Alert archive / Iowa / Severe Thunderstorm Warnings in 1986

Severe Thunderstorm Warning 101, NWS Des Moines, IA

July 28, 1986Polk County, Story County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jul 28, 1986, 10:14 PM CDT for Polk County, Story County, Iowa. It was in force for 46 min. 6 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
Jul 28, 1986, 10:14 PM CDT (03:14 UTC)
Expired
Jul 28, 1986, 11:00 PM CDT
In force
46 min
Issued by
NWS Des Moines, IA
Area
Whole counties

Counties Polk County, IA, Story 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
Jul 28, 10:16 PM CDTThunderstorm Wind 52Polk, IA
Jul 28, 10:20 PM CDTThunderstorm Wind 54Polk, IA
Jul 28, 10:27 PM CDTThunderstorm Wind 69Polk, IA
Jul 28, 10:28 PM CDTThunderstorm Wind 52Story, IA
Jul 28, 10:44 PM CDTThunderstorm Wind 58Polk, IA
Jul 28, 10:48 PM CDTThunderstorm Wind 61Polk, 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

Omaha, NE (KOAX), launched 00:00Z, 3.2 hours before the alert went out and 245 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°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 00:00Z on 1986-07-29The 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 290314
SVRDSM
IAC153-169-121-290400-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
1014 PM CDT MON JUL 28 1986

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM
WARNING EFFECTIVE UNTIL 1100 PM CDT FOR PEOPLE IN THE FOLLOWING
COUNTIES OF

CENTRAL IOWA...POLK...STORY AND MADISON

AT 1013 PM..DES MOINES RADAR INDICATED A LINE OF SEVERE
THUNDERSTORMS STRETCHING FROM NEAR AMES..TO ABOUT 10 MILES
NORTHWEST OF DES MOIES..TO 25 MILES WEST OF DES MOINES.

THIS LINE OF STORMS WAS MOVING SOUTHEAST AT 35 TO 40 MILES AN
HOUR.

THIS WARNING INCLUDES THE CITIES OF DES MOINES..AMES..ANKENY..
PERRY..AND DALLAS CENTER.

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.

THESE STORMS CAN AND OCCASIONALLY DO PRODUCE TORNADOES WITH LITTLE
OR NO ADVANCE WARNING..SO BE` ON THE LOOKOUT AND BE PREPARED TO MOVE
TO A PLACE OF SAFETY IF ONE IS SPOTTED.

BARLOW/TRUETT

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 28, 5:35 PM CDT, 4 hours 39 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
Special weather statement, Jul 28, 8:53 PM CDT, 1 hour 21 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
845 PM CDT MON JUL 28 1986

A NARROW BAND OF SHOWERS AND THUNDERSTORMS HAVE DEVELOPED IN
NORTHCENTRAL IOWA.  THESE SHOWERS AND THUNDERSTORMS WERE THE RESULT
OF OUT RUSHING WINDS FROM THE STRONG THUNDERSTORM SOUTH OF SPENCER.

THE BAND OF RAIN EXTENDED FROM 30 MILES WEST OF MASON CITY..NEAR
ALGONA..TO 40 MILES SOUTHWEST OF WATERLOO..NEAR ELDORA.  THESE
THUNDERSTRORMS WERE MOVING EAST AT 20 MILES AN HOUR.

AT THE PRESENT TIME RAIN AND LIGHTNING COULD  OCCUR AS THESE SHOWERS
AND THUNDERSTORMS MOVE INTO HANCOCK..FRANKLIN AND GRUNDY COUNTIES.
HAMILTON
Special weather statement, Jul 28, 10:05 PM CDT, 9 minutes before
<PQ<
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
1005 PM CDT MON JUL 28 1986

..TORNADO WATCH NUMBER 422 HAS BEEN CANCELLED FOR A LARGE PORTION
OF NORTHWEST IOWA..

...TORNADO WATCH NUMBER 423 REMAINS IN EFFECT UNTIL 2 AM FOR WEST
CENTRAL..CENTRAL..SOUTHWEST AND AND SOUTH CENTRAL IOWA...

WATCH NUMBER 422 HAS BEEN CANCELLED FOR MOST OF NORTHWEST IOWA
AS THE THUNDERSTORMS HAVE ALREADY PASSED THROUGH THE AREA.
THE LINE OF THUNDERSTORMS HAVE CONTINUED TO WREAK HAVOC AS
IT HAS MOVED INTO WEST CENTRAL AND CENTRAL IOWA.  FOR THOSE
FAMILIAR WITH THE ZONE ALIGNMENT..ZONES 1..4 AND 5 HAVE BEEN
CLEARED OF THE TORNADO WATCH.

REMEMBER..A TORNADO WATCH REMAINS IN E\FFECT UNTIL 2 AM FOR
MUCH OF WEST CENTRAL..CENTRAL..SOUTH CENTRAL AND SOUTHWEST IOWA.

DOWD

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, 7:48 PM CDTTornado WarningDMXClay32 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 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

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.