Alert archive / Iowa / Tornado Warnings in 1986

Tornado Warning 12, NWS Omaha, NE

July 30, 1986Montgomery County, Iowa

NWS Omaha, NE issued this tornado warning at Jul 30, 1986, 11:26 PM CDT for Montgomery County, Iowa. It was in force for 34 min.

The area

The counties it named.

The facts

Issued
Jul 30, 1986, 11:26 PM CDT (04:26 UTC)
Expired
Jul 31, 1986, 12:00 AM CDT
In force
34 min
Issued by
NWS Omaha, NE
Area
Whole counties

County Montgomery 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, 4.4 hours before the alert went out and 107 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 1986-07-31Temperature 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 1986-07-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 20 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
3632 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
20 m²/s²
0-3 km storm-relative helicity
118 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 KOMA 310426
TOROMA
IAC137-310500-

BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED 
TORNADO WARNING
NATIONAL WEATHER SERVICE OMAHA NE
1126 PM CDT WED JUL 30 1986

THE NATIONAL WEATHER SERVICE HAS ISSUED A TORNADO WARNING 
EFFECTIVE UNTIL 1200 AM CDT FOR PEOPLE IN THE FOLLOWING COUNTY OF

SOUTHWEST IOWA...EASTERN MONTGOMERY

AT 1125 PM RADAR INDICATED A POSSIBLE TORNADO NEAR ELLIOTT IOWA ABOUT
40 MILES EASTSOUTHEAST OF OMAHA.  THE STORM WAS MOVING SOUTHEAST
AT 15 MPH.

PERSONS IN THE WARNED AREA SHOULD TAKE SHELTER IN A BASEMENT IF
AVAILABLE.  OTHERWISE GO TO A SMALL INTERIOR ROOM ON THE LOWEST
FLOOR.  CARS AND MOBILE HOMES SHOULD BE ABANDONED.

IF YOU ARE CAUGHT IN THE OPEN..TRY TO HIDE IN A DEPRESSION LIKE
A DITCH OR CULVERT.

GAVERS

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 30, 7:09 PM CDT, 4 hours 17 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE OMAHA NE
705 PM CDT WED JUL 30 1986

SEVERE THUNDERSTORM WATCH NUMBER 434 REMAINS IN EFFECT FOR PARTS OF
EASTERN NEBRASKA UNTIL 10 PM CDT TONIGHT.

AT 7PM CDT THUNDERSTORMS WERE OCCURRING IN NORTHERN MISSOURI AND
SOUTHERN IOWA BUT NO STORMS HAD DEVELOPED IN EASTERN NEBRASKA.

IT NOW APPEARS DOUBTFUL THAT SEVERE WEATHER WILL DEVELOP IN EASTERN
NEBRASKA THIS EVENING..THE WATCH WILL LIKELY BE CANCELLED WITHIN
ONE TO TWO HOURS.

GAVERS
Special weather statement, Jul 30, 10:41 PM CDT, 45 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE OMAHA NE
1040 PM CDT WED JUL 30 1986

INTENSE THUNDERSTORMS HAVE DEVELOPED IN POTTAWATTAMIE COUNTY OF
SOUTHWEST IOWA.  THE STORMS WERE CENTERED BETWEEN OAKLAND AND HANCOCK..
ABOUT 30 MILES EAST OF OMAHA.

GUSTY WINDS..HAIL..DANGEROUS LIGHTNING AND HEAVY RAINS CAN BE EXPECTED
WITH THESE STORMS UNTIL AROUND 1130 PM CDT TONIGHT.

GAVERS

The office that day

Everything else NWS Omaha, NE issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 30, 10:54 PM CDTSevere Thunderstorm WarningOAXPottawattamie66 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.