Alert archive / Iowa / Tornado Warnings in 1986

Tornado Warning 17, NWS Des Moines, IA

July 28, 1986Clay County, Iowa

NWS Des Moines, IA issued this tornado warning at Jul 28, 1986, 7:48 PM CDT for Clay County, Iowa. It was in force for 32 min.

The area

The counties it named.

The facts

Issued
Jul 28, 1986, 7:48 PM CDT (00:48 UTC)
Expired
Jul 28, 1986, 8:20 PM CDT
In force
32 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Clay 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, 0.8 hours before the alert went out and 220 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 KDSM 290048
TORDSM
IAC041-290120-

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

THE NATIONAL WEATHER SERVICE HAS ISSUED A TORNADO WARNING
EFFECTIVE UNTIL 820 PM CDT FOR PEOPLE IN THE FOLLOWING COUNTY OF

NORTHWEST IOWA...CLAY

AT 732 PM CDT WEATHER SERVICE RADAR IN DES MOINES INDICATED AN
EXTREMELY INTENSE THUNDERSTORM..WITH THE STRONGEST PORTION OF THE
STORM JUST ENTERING NORTHWEST CLAY COUNTY.  THERE HAVE ALREADY
BEEN REPORTS OF 50 TO 70 MILE AN HOUR WINDS NORTHWEST OF SPENCER
IN THIS STORM.  THE STORM WAS MOVING FROM THE NORTHWEST AT 30 TO
35 MILES AN HOUR.

THIS WARNING INCLUDES THE TOWNS OF ROSSIE AND GREENVILLE.

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 AUTOMOBILE..
LEAVE AT ONCE.  TAKE COVER IN A STORM SHELTER..OR LIE IN A NEARBY
DITCH OR DEPRESSION.

DOWD/BARLOW

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, 2 hours 13 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

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, 7:57 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, 9:10 PM CDTTornado WarningDMXCrawford20 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.