Alert archive / Illinois / Tornado Warnings in 1987

Tornado Warning 1, NWS Quad Cities, IA

May 18, 1987Henry County, Illinois

NWS Quad Cities, IA issued this tornado warning at May 18, 1987, 6:41 PM CDT for Henry County, Illinois. It was in force for 34 min. 1 report 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
May 18, 1987, 6:41 PM CDT (23:41 UTC)
Expired
May 18, 1987, 7:15 PM CDT
In force
34 min
Issued by
NWS Quad Cities, IA
Area
Whole counties

County Henry County, IL

The radar

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

What was reported inside it

TimeReportWhereRemark
May 18, 7:00 PM CDTThunderstorm Wind 0Henry, 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. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.

The nearest sounding before it

Peoria Regional, IL (KPIA), launched 12:00Z, 11.7 hours before the alert went out and 88 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, Peoria Regional, IL at 12:00Z on 1987-05-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 153 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, Peoria Regional, IL at 12:00Z on 1987-05-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 111 square meters per square second.1939Sfc1 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
153 J/kg
Mixed-layer CIN
-55 J/kg
Mixed-layer LCL
691 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
111 m²/s²
0-3 km storm-relative helicity
109 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 KMLI 182341 RRA
TORMLI
ILC073-190045-

BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED 
TORNADO WARNING
NATIONAL WEATHER SERVICE MOLINE IL
641 PM CDT MON MAY 18 1987

THE NATIONAL WEATHER SERVICE HAS ISSUED A TORNADO WARNING 
EFFECTIVE UNTIL 745 PM CDT FOR PEOPLE IN THE FOLLOWING COUNTY OF

NORTHWEST ILLINOIS...EASTERN HENRY

AT 630 PM CDT THE ANNAWAN POLICE DEPARTMENT REPORTED A FUNNEL
CLOUD NORTH OF ANNAWAN WITH LITTLE MOVEMENT.  ANNAWAN IS
28 MILES EAST OF THE QUAD CITIES.

IF YOU ARE IN THE PATH OF THIS TORNADO...TAKE COVER IMMEDIATELY.
A BASEMENT...INTERIOR HALLWAY...OR A ROOM ON THE LOWEST FLOOR IS
THE SAFEST PLACE.  TAKE COVER IN A STORM SHELTER OR LIE IN A
NEARBY DITCH OR DEPRESSION.

IF TIME PERMITS..ASK THE NEAREST LAW ENFORCEMENT DAGENCY TO RELAY
YOUR REPORT OF SEVERE WEATHER TO THE NATIONAL WEATHER SERVICE.

ATTN ISP 7 AND 1

KRAEMER

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, May 18, 2:40 PM CDT, 4 hours 1 minute before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DUBUQUE IA
240 PM CDT MON MAY 18 1987

...STRONG THUNDERSTORMS IN CENTRAL AND WESTERN CLAYTON COUNTY...

AT 235 PM CDT STRONG THUNDERSTORMS WERE CONTINUING TO DRIFT SLOWLY
ACROSS WESTERN AND CENTAL PORTION OF CLAYTON COUNTY IN NORTHEAST
IOWA.  THE STRONGEST THUNDERSTORMS WERE NEAR ELKADER...50 MILES
NORTHWEST OF DUBUQUE.

THE THUNDERSTORMS WERE MOVING VERY SLOWLY TO THE EAST AT 5 TO 10
MILES AN HOUR.

THE CLAYTON COUNTY SHERIFFS DEPARTMENT REPORTED VERY HEAVY RAIN AND
SMALL HAIL AS THE STORMS APPROACHED ELKADER.  NO SEVERE WEATHER HAD
BEEN REPORTED AS OF 235 PM CDT FROM THESE STORMS.

THE THUNDERSTORMS WILL PRODUCE HEAVY RAINS...FREQUmENT LIGHTNING AND
POSSIBLY SMALL HAIL AS THEY MOVE ACROSS THE COUNTY.  THE HEAVY RAINS
COULD PRODUCE SOME FLOODING.

IF THREATENING WEATHER APPROACHES...TAKE NECCESARY PRECAUTIONS.

