Alert archive / Iowa / Severe Thunderstorm Warnings in 1986

Severe Thunderstorm Warning 71, NWS Des Moines, IA

July 12, 1986Clarke County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jul 12, 1986, 1:29 AM CDT for Clarke County, Iowa. It was in force for 46 min.

The area

The counties it named.

The facts

Issued
Jul 12, 1986, 1:29 AM CDT (06:29 UTC)
Expired
Jul 12, 1986, 2:15 AM CDT
In force
46 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Clarke 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, 6.5 hours before the alert went out and 219 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 1986-07-12Temperature 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 1986-07-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 46 square meters per square second.193958Sfc1 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
3578 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
46 m²/s²
0-3 km storm-relative helicity
81 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 120629
SVRDSM
IAC039-120715-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
129 AM CDT SAT JUL 12 1986

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM
WARNING EFFECTIVE UNTIL 215 AM CDT FOR PEOPLE IN THE FOLLOWING
COUNTY OF

SOUTH CENTRAL IOWA...NORTHERN CLARKE

AT 120 AM..DES MOINES WEATHER RADAR INDICATED A SEVERE THUNDER-
STORM IN NORTHWEST CLARKE COUNTY OF SOUTH CENTRAL IOWA..OR ABOUT
25 TO 30 MILES SOUTH SOUTHWEST OF DES MOINES.

THE STORM WAS MOVING EAST AROUND 30 MILES AN HOUR AND WILL MOVE
ACROSS THE NORTHERN HALF OF CLARKE COUNTY AND INTO OSCEOLA BY 140 AM.

REMEMBER..A SEVERE THUNDERSTORM CAN PRODUCE DAMAGING WINDS IN EXCESS
OF 60 MPH..LARGE HAIL..DEADLY LIGHTNING..AND HEAVY RAINS THAT CAN
QUICKLY FLOOD LOW LYING AREAS.

IF THREATENING WEATHER APPROACHES..YOU SHOULD GO TO A SAFE PLACE
IMMEDIATELY.  IF SEVERE WEATHER CONDITIONS ARE OBSERVED..PLEASE #ASK
THE NEAREST LAW ENFORCEMENT AGENCY TO RELAY YOUR REPORT TO THE
NATIONAL WEATHER SERVICE.

MYERS

What forecasters said that day

The local office's own words before this severe thunderstorm 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 11, 11:39 PM CDT, 1 hour 50 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
1135 PM CDT FRI JUL 10 1986

...SEVERE THUNDERSTORM WATCH FOR SOUTHWEST IOWA TILL 5 AM CDT...

NO SEVERE WEATHER HAS BEEN REPORTED IN IOWA SINCE 1100 PM.

AT 1130 PM CDT...
A STRONG THUNDERSTORM WAS INDICATED IN WEST CENTRAL IOWA ALONG
THE MISSOURI RIVER NEAR MONDAMIN..WHICH IS 35 MILES NORTH OF
COUNCIL BLUFFS.  THIS STORM WAS MOVING EAST AT 35 MILES AN HOUR.

ISOLATED THUNDERSHOWERS WERE LOCATED IN NORTHEAST IOWA 45 MILES NORTH-
WEST OF DUBUQUE NEAR ELKADER AND OVER EAST CENTRAL IOWA 30 MILES NORTH-
WEST OF DAVENPORT NEAR TIPTON.  THESE THUNDERSTORMS WERE MOVING
EAST AT 20 MILES AN HOUR.

FE)RRY
Special weather statement, Jul 12, 1:11 AM CDT, 18 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
1235 AM CDT SAT JUL 12 1986

...SEVERE THUNDERSTORM WATCH FOR SOUTHWEST IOWA TILL 5 AM CDT...

NO SEVERE WEATHER HAS BEEN REPORTED IN IOWA SINCE 1130 PM.

AT 1235 PM CDT...
AN INTENSE THUNDERSTORM WAS INDICATED OVER SOUTHWEST IOWA 20 MILES
NORTHEAST OF COUNCIL BLUFFS.  THIS STORM WILL PRODUCE VERY HEAVY
RAIN AND POSSIBLE SOME LARGE HAIL AND HIGH WINDS AS IT MOVES EAST
AT 30 MILES AN HOUR.  THIS STORM SHOULD BE NEAR ATLANTIC BY 130 AM.

OTHER THUNDERSTORMS WERE LOCATED OVER SOUTH CENTRAL..SOUTHWEST AND
WEST CENTRAL IOWA SOUTHWEST OF A LINE FROM LAMONI TO SIOUX CITY.
THESE THUNDERSTORMS WER ALSO MOVING EAST AT 30 MILES AN HOUR.

FERRY

Nearby

Severe Thunderstorm Warnings in Iowa, 1986Every severe thunderstorm warning 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.