Alert archive / Iowa / Severe Thunderstorm Warnings in 1987
Severe Thunderstorm Warning 9, NWS Quad Cities, IA
NWS Quad Cities, IA issued this severe thunderstorm warning at Jun 17, 1987, 4:30 PM CDT for Clayton County, Delaware County, Iowa. It was in force for 50 min. 3 reports 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
- Jun 17, 1987, 4:30 PM CDT (21:30 UTC)
- Expired
- Jun 17, 1987, 5:20 PM CDT
- In force
- 50 min
- Issued by
- NWS Quad Cities, IA
- Area
- Whole counties
Counties Clayton County, IA, Delaware County, IA
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
| Time | Report | Where | Remark |
|---|---|---|---|
| Jun 17, 4:56 PM CDT | Thunderstorm Wind 52 | Delaware, IA | |
| Jun 17, 5:00 PM CDT | Thunderstorm Wind 50 | Clayton, IA | |
| Jun 17, 5:05 PM CDT | Thunderstorm Wind 55 | Clayton, IA |
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, 9.5 hours before the alert went out and 265 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
- 466 J/kg
- Mixed-layer CIN
- -105 J/kg
- Mixed-layer LCL
- 1030 m above ground
- 0-6 km bulk shear
- 8 kt
- 0-1 km storm-relative helicity
- -12 m²/s²
- 0-3 km storm-relative helicity
- 2 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 KDBQ 172132 SVRDBQ IAC043-055-172230- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE DUBUQUE IA 430 PM CDT WED JUN 17 1987 THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 530 PM CDT FOR PEOPLE IN THE FOLLOWING COUNTIES OF NORTHEAST IOWA...CLAYTON AND DELAWARE. A LINE OF SEVERE THUNDERSTORMS WERE MOVING INTO THE WESTERN PORTIONS OF CLAYTON AND DELAWARE COUNTIES IN NORTHEAST IOWA. WIND GUSTS OF 60 MILES AN HOUR WERE REPORTED IN ELKADER...45 MILES NORTHWEST OF DUBUQUE. THE SEVERE THUNDERSTORMS WERE MOVING TO THE NORTHEAST AT 35 MILES AN HOUR. IF YOU ARE IN THE PATH OF THIS STORM...OR SEE THREATENING WEATHER APPROACH...TAKE COVER IMMEDIATELY. REMEMBER, SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE TORNADOES WITH LITTLE OR NO ADVANCE WARNING. REMAIN CALM BUT BE ALERT TO RAPIDLY CHANGING WEATHER CONDITIONS. TO REPORT SEVERE WEATHER HAVE YOUR LOCAL LAW ENFORCEMENT AGENCY RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE. ASMUS
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, Jun 17, 3:46 PM CDT, 44 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DUBUQUE IA 345 PM CDT WED JUN 17 1987 ...SEVERE THUNDERSTORM WATCH FOR MOST OF THE TRI-STATE AREA UNTIL 800 PM CDT... AT 340 THIS AFTERNOON A LINE OF STRONG THUNDERSTORMS WAS PREPARING TO MOVE INTO THE WESTERN PORTIONS OF THE DUBUQUE TRI-STATE AREA. THE LINE OF THUNDERSTORMS EXTENDED FROM NEAR DECORAH...IN NORTH- EAST IOWA...THROUGH INDEPENDENCE...50 MILES WEST OF DUBUQUE...TO NEAR CEDAR RAPIDS. THE LINE OF THUNDERSTORMS WAS MOVING TO THE NORTHEAST AT 25 TO 30 MILES AN HOUR. THESE THUNDERSTORMS WILL MOVE INTO WESTERN CLAYTON AND DELAWARE COUNTIES OF NORTHEAST IOWA BETWEEN 400 AND 430 PM CDT. THESE THUNDERSTORMS WILL PRODUCE HEAVY RAIN AND DANGEROUS LIGHTNING AS THEY MOVE ACROSS THE AREA. THEY MAY ALSO PRODUCE HAIL AND STRONG GUSTY WINDS. TTHESE STORMS DID PRODUCE SOME SEVERE WEATHER AS THEY MOVED ACROSS CENTRAL AND NORTH- CENTRAL IOWA EARLIER THIS AFTERNOON. ASMUS
Nearby
Severe Thunderstorm Warnings in Iowa, 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.