Alert archive / Iowa / Tornado Warnings in 1986

Tornado Warning 14, NWS Des Moines, IA

July 8, 1986Decatur County, Iowa

NWS Des Moines, IA issued this tornado warning at Jul 8, 1986, 10:31 PM CDT for Decatur County, Iowa. It was in force for 29 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
Jul 8, 1986, 10:31 PM CDT (03:31 UTC)
Expired
Jul 8, 1986, 11:00 PM CDT
In force
29 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Decatur 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 8, 10:45 PM CDTTornado F0Decatur, 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, 3.5 hours before the alert went out and 226 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 1986-07-09Temperature 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 1986-07-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 68 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
3591 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
68 m²/s²
0-3 km storm-relative helicity
105 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 KDSM 090337 COR
TORDSM
IAC053-090400-

BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED
TORNADO WARNING    ..CORRECTION FOR DIRECTION OF MOVEMENT..
NATIONAL WEATHER SERVICE DES MOINES IA
1035 PM CDT TUE JUL 8 1986

THE NATIONAL WEATHER SERVICE HAS ISSUED A TORNADO WARNING
EFFECTIVE UNTIL 1100 PM CDT FOR PEOPLE IN THE FOLLOWING COUNTY OF

SOUTH CENTRAL IOWA...SOUTHWEST DECATUR

A TORNADO WAS REPORTED ON THE GROUND AT APPROXIMATELY 1015 PM CDT
6 MILES NORTHWEST OF LAMONIA..WHICH IS ABOUT 60 MILES SOUTH OF
DES MOINES.

WEATHER RADAR FROM THE WEATHER SERVICE IN DES MOINES CONTINUED TO
SHOW STRONG THUNDERSTORMS IN THE AREA AT 1025 PM CDT..MOVING TO
THE SOUTHEAST AT 30 MILES AN HOUR.

THIS WARNING INCLUDES THE TOWNS OF LAMONI AND DAVIS CITY.

IF A TORNADO APPROACHES..TAKE COVER IMMEDIATELY.  A BASEMENT..
INTERIOR HALLWAY..OR A ROOM ON THE LOWEST FLOOR IS THE SAFEST PLACE
IN MOST BUILDINGS.  IF YOU ARE IN A MOBILE HOME OR AN AUTOeMOBILE..
LEAVE AT ONCE.  TAKE COVER IN A STORM SHELTER..OR LIE IN A NEARBY
DITCH OR DEPRESSION.

DOWD/TRUETT

What forecasters said that day

The local office's own words before this tornado 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, Jul 8, 4:42 PM CDT, 5 hours 49 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
438 PM CDT TUE JUL 8 1986

A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR PARTS OF NORTHWEST AND
NORTH CENTRAL IOWA UNTIL 7PM THIS EVENING.

NO SEVERE WEATHER WAS REPORTED IN IOWA BETWEEN 335 AND 435 PM CDT.

AT 434 PM CDT...
VERY STRONG THUNDERSTORMS WERE OCCURRING OVER NORTH CENTRAL..NORTHWEST
AND PARTS OF WEST CENTRAL IOWA.  THE STRONGEST STORMS WERE IN A 20 MILE
WIDE AREA EXTENDING FROM 30 MILES SOUTHEAST OF SIOUX CITY..TO NEAR
SPENCER..THEN EAST TO JUST NORTH OF MASON CITY.  THESE STORMS WILL
PRODUCE VERY HEAVY RAIN..GUSTY WINDS AND POSSIBLY SOME SMALL HAIL.

ELSEWHERE..A FEW THUNDERSHOWERS HAD DEVELOPED OVER EAST CENTRAL IOWA.
THEY WERE IN AND JUST NORTH OF CEDAR RAPIDS.

THE STORMS WERE ALL MOVING EAST AT 30 MILES AN HOUR.  BOTH AREAL
COVERAGE AND INTENSITY WERE INCREASING.

SCHUMACHER
Special weather statement, Jul 8, 8:58 PM CDT, 1 hour 33 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
855 PM CDT TUE JUL 8 1986

A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR THE SOUTHERN TWO-THIRDS OF
IOWA UNTIL 12 MIDNIGHT.

NO SEVERE WEATHER WAS REPORTED IN IOWA BETWEEN 730 PM AND 845 PM THIS
EVENING.

AT 850 PM CDT...
THE HEAVIEST STORMS WERE IN EASTERN IOWA..IN A NARROW LINE FROM 40 MILES
EAST OF DES MOINES TO NEAR THE QUAD CITIES.  THESE STORMS WERE MOVING
SOUTHEAST AT 30 MILES AN HOUR.

IN WEST CENTRAL IOWA..THE STORMS WERE IN A LINE THAT STRETCHED FROM
JUST SOUTHWEST OF DES MOINES TO JUST SOUTH OF COUNCIL BLUFFS.
THESE STORMS WERE ALSO MOVING SOUTHEAST AT 30 MILES AN HOUR.

IN ADDITION..SCATTERED SHOWERS WERE OVER NORTHEAST IOWA.

TRUETT/SCHUMACHER
Local storm report, Jul 8, 10:22 PM CDT, 9 minutes before
LOCAL STORM REPORT
NATIONAL WEATHER SERVICE WATERLOO IA
1021 PM CDT TUE JUL 8 1986

625 PM CDT 3/4 INCH HAIL AT DUNKERTON IN BLACK HAWK COUNTY.

630 PM CDT GOLF BALL SIZE HAIL 6 MILES EAST OF WATERLOO AIURPORT.

645 PM CDT 8 INCH TREE LIMB DOWN ON STATE STREET IN CEDAR FALLS.

650 PM CDT TREE LIMBS DOWN ON JEFFERSON STREET IN WATERLOO.

755 PM CDT 2.6 INCHES OF RAIN IN JANESVILLE.

800 PM CDT 1.38 INCHES OF RAIN IN DENVER.

GOODSON

The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 8, 7:08 PM CDTSevere Thunderstorm WarningDMXAudubon37 min
Jul 8, 7:28 PM CDTSevere Thunderstorm WarningDMXGuthrie36 min
Jul 8, 8:25 PM CDTSevere Thunderstorm WarningDMXPoweshiek22 min
Jul 8, 9:05 PM CDTTornado WarningDMXPoweshiek25 min
Jul 8, 9:39 PM CDTTornado WarningDMXRinggold, Taylor26 min
Jul 8, 10:45 PM CDTSevere Thunderstorm WarningDMXAppanoose, Monroe30 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.