Alert archive / Iowa / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 152, NWS Des Moines, IA

July 4, 1990Adair County, Madison County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jul 4, 1990, 6:15 PM CDT for Adair County, Madison County, Iowa. It was in force for 45 min.

The area

The counties it named.

The facts

Issued
Jul 4, 1990, 6:15 PM CDT (23:15 UTC)
Expired
Jul 4, 1990, 7:00 PM CDT
In force
45 min
Issued by
NWS Des Moines, IA
Area
Whole counties

Counties Adair County, IA, Madison 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 12:00Z, 11.3 hours before the alert went out and 178 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 12:00Z on 1990-07-04Temperature 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 12:00Z on 1990-07-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -57 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
3633 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
-57 m²/s²
0-3 km storm-relative helicity
-30 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 042315
SVRDSM
IAC001-121-050000-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
615 PM CDT WED JUL 4 1990
 
THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  700 PM CDT
FOR PEOPLE IN THE FOLLOWING COUNTIES...
 
IN SOUTHWEST IOWA
          ...NORTHEASTERN ADAIR
IN SOUTH CENTRAL IOWA
          ...NORTHWESTERN MADISON
 
AT 610 PM CDT...WEATHER RADAR IN DES MOINES INDICATED A SEVERE
THUNDERSTORM OVER NORTHEAST ADAIR COUNTY...OR ABOUT 35 MILES WEST OF
DES MOINES.
 
THE STORM WAS MOVING EAST AT ABOUT 15 MILES AN HOUR AND WILL AFFECT
THE CITIES OF GREENFIELD AND EARLHAM BETWEEN 615 AND 640 PM...AND
WINTERSETT BETWEEN 630 AND 700 PM.
 
THIS STORM PRODUCED HEAVY RAIN...LARGE HAIL...AND STRONG WINDS 6 MILES
NORTH OF FONTANELLE AT 554 PM CDT.
 
 
IF YOU ARE CAUGHT OUTSIDE...SEEK SHELTER FROM THE WEATHER IN A
STRONG BUILDING.  DAMAGING WIND...LARGE HAIL...VERY HEAVY RAIN...
AND DEADLY LIGHTNING ARE ALL POSSIBLE IN SEVERE THUNDERSTORMS.
STAY INSIDE AWAY FROM WINDOWS UNTIL THE STORM HAS PASSED.

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 4, 4:03 PM CDT, 2 hours 12 minutes before
IAZ003-007>015-050230-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
405 PM CDT WED THE FOURTH OF JULY 1990

...EXCESSIVE HEAT OVER MUCH OF IOWA INTO THE EARLY EVENING HOURS...

THE HEAT INDEX HAS REACHED HIGH LEVELS THIS AFTERNOON.  TEMPERATURES
IN THE 90S TO AROUND 100 DEGREES...COMBINED WITH THE RATHER HIGH
RELATIVE HUMIDITY...HAVE PRODUCED A HEAT INDEX OF 105 TO 115 DEGREES
THIS AFTERNOON.  THESE READING WILL SLOWLY LOWER DURING THE EVENING.

PEOPLE WORKING OUT-OF-DOORS...THOSE LIVING IN UN-AIRCONDITIONED SPACES
...THE ELDERLY...AND PEOPLE IN POOR HEALTH SHOULD TAKE PRECAUTIONS AS
PROLONGED EXPOSURE TO THESE CONDITIONS OR STRENUOUS PHYSICAL ACTIVITY
CAN LEAD TO HEAT EXHAUSTION OR POSSIBLE HEAT STROKE.

HOUSEHOLD PETS ALSO NEED TO BE WATCHED...TO AVOID DANGERS OF THE HEAT.

AT 400 PM TEMPERATURES WERE IN THE 90S TO NEAR 100 OVER MUCH OF
IOWA...WITH FAIRLY HIGH HUMIDITY.  THIS COMBINATION OF HEAT AND
HUMIDITY HAS RESULTED IN HEAT INDICES OF 100 TO 110 DEGREES.  THESE
CONDITIONS WILL SLOWLY IMPROVE AS THE TEMPERATURES DROP NEAR SUNSET.

