Alert archive / Iowa / Tornado Warnings in 1986

Tornado Warning 21, NWS Sioux Falls, SD

July 28, 1986Sioux County, Iowa

NWS Sioux Falls, SD issued this tornado warning at Jul 28, 1986, 7:16 PM CDT for Sioux County, Iowa. It was in force for 29 min. 2 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
Jul 28, 1986, 7:16 PM CDT (00:16 UTC)
Expired
Jul 28, 1986, 7:45 PM CDT
In force
29 min
Issued by
NWS Sioux Falls, SD
Area
Whole counties

County Sioux 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
Jul 28, 7:20 PM CDTThunderstorm Wind 52Sioux, IA
Jul 28, 7:35 PM CDTThunderstorm Wind 52Sioux, 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, 0.3 hours before the alert went out and 197 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 1986-07-29Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 00:00Z on 1986-07-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 74 square meters per square second.1939587897Sfc1 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
3613 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
74 m²/s²
0-3 km storm-relative helicity
119 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 290016
TORFSD
IAC167-290045-

BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED 
TORNADO WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
716 PM CDT MON JUL 28 1986

THE NATIONAL WEATHER SERVICE HAS ISSUED A TORNADO WARNING 
EFFECTIVE UNTIL 745 PM CDT FOR PEOPLE IN THE FOLLOWING COUNTY OF

NORTHWEST IOWA...SIOUX

SOME OF THE CITIES INCLUDED IN THIS WARNING ARE SIOUX CENTER AND
ORANGE CITY IOWA.

AT 705 PM CDT  A FUNNEL CLOUD WAS REPORTED NEAR ROCK VALLEY IOWA
AND AT 710 PM CDT A FUNNEL CLOUD WAS REPORTED 2 MILES SOUTH OF
GEORGE IOWA. THESE THUNDERSTORMS WERE MOVING EASTSOUTHEAST AT
30 MPH.

IF YOU ARE IN THE PATH OF THIS TORNADO...YOU SHOULD GO TO A BASEMENT
SHELTER IF 8AVAILABLE. OTHERWISE GO TO A CENTRAL INTERIOR ROOM ON THE
LOWEST FLOOR POSSIBLE. CARS AND MOBILE HOMES SHOULD BE ABANDONED FOR
A REINFORCED BUILDING.

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 28, 7:03 PM CDTSevere Thunderstorm WarningFSDOsceola57 min
Jul 28, 7:03 PM CDTSevere Thunderstorm WarningFSDLyon57 min
Jul 28, 7:22 PM CDTTornado WarningFSDWoodbury38 min
Jul 28, 7:29 PM CDTSevere Thunderstorm WarningFSDO'Brien61 min
Jul 28, 7:43 PM CDTTornado WarningFSDO'Brien62 min
Jul 28, 8:02 PM CDTSevere Thunderstorm WarningFSDSioux58 min
Jul 28, 8:03 PM CDTTornado WarningFSDMonona, Woodbury27 min
Jul 28, 8:18 PM CDTTornado WarningFSDCherokee47 min
Jul 28, 8:34 PM CDTTornado WarningFSDMonona26 min
Jul 28, 9:02 PM CDTSevere Thunderstorm WarningFSDMonona58 min

Nearby

Tornado Warnings in Iowa, 1986Every tornado warning in 1986Tornadoes 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.