Alert archive / Iowa / Severe Thunderstorm Warnings in 1986

Severe Thunderstorm Warning 69, NWS Des Moines, IA

July 8, 1986Poweshiek County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jul 8, 1986, 8:25 PM CDT for Poweshiek County, Iowa. It was in force for 22 min.

The area

The counties it named.

The facts

Issued
Jul 8, 1986, 8:25 PM CDT (01:25 UTC)
Expired
Jul 8, 1986, 8:47 PM CDT
In force
22 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Poweshiek 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

Peoria Regional, IL (KPIA), launched 00:00Z, 1.4 hours before the alert went out and 270 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, Peoria Regional, IL at 00:00Z on 1986-07-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1445 joules per kilogram.LCLLFCEL10008507005003002001001 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, Peoria Regional, IL at 00:00Z on 1986-07-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 129 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
1445 J/kg
Mixed-layer CIN
-29 J/kg
Mixed-layer LCL
1379 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
129 m²/s²
0-3 km storm-relative helicity
208 m²/s²
Significant tornado parameter
0.3
Supercell composite
7.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KDSM 090127
SVRDSM
IAC157-090200-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
825 PM CDT TUE JUL 8 1986

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM
WARNING EFFECTIVE UNTIL 900 PM CDT FOR PEOPLE IN THE FOLLOWING
COUNTY OF

CENTRAL IOWA...SOUTHEAST HALF OF POWESHIEK.

AT 820 PM CDT RADAR AT THE NATIONAL WEATHER SERVICE IN DES MOINES
INDICATED A SEVERE STORM MOVING SOUTHEAST AT 30 MILES AN HOUR
MOVING ACROSS POWESHIEK COUNTY.

AT 820 PM CDT AN OBSERVER AT HARTWICK REPORTED WINDS OF UP TO 60
MPH.  HARTWICK IS 40 MILES EAST OF IOWA CITY.

TOWNS AND CITIES THAT ARE MOST VULNERABLE TO THIS STORM INCLUDE
BROOKLYN AND MONTEZUMA.

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.  PEOPLE IN THE PATH OF THIS STORM
SHOULD TAKE APPROPRIATE ACTION IMMEDIATELY.

DOWD/MS

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 8, 2:42 PM CDT, 5 hours 43 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
2 35PM CDT TUE JUL 8 1986

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

AT 230 PM CDT...NO SEVERE WEATHER HAD BEEN REPORTED IN IOWA..HOWEVER
A FEW SHOWERS AND THUNDERSHOWERS HAD ENTERED EXTREME NORTHWEST IOWA
AND WERE LOCATED NEAR SIOUX CENTER..ABOUT 35 MILES SOUTHEAST OF SIOUX
FALLS.

HEAVIER THUNDERSTORMS WERE LOCATED IN SOUTHWEST AND SOUTH CENTRAL
MINNESOTA..AND IN NORTHEAST NEBRASKA.

THESE THUNDERSTORMS WERE MOVING TO THE SOUTHEAST AT 30 MILES AN HOUR..
AND WILL BE ENTERING IOWA NEAR SPIRIT LAKE..AND ALSO NEAR SIOUX CITY.
|
SCOTT
Special weather statement, Jul 8, 3:41 PM CDT, 4 hours 44 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
339 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 235 AND 335 PM CDT.

AT 331 PM CDT...
SCATTERED SHOWERS AND THUNDERSTORMS WERE LOCATED OVER EXTREME NORTHWEST
IOWA.  THEY WERE GENERALLY BETWEEN SIOUX CITY AND THE SPENCER AREA.

A VERY STRONG STORM WAS LOCATED OVER NORTHEAST NEBRASKA.  THIS STORM
WILL MOVE INTO THE ONAWA AREA OF WEST CENTRAL IOWA BY 400 PM.

THE SHOWERS AND STORMS WERE MOVING SOUTHEAST AT 30 MILES AN HOUR.

SCHUMACHER
Special weather statement, Jul 8, 4:42 PM CDT, 3 hours 43 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

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, 9:05 PM CDTTornado WarningDMXPoweshiek25 min
Jul 8, 9:39 PM CDTTornado WarningDMXRinggold, Taylor26 min
Jul 8, 10:31 PM CDTTornado WarningDMXDecatur29 min
Jul 8, 10:45 PM CDTSevere Thunderstorm WarningDMXAppanoose, Monroe30 min

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.