Alert archive / Iowa / Tornado Warnings in 1986

Tornado Warning 20, NWS Des Moines, IA

July 28, 1986Crawford County, Iowa

NWS Des Moines, IA issued this tornado warning at Jul 28, 1986, 9:10 PM CDT for Crawford County, Iowa. It was in force for 20 min.

The area

The counties it named.

The facts

Issued
Jul 28, 1986, 9:10 PM CDT (02:10 UTC)
Expired
Jul 28, 1986, 9:30 PM CDT
In force
20 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Crawford 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 00:00Z, 2.2 hours before the alert went out and 114 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°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 00:00Z on 1986-07-29The 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 KDSM 290210
TORDSM
IAC047-290230-

BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED 
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
910 PM CDT MON JUL 28 1986

THE NATIONAL WEATHER SERVICE HAS ISSUED A TORNADO WARNING 
EFFECTIVE UNTIL 930 PM CDT FOR PEOPLE IN THE FOLLOWING COUNTY OF

WEST CENTRAL IOWA...SOUTHWEST CRAWFORD

AT 905 PM...A TORNADO WAS REPORTED NEAR CHARTER OAK IN
EXTREME WEST CENTRAL CRAWFORD COUNTY..ABOUT 50 MILES SO%UTHEAST
OF SIOUX CITY

THE STORM WAS MOVING SOUTHEAST AT 35 MILES AN HOUR.

 IF YOU ARE IN THE PATH OF THIS STORM..TAKE COVER
 IMMEDIATELY.

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 28, 5:35 PM CDT, 3 hours 35 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
535 PM CDT MON JUL 28 1986

..A TORNADO WATCH IS IN EFFECT FOR A LARGE PART OF WESTERN IOWA
UNTIL 11 PM..

AT 530 PM CDT..NO PRECIPITATION WAS OCCURRING IN IOWA..HOWEVER
VERY STRONG THUNDERSTORMS WERE RAPIDLY DEVELOPING OVER WESTERN
MINNESOTA..NORTHEAST NEBRASKA AND SOUTHEAST SOUTH DAKOTA.

THESE STORMS WERE MOVING SOUTHEAST AT 25 TO 30 MILES AN HOUR A"ND
SHOULD BE ENTERING NORTHWEST IOWA AROUND 7 PM THIS EVENING.

BARLOW
Special weather statement, Jul 28, 8:53 PM CDT, 17 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
845 PM CDT MON JUL 28 1986

A NARROW BAND OF SHOWERS AND THUNDERSTORMS HAVE DEVELOPED IN
NORTHCENTRAL IOWA.  THESE SHOWERS AND THUNDERSTORMS WERE THE RESULT
OF OUT RUSHING WINDS FROM THE STRONG THUNDERSTORM SOUTH OF SPENCER.

THE BAND OF RAIN EXTENDED FROM 30 MILES WEST OF MASON CITY..NEAR
ALGONA..TO 40 MILES SOUTHWEST OF WATERLOO..NEAR ELDORA.  THESE
THUNDERSTRORMS WERE MOVING EAST AT 20 MILES AN HOUR.

AT THE PRESENT TIME RAIN AND LIGHTNING COULD  OCCUR AS THESE SHOWERS
AND THUNDERSTORMS MOVE INTO HANCOCK..FRANKLIN AND GRUNDY COUNTIES.
HAMILTON

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 28, 7:07 PM CDTSevere Thunderstorm WarningDMXClay63 min
Jul 28, 7:48 PM CDTTornado WarningDMXClay32 min
Jul 28, 7:57 PM CDTTornado WarningDMXBuena Vista, Pocahontas58 min
Jul 28, 8:07 PM CDTTornado WarningDMXBuena Vista48 min
Jul 28, 8:51 PM CDTSevere Thunderstorm WarningDMXCalhoun, Pocahontas, Webster64 min
Jul 28, 9:22 PM CDTSevere Thunderstorm WarningDMXCarroll, Greene58 min
Jul 28, 9:34 PM CDTTornado WarningDMXCarroll, Crawford56 min
Jul 28, 9:48 PM CDTSevere Thunderstorm WarningDMXGuthrie42 min
Jul 28, 9:48 PM CDTSevere Thunderstorm WarningDMXBoone, Dallas, Hamilton42 min
Jul 28, 10:14 PM CDTSevere Thunderstorm WarningDMXPolk, Story46 min
Jul 28, 10:14 PM CDTSevere Thunderstorm WarningDMXMadison46 min
Jul 28, 10:27 PM CDTTornado WarningDMXJasper, Polk53 min
Jul 28, 10:31 PM CDTSevere Thunderstorm WarningDMXWarren49 min
Jul 28, 10:31 PM CDTSevere Thunderstorm WarningDMXMarshall49 min
Jul 28, 10:46 PM CDTSevere Thunderstorm WarningDMXMarion54 min
Jul 28, 10:54 PM CDTSevere Thunderstorm WarningDMXClarke, Lucas46 min
Jul 28, 11:16 PM CDTSevere Thunderstorm WarningDMXMahaska, Monroe44 min
Jul 28, 11:16 PM CDTSevere Thunderstorm WarningDMXPoweshiek44 min
Jul 28, 11:22 PM CDTSevere Thunderstorm WarningDMXAdair98 min
Jul 28, 11:38 PM CDTTornado WarningDMXAdair, Union97 min
Jul 28, 11:47 PM CDTSevere Thunderstorm WarningDMXKeokuk, Wapello43 min
Jul 28, 11:47 PM CDTSevere Thunderstorm WarningDMXAppanoose, Davis43 min
Jul 29, 12:10 AM CDTSevere Thunderstorm WarningDMXJefferson, Van Buren50 min
Jul 29, 12:50 AM CDTSevere Thunderstorm WarningDMXDecatur, Wayne55 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; the sounding from the Mesonet's radiosonde archive.