Alert archive / Illinois / Tornado Warnings in 1991

Tornado Warning 9, NWS Lincoln, IL

April 29, 1991Boone County, Illinois

NWS Lincoln, IL issued this tornado warning at Apr 29, 1991, 7:58 PM CDT for Boone County, Illinois. It was in force for 32 min.

The area

The counties it named.

The facts

Issued
Apr 29, 1991, 7:58 PM CDT (00:58 UTC)
Expired
Apr 29, 1991, 8:30 PM CDT
In force
32 min
Issued by
NWS Lincoln, IL
Area
Whole counties

County Boone County, IL

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 00:00Z, 1.0 hours before the alert went out and 247 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, Green Bay/Straub, WI at 00:00Z on 1991-04-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 22 joules per kilogram.LCLLFCEL10008507005003002001001 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, Green Bay/Straub, WI at 00:00Z on 1991-04-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 95 square meters per square second.1939587897117Sfc1 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
22 J/kg
Mixed-layer CIN
-124 J/kg
Mixed-layer LCL
956 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
95 m²/s²
0-3 km storm-relative helicity
114 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KRFD 300058
TORRFD
ILC007-300130-

BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED 
TORNADO WARNING 
NATIONAL WEATHER SERVICE ROCKFORD IL
758 PM CDT MON APR 29 1991

THE NATIONAL WEATHER SERVICE HAS ISSUED A TORNADO WARNING 
EFFECTIVE UNTIL 830 PM CDT FOR PEOPLE IN THE FOLLOWING COUNTY

   IN THE NORTH CENTRAL PART OF ILLINOIS
      BOONE

AT 7 55 PM...THE ILLINOIS STATE POLICE HAS REPORTED A TORNADO
ON THE GROUND NEAR INTERSTATE 39 AND BAXTER ROAD IN WINNEBAGO
COUNTY. THE STORM WAS MOVING TO THE NORTHEAST AT 30 MPH.

SOME COMMUNITIES THAT WILL BE AFFECTED BY THIS TORNADO...
BELVIDERE

PERSONS IN THE PATH OF THIS DANGEROUS STORM TAKE COVER IMMEDIATELY
IN A BASEMENT OR SMALL CENTRAL INTERIOR ROOM ON THE LOWEST FLOOR.
ABANDON CARS... FARM MACHINERY AND MOBILE HOMES FOR REINFORCED
BUILDING.  IF OUT-OF-DOORS GO TO A REINFORCED SHELTER OR DITCH...
CULVERT OR RAVINE.  THIS IS A SERIOUS SITUATION... YOUR LIFE MAY
DEPEND ON HOW QUICKLYc YOU RESPOND TO THIS TORNADO WARNING!

ATTN: ISP DIST  16.                                  SANDERS

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 29, 7:13 PM CDT, 45 minutes before
ILZ009-010-300115-

SHORT TERM WEATHER FOR CENTRAL AND EASTCENTRAL ILLINOIS
NATIONAL WEATHER SERVICE SPRINGFIELD IL
705 PM CDT MON APR 29 1991

A LINE OF STRONG THUNDERSTORMS HAVE DEVELOPED OVER CENTRAL ILLINOIS.
THE LINE EXTENDED FROM JUST EAST OF SPRINGFIELD NORTH TO 30 MILES
NORTHEAST OF PEORIA.  THE STORMS WERE MOVING TO THE NORTH AT 30 MPH
WHILE THE LINE WAS MOVING TO THE EAST AT 30 MPH.

THE STRONGEST STORMS WERE LOCATED IN LOGAN COUNTY JUST EAST OF LINCOLN
AND 10 MILES NORTHWEST AND 10 MILES SOUTHWEST OF MT PULASKI.  THE STORMS
WILL MOVE INTO DEWITT AND NORTHERN MACON COUNTIES BY 730 PM.

DAMAGING WINDS...HAIL...VERY HEAVY RAIN AND DANGEROUS LIGHTNING MAY
ACCOMPANY THESE STORMS.

BE ALERT TO THE RAPIDLY CHANGING WEATHER CONDITIONS AND LISTEN FOR
FURTHER UPDATES OR POSSIBLE WARNINGS.

MUNDY
ATTN ISP DIST...9...6...10
Special weather statement, Apr 29, 7:14 PM CDT, 44 minutes before
ILZ009-010-300115-

SPECIAL WEATHER STATEMENT...CORRECTION...
NATIONAL WEATHER SERVICE SPRINGFIELD IL
710 PM CDT MON APR 29 1991

A LINE OF STRONG THUNDERSTORMS HAVE DEVELOPED OVER CENTRAL ILLINOIS.
THE LINE EXTENDED FROM JUST EAST OF SPRINGFIELD NORTH TO 30 MILES
NORTHEAST OF PEORIA.  THE STORMS WERE MOVING TO THE NORTH AT 30 MPH
WHILE THE LINE WAS MOVING TO THE EAST AT 30 MPH.

THE STRONGEST STORMS WERE LOCATED IN LOGAN COUNTY JUST EAST OF LINCOLN
AND 10 MILES NORTHWEST AND 10 MILES SOUTHWEST OF MT PULASKI.  THE STORMS
WILL MOVE INTO DEWITT AND NORTHERN MACON COUNTIES BY 730 PM.

DAMAGING WINDS...HAIL...VERY HEAVY RAIN AND DANGEROUS LIGHTNING MAY
ACCOMPANY THESE STORMS.

BE ALERT TO THE RAPIDLY CHANGING WEATHER CONDITIONS AND LISTEN FOR
FURTHER UPDATES OR POSSIBLE WARNINGS.
MUNDY
ATTN ISP DIST...9...6...10

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 29, 7:04 PM CDTTornado WarningILXMcLean, Woodford26 min
Apr 29, 7:33 PM CDTTornado WarningILXMcLean, Woodford27 min
Apr 29, 7:40 PM CDTSevere Thunderstorm WarningILXChristian, Macon65 min
Apr 29, 7:40 PM CDTSevere Thunderstorm WarningILXDeWitt65 min
Apr 29, 7:41 PM CDTTornado WarningILXDeKalb, Lee34 min
Apr 29, 8:02 PM CDTTornado WarningILXMcLean58 min
Apr 29, 8:31 PM CDTTornado WarningILXDeWitt, Piatt44 min

Nearby

Tornado Warnings in Illinois, 1991Every tornado warning in 1991Tornadoes in 1991

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.