lying areas.

Gusty southerly winds up to 45 to 50 mph are expected outside of
thunderstorms through early this evening.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Friday...
  Limited Flooding Risk.
  Limited Thunderstorm Risk...with an associated:
     Level 1 of 5 Severe Thunderstorm Risk.
Saturday...
  Limited Flooding Risk.
  Limited Thunderstorm Risk.

DISCUSSION...

Additional waves of showers and thunderstorms are possible Friday
afternoon into Saturday morning. A few storms may be severe.

Localized river flooding will be possible as recent heavy rains
result in continued river rises.

.SPOTTER INFORMATION STATEMENT...

Spotters will likely be needed through this evening.

GENERAL STORM MOTION OF THE DAY:

Moving toward the northeast at 45 to 55 mph.

LMZ740>745-032000-
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-
249 PM CDT Thu Apr 2 2026

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...Tonight.

Weather hazards expected...

  Gale force winds and very hazardous waves.
  Elevated Thunderstorm Risk...with an associated:
     Thunderstorm Waterspout Risk
     Level 2 of 5 Thunderstorm Wind Gust Risk...up to 55 knots.
     Level 1 of 5 Hail Risk...up to quarter size.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Friday...
  Limited Thunderstorm Risk.
Saturday...
  Hazardous conditions for small craft are likely.
  Limited Thunderstorm Risk.
Sunday through Wednesday...
  Hazardous conditions for small craft are likely.

Visit us at www.weather.gov/chicago

In the hours before

Local storm report, Apr 2, 6:38 PM CDT, 1 hour 2 minutes before

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Local storm report, Apr 2, 7:08 PM CDT, 32 minutes before

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Local storm report, Apr 2, 7:23 PM CDT, 17 minutes before

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The office that day

Everything else NWS Chicago, IL issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 2, 7:00 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LOT	Boone, DeKalb, Kane, McHenry, Ogle	60 min
Apr 2, 7:01 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LOT	Boone, DeKalb, Kane, McHenry, Ogle	59 min
Apr 2, 7:06 PM CDT	Severe Thunderstorm Warning	LOT	DeKalb, LaSalle	24 min
Apr 2, 7:11 PM CDT	Severe Thunderstorm Warning	LOT	LaSalle, Livingston	34 min
Apr 2, 7:30 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LOT	DeKalb, DuPage, Grundy, Kane, Kendall, LaSalle and 1 more	45 min
Apr 2, 7:43 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LOT	Grundy, Kendall, LaSalle, Livingston	62 min
Apr 2, 7:52 PM CDT	Special Marine Warning	LOT		113 min
Apr 2, 8:01 PM CDT	Areal Flood Advisory	LOT	Boone, DeKalb, McHenry	3 hr
Apr 2, 8:02 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LOT	Cook, DuPage, Will	58 min
Apr 2, 8:23 PM CDT	Severe Thunderstorm Warning	LOT	Cook, Will	67 min
Apr 2, 8:59 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LOT	Cook, Will	31 min
Apr 2, 9:40 PM CDT	Special Marine Warning	LOT		65 min
Apr 2, 10:13 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LOT	Cook, DuPage, Grundy, Will	47 min
Apr 2, 10:20 PM CDT	Severe Thunderstorm Warning Considerable damage threat	LOT	Grundy	25 min
Apr 2, 10:24 PM CDT	Special Marine Warning	LOT		96 min
Apr 2, 10:32 PM CDT	Severe Thunderstorm Warning	LOT	Cook	43 min
Apr 2, 10:52 PM CDT	Severe Thunderstorm Warning	LOT	Cook, Grundy, Kankakee, Will	68 min
Apr 2, 11:58 PM CDT	Special Marine Warning	LOT		47 min
Apr 3, 12:58 AM CDT	River Flood Warning	LOT	LaSalle	45 hr
Apr 3, 11:58 AM CDT	River Flood Warning	LOT	Bureau, LaSalle, Putnam	7 days
Apr 3, 3:01 PM CDT	River Flood Warning	LOT	Winnebago	3 days
Apr 3, 3:56 PM CDT	Flood Watch	LOT	Boone, Cook, DeKalb, DuPage, Ford, Grundy and 12 more	18 hr
Apr 2, 11:12 PM CDT	Severe Thunderstorm Warning	LOT	Lake, Porter	79 min
Apr 3, 1:02 AM CDT	River Flood Watch	LOT	Lake, Newton	20 hr
Apr 3, 11:05 AM CDT	River Flood Watch	LOT	Jasper, Porter	19 hr
Apr 3, 4:39 PM CDT	Tornado Warning	LOT	Benton	21 min

Nearby

Tornado Warnings in Illinois, 2026 Every tornado warning in 2026 Tornadoes in 2026

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.