Alert archive / Iowa / Severe Thunderstorm Warnings in 1987
Severe Thunderstorm Warning 2, NWS Quad Cities, IA
NWS Quad Cities, IA issued this severe thunderstorm warning at May 20, 1987, 5:10 PM CDT for Scott County, Iowa. It was in force for 50 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 20, 1987, 5:10 PM CDT (22:10 UTC)
- Expired
- May 20, 1987, 6:00 PM CDT
- In force
- 50 min
- Issued by
- NWS Quad Cities, IA
- Area
- Whole counties
County Scott 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 |
|---|---|---|---|
| May 20, 5:50 PM CDT | Thunderstorm Wind 52 | Scott, 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, 10.2 hours before the alert went out and 137 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
- 1840 J/kg
- Mixed-layer CIN
- -73 J/kg
- Mixed-layer LCL
- 690 m above ground
- 0-6 km bulk shear
- 30 kt
- 0-1 km storm-relative helicity
- 56 m²/s²
- 0-3 km storm-relative helicity
- 65 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.8
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KMLI 202210 SVRMLI IAC163-ILC161-131-073-202300- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE MOLINE IL 510 PM CDT WED MAY 20 1987 THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 600 PM CDT FOR PEOPLE IN THE FOLLOWING COUNTIES OF EXTREME EAST IOWA...EASTERN SCOTT NORTHWEST ILLINOIS...ROCK-ISLAND...NORTHERN MERCER AND HENRY AT 502 PM CDT A SEVERE THUNDERSTORM WAS IN THE QUAD CITIES AREA MOVING EAST ABOUT 25 TO 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 A4REAS. 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 20, 2:00 PM CDT, 3 hours 10 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE MOLINE IL 159 PM CDT WED MAY 20 1987 ...STRONG THUNDERSTORMS DEVELOPING RAPIDLY IN SOUTHEAST IOWA... AT 155 PM CDT...NUMEROUS THUNDERSTORMS..SOME STRONG..WERE OVER SOUTHEAST IOWA BOUNDED BY A LINE FROM MT PLEASANT TO BURLINGTON TO KEOKUK TO MT PLEASANT. ANOTHER CLUSTER OF THUNDERSTORMS WAS NEAR COLUMBUS JUNCTION IOWA ABOUT 40 MILES WESTSOUTHWEST OF THE QUAD CITIES. SOME OF THESE STORMS MAY BE ACCOMPANIED BY BRIEF HEAVY RAIN.. STRONG WIND GUSTS AND POSSIBLE SMALL HAIL. MOVEMENT WAS TO NORTHNORTHEAST ABOUT 25 MPH. WIGGINS
Special weather statement, May 20, 4:15 PM CDT, 55 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE MOLINE IL 415 PM CDT WED MAY 20 1987 AT 410 PM CDT A CLUSTER OF STRONG THUNDERSTORMS WAS BETWEEN MUSCATINE AND DURANT IN EASTERN IOWA..OR ABOUT 20 MILES WEST OF THE QUAD CITIES. THESE STORMS ARE LIKELY TO PRODUCE HEAVY DOWNPOURS..HAIL..STRONG WINDS AND FREQUENT DANGEROUS LIGHTNING AS THEY MOVE TO THE NORTHNORTHEAST ABOUT 30 MPH. ANOTHER STRONG THUNDERSTORM WAS NEAR MORNING SUN IOWA ABOUT 50 PMILES SOUTHWEST OF THE QUAD CITIES. THESE STORMS WERE PART OF A LARGER AREA OF SHOWERS AND THUNDERSTORMS THAT COVERED MOST OF SOUTHEAST IOWA AND A SMALL SECTION OF WESTERN ILLINOIS. MOVEMENT WAS TO THE NORTH ABOUT 30 MPH. WIGGINS
The office that day
Everything else NWS Quad Cities, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 20, 3:24 PM CDT | Tornado Warning | DVN | Cedar, Muscatine | 21 min |
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.