ASMUS
Special weather statement, May 18, 3:40 PM CDT, 3 hours 1 minute before
TTAAOO KDBQ 182040??ALL

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DUBUQUE IA
340 PM CDT MON MAY 18 1987

...MORE HEAVY THUNDERSTORMS FOR CLAYTON COUNTY IN NORTHEAST IOWA...

AT 335 PM CDT STRONG THUNDERSTORMS ACTIVITY CONTINUED IN EASTERN
CLAYTON COUNTY NEAR GARNIVILLO.  MORE STRONG THUNDERSTORMS WERE
INDICATED IN FAYETTE COUNTY AND THESE THUNDERSTORMS WILL BE MOVING
INTO WESTERN CLAYTON COUNTY BETWEEN 400 AND 430 THIS AFTERNOON.

THE THUNDERSTORMS WERE MOVING VERY SLOWLY TO THE EAST-SOUTHEAST AT 10
TO 15 MILES AN HOUR.

THE STRONG THUNDERSTORMS NEAR GARNIVILLO...35 MILES NORTHWEST OF
DUBUQUE...HAD PRODUCED MARBLE SIZE HAIL AND VERY HEAVY RAIN SINCE 300
PM.  THE STORMS IN FAYETTE COUNTY...15 MILES WEST OF ELKADER WERE
PRODUCING VERY HEAVY RAIN AND WERE CAPABLE OF PRODUCING HAIL AS WELL.

THE THUNDERSTORMS WILL CONTINUE TO PRODUCE HEAVY RAIN...FREQUENT
LIGHTNING AND POSSIBLY SMALL HAIL AS THEY MOVE ACROSS CLAYTON COUNTY.
THE HEAVY RAINS COULD? PRODUCE SOME FLODDING.

IF THREATENING WEATHER APPROACHES...TAKE NECCESARY PRECAUTIONS.

ASMUS
Special weather statement, May 18, 5:10 PM CDT, 1 hour 31 minutes before
TTAAOO KDBQ 182210??ALL

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DUBUQUE IA
510 PM CDT MON MAY 18 1987

...HEAVY THUNDERSTORMS FOR SOUTHERN CLAYTON COUNTY AND NORTHERN
DELAWARE SOUTNYIN NORTHEAST IOWA...

AT 505 PM CDT A LINE OF STRONG THUNDERSTORMS EXTENDED FROM SOUTHERN
CLAYTON...IN NORTHEAST IOWA...INTO PORTIONS OF EASTERN IOWA.  THE
NORTHERN END OF THE LINE WAS NEAR ELKPORT IN SOUTHERN CLAYTON
COUNTY...35 MILES NORTHWEST OF DUBUQUE.  THE LINE EXTENDED TO THE
SOUTHWEST TO NEAR INDEPENDENCE AND THEN TO NEAR CEDAR RAPIDS.

THE THUNDERSTORMS WERE MOVING SLOWLY TO THE EAST-SOUTHEAST AT 20 TO 25
MILES AN HOUR.

THESE THUNDERSTORMS WILL PRODUCE HEAVY RAIN...FREQUENT LIGHTNING AND
POSSIBLY SMALL HAIL AS THEY MOVE ACROSS SOUTHERN CLAYTON COUNTY AND
INTO WESTERN DELAWARE COUNTY IN NORTHEAST IOWA.  THE HEAVY RAINS WILL
LIKELY PRODUCE SOME FLOODING ESPECIALLY ALONG SMALL CREEKS AND IN LOW
LYING AREAS.  STREET FLOODING IS ALSO POSSIBLE WITH THESE SLOW MOVING
STORMS.

OTHER SHOWERS AND THUNDERSHOWERS COVER NORTHEAST IOWA AND SOUTHWESTERN
WISCONSIN.

IF THREATENING WEATHER APPROACHES...TAKE NECCESARY PRECAUTIONS.

ASMUS
Special weather statement, May 18, 5:45 PM CDT, 56 minutes before
TTAAOO KDBQ 182245??ALL

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DUBUQUE IA
545 PM CDT MON MAY 18 1987

...STRONG THUNDERSTORMS MOVING INTO WESTERN PORTIONS OF THE TRISTATE
AREA...

