Alert archive / Illinois / Flash Flood Warnings in 2021

Flash Flood Warning 2, NWS Chicago, IL

June 26, 20214 counties in Illinois; Lake County, Porter County, Indiana

NWS Chicago, IL issued this flash flood warning at Jun 26, 2021, 3:50 PM CDT for 4 counties in Illinois; Lake County, Porter County, Indiana. It was in force for 6 hr. 2 reports 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
Jun 26, 2021, 3:50 PM CDT (20:50 UTC)
Expired
Jun 26, 2021, 9:45 PM CDT
In force
6 hr
Issued by
NWS Chicago, IL
Area
Storm-based polygon
Flood severity
None

Counties Cook County, IL, Grundy County, IL, Kankakee County, IL, Will County, IL, Lake County, IN, Porter County, IN

The radar

The Chicago radar (KLOT), 38 km from the middle of the area, began a volume at 20:49 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

TimeReportWhereRemark
Jun 26, 6:00 PM CDTFLASH FLOOD1 Wnw Glenwood, ILPHOTOS SHARED ON SOCIAL MEDIA SHOW GEORGE ARQUILLA PARK IN GLENWOOD FLOODED.
Jun 26, 6:00 PM CDTFLASH FLOOD2 N Manhattan, ILPARTS OF BAKER RD AND NELSON RD FLOODED NORTH OF MANHATTAN.

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, 8.8 hours before the alert went out and 175 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-pSkew-T log-p diagram, Lincoln, IL at 12:00Z on 2021-06-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 683 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 12:00Z on 2021-06-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 263 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
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

Open this sounding in Storm Lab

The text

As transmitted.

610 
WGUS53 KLOT 262050
FFWLOT
ILC031-063-091-197-INC089-127-270245-
/O.NEW.KLOT.FF.W.0002.210626T2050Z-210627T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Chicago IL
350 PM CDT Sat Jun 26 2021

The National Weather Service in Chicago has issued a

* Flash Flood Warning for...
  Southeastern Cook County in northeastern Illinois...
  East Central Grundy County in northeastern Illinois...
  Northeastern Kankakee County in northeastern Illinois...
  Will County in northeastern Illinois...
  Lake IN County in northwestern Indiana...
  West Central Porter County in northwestern Indiana...

* Until 945 PM CDT.

* At 350 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 3 inches of rain 
  have already fallen over the past few hours across parts of the 
  warned area, with additional thunderstorms producing torrential 
  rain moving into the warned area. Flash flooding is ongoing or 
  expected to begin shortly.

  HAZARD...Flash flooding.

  SOURCE...Doppler radar.

  IMPACT...Rapid-onset flooding of small creeks and streams,
           urban areas, highways, streets and underpasses, as
           well as other poor drainage and low lying areas.

* Some locations that will experience flash flooding include...
  Chicago, Joliet, Hammond, Gary, Orland Park, Tinley Park, Oak 
  Lawn, Calumet City, Portage, Merrillville, Chicago Heights, 
  Roseland, Englewood, South Shore, East Chicago, Schererville, 
  Hobart, Lansing, Oak Forest and Crown Point.

Additional rainfall amounts of 1 to 3 inches are possible in the 
warned area over the next 1 to 2 hours.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Warning means rapid-onset flooding is imminent or may 
already be occurring. Persons along creeks, drainage ditches, and 
other waterways should take immediate precautions to protect life 
and property.

Expect flash flooding of creeks, ditches, canals, and storm sewers, 
as well roadways, underpasses, farmland, and other poor drainage 
areas.

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.



&&

LAT...LON 4147 8825 4180 8758 4177 8748 4173 8747
      4172 8746 4172 8740 4170 8737 4167 8737
      4166 8735 4167 8721 4143 8722 4130 8753
      4130 8801 4120 8801 4120 8825

FLASH FLOOD...RADAR INDICATED

$$

RC
4 follow-up statements
947 
WGUS73 KLOT 262221
FFSLOT

Flash Flood Statement
National Weather Service Chicago IL
521 PM CDT Sat Jun 26 2021

ILC031-063-091-197-INC089-127-270245-
/O.CON.KLOT.FF.W.0002.000000T0000Z-210627T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cook IL-Grundy IL-Kankakee IL-Will IL-Lake IN IN-Porter IN-
521 PM CDT Sat Jun 26 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 945 PM CDT THIS 
EVENING FOR SOUTHEASTERN COOK, EAST CENTRAL GRUNDY, NORTHEASTERN 
KANKAKEE, WILL, LAKE IN AND WEST CENTRAL PORTER COUNTIES...

At 521 PM CDT, Trained weather spotters and the public reported 
flash flooding across the warned area, with radar indicating heavy 
rain across portions of the warned area. Between 1 and 3 inches of 
rain have already fallen. Flash flooding is ongoing or worsening.

HAZARD...Flash flooding.

SOURCE...Trained spotters and the public.

IMPACT...Rapid-onset flooding of small creeks and streams, urban
         areas, highways, streets and underpasses, as well as
         other poor drainage and low lying areas.

