Alert archive / Illinois / Tornado Warnings in 1991

Tornado Warning 29, NWS Lincoln, IL

July 7, 1991Boone County, Illinois

NWS Lincoln, IL issued this tornado warning at Jul 7, 1991, 4:03 PM CDT for Boone County, Illinois. It was in force for 19 min.

The area

The counties it named.

The facts

Issued
Jul 7, 1991, 4:03 PM CDT (21:03 UTC)
Expired
Jul 7, 1991, 4:22 PM CDT
In force
19 min
Issued by
NWS Lincoln, IL
Area
Whole counties

County Boone County, IL

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 12:00Z, 9.1 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 12:00Z on 1991-07-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 1991-07-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -67 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1805 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
-67 m²/s²
0-3 km storm-relative helicity
75 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 072103
TORRFD
ILC007-072145-

BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED 
TORNADO WARNING 
NATIONAL WEATHER SERVICE ROCKFORD IL
403 PM CDT SUN JUL 7 1991

THE NATIONAL WEATHER SERVICE HAS ISSUED A TORNADO WARNING 
EFFECTIVE UNTIL 445 PM CDT FOR PEOPLE IN THE FOLLOWING COUNTY

   IN THE NORTH CENTRAL PART OF ILLINOIS
      NORTHERN BOONE

AT 4 PM CDT...RADAR INDICATED A POSSIBLE TORNADO DEVELOPING
5 MILES NORTHWEST OF BELVIDERE. THIS STORM IS MOVING TO THE
EAST AT 45 MPH.

SOME COMMUNITIES THAT WILL BE AFFECTED BY THIS TORNADO...
POPLAR GROVE...CAPRON.

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 QUICKLY YOU RESPOND TO THIS TORUNADO 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, Jul 7, 1:38 PM CDT, 2 hours 25 minutes before
ILZ005-006-007-009-080200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEORIA IL
140 PM CDT SUN JUL 7 1991

...TEMPERATURES ACROSS THE HEART OF ILLINOIS ARE RISING INTO THE
MID 90S WITH HIGH HUMIDITY...

HIGH TEMPERATURES TODAY IN THE PEORIA AREA AS WELL AS MUCH OF THE
HEART OF ILLINOIS ARE EXPECTED TO RISE INTO THE MID TO UPPER 90S
ALONG WITH HIGH HUMIDITY. THIS COMBINATION WILL MAKE IT FEEL MUCH
HOTTER. THIS AFTERNOONS HEAT INDEX WILL RANGE FROM 100 TO POSSIBLY
107 DEGREES...IN SHADY AREAS.

THESE HEAT INDEX VALUES COULD BE DANGEROUS TO PEOPLE PARTICIPATING
IN OUT OF DOORS ACTIVITIES.

PROLONGED EXPOSURE OR PHYSICAL ACTIVITIES TO THE HEAT SHOULD BE
REDUCED OR EVEN ELIMINATED. PROTECTION OF PETS AND SMALL LIVESTOCK
SHOULD ALSO BE PROTECTED FROM THE HEAT.

IF YOU ARE OUT DOORS...DRINK PLENTY OF NON ALCOHOLIC  BEVERAGES...
EVEN IF YOU DON'T FEEL THIRSTY.

WEAR LIGHTWEIGHT...LIGHT COLORED CLOTHING.

ELDERLY PERSONS...SMALL CHILDREN...CHRONIC INVALIDS...AND PEOPLE
ON CERTAIN MEDICATIONS OR DRUGS ARE MORE SUSCEPTABLE TO HEAT DISORDERS.

TOO MUCH HEAT CAN CAUSE...SUNBURN...HEAT CRAMPS...HEAT EXHAUSTION...AND
HEAT STROKE.

HEAT STROKE IS A SEVERE MEDICAL EMERGENCY. SUMMON EMERGENCY MEDICAL
ASSISTANCE OR GET THE VICTIM TO A HOSPITAL IMMEDIATELY. DELAY CAN
BE FATAL.

