Alert archive / Illinois / Flash Flood Warnings in 1997

Flash Flood Warning 13, NWS Chicago, IL

February 21, 1997Cook County, Lake County, McHenry County, Illinois; Lake County, Indiana

NWS Chicago, IL issued this flash flood warning at Feb 21, 1997, 11:35 AM CST for Cook County, Lake County, McHenry County, Illinois; Lake County, Indiana. It was in force for 6 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Feb 21, 1997, 11:35 AM CST (17:35 UTC)
Expired
Feb 21, 1997, 6:00 PM CST
In force
6 hr
Issued by
NWS Chicago, IL
Area
Whole counties

Counties Cook County, IL, Lake County, IL, McHenry County, IL, Lake County, IN

The radar

The Chicago radar (KLOT), 50 km from the middle of the area, began a volume at 17:36 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, 5.6 hours before the alert went out and 217 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 1997-02-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 21 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 1997-02-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 54 square meters per square second.1939587897Sfc1 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
21 J/kg
Mixed-layer CIN
-32 J/kg
Mixed-layer LCL
806 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
54 m²/s²
0-3 km storm-relative helicity
179 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Special weather statement, Feb 21, 5:50 AM CST, 5 hours 45 minutes before
ILZ003>006-008-010>014-019>023-032>033-039-INZ001-211700-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHICAGO IL
600 AM CST FRI FEB 21 1997

FOR NORTH CENTRAL AND NORTHEAST ILLINOIS AND LAKE COUNTY INDIANA

A LOW PRESSURE SYSTEM IN THE SOUTHERN PLAINS WILL MOVE NORTHEAST TO
ILLINOIS TODAY. AN EXTENEDED PERIOD OF RAIN WILL ACCOMPANY THE SYSTEM AS
IT APPROACHES NORTHERN ILLINOIS. THE RAIN MAY BE HEAVY AT TIMES AND WILL
POSE A THREAT OF FLOODING. A FLOOD WATCH REMAINS IN EFFECT TODAY FOR
NORTH CENTRAL AND NORTHEAST ILLINOIS AND NORTHEAST INDIANA. IF YOU LIVE
ALONG SMALL STREAMS AND LOW LYING AREAS PRONE TO FLOODING BE ALERT FOR
FLOODING CONDITIONS TODAY.

AS THE LOW PRESSURE CENTER PASSES THROUGH ILLINOIS COLDER AIR WILL HELP
CHANGE THE RAIN TO SNOW. THE CHANGEOVER WILL BEGIN BY LATE AFTERNOON OR
EVENING. AT FIRST THE RAIN WILL BE MIXED WITH WET SNOW BUT AS
TEMPERATURES CONTINUE TO FALL THE RAIN WILL CHANGE TO ALL SNOW. SNOWFALLz
AMOUNTS OF 3 TO 5 INCHES ARE EXPECTED BEFORE THE SNOW ENDS LATE TONIGHT
AND EARLY SATURDAY.

SOMREK
Special weather statement, Feb 21, 5:58 AM CST, 5 hours 37 minutes before
ILZ003>006-008-010>014-019>023-032>033-039-INZ001-211700-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHICAGO IL
600 AM CST FRI FEB 21 1997

FOR NORTH CENTRAL AND NORTHEAST ILLINOIS AND LAKE COUNTY INDIANA

A LOW PRESSURE SYSTEM IN THE SOUTHERN PLAINS WILL MOVE NORTHEAST TO
ILLINOIS TODAY. AN EXTENEDED PERIOD OF RAIN WILL ACCOMPANY THE SYSTEM AS
IT APPROACHES NORTHERN ILLINOIS. THE RAIN MAY BE HEAVY AT TIMES AND WILL
POSE A THREAT OF FLOODING. A FLOOD WATCH REMAINS IN EFFECT TODAY FOR
NORTH CENTRAL AND NORTHEAST ILLINOIS AND NORTHEAST INDIANA. IF YOU LIVE
ALONG SMALL STREAMS AND LOW LYING AREAS PRONE TO FLOODING BE ALERT FOR
FLOODING CONDITIONS TODAY.

AS THE LOW PRESSURE CENTER PASSES THROUGH ILLINOIS COLDER AIR WILL HELP
CHANGE THE RAIN TO SNOW. THE CHANGEOVER WILL BEGIN BY LATE AFTERNOON OR
EVENING. AT FIRST THE RAIN WILL BE MIXED WITH WET SNOW BUT AS
TEMPERATURES CONTINUE TO FALL THE RAIN WILL CHANGE TO ALL SNOW. SNOWFALLJ
AMOUNTS OF 3 TO 5 INCHES ARE EXPECTED BEFORE THE SNOW ENDS LATE TONIGHT
AND EARLY SATURDAY.

SOMREK
Special weather statement, Feb 21, 6:00 AM CST, 5 hours 35 minutes before
ILZ003>006-008-010>014-019>023-032>033-039-INZ001-211700-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHICAGO IL
600 AM CST FRI FEB 21 1997

FOR NORTH CENTRAL AND NORTHEAST ILLINOIS AND LAKE COUNTY INDIANA

A LOW PRESSURE SYSTEM IN THE SOUTHERN PLAINS WILL MOVE NORTHEAST TO
ILLINOIS TODAY. AN EXTENEDED PERIOD OF RAIN WILL ACCOMPANY THE SYSTEM AS
IT APPROACHES NORTHERN ILLINOIS. THE RAIN MAY BE HEAVY AT TIMES AND WILL
POSE A THREAT OF FLOODING. A FLOOD WATCH REMAINS IN EFFECT TODAY FOR
NORTH CENTRAL AND NORTHEAST ILLINOIS AND NORTHEAST INDIANA. IF YOU LIVE
ALONG SMALL STREAMS AND LOW LYING AREAS PRONE TO FLOODING BE ALERT FOR
FLOODING CONDITIONS TODAY.

