Alert archive / Iowa / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 63, NWS Des Moines, IA

June 22, 1997Humboldt County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jun 22, 1997, 5:45 PM CDT for Humboldt County, Iowa. It was in force for 45 min. 3 reports 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, 5:45 PM CDT (22:45 UTC)
Expired
Jun 22, 1997, 6:30 PM CDT
In force
45 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Humboldt County, IA

The radar

The Des Moines radar (KDMX), 123 km from the middle of the area, began a volume at 22:46 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, 5:46 PM CDTHail 1.75Humboldt, IA
Jun 22, 5:48 PM CDTHail 1.75Dakota City, IA
Jun 22, 6:03 PM CDTHail 2.75Humboldt, 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, 10.8 hours before the alert went out and 236 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.

004 
WUUS1 KDSM 222244 RRA
SVRDSM
IAC091-222330-
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
545 PM CDT SUN JUN 22 1997

* SEVERE THUNDERSTORM WARNING FOR
  HUMBOLDT COUNTY - NORTH CENTRAL IOWA

* UNTIL 630 PM CDT
 
* SOME AREAS AFFECTED
    HUMBOLDT
    THOR
    DAKOTA CITY

* AT 540 PM CDT RADAR INDICATED A SEVERE THUNDERSTORM SOUTH OF
  HUMBOLT...10 MILES NORTH OF FORT DODGE MOVING NORTHEAST AT 20 MPH.

* THE STORM WILL BE NEAR HUMBOLDT AND DAKOTA CITY AT 545 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, 11:51 AM CDT, 5 hours 54 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-222055-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
1152 AM CDT SUN JUN 22 1997

HAZARD--ISOLATED THUNDERSTORMS CAPABLE OF PRODUCING WIND GUSTS TO 60
MPH AND VERY HEAVY RAINFALL IN A SHORT PERIOD OF TIME.

AREA OF CONCERN--NORTH OF HIGHWAY 20.

TIMING DETAILS--BETWEEN 200 AND 600 PM.

METEOROLOGICAL COMMENTS--A WARM FRONT OVER CENTRAL IOWA EARLY THIS
AFTERNOON WILL ADVANCE INTO NORTHERN IOWA BY LATE AFTERNOON. SOUTHERLY
WINDS AT THE LOW LEVELS ARE FORECAST TO GRADUALLY INCREASE OVER THE
CENTRAL PLAINS LATE THIS AFTERNOON AS AN UPPER LEVEL DISTURBANCE PUSHES
INTO THE DAKOTAS AND WESTERN MINNESOTA. THE STRONGEST MOISTURE
CONVERGENCE AND UPPER LEVEL DIVERGENCE WILL BE OVER THE DAKOTAS AND
SOUTHERN MINNESOTA THIS AFTERNOON AND EVENING. HOWEVER...A CONVECTIVELY
INDUCED OUTFLOW BOUNDARY EXISTS ACROSS NORTHWEST AND NORTH CENTRAL IOWA
AND THIS COULD FOCUS THUNDERSTORM DEVELOPMENT BY MID AFTERNOON IN THIS
AREA. ONE NEGATIVE FACTOR WILL BE THE WARMING TEMPERATURES AROUND
10,000 FEET THIS AFTERNOON WHICH MAY KEEP THUNDERSTORMS FROM BECOMING A
WIDESPREAD PROBLEM OVER NORTHERN IOWA.

SEVERAL THUNDERSTORM COMPLEXES ARE FORECAST TO DEVELOP ACROSS THE
DAKOTAS AND MINNESOTA LATE THIS AFTERNOON AND OVERNIGHT WHICH COULD
SPILL INTO THE FAR NORTHERN COUNTIES OF 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 LATE THIS AFTERNOON OR
EVENING OVER NORTHERN IOWA. SHORT TERM FORECASTS THIS AFTERNOON WILL
OUTLINE THE AREA OR AREAS OF CONCERN WITH AN UPDATED CENTRAL IOWA
THUNDERSTORM OUTLOOK SCHEDULED FOR AROUND 300 PM.

SMITH
Special weather statement, Jun 22, 11:52 AM CDT, 5 hours 53 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-222055-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
1152 AM CDT SUN JUN 22 1997

HAZARD--ISOLATED THUNDERSTORMS CAPABLE OF PRODUCING WIND GUSTS TO 60
MPH AND VERY HEAVY RAINFALL IN A SHORT PERIOD OF TIME.

AREA OF CONCERN--NORTH OF HIGHWAY 20.

TIMING DETAILS--BETWEEN 200 AND 600 PM.

METEOROLOGICAL COMMENTS--A WARM FRONT OVER CENTRAL IOWA EARLY THIS
AFTERNOON WILL ADVANCE INTO NORTHERN IOWA BY LATE AFTERNOON. SOUTHERLY
WINDS AT THE LOW LEVELS ARE FORECAST TO GRADUALLY INCREASE OVER THE
CENTRAL PLAINS LATE THIS AFTERNOON AS AN UPPER LEVEL DISTURBANCE PUSHES
INTO THE DAKOTAS AND WESTERN MINNESOTA. THE STRONGEST MOISTURE
CONVERGENCE AND UPPER LEVEL DIVERGENCE WILL BE OVER THE DAKOTAS AND
SOUTHERN MINNESOTA THIS AFTERNOON AND EVENING. HOWEVER...A CONVECTIVELY
INDUCED OUTFLOW BOUNDARY EXISTS ACROSS NORTHWEST AND NORTH CENTRAL IOWA
AND THIS COULD FOCUS THUNDERSTORM DEVELOPMENT BY MID AFTERNOON IN THIS
AREA. ONE NEGATIVE FACTOR WILL BE THE WARMING TEMPERATURES AROUND
10,000 FEET THIS AFTERNOON WHICH MAY KEEP THUNDERSTORMS FROM BECOMING A
WIDESPREAD PROBLEM OVER NORTHERN IOWA.

SEVERAL THUNDERSTORM COMPLEXES ARE FORECAST TO DEVELOP ACROSS THE
DAKOTAS AND MINNESOTA LATE THIS AFTERNOON AND OVERNIGHT WHICH COULD
SPILL INTO THE FAR NORTHERN COUNTIES OF 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 LATE THIS AFTERNOON OR
EVENING OVER NORTHERN IOWA. SHORT TERM FORECASTS THIS AFTERNOON WILL
OUTLINE THE AREA OR AREAS OF CONCERN WITH AN UPDATED CENTRAL IOWA
THUNDERSTORM OUTLOOK SCHEDULED FOR AROUND 300 PM.

SMITH
Special weather statement, Jun 22, 3:00 PM CDT, 2 hours 45 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, 6:43 PM CDTSevere Thunderstorm WarningDMXHancock47 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.