REMEMBER...THE HEAT INDEX WAS DEVISED FOR SHADY...LIGHT WIND CONDITIONS.
EXPOSURE TO FULL SUN CAN INCREASE HEAT INDEX VALUES BY UP TO 15 DEGREES.

STUMETZ
Special weather statement, Jul 7, 1:45 PM CDT, 2 hours 18 minutes before
ILZ005-006-007-009-080200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEORIA IL
140 PM CDT SUN JUL 7 1991

...TEMPERATURES ACROSS THE HEART OF ILLINOIS ARE RISING INTO THE
MID 90S WITH HIGH HUMIDITY...

HIGH TEMPERATURES TODAY IN THE PEORIA AREA AS WELL AS MUCH OF THE
HEART OF ILLINOIS ARE EXPECTED TO RISE INTO THE MID TO UPPER 90S
ALONG WITH HIGH HUMIDITY. THIS COMBINATION WILL MAKE IT FEEL MUCH
HOTTER. THIS AFTERNOONS HEAT INDEX WILL RANGE FROM 100 TO POSSIBLY
107 DEGREES...IN SHADY AREAS.

THESE HEAT INDEX VALUES COULD BE DANGEROUS TO PEOPLE PARTICIPATING
IN OUT OF DOORS ACTIVITIES.

PROLONGED EXPOSURE OR PHYSICAL ACTIVITIES TO THE HEAT SHOULD BE
REDUCED OR EVEN ELIMINATED. PROTECTION OF PETS AND SMALL LIVESTOCK
FROM THE HEAT IS ALSO ADVISED.

IF YOU ARE OUT DOORS...DRINK PLENTY OF NON ALCOHOLIC  BEVERAGES...
EVEN IF YOU DON'T FEEL THIRSTY.

WEAR LIGHTWEIGHT...LIGHT COLORED CLOTHING.

ELDERLY PERSONS...SMALL CHILDREN...CHRONIC INVALIDS...AND PEOPLE
ON CERTAIN MEDICATIONS OR DRUGS ARE MORE SUSCEPTABLE TO HEAT DISORDERS.

TOO MUCH HEAT CAN CAUSE...SUNBURN...HEAT CRAMPS...HEAT EXHAUSTION...AND
HEAT STROKE.

HEAT STROKE IS A SEVERE MEDICAL EMERGENCY. SUMMON EMERGENCY MEDICAL
ASSISTANCE OR GET THE VICTIM TO A HOSPITAL IMMEDIATELY. DELAY CAN
BE FATAL.

REMEMBER...THE HEAT INDEX WAS DEVISED FOR SHADY...LIGHT WIND CONDITIONS.
EXPOSURE TO FULL SUN CAN INCREASE HEAT INDEX VALUES BY UP TO 15 DEGREES.

STUMETZ

/CORRECTION TO WORDING/
Special weather statement, Jul 7, 3:36 PM CDT, 27 minutes before
ILZ005-072200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEORIA IL
335 PM CDT SUN JUL 7 1991

...TORNADO WATCH UNTIL 10 PM CDT FOR NORTHERN ILLINOIS WHICH
INCLUDES BUREAU AND PUTNAM COUNTIES...

AT 330 PM CDT NO SHOWERS OR THUNDERSTORMS WERE INDICATED NEAR OR
IN BUREAU AND PUTNAM COUNTIES.

POSSIBLE TORNADOES AND SEVERE THUNDERSTORMS ARE EXPECTED TO DEVELOPE
ALONG A COLD FRONT MOVING SOUTHEAST FROM IOWA THIS EARLY AFTERNOON
AND EVENING4.

STAY TUNED TO NOAA WEATHER RADIO OR YOUR LOCAL NEWS MEDIA FOR
FURTHER WATCH INFORMATION OR WARNINGS THAT MAY BE REQUIRED.

ATTN ISP DIST 17
STUMETZ

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 7, 5:32 AM CDTSevere Thunderstorm WarningILXDeKalb, Ogle43 min
Jul 7, 4:20 PM CDTSevere Thunderstorm WarningILXDeKalb, Lee40 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.