Alert archive / Iowa / Severe Thunderstorm Warnings in 1986

Severe Thunderstorm Warning 152, NWS Sioux Falls, SD

August 1, 1986O'Brien County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at Aug 1, 1986, 7:28 PM CDT for O'Brien County, Iowa. It was in force for 62 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
Aug 1, 1986, 7:28 PM CDT (00:28 UTC)
Expired
Aug 1, 1986, 8:30 PM CDT
In force
62 min
Issued by
NWS Sioux Falls, SD
Area
Whole counties

County O'Brien 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
Aug 1, 7:36 PM CDTThunderstorm Wind 50O'Brien, IA
Aug 1, 8:06 PM CDTThunderstorm Wind 50O'Brien, IA
Aug 1, 8:08 PM CDTThunderstorm Wind 50O'Brien, 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, 0.5 hours before the alert went out and 206 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 1986-08-02Temperature 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 1986-08-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 8 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
3554 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
8 m²/s²
0-3 km storm-relative helicity
22 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 020028 RRA
SVRSUX
IAC141-020130-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX-CITY IA
728 PM CDT FRI AUG  1 1986
 
THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WARNING
EFFECTIVE UNTIL  830 PM CDT FOR PEOPLE IN THE FOLLOWING COUNTIES:
 
IN NORTHWEST IOWA
          ..OBRIEN

 
 
AT 725 PM CDT RADAR A LINE OF INTENSE THUNDERSTORMS ALONG THE O-BRIEN
AND OSCEOLA COUNTY LINE...65 MILES NORTHEAST OF SIOUX CITY.
 
THESE THUNDERSTORMS WERE MOVING SOUTHEAST AT 30 MILES AN HOUR.
 
 
SEVERE THUNDERSTORMS CAN...AND OCCASIONALLY DO... PRODUCE TORNADOES WI
OUR WARNING.
 
IF YOU ARE CAUGHT OUTSIDE, SEEK SHELTER FROM THE WEATHER IN A
STRONG BUILDING.  DAMAGING WIND, LARGE HAIL, VERY HEAVY RAIN, AND
DEADLY LIGHTNING ARE ALL POSSIBLE IN SEVERE THUNDERSTORMS.  STAY
INSIDE AWAY FROM WINDOWS UNTIL THE STORM HAS PASSED.
 
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 55 MPH,
DESTRUCTIVE HAIL, DEADLY LIGHTNING AND VERY HEAVY RAIN.  FOR YOUR
PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR
HOME OR BUSINESS.  HEAVY RAINS FLOOD ROADS QUICKLY SO DON'T DRIVE
INTO AREAS WHERE WATER COVERS THE ROAD.
SHERLIN

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, Aug 1, 5:53 PM CDT, 1 hour 35 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
550 PM CDT FRI AUG 1 1986

...SEVERE THUNDERSTORM WATCH UNTIL 900 PM CDT FOR PARTS OF EASTERN
SOUTH DAKOTA..SOUTHERN MINNESOTA..AND NORTHERN IOWA...

AT 550 PM CDT A LINE OF INTENSE THUNDERSTORMS EXTENDED FROM 10 MILES
NORTH OF SIOUX FALLS NEAR DELL RAPIDS TO 25 MILES EAST/NORTHEAST OF
WORHTINGTON MINNESOTA NEAR FAIRMONT MINNESOTA. THIS LINE OF INTENSE
THUNDERSTORMS WAS PRODUCING PEA SIZE HAIL..HEAVY RAINS..DANGEROUS
LIGHTNING..AND PERHAPS GUSTY WINDS AS IT MOVES SOUTHEAST AT 20 MPH.

THIS LINE OF INTENSE THUNDERSTORMS WILL AFFECT THE AREA FROM SIOUX
FALLS EAST THROUGH WORTHINGTON AND JACKSON TO FAIRMONT MINNESOTA
BETWEEN 600 PM CDT AND 800 PM CDT.

PEA SIZE HAIL AND VERY HEAVY RAINS WERE REPORTED OVER COTTONWOOD
COUNTY IN SOUTHWESTERN MINNESOTA AS THE THUNDERSTORMS MOVED THROUGH
THAT COUNTY BETWEEN 400 AND 530 PM CDT.
<
AT 550 PM CDT ANOTHER LINE OF THUNDERSTORMS WITH BRIEF HEAVY RAINS
EXTENDED FROM 15 MILES WEST OF SIOUX FALLS BACK TO 25 MILES SOUTHWEST
OF MITCHELL SOUTHH DAKOTA. THESE THUNDERSTORMS WERE ALSO MOVING TO
THE SOUTHEAST AND WILL AFFECT THE AREA SOUTH OF SIOUX FALLS BETWEEN
600 PM CDT AND 800 PM CDT.

NO SEVERE WEATHER HAS BEEN REPORTED SINCE THE SEVERE THUNDERSTORM
WATCH WENT INTO EFFECT.

EVENTUALLY NORTHWESTERN IOWA WILL EXPERIENCE THE SCATTERED THUNDERSTORMS
BETWEEN 700 PM CDT AND 900 PM CDT.
KAPELA
Special weather statement, Aug 1, 6:05 PM CDT, 1 hour 23 minutes before
RADAR SUMMARY AND SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HURON SD
545 PM CDT FRI AUG 1 1986

...A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR EASTERN SOUTH
 DAKOTA AND MINNESOTA UNTIL 9:00 PM CDT...

