Alert archive / Iowa / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 7, NWS Sioux Falls, SD

May 30, 1987Monona County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at May 30, 1987, 9:04 PM CDT for Monona County, Iowa. It was in force for 56 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 30, 1987, 9:04 PM CDT (02:04 UTC)
Expired
May 30, 1987, 10:00 PM CDT
In force
56 min
Issued by
NWS Sioux Falls, SD
Area
Whole counties

County Monona 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

TimeReportWhereRemark
May 30, 9:15 PM CDTThunderstorm Wind 52Monona, 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

Omaha, NE (KOAX), launched 00:00Z, 2.1 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, Omaha, NE at 00:00Z on 1987-05-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Omaha, NE at 00:00Z on 1987-05-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 35 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3536 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
35 m²/s²
0-3 km storm-relative helicity
86 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 KSUX 310204
SVRSUX
IAC133-310300-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX CITY IA
904 PM CDT SAT MAY 30 1987

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM 
WARNING EFFECTIVE UNTIL 1000 PM CDT FOR PEOPLE IN THE FOLLOWING 
COUNTY OF

WEST CENTRAL IOWA...
 CENTRAL MONONA

AT 858 PM RADAR SHOWED A SEVER THUNDERSTORM 35 MILES SOUTHEAST OF
SIOUX CITY IN WEST CENTRAL MONONA COUNTY IOWA.
THIS THUNDERSTORM WAS MOVING EAST AT 25 MILES AN HOUR.

REMEMBER..A SEVERE THUNDERSTORM CAN PRODUCE DAMAGING WINDS IN EXCESS
OF 60 MPH..LARGE HAIL..DEADLY LIGHTNING..AND HEAVY RAINS THAT CAN
QUICKLY FLOOD LOW LYING AREAS.  PEOPLE IN THE PATH OF THIS STORM
SHOULD TAKE APPROPRIATE ACTION IMMEDIATELY.

IF THREATENING WEATHER APPROACHES...YOU SHOULD GO TO A SAFE PLACE
IMMEDIATELY.  IF SEVERE WEATHER CONDITIONS ARE OBSERVED..PLEASE ASK
THE NEAREST LAW ENFORCEMENT AGENCY TO RELAY YOUR REPORT TO THE
NATIONAL WEATHER SERVICE.

  QUINN

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 30, 5:47 PM CDT, 3 hours 17 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE HURON SD
540 PM CDT SAT MAY 30 1987

AT 530 PM CDT....SCATTERED INTENSE THUNDERSTORMS...SOME WITH VERY HEAVY
RAIN CONTINUED OVER NORTH CENTRAL AND NORTHEASTERN SOUTH DAKOTA...
AND HAD DEVELOPED OVER NORTHERN NEBRASKA.

THE STORMS WERE LOCATED 20 MILES EITHER SIDE OF A LINE FROM
MOBRIDGE TO WATERTOWN. ANOTHER AREA OF STORMS WERE 30 MILES SOUTH OF
A LINE FROM YANKTON TO VALENTINE NEBRASKA...40 MILES SOUTHWEST OF
WINNER.

THE STRONGEST STORMS WERE NORTHERN FAULK AND SPINK COUNTIES...NEAR
CRESBARD AND NORTHVILLE. ANOTHER STRONG STORM WAS NEAR BUTTE NEBRASKA
...50 MILES SOUTHEAST OF WINNER. THESE STORMS MAY HAVE STRONG GUSTY
WINDS...FREQUENT LIGHTNING AND HAIL.

MOVEMENT WAS EAST AT 5 MILES AN HOUR.

EDDY
Special weather statement, May 30, 6:41 PM CDT, 2 hours 23 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE HURON SD
640 PM CDT SAT MAY 30 1987

AT 630 PM CDT....SCATTERED INTENSE THUNDERSTORMS...SOME WITH VERY HEAVY
RAIN CONTINUED OVER NORTH CENTRAL AND NORTHEASTERN SOUTH DAKOTA...
NORTHERN NEBRASKA...AND HAD MOVED INTO WESTERN MINNESOTA.

THE STORMS WERE LOCATED 20 MILES NORTHEAST OF A LINE FROM MOBRIDGE
TO HURON. ANOTHER AREA OF STORMS WERE SOUTH OF LINE FROM YANKTON
TO VALENTINE NEBRASKA...40 MILES SOUTHWEST OF WINNER.

THE STRONGEST STORMS IN SOUTH DAKOTA WERE IN SOUTHERN SPINK COUNTY...
NEAR TULARE AND IN CENTRAL EDMUNDS COUNTY...NEAR ROSCOE.
THESE STORMS MAY HAVE STRONG GUSTY WINDS...FREQUENT LIGHTNING AND SMALL
HAIL.

