Alert archive / Iowa / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 46, NWS Des Moines, IA

June 8, 1990Keokuk County, Mahaska County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jun 8, 1990, 2:33 AM CDT for Keokuk County, Mahaska County, Iowa. It was in force for 42 min.

The area

The counties it named.

The facts

Issued
Jun 8, 1990, 2:33 AM CDT (07:33 UTC)
Expired
Jun 8, 1990, 3:15 AM CDT
In force
42 min
Issued by
NWS Des Moines, IA
Area
Whole counties

Counties Keokuk County, IA, Mahaska 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, 7.6 hours before the alert went out and 331 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 1990-06-08Temperature 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 1990-06-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 165 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
3632 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
165 m²/s²
0-3 km storm-relative helicity
158 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 080733
SVRDSM
IAC107-123-080815-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING 
NATIONAL WEATHER SERVICE DES MOINES IA
233 AM CDT FRI JUN 8 1990

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM 
WARNING EFFECTIVE UNTIL 315 AM CDT FOR PEOPLE IN THE FOLLOWING 
COUNTIES

   IN THE SOUTHEAST PART OF IOWA
      WESTERN KEOKUK...

   IN THE SOUTH CENTRAL PART OF IOWA
      EASTERN MAHASKA...

AT 230 AM CDT...WEATHER RADAR INDICATED A SEVERE THUNDERSTORM
NEAR WHAT CHEER OR 30 MILES NORTH OF OTTUMWA IN SOUTH CENTRAL
IOWA.  THE STORM WAS MOVING SOUTHEAST AT 30 MILES AN HOUR.

PEOPLE IN THE TOWNS OF WHAT CHEER...OSKALOOSA...AND DELTA AND
NEARBY COMMUNITIES SHOULD BE ON THE LOOKOUT.

REMEMBER...SEVERE THUNDERSTORMS PRODUCE WINDS IN EXCESS OF 60 MILES
AN HOUR...LARGE HAIL...DANGEROUS LIGHTNING...AND VERY HEAVY RAINS.
FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR
OF YOU HOME OR BUSINESS.  HEAVY RAINS FLOOD ROADS QUICKLY SO DO NOT
DRIVE INTO AREAS WHERE WATER COVERS THE ROAD.

IN ADDITION...THESE STORMS CAN AND OCCASIONALLY DO PRODUCE TORNADOES
WITH LITTLE OR NO ADVANCED WARNING SO BE ON THE LOOKOUT.

MCQUIRTER

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, Jun 8, 1:42 AM CDT, 51 minutes before
IAZALL-080730-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
140 AM CDT FRI JUN 8 1990

AT 131 AM CDT...SCATTERED INTENSE AND VERY STRONG THUNDERSTORMS WERE
OCCURRING OVER SOUTH CENTRAL AND EAST CENTRAL IOWA.

THE STRONGEST STORMS ARE LOCATED NEAR GRINNELL...50 MILES NORTHEAST OF
DES MOINES...AND 20 TO 30 MILES SOUTHWEST OF CEDAR RAPIDS...NEAR
WILLIAMSBURG.  THESE THUNDERSTORMS ARE PRODUCING VERY HEAVY RAINFALLq
AND ARE CAPABLE OF PRODUCING SMALL HAIL AND STRONG WIND.

THE THUNDERSTORMS ARE MOVING EAST AT 25 MILES AN HOUR.

ALSO...ISOLATED SHOWERS AND THUNDERSHOWERS WERE OVER THE EXTREME
SOUTHEAST COUNTIES OF IOWA.

DM

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 8, 1:26 AM CDTSevere Thunderstorm WarningDMXPoweshiek, Tama24 min
Jun 8, 2:07 AM CDTSevere Thunderstorm WarningDMXIowa, Poweshiek53 min

Nearby

Severe Thunderstorm Warnings in Iowa, 1990Every severe thunderstorm warning in 1990

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.