Alert archive / Iowa / Severe Thunderstorm Warnings in 1986

Severe Thunderstorm Warning 41, NWS Des Moines, IA

May 12, 1986Clay County, Dickinson County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at May 12, 1986, 5:50 PM CDT for Clay County, Dickinson County, Iowa. It was in force for 40 min. 2 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
May 12, 1986, 5:50 PM CDT (22:50 UTC)
Expired
May 12, 1986, 6:30 PM CDT
In force
40 min
Issued by
NWS Des Moines, IA
Area
Whole counties

Counties Clay County, IA, Dickinson County, IA

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

What was reported inside it

TimeReportWhereRemark
May 12, 6:20 PM CDTHail 1Clay, IA
May 12, 6:25 PM CDTHail 0.75Clay, IA

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.

The nearest sounding before it

Minneapolis, MN (KSTC), launched 12:00Z, 10.8 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, Minneapolis, MN at 12:00Z on 1986-05-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 62 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, Minneapolis, MN at 12:00Z on 1986-05-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 134 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
62 J/kg
Mixed-layer CIN
-206 J/kg
Mixed-layer LCL
776 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
134 m²/s²
0-3 km storm-relative helicity
93 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 122252
SVRDSM
IAC041-059-122330-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
550 PM CDT MON MAY 12 1986

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM
WARNING EFFECTIVE UNTIL 630 PM CDT FOR PEOPLE IN THE FOLLOWING
COUNTIES OF

NORTHWEST IOWA...CLAY AND SOUTHERN DICKINSON

THIS WARNING INCLUDES THE CITIES OF SPENCER..LANGDON AND EVERLY.

AT 545 PM RADAR INDICATED A SEVERE STORM IN SOUTHWEST DICKINSON
COUNTY AND THAT THE STORM WAS BUILDING INTO NORTHWEST CLAY COUNTY.
THE STORM WAS MOVING TO THE EAST AT 15 MILES AN HOUR.

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.

WEINBRECHT

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, May 12, 3:41 PM CDT, 2 hours 9 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
340 PM CDT MON MAY 12 1986

...SEVERE THUNDERSTORM WATCH FOR PART OF NORTHERN IOWA UNTIL 9PM...

AS OF 330 PM THERE WERE NO THUNDERSTORMS IN IOWA. HOWEVER A STRONG
THUNDERSTORM WAS LOCATED IN EXTREME SOUTHWEST MINNESOTA BUT WAS
MOVING NORTHEAST AT 35 MILES AN HOUR. THAT STORM POSES NO THREAT TO
IOWA BUT THUNDERSTORMS COULD DEVELOP AT ANY TIME IN NORTHWEST AND
NORTH CENTRAL PARTS OF THE STATE.
OBRIEN

The office that day

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

IssuedProductOfficeCountiesLasted
May 12, 4:35 PM CDTSevere Thunderstorm WarningDMXDickinson40 min
May 12, 5:15 PM CDTSevere Thunderstorm WarningDMXDickinson30 min
May 12, 6:31 PM CDTSevere Thunderstorm WarningDMXBuena Vista, Clay24 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.