Some locations that will experience flash flooding include...
South Chicago, Joliet, Hammond, Gary, Orland Park, Tinley Park, Oak 
Lawn, Calumet City, Portage, Merrillville, Chicago Heights, 
Roseland, Englewood, South Shore, East Chicago, Schererville, 
Hobart, Lansing, Oak Forest and Crown Point.

Additional rainfall amounts up to 1 inch are possible in the warned 
area over the next hour.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Expect flash flooding of creeks, ditches, canals, and storm sewers, 
as well roadways, underpasses, and other poor drainage areas.

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

&&

LAT...LON 4147 8825 4180 8758 4177 8748 4173 8747
      4172 8746 4172 8740 4170 8737 4167 8737
      4166 8735 4167 8721 4143 8722 4130 8753
      4130 8801 4120 8801 4120 8825

FLASH FLOOD...OBSERVED

$$

RC
680 
WGUS73 KLOT 262357
FFSLOT

Flash Flood Statement
National Weather Service Chicago IL
657 PM CDT Sat Jun 26 2021

ILC031-063-091-197-INC089-127-270245-
/O.CON.KLOT.FF.W.0002.000000T0000Z-210627T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cook IL-Grundy IL-Kankakee IL-Will IL-Lake IN IN-Porter IN-
657 PM CDT Sat Jun 26 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 945 PM CDT THIS 
EVENING FOR SOUTHEASTERN COOK, EAST CENTRAL GRUNDY, NORTHEASTERN 
KANKAKEE, WILL, LAKE IN AND WEST CENTRAL PORTER COUNTIES...

At 657 PM CDT, Emergency management, trained spotters, and the 
public reported flash flooding ongoing in the warned area. Between 
1.5 and 3 inches of rain fell in a short period during the afternoon 
across much of the warned area. The heavy rain has ended, but flash 
flooding is likely to continue due to runoff and streams being out 
of their banks.

HAZARD...Flash flooding.

SOURCE...Emergency management.

IMPACT...Rapid-onset flooding of small creeks and streams, urban
         areas, highways, streets and underpasses, as well as
         other poor drainage and low lying areas.

Some locations that will experience flash flooding include...
  Chicago, Joliet, Hammond, Gary, Orland Park, Tinley Park, Oak 
  Lawn, Calumet City, Portage, Merrillville, Chicago Heights, 
  Roseland, Englewood, South Shore, East Chicago, Schererville, 
  Hobart, Lansing, Oak Forest and Crown Point.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Expect flooding of creeks, ditches, canals, and storm sewers, as 
well roadways, underpasses, and other poor drainage areas.

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles. Do not attempt to walk across any flooded 
roads.

&&

LAT...LON 4147 8825 4180 8758 4177 8748 4173 8747
      4172 8746 4172 8740 4170 8737 4167 8737
      4166 8735 4167 8721 4143 8722 4130 8753
      4130 8801 4120 8801 4120 8825

FLASH FLOOD...OBSERVED

$$

RC
212 
WGUS73 KLOT 270135
FFSLOT

Flash Flood Statement
National Weather Service Chicago IL
835 PM CDT Sat Jun 26 2021

ILC031-063-091-197-INC089-127-270245-
/O.CON.KLOT.FF.W.0002.000000T0000Z-210627T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cook IL-Grundy IL-Kankakee IL-Will IL-Lake IN IN-Porter IN-
835 PM CDT Sat Jun 26 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 945 PM CDT THIS 
EVENING FOR SOUTHEASTERN COOK, EAST CENTRAL GRUNDY, NORTHEASTERN 
KANKAKEE, WILL, LAKE IN AND WEST CENTRAL PORTER COUNTIES...

At 835 PM CDT, Emergency management, trained spotters, and the 
public reported flash flooding ongoing in the warned area. Between 
1.5 and 3 inches of rain fell in a short period during the afternoon 
across much of the warned area. The heavy rain has ended, but flash 
flooding is likely to continue due to runoff and streams being out 
of their banks.

HAZARD...Flash flooding.

SOURCE...Trained spotters and the public.

IMPACT...Rapid-onset flooding of small creeks and streams, urban
         areas, highways, streets and underpasses, as well as
         other poor drainage and low lying areas.

Some locations that will experience flash flooding include...
South side of Chicago, Joliet, Hammond, Gary, Orland Park, Tinley 
Park, Oak Lawn, Calumet City, Portage, Merrillville, Chicago 
Heights, Roseland, Englewood, South Shore, East Chicago, 
Schererville, Hobart, Lansing, Oak Forest and Crown Point.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Expect flooding of creeks, ditches, canals, and storm sewers, as 
well roadways, underpasses, and other poor drainage areas.

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles. Do not attempt to walk across any flooded 
roads.

