Alert archive / Illinois / Severe Thunderstorm Warnings in 1987
Severe Thunderstorm Warning 4, NWS Quad Cities, IA
NWS Quad Cities, IA issued this severe thunderstorm warning at May 21, 1987, 8:42 PM CDT for Henry County, Whiteside County, Illinois. It was in force for 48 min.
The area
The counties it named.
The facts
- Issued
- May 21, 1987, 8:42 PM CDT (01:42 UTC)
- Expired
- May 21, 1987, 9:30 PM CDT
- In force
- 48 min
- Issued by
- NWS Quad Cities, IA
- Area
- Whole counties
Counties Henry County, IL, Whiteside 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, 1.7 hours before the alert went out and 105 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.
- Mixed-layer CAPE
- 2351 J/kg
- Mixed-layer CIN
- -7 J/kg
- Mixed-layer LCL
- 1819 m above ground
- 0-6 km bulk shear
- 19 kt
- 0-1 km storm-relative helicity
- 55 m²/s²
- 0-3 km storm-relative helicity
- 98 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KMLI 220142 SVRMLI ILC073-195-220230- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE MOLINE IL 842 PM CDT THU MAY 21 1987 THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 930 PM CDT FOR PEOPLE IN THE FOLLOWING COUNTIES OF NORTHWEST ILLINOIS...HENRY AND SOUTHERN WHITESIDE AT 837 PM CDT RADAR AT THE QUAD CITIES AIRPORT INDICATED SEVERE THUNDERSTORMS NEAR GENESEO AND SOUTHWEST OF WOODHULL. BOTH WERE MOVING NORTHEAST AT 30 MPH. SEVERE THUNDERSTORMS CAN PRODUCE ANY OR ALL OF THE FOLLOWING... DAMAGING WINDS OF 60 MPH OR MORE...LARGE HAIL...DEADLY LIGHTNING ...AND HEAVY RAINS THAT CAN QUICKLY FLOOD LOW LYING AREAS. PEOPLE IN THE PATH OF THIS STORM SHOULD TAKE COVER IMMEDIATELY. SEVERE THUNDERSTORMS CAN AND SOMETIMES DO PRODDUCE TORNADOES... SO BE ON THE LOOKOUT AND BE PREPARED TO MOVE TO A PLACE OF SAFETY IF ONE IS SPOTTED. THIS STORM IS ACCOMPANIED BY FREQUENT INTENSE LIGHTNING. SEEK SHELTER IMMEDIATELY. REMEMBER...LIGHTNING KILLS MORE POEPLE EACH YEAR THAN ANY OTHER NATURAL EVENT. THESE SLOW MOVING THUNDERSTORMS MAY CAUSE FLOODING OF SMALL STREAMS AND UNDERPASSES. DO NOT DRIVE THROUGH FLOODED AREAS. IF TIME PERMITS...ASK THE NEAREST LAW ENFORCEMENT AGENCY TO RELAY YOUR REPORT OF SEVERE WEATHER TO THE NATIONAL WEATHER SERVICE. ATTN ISP 7 AND 1 LEWIS
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, May 21, 7:16 PM CDT, 1 hour 26 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DUBUQUE IA 715 PM CDT THU MAY 21 1987 ...TORNADO WATCH UNTIL 9 PM FOR GRANT AND LAFAYETTE COUNTIES IN SOUTHWEST WISCONSIN... ...TORNADO WATCH FOR DELAWARE...DUBUQUE...JACKSON...AND JONES COUNTIES IN NORTHEAST IOWA AND JO-DAVIESS COUNTY IN NORTHWEST ILLINIOS UNTIL 10 PM CDT... AT 710 PM CDT SCATTERED THUNDERSTORMS WERE MOVING OUT OF EASTERN GRANT COUNTY IN SOUTHWEST WISCONSIN. THE STRONGEST THUNDERSTORM WAS ABOUT 15 MILES NORTH OF PLATTEVILLE. THE THUNDERSTORMS WERE MOVING TO THE NORTHEAST AT 40 MILES AN HOUR. ANOTHER AREA OF THUNDERSTORMS WAS ABOUT 15 MILES EAST OF CEDAR RAPIDS...IN EASTERN IOWA...MOVING INTO SOUTHERN JONES COUNTY. THESE THUNDERSTORMS MAY PRODUCE HEAVY RAIN AND BREIF GUSTY WINDS AS THEY MOVE ACROSS JONES COUNTY BETWEEN 730 PM CDT AND 900 PM CDT. THESE STORMS WERE ALSO MOVING TO THE NORTHEAST AT 40 MILES AN HOUR. NO SEVERE WEATHER HAD BEEN REPORTED AROUND THE TRI-STATE AREA AS OF 710 THIS EVENING. PERSONS IN TRI-STATE AREA SHOULD BE ON THE LOOKOUT FOR SEVERE WEATHER AND BE PREPARED TO TAKE COVER IF THREATENING WEATHER APPROACHES. ASMUS
