Alert archive / Iowa / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 73, NWS Des Moines, IA

June 24, 1997Sac County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jun 24, 1997, 5:37 PM CDT for Sac County, Iowa. It was in force for 43 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
Jun 24, 1997, 5:37 PM CDT (22:37 UTC)
Expired
Jun 24, 1997, 6:20 PM CDT
In force
43 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Sac County, IA

The radar

The Des Moines radar (KDMX), 135 km from the middle of the area, began a volume at 22:40 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
Jun 24, 6:00 PM CDTHail 1.75Ulmer, 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 nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 10.6 hours before the alert went out and 158 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 1997-06-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 469 joules per kilogram.LCLLFCEL10008507005003002001001 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 1997-06-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 181 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
469 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
521 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
181 m²/s²
0-3 km storm-relative helicity
190 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.3

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KDSM 242237 RRA
SVRDSM
IAC161-242320-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
537 PM CDT TUE JUN 24 1997

* SEVERE THUNDERSTORM WARNING FOR
  SOUTHERN SAC COUNTY - WEST CENTRAL IOWA

* UNTIL 620 PM CDT
 
* SOME AREAS AFFECTED
    WALL LAKE
    CARNARVON
    ULMER
    AUBURN

* AT 534 PM CDT RADAR INDICATED A SEVERE THUNDERSTORM 3 MILES SOUTH OF
  ODEBOLT OR 60 MILES WEST OF FORT DODGE MOVING EAST AT 20 MPH.

* THE STORM WILL BE NEAR WALL LAKE AT 550 PM.

HAIL UP TO ONE INCH IN DIAMETER IS LIKELY IN THIS STORM.  PEOPLE ON
BLACK HAWK LAKE SHOULD TAKE COVER NOW.  THIS IS A DANGEROUS STORM. DO
NOT GO OUTDOORS.


KULA

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 24, 3:18 PM CDT, 2 hours 19 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-250500-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
320 PM CDT TUE JUN 24 1997

HAZARD -- ISOLATED SEVERE THUNDERSTORMS AND HEAVY RAINFALL.

AREA OF CONCERN -- ENTIRE OUTLOOK AREA FOR THUNDERSTORM ACTIVITY WITH
THE GREATEST CHANCES FOR SEVERE THUNDERSTORMS AND HEAVY RAIN OVER THE
SOUTHWEST QUARTER.

TIMING DETAILS -- BETWEEN 600 PM AND MIDNIGHT.

METEOROLOGICAL COMMENTS -- A COLD FRONT LOCATED FROM MINNESOTA ACROSS
SOUTHEAST SOUTH DAKOTA AND INTO NEBRASKA WILL GRADUALLY MOVE THROUGH
IOWA THIS EVENING.  MOISTURE CONVERGENCE OVER SOUTHWEST IOWA ALONG
WITH PRECIPITABLE WATER VALUES OF UP TO TWO INCHES WILL FOCUS THE
HEAVIEST PRECIPITATION OVER THE SOUTHWEST PORTION OF THE STATE.  CAPE
VALUES STATEWIDE RANGE FROM 2000 TO 2500 J/KG.  AN INFLUX OF COLD AIR
AT 18000 FEET WILL LEAD TO FURTHER DESTABILIZATION THIS EVENING.
SUNSHINE LATE IN THE AFTERNOON WILL ALSO ENHANCE THE LIKELIHOOD OF
STRONG THUNDERSTORMS.  AT THIS TIME IT APPEARS THAT THUNDERSTORMS WILL
DEVELOP OVER WESTERN IOWA AFTER 600 PM AND THEN SPREAD EAST OVER THE
REMAINDER OF CENTRAL IOWA.  DUE TO THE COPIOUS AMOUNTS OF MOISTURE
AVAILABLE...RAINFALL RATES IN EXCESS OF ONE INCH PER HOUR ARE LIKELY.

PRECAUTIONS -- SPOTTER ACTIVATION MAYBE REQUIRED THIS EVENING.
EMERGENCY MANAGERS SHOULD REMAIN ALERT OF THE LATEST SHORT-TERM
FORECAST FOR THEIR AREA.

SCHAFER
Special weather statement, Jun 24, 3:20 PM CDT, 2 hours 17 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-250500-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
320 PM CDT TUE JUN 24 1997

HAZARD -- ISOLATED SEVERE THUNDERSTORMS AND HEAVY RAINFALL.

AREA OF CONCERN -- ENTIRE OUTLOOK AREA FOR THUNDERSTORM ACTIVITY WITH
THE GREATEST CHANCES FOR SEVERE THUNDERSTORMS AND HEAVY RAIN OVER THE
SOUTHWEST QUARTER.

TIMING DETAILS -- BETWEEN 600 PM AND MIDNIGHT.

METEOROLOGICAL COMMENTS -- A COLD FRONT LOCATED FROM MINNESOTA ACROSS
SOUTHEAST SOUTH DAKOTA AND INTO NEBRASKA WILL GRADUALLY MOVE THROUGH
IOWA THIS EVENING.  MOISTURE CONVERGENCE OVER SOUTHWEST IOWA ALONG
WITH PRECIPITABLE WATER VALUES OF UP TO TWO INCHES WILL FOCUS THE
HEAVIEST PRECIPITATION OVER THE SOUTHWEST PORTION OF THE STATE.  CAPE
VALUES STATEWIDE RANGE FROM 2000 TO 2500 J/KG.  AN INFLUX OF COLD AIR
AT 18000 FEET WILL LEAD TO FURTHER DESTABILIZATION THIS EVENING.
SUNSHINE LATE IN THE AFTERNOON WILL ALSO ENHANCE THE LIKELIHOOD OF
STRONG THUNDERSTORMS.  AT THIS TIME IT APPEARS THAT THUNDERSTORMS WILL
DEVELOP OVER WESTERN IOWA AFTER 600 PM AND THEN SPREAD EAST OVER THE
REMAINDER OF CENTRAL IOWA.  DUE TO THE COPIOUS AMOUNTS OF MOISTURE
AVAILABLE...RAINFALL RATES IN EXCESS OF ONE INCH PER HOUR ARE LIKELY.

PRECAUTIONS -- SPOTTER ACTIVATION MAYBE REQUIRED THIS EVENING.
EMERGENCY MANAGERS SHOULD REMAIN ALERT OF THE LATEST SHORT-TERM
FORECAST FOR THEIR AREA.

SCHAFER

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; radar from the NEXRAD Level II archive.