Alert archive / Illinois / Tornado Warnings in 1994

Tornado Warning 2, NWS Chicago, IL

April 26, 1994Iroquois County, Illinois

NWS Chicago, IL issued this tornado warning at Apr 26, 1994, 8:52 PM CDT for Iroquois County, Illinois. It was in force for 38 min.

The area

The counties it named.

The facts

Issued
Apr 26, 1994, 8:52 PM CDT (01:52 UTC)
Expired
Apr 26, 1994, 9:30 PM CDT
In force
38 min
Issued by
NWS Chicago, IL
Area
Whole counties

County Iroquois County, IL

The nearest sounding before it

Dayton/James M C, OH (KDAY), launched 00:00Z, 1.9 hours before the alert went out and 321 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, Dayton/James M C, OH at 00:00Z on 1994-04-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 981 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Dayton/James M C, OH at 00:00Z on 1994-04-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 70 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
981 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
1633 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
70 m²/s²
0-3 km storm-relative helicity
178 m²/s²
Significant tornado parameter
0.2
Supercell composite
3.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KCHI 270153
TORCHI
ILC075-270230-
 
BULLETIN - EBS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE CHICAGO IL
852 PM CDT TUE APR 26 1994
 
THE NATIONAL WEATHER SERVICE IN CHICAGO HAS ISSUED A
TORNADO WARNING EFFECTIVE UNTIL  930 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN EAST CENTRAL ILLINOIS
 
   ...IROQUOIS COUNTY
 
AT 8 52 PM CDT A TORNADO WAS INDICATED BY DOPPLER RADAR IN NORTHERN FORD
COUNTY NEAR THE TOWN OF ROBERTS...OR ABOUT 23 MILES SOUTHWEST OF
WATSEKA. THE STORM IS MOVING TO THE NORTHEAST AT 50 MPH AND WILL BE
AFFECTING THAWVILLE...GILMAN...AND DANFORTH BY 9 30 PM CDT.
 
 
THIS IS A DANGEROUS STORM SITUATION.  ACT QUICKLY.  IF YOU ARE
IN THE PATH OF THIS TORNADO MOVE TO A SHELTER BELOW GROUND IF
AVAILABLE.  OTHERWISE...GO TO A SMALL INTERIOR ROOM ON THE LOWEST
FLOOR POSSIBLE.  GET AWAY FROM WINDOWS.  ABANDON CARS AND MOBILE HOME
FOR A REINFORCED BUILDING OR GET INTO A DITCH OR CULVERT.
 
 
MERZLOCK

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.

In the hours before

Special weather statement, Apr 26, 4:58 PM CDT, 3 hours 54 minutes before
ILZ014-021>023-270000-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO IL
456 PM CDT TUE APR 26 1994

...THUNDERSTORMS HAVE DEVELOPED OVER NORTHEAST ILLINOIS LATE THIS
AFTERNOON...

AT 450 PM NATIONAL WEATHER SERVICE RADAR SHOWED THUNDERSTORMS OVER
GRUNDY COUNTY.  THE STORMS WERE MOVING NORTHEAST AT 55 MPH AND WILL
MOVE ACROSS CENTRAL WILL COUNTY INCLUDING JOLIET AND NEW LENOX BETWEEN
500 AND 530 PM.  THE STORMS WILL LIKELY REACH SOUTHWESTERN COOK COUNTY
AROUND 530 PM.

THESE STORMS WILL LIKELY CONTAIN STRONG WINDS...FREQUENT LIGHTNING...AND
BRIEF HEAVY RAIN.  PEOPLE IN THE PATH OF THESE STORMS SHOULD MOVE
INDOORS FOR THEIR PROTECTION.

TAYLOR
Special weather statement, Apr 26, 5:53 PM CDT, 2 hours 59 minutes before
ILZ022--013-020-021--032-023-014-270000-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO IL
550 PM CDT TUE APR 26 1994

...THE SEVERE THUNDERSTORMS WARNINGS FOR SOUTHERN COOK AND WESTERN WILL
COUNTIES HAVE EXPIRED AT 545 PM...

THE SEVERE STORMS ACROSS WILL AND SOUTHERN COOK COUNTIES HAVE
WEAKENED SINCE 530 PM. HOWEVER AT 550 PM WEATHER SERVICE DOPPLER RADAR SHOWED
STRONG THUNDERSTORMS SCATTERED ACROSS THE SOUTH SIDE OF CHICAGO...OVER LEMONT
AND NORTHWEST GRUNDY COUNTY ABOUT 7 MILES NORTHWEST OF MORRIS. ADDITIONAL
THUNDERSTORMS WERE DEVELOPING TO THE SOUTHWEST OF CHICAGO BETWEEN PEORIA AND
JOLIET. ALL STORMS WERE MOVING TO THE NORTHEAST AT 55 MPH AND WILL LIKELY
CONTAIN STRONG WIRNDS...FREQUENT LIGHTNING...AND BRIEF HEAVY RAIN AS THEY TRACK
ACROSS THE SOUTH SIDE OF CHICAGO AND SOUTHERN LAKE MICHIGAN. PEOPLE IN THE
PATH OF THESE STORMS SHOULD MOVE INDOORS FOR THEIR PROTECTION.

RANDALL

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 26, 7:08 PM CDTSevere Thunderstorm WarningLOTLivingston28 min
Apr 26, 7:27 PM CDTSevere Thunderstorm WarningLOTCook, Will48 min
Apr 26, 8:16 PM CDTSevere Thunderstorm WarningLOTFord, Iroquois44 min
Apr 26, 8:26 PM CDTTornado WarningLOTKankakee34 min
Apr 26, 9:01 PM CDTSevere Thunderstorm WarningLOTCook29 min
Apr 26, 9:15 PM CDTSevere Thunderstorm WarningLOTFord, Livingston45 min
Apr 26, 9:31 PM CDTTornado WarningLOTIroquois29 min
Apr 26, 10:30 PM CDTSevere Thunderstorm WarningLOTFord, Iroquois30 min
Apr 26, 11:00 PM CDTSevere Thunderstorm WarningLOTIroquois30 min

Nearby

Tornado Warnings in Illinois, 1994Every tornado warning in 1994Tornadoes in 1994

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.