Alert archive / Iowa / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 166, NWS Des Moines, IA

August 19, 1990Boone County, Polk County, Story County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Aug 19, 1990, 4:46 PM CDT for Boone County, Polk County, Story County, Iowa. It was in force for 29 min.

The area

The counties it named.

The facts

Issued
Aug 19, 1990, 4:46 PM CDT (21:46 UTC)
Expired
Aug 19, 1990, 5:15 PM CDT
In force
29 min
Issued by
NWS Des Moines, IA
Area
Whole counties

Counties Boone County, IA, 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.

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 9.8 hours before the alert went out and 235 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 1990-08-19Temperature 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 1990-08-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 23 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3642 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
23 m²/s²
0-3 km storm-relative helicity
84 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 192143
SVRDSM
IAC015-153-169-192215-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
446 PM CDT SUN AUG 19 1990
 
THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  515 PM CDT
FOR PEOPLE IN THE FOLLOWING COUNTIES...
 
IN CENTRAL IOWA
          ...SOUTHERN BOONE...NORTHERN POLK...SOUTHERN STORY
 
AT 445 PM CDT...WEATHER RADAR IN DES MOINES INDICATED A SEVERE
THUNDERSTORM ABOUT 15 MILES NORTH OF DES MOINES. THIS STORM WILL BE
AFFECTING THE TOWNS HUXLEY..LUTHER...ANKENY AND AMES.
 
BOATERS ON SAYLORVILE LAKE SHOULD SEEK SAFE SHELTER IMMEDIATELY.
 
THE STORM WAS MOVING NORTHEAST AT 30 MILES AN HOUR.
 
JM
 
 
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 YOUR HOME OR BUSINESS.  HEAVY RAINS F!LOOD ROADS QUICKLY SO
DON'T DRIVE INTO AREAS WHERE WATER COVERS THE ROAD.

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, Aug 19, 4:23 PM CDT, 23 minutes before
IAZ010-192215-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
420 PM CDT SUN AUG 18 1990

THUNDERSTORMS HAD DEVEOLOPED JUST TO THE WEST AND NORTH OF DES MOINES.
AT 415 PM...THE THUNDERSTORMS WERE LOCATED OVER THE WESTERN AND
NORTHERN SUBURBS.  THE STORMS WERE MOVING NORTHEAST AT 25 MILES AN HOUR.
BRIEF HEAVY RAINS AND WIND GUSTS OF 30 TO 40 MILES WILL OCCUR WITH
THUNDERSTORMS.

THE SOUTHERN AND EASTERN SECTIONS OF THE METRO AREA WILL ESCAPE MOST
OF THE RAIN FROM THESE STORMS.  HOWEVER...THE ATMOSPHERE IS RIPE FOR
THUNDERSTORM DEVELOPMENT AND STORMS MAY POP UP JUST ABOUT ANYWHERE IN
CENTRAL IOWA DURING THE NEXT COUPLE OF HOURS.

DLF

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 18, 8:39 PM CDTSevere Thunderstorm WarningDMXEmmet, Palo Alto21 min
Aug 18, 9:04 PM CDTSevere Thunderstorm WarningDMXKossuth, Palo Alto41 min
Aug 19, 5:53 PM CDTSevere Thunderstorm WarningDMXHancock, Wright27 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.