Alert archive / Indiana / Flash Flood Warnings in 2012

Flash Flood Warning 2, NWS Chicago, IL

May 3, 2012Lake County, Indiana; Cook County, Illinois

NWS Chicago, IL issued this flash flood warning at May 3, 2012, 10:10 PM CDT for Lake County, Indiana; Cook County, Illinois. It was in force for 5 hr. 4 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: May 3, 2012, 10:10 PM CDT (03:10 UTC)
Expired: May 4, 2012, 3:24 AM CDT
In force: 5 hr
Issued by: NWS Chicago, IL
Area: Storm-based polygon
Flood severity: None

Counties Cook County, IL, Lake County, IN

The radar

The Chicago radar (KLOT), 30 km from the middle of the area, began a volume at 03:10 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
May 3, 10:15 PM CDT	HEAVY RAIN 2.7	1 Ssw Oak Lawn, IL	IN 60 MINUTES
May 3, 10:15 PM CDT	HEAVY RAIN 2.7	Oak Lawn, IL	IN 60 MINUTES
May 3, 11:30 PM CDT	FLASH FLOOD	4 Nne Alsip, IL	KEDZIE FLOODED BETWEEN 87TH AND 103RD ST
May 3, 11:42 PM CDT	FLASH FLOOD	3 N Alsip, IL	CICERO AVE FLOODED NEAR 103RD

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 00:00Z, 3.2 hours before the alert went out and 182 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: 1905 J/kg
Mixed-layer CIN: -30 J/kg
Mixed-layer LCL: 1071 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 12 m²/s²
0-3 km storm-relative helicity: 96 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

554 
WGUS53 KLOT 040310
FFWLOT
ILC031-INC089-040900-
/O.NEW.KLOT.FF.W.0002.120504T0310Z-120504T0900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1010 PM CDT THU MAY 3 2012

THE NATIONAL WEATHER SERVICE IN CHICAGO HAS ISSUED A

* FLASH FLOOD WARNING FOR URBAN AREAS AND SMALL STREAMS IN...
  NORTHWESTERN LAKE COUNTY IN NORTHWEST INDIANA...
  SOUTHERN COOK COUNTY IN NORTHEAST ILLINOIS...

* UNTIL 400 AM CDT

* AT 1007 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE
  WARNED AREA. NEAR OAK LAWN...RADAR ESTIMATED RAINFALL TOTALS       
  EXCEED 1.5 INCHES FROM JUST THE PAST HOUR.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. OAK LAWN WAS AT THE CENTER OF THE HEAVIEST RAINFALL.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES
AS WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.

&&

LAT...LON 4147 8775 4150 8779 4156 8779 4156 8787
      4159 8791 4164 8791 4164 8798 4168 8803
      4169 8796 4173 8791 4184 8760 4177 8756
      4175 8753 4170 8751 4168 8745 4169 8743
      4167 8741

$$

LENNING

5 follow-up statements

015 
WGUS73 KLOT 040405
FFSLOT

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1105 PM CDT THU MAY 3 2012

ILC031-INC089-040900-
/O.CON.KLOT.FF.W.0002.000000T0000Z-120504T0900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
COOK IL-LAKE IN-
1105 PM CDT THU MAY 3 2012

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR NORTHWESTERN LAKE AND
SOUTHERN COOK COUNTIES UNTIL 400 AM CDT...

AT 1059 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA...WITH 
ESTIMATES BETWEEN 2 AND 3 INCHES OF RAIN OVER PORTIONS OF THE 
AREA...ESPECIALLY BETWEEN BLUE ISLAND AND PALOS PARK.

RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...BLUE 
ISLAND...MIDLOTHIAN...OAK LAWN...PALOS PARK...AND SURROUNDING AREAS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLOODING IS OBSERVED...ACT QUICKLY. DO NOT
ENTER THE WATER. TURN AROUND AND MOVE UP TO HIGHER GROUND. DO NOT
STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

&&

LAT...LON 4147 8775 4150 8779 4156 8779 4156 8787
      4159 8791 4164 8791 4164 8798 4168 8803
      4169 8796 4173 8791 4184 8760 4177 8756
      4175 8753 4170 8751 4168 8745 4169 8743
      4167 8741

$$

LENNING

039 
WGUS73 KLOT 040511
FFSLOT

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1211 AM CDT FRI MAY 4 2012

ILC031-INC089-040900-
/O.CON.KLOT.FF.W.0002.000000T0000Z-120504T0900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
COOK IL-LAKE IN-
1211 AM CDT FRI MAY 4 2012

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR NORTHWESTERN LAKE AND
SOUTHERN COOK COUNTIES UNTIL 400 AM CDT...

AT 1205 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
ONGOING THUNDERSTORMS ACROSS THE WARNED AREA WHERE HEAVY RAIN AND 
FLOODING HAVE BEEN OCCURRING.

RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
PERSIST.  LOCAL LAW ENFORCEMENT REPORTS HIGH STANDING WATER AND 
FLOODING IN SOME LOCATIONS AROUND OAK LAWN AND HOMETOWN.  OTHER 
LOCATIONS LIKELY TO EXPERIENCE FLOODING ISSUES OVERNIGHT INCLUDE 
BLUE ISLAND...ALSIP...PALOS HEIGHTS...AND CRESTWOOD.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY.

&&

LAT...LON 4147 8775 4150 8779 4156 8779 4156 8787
      4159 8791 4164 8791 4164 8798 4168 8803
      4169 8796 4173 8791 4184 8760 4177 8756
      4175 8753 4170 8751 4168 8745 4169 8743
      4167 8741

$$

LENNING

344 
WGUS73 KLOT 040618
FFSLOT

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
118 AM CDT FRI MAY 4 2012

ILC031-INC089-040900-
/O.CON.KLOT.FF.W.0002.000000T0000Z-120504T0900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
COOK IL-LAKE IN-
118 AM CDT FRI MAY 4 2012

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR NORTHWESTERN LAKE AND
SOUTHERN COOK COUNTIES UNTIL 400 AM CDT...

