Alert archive / Iowa / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 191, NWS Des Moines, IA

September 8, 1990Decatur County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Sep 8, 1990, 4:22 AM CDT for Decatur County, Iowa. It was in force for 53 min.

The area

The counties it named.

The facts

Issued
Sep 8, 1990, 4:22 AM CDT (09:22 UTC)
Expired
Sep 8, 1990, 5:15 AM CDT
In force
53 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Decatur 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, 9.4 hours before the alert went out and 226 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 1990-09-08Temperature 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 1990-09-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -5 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
3556 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
-5 m²/s²
0-3 km storm-relative helicity
10 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 080924
SVRDSM
IAC053-081015-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
422 AM CDT SAT SEP 8 1990
 
THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  515 AM CDT
FOR PEOPLE IN THE FOLLOWING COUNTY...
 
IN SOUTH CENTRAL IOWA
          ...DECATUR
 
AT 410 AM...AN OBSERVER AT LAMONI REPORTED HAIL OF 3/4 INCH SIZE
OCCURRING. AT 415 AM...NATIONAL WEATHER SERVICE RADAR INDICATED A
STRONG THUNDERSTORM IN THE VICINITY OF LAMONI...WHICH IS 65 TO 70
MILES SOUTH OF DES MOINES.
 
THE STORM WAS MOVING EAST AT 15 MILES AN HOUR.
 
THIS WARNING INCLUDES THE TOWNS AND CITIES OF LAMONI...LEON... DAVIS
CITY...PLEASANTON...AND NINE EAGLES STATE PARK.
 
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60
MPH...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN.
FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR
OF YOURZ HOME OR BUSINESS.  HEAVY RAINS FLOOD ROADS QUICKLY SO
DON'T DRIVE INTO AREAS WHERE WATER COVERS THE ROAD.
 
DOWD/KS

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, Sep 7, 10:44 PM CDT, 5 hours 38 minutes before
IAZALL-080445-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
1043 PM CDT FRI SEP 7 1990

AT 1029 PM...INTENSE THUNDERSTORMS WERE LOCATED IN CENTRAL IOWA...5
MILES WEST OF MONROE AND JUST NORTHEAST OF NEWTON.  VERY HEAVY RAIN...
SMALL HAIL...WIND TO 40 MILES AN HOUR AND FREQUENT LIGHTNING CAN BE
EXPECTED.  THESE STORMS WILL BE IN PELLA AND GRINELL AREAS BY AROUND
1130 PM.

AN INTENSE THUNDERSTORM WAS ALSO INDICATED IN SOUTHWEST IOWA...NEAR
CUMBERLAND OR 45 MILES EAST OF COUNCIL BLUFFS.  VERY HEAVY RAIN...
SMALL HAIL...WIND TO 40 MILES AN HOUR AND DANGEROUS LIGHTNING CAN BE
EXPECTED.

OTHERWISE...SHOWERS AND THUNDERSTORMS COVERED A LARGE PART OF NORTH
CENTRAL...PART OF NORTHEAST...CENTRAL...WEST CENTRAL AND SOUTHWEST
IOWA.  THE  LEADING EDGE OF THE PRECIPITATION EXTENDED FROM 35 MILES
EAST OF MASON CITY...THROUGH WATERLOO...TO TAMA...TO 20 MILES EAST
OF DES MOINES.

THE SHOWERS AND THUNDERSTORMSo WERE MOVING SOUTHEAST AT 20 TO 25 MILES
AN HOUR._

HUTTON
Special weather statement, Sep 7, 11:46 PM CDT, 4 hours 36 minutes before
IAZALL-080545-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
1144 PM CDT FRI SEP 7 1990

AT 1125 PM...VERY STRONG THUNDERSTORMS WERE INDICATED IN NORTHERN
MARION COUNTY NORTHWEST OF PELLA AND ALSO NEAR MONTEZUMA.  THESE STORMS
HAD DECREASED IN INTENSITY SINCE 11PM...BUT COULD STILL PRODUCE VERY
HEAVY RAIN...WIND TO 30 MILES AN HOUR AND DANGEROUS CLOUD TO GROUND
LIGHTNING.

OTHER VERY STRONG THUNDERSTORMS WERE IN SOUTHWEST IOWA...FROM JUST
WEST OF CRESTON TO SOUTH OF AFTON...45 TO 50 MILES SOUTHWEST OF DES
MOINES.  HEAY RAIN...SMALL HAIL...WIND TO 40 MILES AN HOUR AND
DANGEROUS LIGHTNING CAN BE EXPECTED.

OTHERWISE...SHOWERS AND THUNDERSTORMS WERE IN AN AREA BOUNDED BY A
LINE FROM WEBSTER CITY...TO 50 MILES NORTH OF WATERLOO...TO 20 MILES
WEST OF CEDAR RAPIDS...TO 25 MILES SOUTHEAST OF DES MOINES AND BACK
TO WEBSTER CITY.  OTHER SHOWERS AND THUNDERSTORMS WERE JUST WEST OF
OSCEOLA AND SOUTHEAST OF GREENFIELD.

THE SHOWERS AND THUNDERSTORMS WERE MOVING SOUTHEAST AT 20 TO 25 MILES
AN HOUR.

HUTTON
Special weather statement, Sep 8, 12:46 AM CDT, 3 hours 36 minutes before
IAZALL-080645-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
1240 AM CDT SAT SEP 8 1990

AT 1232 AM...ISOLATED VERY STRONG THUNDERSTORMS WERE OVER SOUTHWEST AND
SOUTH CENTRAL IOWA.  THE STORMS WERE 25 TO 50 MILES SOUTHWEST OF DES
MOINES NEAR WINTERSET...GREENFIELD...AFTON AND MT AYR.  ALONG WITH THE
EXTREMELY HEAVY RAINS...PEA TO MARBLE SIZE HAIL AND WINDS TO 45 MILES
AN HOUR ARE LIKELY.  MOVEMENT WAS EAST 15 TO 20 MILES AN HOUR.

ALSO...SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS EXTENDED FROM NORTH
CENTRAL AND NORTHEAST IOWA INTO THE SOUTHEASTERN COUNTIES.  THE STRONG-
EAST STORM WAS DUE NORTH OF OTTUMWA NEAR WHAT CHEER.  AT THIS TIME ONLY
BRIEF HEAVY RAINS AREA EXPECTED FROM THIS STORM.  MOVEMENT WAS SOUTHEAST
AT 25 MILES AN HOUR.

KS
Special weather statement, Sep 8, 1:45 AM CDT, 2 hours 37 minutes before
IAZALL-080745-

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

AT 129 AM...ISOLATED STRONG THUNDERSTORMS HAD DEVELOPED OVER CENTRAL
IOWA DURING THE PAST HOUR.  THE STORMS NOW EXTENDED FROM DALLAS CENTER
TO JUST WEST OF THE DES MOINES METRO AREA.  ALONG WITH THE HEAVY RAINS
...WINDS TO 40 MILES AN HOUR ARE LIKELY.

ISOLATED STRONG STORMS WERE OVER THE SOUTH CENTRAL COUNTIES NEAR OSCEOLA
AND JUST NORTH OF LAMONI.  BRIEF HEAVY RAINS AND WINDS TO 40 MILES AN
HOUR ARE ALSO LIKELY WITH THESE STORMS.

THE STORMS WERE MOVING EAST AT 20 MILES AN HOUR.

ALSO...SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS CONTINUED OVER THE
EASTERN THIRD OF THE STATE.  MOVEMENT WAS SOUTHEAST AT 25 MILES AN HOUR.

KS

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.