Special weather statement, May 21, 7:25 PM CDT, 1 hour 17 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE MOLINE IL 725 PM CDT THU MAY 21 1987 ...STRONG THUNDERSTORMS CONTINUE IN SOUTHEASTERN IOWA... AT 720 PM CDT STRONG THUNDERSTORMS WERE LOCATED MIDWSY BETWEEN MORNING SUN AND WAPELLO IOWA ABOUT 45 MILES SOUTHWEST OF THE QUAD CITIES, ANOTHER ONE WAS ABOUT 5 MILES WEST OF MUSCATINE IOWA AND STILL ANOTHER ABOUT 15 MILES WEST OF FORT MADISON IOWA. THESE STORMS ARE CAPABLE OF PRODUCING STRONG WINDS..HAIL AND HEAVY RAIN ALONG WITH FREQUENT DANGEROUS LIGHTNING. MOVEMENT WAS TO THE NORTHEAST ABOUT 40 MPH. THE LEADING EDGE OF THESTORMS COULD REACH PORTIONS OF THE QUAD CITY METRO AREA BETWEEN 8 AND 9 PM IF THEY HOLD TOGETHER AND REMAIN ON THE PRESENT TRACK. WIGGINS
Special weather statement, May 21, 7:49 PM CDT, 53 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DUBUQUE IA 750 PM CDT THU MAY 21 1987 ...TORNADO WATCH UNTIL 9 PM CDT FOR GRANT AND LAFAYETTE COUNTIES IN SOUTHWEST WISCONSIN... ...TORNADO WATCH FOR JO-DAVIESS COUNTY IN NORTHWEST ILLINIOS UNTIL 10 PM CDT... THE TORNADO WATCH WHICH WAS TO BE IN EFFECT UNTIL 10 PM CDT FOR THE NORTHEAST IOWA COUNTIES OF DUBUQUE...DELAWARE...JACKSON...JONES... HAS BEEN CANCELLED. AT 745 PM CDT WEATHER RADAR INDICATED SCATTERED THUNDERSTORMS IN NORTHERN LAFAYETTE COUNTY WISCONSIN...NEAR CALAMINE...30 MILES NORTHEAST OF DUBUQUE. OTHER SCATTERED THUNDERSHOWERS WERE INDICATED IN SOUTHERN JACKSON AND JONES COUNTIES OF EASTERN IOWA. ALL THE PRECIPITATION WAS MOVING TO THE NORTHEAST AT AROUND 40 MILES AN HOUR. NO SEVERE WEATHER HAD BEEN REPORTED AROUND THE TRI-STATE AREA AS OF 745 THIS EVENING. ASMUS
Special weather statement, May 21, 7:54 PM CDT, 48 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE MOLINE IL 755 PM CDT THU MAY 21 1987 ...TORNADO WATCH IN EFFECT UNTIL 10 PM CDT... A CLUSTER OF STRONG THUNDERSTORMS WAS OVER MERCER COUNTY ILLINOIS JUST EAST OF ALEDO OR ABOUT 18 MILES SOUTHWEST OF THE QUAD CITIES. HICKORY NUT SIZED HAIL WAS REPORTED WITH THIS STORM AT NEW BOSTON ILLINOIS AT 730 PM. MOVEMENT WAS TO THE EASTNORTHEAST ABOUT 45 TO 40 MPH. THIS STORM WILL PASS SOUTH OF THE QUAD CITY AREA. ANOTHER STORM WAS NEAR WAPELLO IOWA ABOUT 45 MILES SOUTHWEST OF THE QUAD CITIES. MOVEMENT WAS TO THE EASTNORTHEAST 35 MPH. WIGGINS
Special weather statement, May 21, 8:16 PM CDT, 26 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE MOLINE IL 815 PM CDT THU MAY 21 1987 ...TORNADO WATCH IN EFFECT UNTIL 10 PM CDT... SEVERAL STRONG THUNDERSTORMS WERE OVER SECTIONS OF WESTERN ILINOIS. THE STRONGEST WAS NEAR GALVA ABOUT 30 MILES SOUTHEAST OF THE QUAD CITIES. ANOTHER WAS JUST SOUTHEAST OF GALESBURG ILLINOIS. THESE WERE MOVING NORTHEAST 30 MPH. A THUNDERSTORM WAS OVER THE SOUTHERN EDGE OF THE QUAD CITIES AND MOVING EASTNORTHEAST ABOUT 30 MPH. ONE STORM REMAINED IN SOUTHEASTERN IOWA JUST WEST OF WAPELLO OR ABOUT 45 MILES SOUTHWEST OF THE QUAD CITIES. MOVEMENT WAS EAST 30 MPH. WIGGINS
Special weather statement, May 21, 8:18 PM CDT, 24 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DUBUQUE IA 820 PM CDT THU MAY 21 1987 ...TORNADO WATCH UNTIL 9 PM FOR GRANT AND LAFAYETTE COUNTIES IN SOUTHWEST WISCONSIN... ...TORNADO WATCH FOR JO-DAVIESS COUNTY IN NORTHWEST ILLINIOS UNTIL 10 PM CDT... AT 815 PM CDT WEATHER RADAR INDICATED A STRONG THUNDERSTORM IN CENTRAL JACKSON COUNTY IN EASTERN IOWA NEAR THE COMMUNITY OF COTTONVILLE...20 MILES SOUTH OF DUBUQUE. THIS THUNDERSTORM WAS MOVING TO THE NORTHEAST AT AROUND 30 MILES AN HOUR. THIS LONE THUNDERSTORM IS CAPABLE OF PRODUCING HEAVY RAIN...BREIF GUSTY WINDS...DANGEROUS LIGHTNING...AND SMALL HAIL AS IT MOVES ACROSS NORTHERN JACKSON COUNTY IOWA AND MOVES INTO EASTERN JO-DAVIESS COUNTY IN NORTHWEST ILLINIOS. NO OTHER PRECIPITATON WAS INDICATED IN THE DUBUQUE AREA. AS OF 815 THIS EVENING...NO SEVERE WEATHER HAD BEEN REPORTED IN THE TRI-STATE AREA. ASMUS
Nearby
Severe Thunderstorm Warnings in Illinois, 1987Every 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.