Alert archive / Illinois / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 76, NWS Lincoln, IL

August 21, 1987Bureau County, Knox County, Stark County, Illinois

NWS Lincoln, IL issued this severe thunderstorm warning at Aug 21, 1987, 5:34 AM CDT for Bureau County, Knox County, Stark County, Illinois. It was in force for 26 min.

The area

The counties it named.

The facts

Issued: Aug 21, 1987, 5:34 AM CDT (10:34 UTC)
Expired: Aug 21, 1987, 6:00 AM CDT
In force: 26 min
Issued by: NWS Lincoln, IL
Area: Whole counties

Counties Bureau County, IL, Knox County, IL, Stark County, IL

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

Peoria Regional, IL (KPIA), launched 00:00Z, 10.6 hours before the alert went out and 57 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: 1095 J/kg
Mixed-layer CIN: -45 J/kg
Mixed-layer LCL: 1543 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 92 m²/s²
0-3 km storm-relative helicity: 231 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 6.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KPIA 211034
SVRPIA
ILC095-011-175-211130-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PEORIA IL
534 AM CDT FRI AUG 21 1987

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM 
WARNING EFFECTIVE UNTIL 630 AM CDT FOR PEOPLE IN THE FOLLOWING 
COUNTIES OF

CENTRAL ILLINOIS...NORTHEAST KNOX...SOUTHWEST BUREAU AND STARK

AT 530 AM CDT WEATHER RADAR INDICATES A SEVERE THUNDERSTORM MOVING
INTO NORTHEASTERN KNOX...STARK...AND SOUTHWEST BUREAU COUNTIES
FROM 10 MILES NORTHEAST OF GALESBURG TO 30 MILES NORTHEAST OF
GALESBURG MOVING RAPIDLY TO THE SOUTHEAST AT 45 TO 50 MPH.

THIS STORM PRODUCED ONE-HALF INCH HAIL AND WIND GUSTS TO 81 MPH
AS IT PASSED THROUGH MOLINE.

IF YOU ARE IN AN AREA THREATENED BY THE STORM..GO TO A REINFORCED
SHELTER AND PREPARE FOR DAMAGING WIND...LARGE HAIL...VERY HEAVY
RAIN AND LIGHTNING.

THIS IS A DANGEROUS STORM.  TAKE COVER IMMEDIATELY.

ATTN ISP DIST... 7x...8...AND 17

LAST/MACH

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, Aug 21, 3:00 AM CDT, 2 hours 34 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEORIA IL
300 AM CDT FRI AUG 21 1987

     ...STRONG THUNDERSTORMS MOVING INTO STARK COUNTY...

AT 255 AM CDT WEATHER SERVICE RADAR INDICATED AN AREA OF SHOWERS
AND STRONG THUNDERSTORMS EXTENDING NORTH OF A LINE FROM BLOOMINGTON
TO GALESBURG IL TO 20 MILES NORTH OF BURLINGTON IA.  THE STRONGEST
THUNDERSTORMS WERE LOCATED IN SOUTHEAST HENRY COUNTY AND NEAR THE
CITY OF MOLINE.

THE STORM IN HENRY COUNTY WILL BE MOVING INTO STARK COUNTY BY 330 AM
AND WILL BE AFFECTING THE TOWNS OF TOULON AND WYOMING...30 MILES NORTH
OF PEORIA.

HEAVY RAIN...DANGEROUS LIGHTNING...AND STRONG GUSTY WINDS CAN BE
EXPECTED WITH THESE STORMS AS THEY MOVE THROUGH THE AREA.  THE RAIN
AREA WAS MOVING TO THE SOUTHEAST AT 30 MPH.

JK LAST

ATTN ISP DIST...8

Special weather statement, Aug 21, 3:40 AM CDT, 1 hour 54 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEORIA IL
340 AM CDT FRI AUG 21 1987

    ...STRONG THUNDERSTORMS NORTH AND WEST OF PEORIA...

AT 335 AM CDT NATIONAL WEATHER SERVICE RADAR INDICATED A LARGE AREA
OF SHOWERS AND STRONG THUNDERSTORMS NORTH OF A LINE FROM CHAMPAIGN
TO PEORIA IL TO 15 MILES EAST OF BURLINGTON IA.  THE STRONGEST
THUNDERSTORMS WERE LOCATED IN NORTHERN KNOX COUNTY..10 MILES EAST
OF GALESBURG...AND IN SOUTHERN BUREAU COUNTY..NEAR TISKILWA WHICH
IS 45 MILES NORTH OF PEORIA.

THESE THUNDERSTORMS ARE MOVING TO THE SOUTHEAST AT 35 MPH AND WILL
BE AFFECTING THE COUNTIES OF PEORIA...STARK...AND BUREAU THROUGHOUT
THE EARLY MORNING HOURS.

HEAVY RAIN...DANGEROUS LIGHTNING...AND STRONG GUSTY WINDS CAN BE
EXPECTED WITH THESE STORMS AS THEY MOVE THROUGH THE AREA.

JK LAST

ATTN ISP DIST...7...8...17

Special weather statement, Aug 21, 4:40 AM CDT, 54 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PEORIA IL
435 AM CDT FRI AUG 21 1987

          ...STRONG THUNDERSTORM OVER PEORIA...

AT 425 AM CDT NATIONAL WEATHER SERVICE RADAR INDICATED A VERY STRONG
THUNDERSTORM OVER PEORIA IL.  A PEAK WIND GUST OF 45 MPH WAS RECORDED
HERE AT THE GREATER PEORIA AIRPORT AT 417 AM AND 0.40 INCHES OF RAIN
FELL IN 15 MINUTES.  THIS THUNDERSTORM IS ENTERING NORTHERN TAZEWELL
COUNTY AND WILL BE AFFECTING THE TOWNS OF PEKIN...MORTON AND MACKINAW.

ANOTHER STRONG THUNDERSTORM WAS OVER WESTERN BUREAU COUNTY.

THE THUNDERSTORMS ARE MOVING TO THE SOUTHEAST AT 35 MPH.

HEAVY RAIN...DANGEROUS LIGHTNING...AND STRONG GUSTY WINDS CAN BE
EXPECTED WITH THESE STORM?S AS THEY MOVE THROUGH THE AREA.

JK LAST

ATTN ISP DIST...7...8...17

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 21, 6:24 AM CDT	Tornado Warning	ILX	Woodford	31 min

Nearby

Severe Thunderstorm Warnings in Illinois, 1987 Every severe thunderstorm warning in 1987

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.