MOVEMENT WAS SOUTH AT 5 MILES AN HOUR.

EDDY
Special weather statement, May 30, 7:36 PM CDT, 1 hour 28 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE HURON SD
730 PM CDT SAT MAY 30 1987

AT 730 PM CDT....SCATTERED INTENSE THUNDERSTORMS...SOME WITH VERY HEAVY
RAIN CONTINUED OVER NORTH CENTRAL AND EAST CENTRAL SOUTH DAKOTA...
NORTHERN NEBRASKA...AND WESTERN MINNESOTA.

THE STORMS WERE LOCATED 30 MILES NORTHEAST OF A LINE FROM MOBRIDGE
TO HURON. ANOTHER AREA OF STORMS WERE SOUTH OF LINE FROM YANKTON
TO WINNER.

THE STRONGEST STORMS IN SOUTH DAKOTA WERE IN SOUTHERN SPINK COUNTY...
NEAR HITCHCOCK AND IN WESTERN MC PHERSON COUNTY...NEAR HILLSVIEW.
THESE STORMS MAY HAVE STRONG GUSTY WINDS...FREQUENT LIGHTNING AND SMALL
HAIL.

MOVEMENT WAS SOUTH AT 5 MILES AN HO#UR.

EDDY
Special weather statement, May 30, 7:42 PM CDT, 1 hour 22 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX CITY IA
740 PM CDT SAT MAY 30 1987

...INTENSE THUNDERSTORMS ARE MOVING INTO DIXON COUNTY NEBRASKA...

AT 735 PM RADAR SHOWED AN INTENSE THUNDERSTORM SOUTHWEST OF NEWCASTLE
IN DIXON COUNTY NEBRASKA. ANOTHER STRONG THUNDERSTORM WAS NEAR WAYNE
NEBRASKA. THESE THUNDERSTORMS ARE CAPABLE OF PRODUCING VERY HEAVY
RAIN...PEA TO MARBLE SIZE HAIL AND WIND GUSTS TO 40 MILES AN HOUR.
THE THUNDEERSTORMS ARE MOVING NORTHEAST AT 20 MILES AN HOUR.

IF YOU ARE IN DIXON COUNTY NEBRASKA OR THE SOUTHWEST PART OF UNION
COUNTY SOUTH DAKOTA...BE PREPARED TO MOVE TO A PLACE OF SAFETY.

QUINN
Special weather statement, May 30, 8:46 PM CDT, 18 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX CITY IA
842 PM CDT SAT MAY 30 1987

...INTENSE THUNDERSTORMS ARE MOVING INTO MONONA COUNTY IOWA...

AT 740 PM RADAR SHOWED AN INTENSE THUNDERSTORM WEST OF ONAWA IN
MONONA COUNTY IOWA...OR 35 MILES SOUTHEAST OF SIOUX CITY. THE MONONA
COUNTY SHERIFF REPORTED WIND GUSTS OF 50 TO 60 MILES AN HOUR AND PEA
SIZE HAIL. THIS THUNDERSTORM WAS MOVING EAST AT 25 MILES AN HOUR.

IF YOU ARE IN T{HE PATH OF THIS STORM MOVE TO A PLACE OF SAFETY IF
SEVERE WEATHER APPROACHES.

OTHER SHOWERS AND THUNDERSTORMS MOVING THROUGH THE SIOUXLAND AREA
WERE PRODUCING VERY HEAVY RAIN AND DANGEROUS LIGHTNING. TAKE COVER
TO AVOID THESE STORMS.

QUINN
Special weather statement, May 30, 8:49 PM CDT, 15 minutes before
SPECIAL WEATHER STATEMENT...CORRECTED TIME...
NATIONAL WEATHER SERVICE SIOUX CITY IA
842 PM CDT SAT MAY 30 1987

...INTENSE THUNDERSTORMS ARE MOVING INTO MONONA COUNTY IOWA...

AT 840 PM RADAR SHOWED AN INTENSE THUNDERSTORM WEST OF ONAWA IN
MONONA COUNTY IOWA...OR 35 MILES SOUTHEAST OF SIOUX CITY. THE MONONA
COUNTY SHERIFF REPORTED WIND GUSTS OF 50 TO 60 MILES AN HOUR AND PEA
SIZE HAIL. THIS THUNDERSTORM WAS MOVING EAST AT 25 MILES AN HOUR.

IF YOU ARE IN THE PATH OF THIS STORM MOVE TO A PLACE OF SAFETY IF
SEVERE WEATHER APPROACHES.

OTHER SHOWERS AND THUNDERSTORMS MOVING THROUGH THE SIOUXLAND AREA
WERE PRODUCING VERY HEAVY RAIN AND DANGEROUS LIGHTNING. TAKE COVER
TO AVOID TH|ESE STORMS.

QUINN

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.