Alert archive / Iowa / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 64, NWS Des Moines, IA

June 22, 1997Hancock County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jun 22, 1997, 6:43 PM CDT for Hancock County, Iowa. It was in force for 47 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 22, 1997, 6:43 PM CDT (23:43 UTC)
Expired
Jun 22, 1997, 7:30 PM CDT
In force
47 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Hancock County, IA

The radar

The Des Moines radar (KDMX), 150 km from the middle of the area, began a volume at 23:45 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 22, 6:48 PM CDTHail 1Kanawha, 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

Minneapolis, MN (KMPX), launched 12:00Z, 11.7 hours before the alert went out and 197 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, Minneapolis, MN at 12:00Z on 1997-06-22Temperature 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, Minneapolis, MN at 12:00Z on 1997-06-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 7 square meters per square second.1939587897117Sfc1 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
1642 m above ground
0-6 km bulk shear
61 kt
0-1 km storm-relative helicity
7 m²/s²
0-3 km storm-relative helicity
94 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 222342 RRA
SVRDSM
IAC081-230030-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
643 PM CDT SUN JUN 22 1997

* SEVERE THUNDERSTORM WARNING FOR
  SOUTHEASTERN HANCOCK COUNTY - NORTH CENTRAL IOWA

* UNTIL 730 PM CDT
 
* SOME AREAS AFFECTED
    KANAWHA
    GOODELL
    KLEMME
    GARNER

* AT 640 PM CDT RADAR INDICATED A SEVERE THUNDERSTORM JUST SOUTH OF
  KANAWHA...OR 40 MILES SOUTHWEST OF MASON CITY PMOVING NORTHEAST AT 25
  MPH.

* THE STORM WILL BE NEAR GARNER AT 700 PM CDT.

THIS IS A DANGEROUS STORM.  DO NOT GO OUTDOORS.

S2

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 22, 3:00 PM CDT, 3 hours 43 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-230300-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
300 PM CDT SUN JUN 22 1997

HAZARD -- ISOLATED THUNDERSTORMS CAPABLE OF PRODUCING WIND GUSTS TO
60 MPH AND VERY HEAVY RAINFALL.

AREA OF CONCERN -- NORTH OF HIGHWAY 20.

TIMING DETAILS -- BETWEEN 500 AND 900 PM.

METEOROLOGICAL COMMENTS -- A WARM FRONT CURRENTLY OVER CENTRAL IOWA
WILL ADVANCE INTO NORTHERN IOWA THIS EVENING.  A WEAK UPPER LEVEL
DISTURBANCE OVER NORTH-CENTRAL IOWA WILL INTERACT WITH THIS FRONT
LEADING TO THE DEVELOPMENT OF ISOLATED THUNDERSTORMS.  ALTHOUGH...THE
ATMOSPHERE REMAINS UNSTABLE WITH LIFTED INDICES OF MINUS 2 TO MINUS 5
...A STRONG TEMPERATURE INVERSION WILL PREVENT WIDESPREAD
THUNDERSTORMS FROM DEVELOPING.  PRECIPITABLE WATER VALUES REMAIN WELL
IN EXCESS OF AN INCH SO ANY STORMS THAT DO DEVELOP WILL PRODUCE
LOCALLY HEAVY RAINFALL.  RAINFALL RATES OF 1 TO 2 INCHES PER HOUR ARE
LIKELY.

LATER TONIGHT...A SECOND UPPER LEVEL DISTURBANCE WILL EXIT THE DAKOTAS
AND MOVE INTO WESTERN MINNESOTA.  WEST TO NORTHWEST FLOW AT MID-LEVELS
MAY CAUSE THUNDERSTORMS ASSOCIATED WITH THIS SYSTEM TO DRIFT SOUTH
INTO IOWA.  PRESENT INDICATIONS SUGGEST THE MAIN THREAT WITH THESE
STORMS WOULD BE WITH VERY HEAVY RAINFALL AND STRONG WINDS DURING THE
OVERNIGHT HOURS.

PRECAUTIONS -- SPOTTER ACTIVATION MAY BE NEEDED THIS EVENING OVER
NORTHERN IOWA.  HEAVY RAINFALL IS LIKELY WITH ANY STORMS THAT DO
DEVELOP TONIGHT SO PEOPLE LIVING IN OR NEAR FLOOD PRONE AREAS ARE
URGED TO MONITOR THE WEATHER.

KUBINA

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 22, 4:54 PM CDTSevere Thunderstorm WarningDMXWebster31 min
Jun 22, 5:45 PM CDTSevere Thunderstorm WarningDMXHumboldt45 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; radar from the NEXRAD Level II archive.