&&

LAT...LON 4147 8825 4180 8758 4177 8748 4173 8747
      4172 8746 4172 8740 4170 8737 4167 8737
      4166 8735 4167 8721 4143 8722 4130 8753
      4130 8801 4120 8801 4120 8825

FLASH FLOOD...OBSERVED

$$

Kluber
433 
WGUS73 KLOT 270240
FFSLOT

Flash Flood Statement
National Weather Service Chicago IL
940 PM CDT Sat Jun 26 2021

ILC031-063-091-197-INC089-127-270250-
/O.EXP.KLOT.FF.W.0002.000000T0000Z-210627T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cook IL-Grundy IL-Kankakee IL-Will IL-Lake IN IN-Porter IN-
940 PM CDT Sat Jun 26 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 945 PM CDT THIS EVENING FOR 
SOUTHEASTERN COOK, EAST CENTRAL GRUNDY, NORTHEASTERN KANKAKEE, WILL, 
LAKE IN AND WEST CENTRAL PORTER COUNTIES...

The heavy rain has ended, with little to no additional rain expected 
tonight. Where ongoing flooding impacts continue, a Flood Advisory 
replaces the Flash Flood Warning. Please continue to heed remaining 
road closures.

LAT...LON 4147 8825 4180 8758 4177 8748 4173 8747
      4172 8746 4172 8740 4170 8737 4167 8737
      4166 8735 4167 8721 4143 8722 4130 8753
      4130 8801 4120 8801 4120 8825

$$

Kluber

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 25, 8:01 PM CDTTornado WarningLOTIroquois31 min
Jun 25, 8:11 PM CDTTornado WarningLOTIroquois22 min
Jun 25, 8:37 PM CDTAreal Flood AdvisoryLOTFord, Iroquois, Kankakee, Livingston5 hr
Jun 25, 9:11 PM CDTSpecial Weather StatementLOTFord64 min
Jun 25, 10:39 PM CDTSpecial Weather StatementLOTFord66 min
Jun 26, 11:27 AM CDTTornado WarningLOTLivingston18 min
Jun 26, 11:34 AM CDTTornado WarningLOTWill26 min
Jun 26, 11:44 AM CDTTornado WarningLOTGrundy, LaSalle, Livingston36 min
Jun 26, 11:49 AM CDTTornado WarningLOTCook26 min
Jun 26, 11:55 AM CDTSpecial Marine WarningLOT2 hr
Jun 26, 12:18 PM CDTFlash Flood WarningLOTCook, DuPage, Will6 hr
Jun 26, 12:33 PM CDTSpecial Marine WarningLOT117 min
Jun 26, 12:34 PM CDTSevere Thunderstorm WarningLOTCook, Will41 min
Jun 26, 12:59 PM CDTSevere Thunderstorm WarningLOTCook11 min
Jun 26, 1:26 PM CDTSevere Thunderstorm WarningLOTCook, Will34 min
Jun 26, 2:08 PM CDTTornado Warning Tornado observedLOTCook, Will25 min
Jun 26, 2:24 PM CDTSpecial Marine WarningLOT2 hr
Jun 26, 2:43 PM CDTAreal Flood AdvisoryLOTCook, Ford, Grundy, Iroquois, Kankakee, LaSalle and 2 more6 hr
Jun 26, 3:31 PM CDTSpecial Marine WarningLOT119 min
Jun 26, 3:34 PM CDTTornado WarningLOTLivingston41 min
Jun 26, 3:56 PM CDTTornado WarningLOTKankakee, Will34 min
Jun 26, 3:57 PM CDTFlash Flood WarningLOTFord, Grundy, Iroquois, Kankakee, Livingston6 hr
Jun 26, 3:57 PM CDTTornado WarningLOTGrundy, Kankakee, Livingston33 min
Jun 26, 4:13 PM CDTSevere Thunderstorm WarningLOTFord, Iroquois, Livingston47 min
Jun 26, 4:23 PM CDTTornado WarningLOTFord, Livingston36 min
Jun 26, 4:26 PM CDTRiver Flood WarningLOTCook28 hr
Jun 26, 4:26 PM CDTTornado WarningLOTCook, Will34 min
Jun 26, 4:30 PM CDTSpecial Marine WarningLOT2 hr
Jun 26, 4:41 PM CDTTornado WarningLOTKankakee34 min
Jun 26, 4:49 PM CDTSevere Thunderstorm WarningLOTFord, Iroquois, Kankakee, Will56 min
Jun 26, 5:21 PM CDTSevere Thunderstorm WarningLOTWill54 min
Jun 26, 5:44 PM CDTSevere Thunderstorm WarningLOTIroquois76 min
Jun 26, 5:54 PM CDTAreal Flood AdvisoryLOTFord, Iroquois, Livingston3 hr
Jun 26, 6:23 PM CDTAreal Flood AdvisoryLOTCook, DuPage, Will7 hr
Jun 26, 6:55 PM CDTRiver Flood WarningLOTLivingston3 days
Jun 26, 1:56 PM CDTSpecial Weather StatementLOTPorter34 min
Jun 26, 2:27 PM CDTSevere Thunderstorm WarningLOTJasper, Lake, Newton, Porter48 min
Jun 26, 5:19 PM CDTTornado WarningLOTLake, Porter13 min
Jun 26, 6:14 PM CDTSevere Thunderstorm WarningLOTBenton, Jasper, Newton76 min

Nearby

Flash Flood Warnings in Illinois, 2021Flash Flood Warnings in Indiana, 2021Every flash flood 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.