MEANWHILE THE HEAT INDICES WILL CONTINUE TO BE HIGH.  IF YOU PLAN ANY
OUTDOOR ACTIVITY...EVEN JUST BEING OUT TO VIEW FIWREWORKS...USE CAUTION
AND SEEK HELP IF YOU BEGIN TO SUFFER THE EFFECTS OF THE HEAT.

DOWD
Special weather statement, Jul 4, 4:04 PM CDT, 2 hours 11 minutes before
IAZ003-007>015-050230-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
405 PM CDT WED THE FOURTH OF JULY 1990

...EXCESSIVE HEAT OVER MUCH OF IOWA INTO THE EARLY EVENING HOURS...

THE HEAT INDEX HAS REACHED HIGH LEVELS THIS AFTERNOON.  TEMPERATURES
IN THE 90S TO AROUND 100 DEGREES...COMBINED WITH THE RATHER HIGH
RELATIVE HUMIDITY...HAVE PRODUCED A HEAT INDEX OF 105 TO 115 DEGREES
THIS AFTERNOON.  THESE READING WILL SLOWLY LOWER DURING THE EVENING.

PEOPLE WORKING OUT-OF-DOORS...THOSE LIVING IN UN-AIRCONDITIONED SPACES
...THE ELDERLY...AND PEOPLE IN POOR HEALTH SHOULD TAKE PRECAUTIONS AS
PROLONGED EXPOSURE TO THESE CONDITIONS OR STRENUOUS PHYSICAL ACTIVITY
CAN LEAD TO HEAT EXHAUSTION OR POSSIBLE HEAT STROKE.

HOUSEHOLD PETS ALSO NEED TO BE WATCHED...TO AVOID DANGERS OF THE HEAT.

AT 400 PM TEMPERATURES WERE IN THE 90S TO NEAR 100 OVER MUCH OF
IOWA...WITH FAIRLY HIGH HUMIDITY.  THIS COMBINATION OF HEAT AND
HUMIDITY HAS RESULTED IN HEAT INDICES OF 100 TO 110 DEGREES.  THESE
CONDITIONS WILL SLOWLY IMPROVE AS THE TEMPERATURES DROP NEAR SUNSET.

MEANWHILE THE HEAT INDICES WILL CONTINUE TO BE HIGH.  IF YOU PLAN ANY
OUTDOOR ACTIVITY...EVEN JUST BEING OUT TO VIEW FIXREWORKS...USE CAUTION
AND SEEK HELP IF YOU BEGIN TO SUFFER THE EFFECTS OF THE HEAT.

DOWD
Special weather statement, Jul 4, 5:58 PM CDT, 17 minutes before
IAZALL-042330-
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
555 PM CDT WED JUL 4 1990

AT 530 PM...AN ISOLATED INTENSE THUNDERSTORM WITH EXTREMELY HEAVY RAIN
AND HAIL HAD DEVELOPED RAPIDLY OVER SOUTHWEST IOWA.  THE STORM WAS
LOCATED 50 MILES WEST OF DES MOINES...JUST NORTHWEST OF GREENFIELD.
THE STORM WAS MOVING EAST AT 15 MILES AN HOUR.  BY 630 PM THE STORM
WILL BE JUST NORTH OF GREENFIELD.

OTHER THUNDERSTORMS HAD DEVELOPED OVER EXTREME SOUTHWEST IOWA...SOUTH
OF COUNCIL BLUFFS.  THESE STORMS WERE MOVING NORTHEAST AT 25 MILES AN
HOUR.

WIDELY SCATTERED SHOWERS WERE OVER NORTH CENTRAL IOWA.  THESE SHOWER
WERE MOVING NORTHEAST AT 35 MILES AN HOUR.

DLF

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 4, 5:37 PM CDTSevere Thunderstorm WarningDMXAdair38 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.