AT 530 PM CDT...WIDELY SCATTERED INTENSE THUNDERSTORMS WITH
VERY HEAVY RAIN WERE LOCATED OVER PARTS OF EASTERN SOUTH DAKOTA
AND SOUTHWEST MINNESOTA.

IN SOUTH DAKOTA AN INTENSE THUNDERSTORM WAS OCCURING 20 MILES
SOUTH OF BROOKINGS..ANOUTHER JUST SOUTHWEST OF MITCHELL..AND
ANOUTHER 30 MILES SOUTHEAST OF HURON.

MOVEMENT WAS EAST AT 25 MILES AN HOUR.

EDDY/SPRINGER
Special weather statement, Aug 1, 6:07 PM CDT, 1 hour 21 minutes before
RADAR SUMMARY AND SPECIAL WEATHER STATEMENT...CORRECTION
NATIONAL WEATHER SERVICE HURON SD
545 PM CDT FRI AUG 1 1986

...A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR EASTERN SOUTH
 DAKOTA AND MINNESOTA UNTIL 9:00 PM CDT...

AT 530 PM CDT...WIDELY SCATTERED INTENSE THUNDERSTORMS WITH
VERY HEAVY RAIN WERE LOCATED OVER PARTS OF EASTERN SOUTH DAKOTA
AND SOUTHWEST MINNESOTA.

IN SOUTH DAKOTA AN INTENSE THUNDERSTORM WAS OCCURING 20 MILES
SOUTH OF BROOKINGS..ANOUTHER JUST SOUTHWEST OF MITCHELL..AND
ANOUTHER 30 MILES SOUTHEAST OF HURON.

MOVEMENT WAS EAST AT 25 MILES AN HOUR.

EDDY/SPRINGER
Special weather statement, Aug 1, 6:09 PM CDT, 1 hour 19 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX CITY IA
608 PM CDT FRI AUG 1 1986

..SEVERE THUNDERSTORM WATCH FOR SIOUX,OBRIEN AND UNION COUNTIES
  TIL 9 PM...

AT 605 PM CDT RADAR INDICATED AN LINE OF STRONG THUNDERSTORMS EXTENDING
FROM 25 MILES SOUTHWEST OF MITCHELL SOUTH DAKOTA TO 15 MILE WEST OF
SIOUX FALLS SOUTH DAKATO. THESES THUNDERSTORMS LIKELY CONTAIN DANGEROUS
LIGHTNING..HEAVY RAIN..GUSTY WINDS AND POSSIBLE SMALL HAIL.

PERSONS IN UNION COUNTY SOUTH DAKOTA SHOULD REMAIN ALERT FOR THREATENING
WEATHER AS THESE THUNDERSTORMS MOVE SOUTHEAST ACROSS THE AREA AT 25 MILES
AN HOUR. THESE STORMS SHOULD ENTER UNION COUNTY AROUND 7 PM.

TANNER
Special weather statement, Aug 1, 6:10 PM CDT, 1 hour 18 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX CITY IA
608 PM CDT FRI AUG 1 1986

..SEVERE THUNDERSTORM WATCH FOR SIOUX,OBRIEN AND UNION COUNTIES
  TIL 9 PM...

AT 605 PM CDT RADAR INDICATED AN LINE OF STRONG THUNDERSTORMS EXTENDING
FROM 25 MILES SOUTHWEST OF MITCHELL SOUTH DAKOTA TO 15 MILE WEST OF
SIOUX FALLS SOUTH DAKATO. THESES THUNDERSTORMS LIKELY CONTAIN DANGEROUS
LIGHTNING..HEAVY RAIN..GUSTY WINDS AND POSSIBLE SMALL HAIL.

PERSONS IN UNION COUNTY SOUTH DAKOTA SHOULD REMAIN ALERT FOR THREATENING
WEATHER AS THESE THUNDERSTORMS MOVE SOUTHEAST ACROSS THE AREA AT 25 MILES
AN HOUR. THESE STORMS SHOULD ENTER UNION COUNTY AROUND 730 PM.

TANNER
Special weather statement, Aug 1, 6:46 PM CDT, 42 minutes before
RADAR SUMMARY AND SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HURON SD
645 PM CDT FRI AUG 1 1986

...A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR EASTERN SOUTH
 DAKOTA AND MINNESOTA UNTIL 9:00 PM CDT...

AT 630 PM CDT...WIDELY SCATTERED INTENSE THUNDERSTORMS WITH
VERY HEAVY RAIN WERE LOCATED OVER PARTS OF EASTERN SOUTH DAKOTA
AND SOUTHWEST MINNESOTA AND NORTHWEST IOWA.

IN SOUTH DAKOTA AN AREA OF INTENSE THUNDERSTORMS WAS OCCURING
10 MILES EITHER SIDE OF A LINE FROM 20 MILES SOUTHWEST OF MITCHELL
TO 15 MILES SOUTHWEST OF SIOUX FALLS.

THESE THUNDERSTORMS MAY PRODUCE VERY HEAVY RAINS..LARGE HAIL..AND
GUSTY WINDS.

MOVEMENT WAS SOUTHEAST AT 25 MILES AN HOUR.
EDDY/SPRINGER

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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.