Alert archive / Iowa / Severe Thunderstorm Warnings in 1986

Severe Thunderstorm Warning 201, NWS Sioux Falls, SD

September 28, 1986Osceola County, Sioux County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at Sep 28, 1986, 6:05 PM CDT for Osceola County, Sioux County, Iowa. It was in force for 55 min.

The area

The counties it named.

The facts

Issued
Sep 28, 1986, 6:05 PM CDT (23:05 UTC)
Expired
Sep 28, 1986, 7:00 PM CDT
In force
55 min
Issued by
NWS Sioux Falls, SD
Area
Whole counties

Counties Osceola County, IA, Sioux County, IA

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

Omaha, NE (KOAX), launched 12:00Z, 11.1 hours before the alert went out and 216 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 12:00Z on 1986-09-28Temperature 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 12:00Z on 1986-09-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 150 square meters per square second.193958Sfc1 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
3615 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
150 m²/s²
0-3 km storm-relative helicity
184 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 KFSD 282305
SVRFSD
IAC143-167-290000-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
605 PM CDT SUN SEP 28 1986

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM 
WARNING EFFECTIVE UNTIL 700 PM CDT FOR PEOPLE IN THE FOLLOWING 
COUNTIES OF

NORTHWEST IOWA...WESTERN OSCEOLA AND EASTERN SIOUX

SOME OF THE CITIES INCLUDED IN THIS WARNING ARE ALTON AND SIBLEY.

AT 600 PM CDT  RADAR INDICATED A SEVERE THUNDERSTORM TEN MILES
NORTHEAST OF IOUX CENTER IOWA. THE SEVERE THUNDERSTORM WAS
MOVING EAST NORTHEAST AT 30 MPH.

 AT 547 PM CDT MARBLE SIZE HAIL WAS REPORTED FIFTEEN MILES
WEST OF ROCK VALLEY AND ONE MILE WEST OF SIOUX CENTER.

IF YOU ARE IN THE PATH OF THIS STORM..YOU SHOULD GET TO A REINFORCED
SHELTER. A SEVERE THUNDERSTORM PRODUCES DAMAGING WINDS IN EXCESS OF
60 MPH..HAIL 3/4 INCH OR LARGER..DEADLY LIGHTNING..AND HEAVY RAIN
THAT CAN QUICKLY FLOOD A LOW LYING ARLEA.

THESE STORMS CAN AND OCCASIONALLY DO PRODUCE A TORNADO WITH LITTLE OR
NO ADVANCE WARNING SO BE ON THE LOOKOUT.

WEILAND

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, Sep 28, 4:49 PM CDT, 1 hour 16 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
445 PM CDT SUN SEP 28 1986

AT 443 PM CDT
A LARGE INTENSE THUNDERSTORM WITH VERY HEAVY RAIN AND POSSIBLE HAIL
DEVELOPED RAPIDLY OVER EASTCENTRAL CLAY INTO NORTHEAST UNION COUNTY IN
EXTREME SOUTHEAST SOUTH DAKOTA. THE STORM RAN FROM ABOUT 5 MILES NORTH
OF VERMILLION TO ALCESTER. THE STORM WAS MOVING TO THE NORTHEAST AT
ABOUT 30 MPH AND WILL MOVE INTO SIOUX COUNTY IOWA BETWEEN 445PM AND
545 PM CDT.

PEOPLE IN THE PATH OF THIS STORM SHOULD BE ALERT TO POSSIBLE SEVERE
WEATHER.
KOSCIELSKI
Special weather statement, Sep 28, 5:13 PM CDT, 52 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX CITY IA
515 PM CDT SUN SEP 28 1986

...TORNADO WATCH FOR IDA...CHEROKEE AND OBRIEN COUNTIES TIL 11PM CDT...

AT 500 PM CDT A TORNADO WATCH WAS IN EFFECT FOR IDA...CHEROKEE AND
OBRIEN COUNTIES OF IOWA UNTIL 1100 PM CDT. NO SEVERE WEATHER HAD BEEN
REPORTED BEFORE 500 PM CDT.

VERY INTENSE THUNDERSTORMS WERE LOCATED IN MONONA COUNTY IOWA AND UNION
COUNTY SOUTH DAKOTA AT 500 PM CDT. THESE STORMS WERE NEAR ONAWA OR ABOUT
25 MILES SOUTHEAST OF SIOUX CITY AND NEAR ALCESTER SOUTH DAKOTA OR ABOUT
40 MILES NORTHWEST OF SIOUX CITY.

THESE STORMS HAVE THE POTENTIAL TO PRODUCE PEA TO MARBLE SIZE HAIL...
STRONG GUSTY WINDS AND HEAVY RAIN AiS THEY MOVE NORTHEAST ACROSS THE
SIOUXLAND AREA AT 35 MILES AN HOUR. STORMS WILL MOVE INTO EASTERN
WOODBURY...SOUTHERN OBRIEN AND IDA COUNTIES BY 600 PM CDT.

KROPP

The office that day

Everything else NWS Sioux Falls, SD issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 28, 5:24 PM CDTTornado WarningFSDSioux36 min
Sep 28, 5:42 PM CDTSevere Thunderstorm WarningFSDLyon63 min

Nearby

Severe Thunderstorm Warnings in Iowa, 1986Every severe thunderstorm warning in 1986

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.