AT 540 PM CDT A LINE OF STRONG THUNDERSTORMS EXTENDED FROM CASSVILLE
WISCONSIN...20 MILES NORTHWEST OF DUBUQUE...TO NEAR DYERSVILLE
IOWA...20 MILES WEST OF DUBUQUE...TO NEAR CEDAR RAPID.

THE THUNDERSTORMS WERE MOVING TO THE SOUTHEAST AT 20 TO 25 MILES AN
HOUR.

THESE THUNDERSTORMS WILL PRODUCE HEAVY RAIN...FREQUENT LIGHTNING AND
POSSIBLY SMALL HAIL AS THEY MOVE ACROSS THE TRI-STATE AREA.  THE HEAVY
RAINS WILL LIKELY PRODUCE SOME FLOODING ESPECIALLY ALONG SMALL CREEKS
AND IN LOW LYING AREAS.  STREET FLOODING IS ALSO POSSIBLE WITH THESE
SLOW MOVING STORMS.

AS OF 540 PM CDT NO SEVERE WEATHER HAD BEEN REPORTED FROM THIS LINE OF
STRONG THUNDERSTORMS.

OTHER SHOWERS AND THUNDERSHOWERS COVER NORTHEAST IOWA AND SOUTHWESTERN
WISCONSIN.

IF THREATENING WEATHER APPROACHES...TAKE NECCESARY PRECAUTIONS.

ASMUS
Special weather statement, May 18, 6:20 PM CDT, 21 minutes before
TTAAOO KDBQ 182320??ALL

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DUBUQUE IA
620 PM CDT MON MAY 18 1987

  ...STRONG THUNDERSTORMS MOVING ACROSS THE TRISTATE AREA...

AT 615 PM CDT SEVERAL STRONG THUNDERSTORMS WERE MOVING ACROSS MUCH OF
THE TRI-STATE AREA.  THE LEADING EDGE OF THE THUNDERSTORMS EXTENDED
FROM ABOUT 15 MILES NORTH OF DUBUQUE TO NEAR ANAMOSA...40 MILES
SOUTHWEST OF DUBUQUE.

THE THUNDERSTORMS WERE MOVING TO THE SOUTHEAST AT 30 TO 35 MILES AN
HOUR.

THESE THUNDERSTORMS WILL PRODUCE HEAVY RAIN...FREQUENT LIGHTNING AND
POSSIBLY SMALL HAIL AS THEY MOVE ACROSS THE TRI-STATE AREA.  THE HEAVY
RAINS WILL LIKELY PRODUCE SOME FLOODING ESPECIALLY ALONG SMALL CREEKS
AND IN LOW LYING AREAS.  STREET FLOODING IS ALSO POSSIBLE WITH THESE
SLOW MOVING STORMS.

AS OF 615 PM CDT NO SEVERE WEATHER HAD BEEN REPORTED FROM THESE STRONG
THUNDERSTORMS.  REPORTS OF VERY HEAVY RAIN...GUSTY WINDS TO AROUND 30
MILES AN HOUR...AND PEA SIZE HAIL HAD BEEN RECEIVED HOWEVER.

OTHER SHOWERS AND THUNDERSHOWERS COVER NORTHEAST IOWA AND SOUTHWESTERN
WISCONSIN.

IF THREATENING WEATHER APPROACHES...TAKE NECCESARY PRECAUTIONS.

ASMUS
Special weather statement, May 18, 6:32 PM CDT, 9 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOLINE IL
625 PM CDT MON MAY 18 1987

STRONG THUNDERSTORMS CONTINUE TO DEVELOP IN ALL DIRECTIONS OF
THE QUAD CITIES.

AT 620 PM CDT  THE STRONGEST THUNDERSTORMS WERE LOCATED IN NORTHEAST
HENRY COUNTY IL.  THIS STORM WAS SHOWING LITTLE MOVEMENT AND WAS
INDICATING VERY HEAVY RAINFALL AND A GOOD POSSIBLITY OF SOME HAIL.

PERSONS IN NORTHEAST HENRY COUNTY SHOULD BE ON THE ALERT FOR THE
POSSIBLITY OF SOME FLOODING IN LOW LYING AREAS.
KRAEMER

Nearby

Tornado Warnings in Illinois, 1987Every tornado warning in 1987Tornadoes 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.