Alert archive / Iowa / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 102, NWS Des Moines, IA

August 16, 1997Marion County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Aug 16, 1997, 8:51 PM CDT for Marion County, Iowa. It was in force for 34 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Aug 16, 1997, 8:51 PM CDT (01:51 UTC)
Expired
Aug 16, 1997, 9:25 PM CDT
In force
34 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Marion County, IA

What was reported inside it

TimeReportWhereRemark
Aug 16, 9:20 PM CDTHail 0.75Melcher, IA

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Aug 16, 7:15 PM CDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 1.9 hours before the alert went out and 219 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, Davenport, at 00:00Z on 1997-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 6428 joules per kilogram.LCLEL10008507005003002001001 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, Davenport, at 00:00Z on 1997-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 58 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
6428 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
765 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
58 m²/s²
0-3 km storm-relative helicity
137 m²/s²
Significant tornado parameter
2.3
Supercell composite
10.9

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KDSM 170151 RRA
SVRDSM
IAC125-170225-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
851 PM CDT SAT AUG 16 1997

* SEVERE THUNDERSTORM WARNING FOR
  MARION COUNTY - SOUTH CENTRAL IOWA

* UNTIL 925 PM CDT
 
* SOME AREAS AFFECTED
    KNOXVILLE
    RED ROCK AREA

* AT 849 PM CDT RADAR INDICATED A SEVERE THUNDERSTORM 10 MILES
  SOUTHWEST OF KNOXVILLE 30 MILES SOUTHEAST OF DES MOINES MOVING
  NORTHEAST 15 MPVH.

* THE STORM WILL BE IN KNOXVILLE BY 905 PM CDT.

THIS IS A DANGEROUS STORM.  DO NOT GO OUTDOORS.




FORSTER/KUBINA

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 16, 3:32 PM CDT, 5 hours 19 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-171200-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
332 PM CDT SAT AUG 16 1997

HAZARD--SCATTERED EVENING SEVERE THUNDERSTORMS WITH DAMAGING WIND THE
PRIMARY CONCERN.

AREA OF CONCERN AND TIMING--SOUTH OF AN ATLANTIC-DUBUQUE LINE AFTER 6 OR
7 PM.

METEOROLOGICAL COMMENTS--MOST OF SOUTHERN IOWA REMAINS QUITE UNSTABLE
WITH LIFTED INDICES AROUND -10 DEGREES AND SATELLITE MEASURED CAPES OF
3000-4000 J/KG. A DEWPOINT FRONT LYING ALONG A DUBUQUE-DES MOINES-
ATLANTIC LINE MAY ACT AS A FOCUS FOR THUNDERSTORMS DEVELOPMENT THIS
EVENING. THE BEST LOW LEVELING FORCING REMAINS IN NORTHEAST KANSAS
HOWEVER WHERE STRONGER LOW LEVEL WINDS ARE IMPINGING THE DEWPOINT FRONT.
A WEAK UPPER LEVEL DISTURBANCE IS NEARING THIS AREA FROM WESTERN KANSAS
NOW...WHICH MAY INDUCE THUNDERSTORMS TO DEVELOP. PRECIPITABLE WATER
VALUES ARE NEAR 2 INCHES SOUTH OF THE FRONT...SO RAINFALL WILL BE
INTENSE IN LOCALIZED AREAS. THE THREAT OF STRONG DAMAGING WINDS HAS
LESSENED A BIT FROM EARLIER TODAY BUT WINDS TO 70 MPH COULD OCCUR.
BETWEEN SUNSET AND MIDNIGHT THE WEATHER THREAT WILL BE REPEAT HEAVY
RAINS OVER THE SAME AREA. RAINFALL AMOUNTS COULD EASILY EXCEED 3-4
INCHES IN SMALL AREAS BETWEEN 10 PM AND 3 AM.

PRECAUTIONS--PEOPLE WITH OUTDOOR PLANS SHOULD STAY ABREAST OF THE
WEATHER THIS EVENING...AND BE PREPARED TO CHANGE PLANS. SPOTTER
ACTIVATION COULD BE NEEDED SOUTH OF AN ATLANTIC-DUBUQUE LINE.

MYERS
Special weather statement, Aug 16, 3:33 PM CDT, 5 hours 18 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-171200-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
332 PM CDT SAT AUG 16 1997

HAZARD--SCATTERED EVENING SEVERE THUNDERSTORMS WITH DAMAGING WIND THE
PRIMARY CONCERN.

AREA OF CONCERN AND TIMING--SOUTH OF AN ATLANTIC-DUBUQUE LINE AFTER 6 OR
7 PM.

METEOROLOGICAL COMMENTS--MOST OF SOUTHERN IOWA REMAINS QUITE UNSTABLE
WITH LIFTED INDICES AROUND -10 DEGREES AND SATELLITE MEASURED CAPES OF
3000-4000 J/KG. A DEWPOINT FRONT LYING ALONG A DUBUQUE-DES MOINES-
ATLANTIC LINE MAY ACT AS A FOCUS FOR THUNDERSTORMS DEVELOPMENT THIS
EVENING. THE BEST LOW LEVELING FORCING REMAINS IN NORTHEAST KANSAS
HOWEVER WHERE STRONGER LOW LEVEL WINDS ARE IMPINGING THE DEWPOINT FRONT.
A WEAK UPPER LEVEL DISTURBANCE IS NEARING THIS AREA FROM WESTERN KANSAS
NOW...WHICH MAY INDUCE THUNDERSTORMS TO DEVELOP. PRECIPITABLE WATER
VALUES ARE NEAR 2 INCHES SOUTH OF THE FRONT...SO RAINFALL WILL BE
INTENSE IN LOCALIZED AREAS. THE THREAT OF STRONG DAMAGING WINDS HAS
LESSENED A BIT FROM EARLIER TODAY BUT WINDS TO 70 MPH COULD OCCUR.
BETWEEN SUNSET AND MIDNIGHT THE WEATHER THREAT WILL BE REPEAT HEAVY
RAINS OVER THE SAME AREA. RAINFALL AMOUNTS COULD EASILY EXCEED 3-4
INCHES IN SMALL AREAS BETWEEN 10 PM AND 3 AM.

PRECAUTIONS--PEOPLE WITH OUTDOOR PLANS SHOULD STAY ABREAST OF THE
WEATHER THIS EVENING...AND BE PREPARED TO CHANGE PLANS. SPOTTER
ACTIVATION COULD >BE NEEDED SOUTH OF AN ATLANTIC-DUBUQUE LINE.

MYERS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 16, 7:51 PM CDTTornado WarningDMXWarren34 min
Aug 16, 8:26 PM CDTTornado WarningDMXWarren14 min
Aug 16, 8:34 PM CDTSevere Thunderstorm WarningDMXMonroe36 min
Aug 16, 8:58 PM CDTSevere Thunderstorm WarningDMXPolk32 min

Nearby

Severe Thunderstorm Warnings in Iowa, 1997Every severe thunderstorm warning in 1997

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.