AT 114 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
ONGOING THUNDERSTORMS ACROSS THE WARNED AREA.

LOCAL LAW ENFORCEMENT IS NOT REPORTING ANY FLOODING ISSUES OR CLOSED 
ROADS AT THIS TIME...BUT RUNOFF FROM EARLIER EXCESSIVE RAINFALL MAY 
STILL BE CAUSING LOCALIZED FLOODING..ESPECIALLY AROUND 
ALSIP...MERRIONETTE PARK...BLUE ISLAND...AND CALUMET PARK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLOODING IS OBSERVED...ACT QUICKLY. DO NOT
ENTER THE WATER. TURN AROUND AND MOVE UP TO HIGHER GROUND. DO NOT
STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

&&

LAT...LON 4147 8775 4150 8779 4156 8779 4156 8787
      4159 8791 4164 8791 4164 8798 4168 8803
      4169 8796 4173 8791 4184 8760 4177 8756
      4175 8753 4170 8751 4168 8745 4169 8743
      4167 8741

$$

LENNING

807 
WGUS73 KLOT 040733
FFSLOT

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
233 AM CDT FRI MAY 4 2012

ILC031-INC089-040900-
/O.CON.KLOT.FF.W.0002.000000T0000Z-120504T0900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
COOK IL-LAKE IN-
233 AM CDT FRI MAY 4 2012

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR NORTHWESTERN LAKE AND
SOUTHERN COOK COUNTIES UNTIL 400 AM CDT...

AT 231 AM CDT...LIGHT RAIN WAS OCCURRING OVER THE WARNED AREA...BUT 
ADDITIONAL THUNDERSTORMS WITH HEAVY RAINFALL WERE APPROACHING.

THE AREA MOST LIKELY TO EXPERIENCE FLOODING PROBLEMS IN THE NEXT 
COUPLE OF HOURS IS SOUTHERN COOK COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOST FLOOD RELATED DEATHS OCCUR IN VEHICLES. DO NOT ATTEMPT TO CROSS
BRIDGES...DIPS...OR OTHER LOW SPOTS IF WATER COVERS THE ROADWAY.
NEVER TRY TO CROSS A FLOWING STREAM...EVEN A SMALL ONE...ON FOOT OR
IN A VEHICLE.

&&

LAT...LON 4147 8775 4150 8779 4156 8779 4156 8787
      4159 8791 4164 8791 4164 8798 4168 8803
      4169 8796 4173 8791 4184 8760 4177 8756
      4175 8753 4170 8751 4168 8745 4169 8743
      4167 8741

$$

LENNING

318 
WGUS73 KLOT 040824
FFSLOT

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
324 AM CDT FRI MAY 4 2012

ILC031-INC089-040836-
/O.CAN.KLOT.FF.W.0002.000000T0000Z-120504T0900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
COOK IL-LAKE IN-
324 AM CDT FRI MAY 4 2012

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR NORTHWESTERN LAKE
AND SOUTHERN COOK COUNTIES IS CANCELLED...

LOCAL LAW ENFORCEMENT REPORTS NO PROBLEMS WITH FLOODING AT THIS 
TIME...WHICH INDICATES EXCESS RUNOFF FROM HEAVY RAIN HAS ENDED OVER 
THE WARNED AREA. LIGHT TO MODERATE RAIN WILL CONTINUE OVERNIGHT INTO 
THE EARLY MORNING...POTENTIALLY SUPPORTING LOCALIZED PONDING.


LAT...LON 4147 8775 4150 8779 4156 8779 4156 8787
      4159 8791 4164 8791 4164 8798 4168 8803
      4169 8796 4173 8791 4184 8760 4177 8756
      4175 8753 4170 8751 4168 8745 4169 8743
      4167 8741

$$

LENNING

The office that day

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

Issued	Product	Office	Counties	Lasted
May 3, 8:43 PM CDT	Flash Flood Watch	LOT	Lake, Porter	7 hr
May 3, 9:50 PM CDT	Severe Thunderstorm Warning	LOT	Lake	55 min
May 3, 7:08 PM CDT	Severe Thunderstorm Warning	LOT	Cook	67 min
May 3, 7:23 PM CDT	Flash Flood Warning	LOT	Cook, DuPage	4 hr
May 3, 8:00 PM CDT	Severe Thunderstorm Warning	LOT	Cook, DuPage	75 min
May 3, 8:07 PM CDT	Severe Thunderstorm Warning	LOT	LaSalle, Livingston	68 min
May 3, 8:12 PM CDT	Special Marine Warning	LOT		2 hr
May 3, 9:19 PM CDT	Special Marine Warning	LOT		116 min
May 3, 9:29 PM CDT	Special Weather Statement	LOT	Will	31 min
May 3, 10:47 PM CDT	Special Weather Statement	LOT	Cook	28 min
May 4, 12:34 AM CDT	Severe Thunderstorm Warning	LOT	Grundy, LaSalle, Livingston	71 min
May 4, 12:46 AM CDT	Flash Flood Warning	LOT	LaSalle, Livingston	6 hr
May 4, 1:26 AM CDT	Severe Thunderstorm Warning	LOT	Ford, Grundy, Iroquois, Kankakee, Livingston	63 min
May 4, 3:07 AM CDT	Marine Dense Fog Advisory	LOT		18 hr

Nearby

Flash Flood Warnings in Indiana, 2012 Flash Flood Warnings in Illinois, 2012 Every flash flood warning in 2012

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.