Alert archive / Iowa / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 87, NWS Des Moines, IA

July 8, 1987Linn County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jul 8, 1987, 8:05 PM CDT for Linn County, Iowa. It was in force for 30 min.

The area

The counties it named.

The facts

Issued
Jul 8, 1987, 8:05 PM CDT (01:05 UTC)
Expired
Jul 8, 1987, 8:35 PM CDT
In force
30 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Linn 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, 1.1 hours before the alert went out and 229 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 1987-07-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2463 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 1987-07-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 47 square meters per square second.1939Sfc1 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
2463 J/kg
Mixed-layer CIN
-9 J/kg
Mixed-layer LCL
1093 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
47 m²/s²
0-3 km storm-relative helicity
112 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 090107
SVRDSM
IAC113-090105-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
805 PM CDT WED JUL 8 1987

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM
WARNING EFFECTIVE UNTIL 835 PM CDT FOR PEOPLE IN THE FOLLOWING
COUNTY OF

EAST CENTRAL IOWA...
LINN

AT 805 PM CDT A SEVERE THUNDERSTORM WAS MOVING THROUGH LINN COUNTY
IN EAST CENTRAL IOWA.  THE STORM CONTINUED TO PRODUCE SEVERE
WEATHER AS IT MOVED EAST.  THE STORM SHOULD BE THROUGH  LINN
COUNTY BY 835 PM.  THE STORM HAS PRODUCED STRONG WINDS THAT HAS
UPROOTED TREES AND DOWNED POWER LINES.  ALSO NUMEROUS REPORTS OF
FUNNEL CLOUDS HAVE BEEN RECEIVED.
THE FOLLOWING TOWNS AND CITIES OF LINN COUNTY ARE INCLUDED IN THE
WARNING...CEDAR RAPIDS...CENTRAL CITY...20 MILES NORTH OF CEDAR
RAPIDS AND MOUNT VERNON...15 MILES SOUTHEAST OF CEDAR RAPIDS.

THE STORM WAS MOVING EAST AT 30 TO 35 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.  PEOPLE IN THE PATH OF THIS STORM
SHOULD TAKE APPROPRIATE ACTION IMMEDIATELY.

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.

FORSTER

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, 2:57 PM CDT, 5 hours 8 minutes before
<PQ<
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
257 PM CDT WED JUL 8 1987

THE SEVERE THUNDERSTORM WARNING FOR WESTERN GUTHRIE COUNTY WILL
EXPIRE AT 300 PM CDT.  THE THUNDERSTORM ACTIVITY IN THIS COUNTY
HAS WEAKENED CONSIDERABLY DURING THE LAST 10 MINUTES.  THEREFORE...
THE WARNING WILL NOT BE RENEWED.

THE THUNDERSTORMS HAD MOVED INTO THE EASTERN HALF OF THE COUNTY.
PEOPLE LIVING IN EASTERN GUTHRIE COUNTY SHOULD EXPECT< SOME HEAVY
RAINS AND MODERATE WINDS AS THESE STORMS PASS THROUGH.  THE STORMS
WERE MOVING NORTH NORTHEAST AROUND 25 MILES AN HOUR.

BIKLE
Special weather statement, Jul 8, 3:08 PM CDT, 4 hours 57 minutes before
<PQ<
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
307 PM CDT WED JUL 8 1987

A VERY STRONG THUNDERSTORM WAS OVER SOUTHWEST APPANOOSE COUNTY AT
303 PM CDT.  THE STORM WAS MOVING NORTH NORTHEAST AT 25 MILES AN HOUR
AND WILL BE ARRIVING AT RATHBUN RESERVOIR ABOUT 310 PM CDT.  RATHBUN
RESERVOIR IS ABOUT 60 MILES SOUTHEAST OF DES MOINES.

BOATERS AND PEOPLE HAVING ACTIVITIES AT RATHBUN RESERVOIR SHOULD SEEK
SAFE HARBOR ANDE SHELTER AS QUICKLY AS POSSIBLE.

THIS STORM IS CAPABLE OF PRODUCING BRIEF HEAVY RAINS AND GUSTY WINDS.

BIKLE
Special weather statement, Jul 8, 3:17 PM CDT, 4 hours 48 minutes before
<PQ<
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
315 PM CDT WED JUL 7 1987

AT 312 PM CDT...RADAR INDICATED A VERY STRONG THUNDERSTORM OVER
SOUTHERN MARION COUNTY...IN THE VICINITY OF KNOXVILLE...THE COUNTY
SEAT...ABOUT 30 MILES SOUTHEAST OF DES MOINES.  THE STORM WAS MOVING
NORTH NORTHEAST AT 25 MILES AN HOUR AND WILL BE AFFECTING RED ROCK
RESERVOIR AT 318 PM CDT.

BOATERS AND PEOPLE HAVING ACTIVITIES AT RED ROCK RESERVKOIR SHOULD
SEEK SAFE HARBOR AND SHELTER AS QUICKLY AS POSSIBLE.

THIS STORM IS CAPABLE OF PRODUCING BRIEF HEAVY RAINS...GUSTY WINDS...
AND POSSIBLE PEA TO MARBLE SIZE HAIL.

BIKLE
Local storm report, Jul 8, 7:54 PM CDT, 11 minutes before
LOCAL STORM REPORT
NATIONAL WEATHER SERVICE WATERLOO IA
800 PM CDT WED JUL 8 1987

TIME          EVENT

630 PM CDT...IN WEST WATERLOO/CEDAR FALLS AREA...EXTENSIVE TREE TOP
             DAMAGE...TREE LIMBS UP TO 8 INCHES IN DIAMETER...PLUS
             A HEALTHY 2 FOOT MAPLE TREE BLOWN OVER. A STORAGE SHED
             BLOWN ABOUT 150 YARDS DOWN THE STREET. SOME ROOF AND
             PORCH DAMAGE. ESTIMATED 65 TO 90 MPH WINDS. ALL DAMAGE
       w      ALONG ONE STREET FOR ABOUT .2 OF A MILE.
HAYS

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 8, 7:06 PM CDTSevere Thunderstorm WarningDMXBenton39 min
Jul 8, 7:27 PM CDTSevere Thunderstorm WarningDMXLinn38 min

Nearby

Severe Thunderstorm Warnings in Iowa, 1987Every severe thunderstorm warning in 1987

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.