Alert archive / Illinois / Severe Thunderstorm Warnings in 1996

Severe Thunderstorm Warning 21, NWS Chicago, IL

April 12, 1996Cook County, DuPage County, Illinois

NWS Chicago, IL issued this severe thunderstorm warning at Apr 12, 1996, 10:29 AM CDT for Cook County, DuPage County, Illinois. It was in force for 46 min. 11 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: Apr 12, 1996, 10:29 AM CDT (15:29 UTC)
Expired: Apr 12, 1996, 11:15 AM CDT
In force: 46 min
Issued by: NWS Chicago, IL
Area: Whole counties

Counties Cook County, IL, DuPage County, IL

The radar

The Chicago radar (KLOT), 35 km from the middle of the area, began a volume at 15:30 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
Apr 12, 10:39 AM CDT	Hail 0.75	Dpa, IL
Apr 12, 10:45 AM CDT	Hail 1.75	Glendale Heights, IL
Apr 12, 10:50 AM CDT	Hail 1	Hanover Park, IL
Apr 12, 10:51 AM CDT	Hail 0.75	Roselle, IL
Apr 12, 10:56 AM CDT	Hail 1	Bloomingdale, IL
Apr 12, 11:10 AM CDT	Hail 1	Carol Stream, IL
Apr 12, 11:10 AM CDT	Hail 1	(Ord)O'Hare Intl Arp, IL
Apr 12, 11:20 AM CDT	Hail 1.75	Skokie, IL
Apr 12, 11:20 AM CDT	Hail 1	Orland Park, IL
Apr 12, 11:24 AM CDT	Hail 0.75	Midlothian, IL
Apr 12, 11:25 AM CDT	Hail 1.75	Chicago, IL

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 3.5 hours before the alert went out and 201 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: 330 J/kg
Mixed-layer CIN: -352 J/kg
Mixed-layer LCL: 968 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 313 m²/s²
0-3 km storm-relative helicity: 355 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KCHI 121546
SVRCHI
ILC031-043-121615-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE CHICAGO IL
1029 AM CDT FRI APR 12 1996
 
THE NATIONAL WEATHER SERVICE IN CHICAGO HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 1115 AM CDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN NORTHEAST ILLINOIS
 
   ...NORTHERN COOK COUNTY...NORTHERN DU PAGE COUNTY
 
AND THE ADJACENT WATERS OF SOUTHERN LAKE MICHIGAN
 
 
AT 1045 AM DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM IN EXTREME
NORTHERN DUPAGE COUNTY JUST EAST OF THE DUPAGE COUNTY AIRPORT OR ABOUT
5 MILE NORTHEAST OF GENEVA.  THE STORM IS MOVING EAST NORTHEAST AT
35 MPH AND WILL PASS BETWEEN ITASCA AND SCHAUMBURG SHORTLY AFTER 11 AM
AND APPROACH THE LAKE MICHIGAN SHORELINE NORTH OF WILLMET BY 1130 AM.
 
THREE QUARTER INCH HAIL WAS REPORTED AT THE DUPAGE COUNTY AIRPORT AT
1035 AM.
 
 
THIS STORM HAS A HISTORY OF PRODUCING LARGE HAIL.  STAY INDOORS...
AWAY FROM WINDOWS!
 
 
 
&

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.

In the hours before

Special weather statement, Apr 12, 5:33 AM CDT, 4 hours 56 minutes before

ILZ003>006-008-010>014-019>023-032-033-039-INZ001-121700-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHICAGO IL
600 AM CDT FRI APR 12 1996

THIS OUTLOOK PERTAINS TO THE FOLLOWING COUNTIES IN NORTHERN ILLINOIS:

BOONE-COOK-DE KALB-DU PAGE-FORD-GRUNDY-IROQUOIS-KANE-KANKAKEE-
KENDALL-LA SALLE-LAKE-LEE-LIVINGSTON-MCHENRY-OGLE-WILL-WINNEBAGO-

AND LAKE COUNTY IN INDIANA

INCLUDING THE CITIES OF AURORA...BELVIDERE...CHICAGO...DE KALB...
DIXON...\GARY IN...JOLIET...KANKAKEE...MORRIS...OTTAWA...PONTIAC...
ROCHELLE...ROCKFORD...WATSEKA...WAUKEGAN...WHEATON...WOODSTOCK

THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS OVER THE AREA THIS
AFTERNOON AND EVENING.

SOMREK

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 12, 10:48 AM CDT	Severe Thunderstorm Warning	LOT	Lake	27 min
Apr 12, 11:10 AM CDT	Severe Thunderstorm Warning	LOT	Cook, Will	65 min
Apr 12, 11:17 AM CDT	Severe Thunderstorm Warning	LOT	Cook	13 min

Nearby

Severe Thunderstorm Warnings in Illinois, 1996 Every severe thunderstorm warning in 1996

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.