AS THE LOW PRESSURE CENTER PASSES THROUGH ILLINOIS COLDER AIR WILL HELP
CHANGE THE RAIN TO SNOW. THE CHANGEOVER WILL BEGIN BY LATE AFTERNOON OR
EVENING. AT FIRST THE RAIN WILL BE MIXED WITH WET SNOW BUT AS
TEMPERATURES CONTINUE TO FALL THE RAIN WILL CHANGE TO ALL SNOW. SNOWFALL
AMOUNTS OF 3 TO 5 INCHES ARE EXPECTED BEFORE THE SNOW ENDS LATE TONIGHT
AND EARLY SATURDAY.

SOMREK
Special weather statement, Feb 21, 10:52 AM CST, 43 minutes before
ILZ003>006-008-010>014-019>023-032>033-039-INZ001-221000-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHICAGO IL
1100 AM CST FRI FEB 21 1997

FOR NORTH CENTRAL AND NORTHEAST ILLINOIS AND LAKE COUNTY INDIANA

...FLOOD WARNING CONTINUES IN EFFECT FOR MOST OF NORTH CENTRAL AND
NORTHEAST ILLINOIS FOR THIS AFTERNOON...

A LOW PRESSURE SYSTEM CENTERED OVER CENTRAL ILLINOIS THIS MORNING WILL
MOVE TO NORTHEAST INDIANA BY THIS EVENING. AS THE LOW MOVES TO INDIANA
THE RAIN WILL GRADUALLY CHANGE OVER TO SNOW ACROSS THE AREA THIS AFTERNOON
AND EVENING. THE HEAVIEST RAINFALL HAS ALREADY ENDED ACROSS THE AREA
BUT AN ADDITIONAL QUARTER TO HALF INCH OF RAIN IS LIKELY THIS AFTERNOON
BEFORE THE PRECIfPITATION CHANGES OVER TO SNOW.

SNOWFALL AMOUNTS OF 2 TO 5 INCHES IS LIKELY LATE THIS AFTERNOON AND
TONIGHT WITH THE HEAVIEST AMOUNTS LIKELY OVER NORTH CENTRAL ILLINOIS.
Special weather statement, Feb 21, 11:00 AM CST, 35 minutes before
ILZ003>006-008-010>014-019>023-032>033-039-INZ001-221000-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHICAGO IL
1100 AM CST FRI FEB 21 1997

FOR NORTH CENTRAL AND NORTHEAST ILLINOIS AND LAKE COUNTY INDIANA

...FLOOD WARNING CONTINUES IN EFFECT FOR MOST OF NORTH CENTRAL AND
NORTHEAST ILLINOIS FOR THIS AFTERNOON...

A LOW PRESSURE SYSTEM CENTERED OVER CENTRAL ILLINOIS THIS MORNING WILL
MOVE TO NORTHEAST INDIANA BY THIS EVENING. AS THE LOW MOVES TO INDIANA
THE RAIN WILL GRADUALLY CHANGE OVER TO SNOW ACROSS THE AREA THIS AFTERNOON
AND EVENING. THE HEAVIEST RAINFALL HAS ALREADY ENDED ACROSS THE AREA
BUT AN ADDITIONAL QUARTER TO HALF INCH OF RAIN IS LIKELY THIS AFTERNOON
BEFORE THE PRECIPITATION CHANGES OVER TO SNOW.

SNOWFALL AMOUNTS OF 2 TO 5 INCHES IS LIKELY LATE THIS AFTERNOON AND
TONIGHT WITH THE HEAVIEST AMOUNTS LIKELY OVER NORTH CENTRAL ILLINOIS.

The office that day

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

IssuedProductOfficeCountiesLasted
Feb 21, 8:14 AM CSTFlash Flood WarningLOTCook, DuPage, Kane, Kendall, Will4 hr
Feb 21, 8:14 AM CSTFlash Flood WarningLOTBoone, DeKalb, Lake, McHenry4 hr
Feb 21, 8:32 AM CSTFlash Flood WarningLOTCook, DeKalb, DuPage, Kane, Kendall, McHenry and 1 more3 hr
Feb 21, 8:32 AM CSTFlash Flood WarningLOTGrundy, LaSalle, Lee, Livingston3 hr
Feb 21, 8:32 AM CSTFlash Flood WarningLOTFord, Iroquois, Kankakee3 hr
Feb 21, 8:32 AM CSTFlash Flood WarningLOTBoone, Ogle, Winnebago3 hr
Feb 21, 8:32 AM CSTFlash Flood WarningLOTLake3 hr
Feb 21, 11:35 AM CSTFlash Flood WarningLOTGrundy, Kankakee, Livingston6 hr
Feb 21, 11:35 AM CSTFlash Flood WarningLOTBoone, Winnebago6 hr
Feb 21, 11:35 AM CSTFlash Flood WarningLOTDuPage, Kane, Kendall, Will6 hr
Feb 21, 11:35 AM CSTFlash Flood WarningLOTDeKalb, LaSalle, Lee, Ogle6 hr
Feb 21, 8:32 AM CSTFlash Flood WarningLOTLake3 hr

Nearby

Flash Flood Warnings in Illinois, 1997Flash Flood Warnings in Indiana, 1997Every flash flood warning in 1997

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.