Alert archive / Iowa / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 94, NWS Des Moines, IA

July 27, 1997Black Hawk County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jul 27, 1997, 1:41 PM CDT for Black Hawk County, Iowa. It was in force for 34 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jul 27, 1997, 1:41 PM CDT (18:41 UTC)
Expired
Jul 27, 1997, 2:15 PM CDT
In force
34 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Black Hawk County, IA

The radar

The Des Moines radar (KDMX), 143 km from the middle of the area, began a volume at 18:40 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.

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 6.7 hours before the alert went out and 177 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 12:00Z on 1997-07-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2407 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, Davenport, at 12:00Z on 1997-07-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 8 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
2407 J/kg
Mixed-layer CIN
-105 J/kg
Mixed-layer LCL
1367 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
8 m²/s²
0-3 km storm-relative helicity
41 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 271841 RRA
SVRDSM
IAC013-271915-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
141 PM CDT SUN JUL 27 1997

* SEVERE THUNDERSTORM WARNING FOR
  BLACK HAWK COUNTY - NORTHEASTERN IOWA

* UNTIL 215 PM CDT
 
* SOME AREAS AFFECTED
    WATERLOO
    HUDSON
    CEDAR FALLS
    LA PORTE CITY

* AT 138 PM CDT LOCAL LAW ENFORCEMENT REPORTED A SEVERE THUNDERSTORM
  NEAR HUDSON OR JUST SOUTHWEST OF WATERLOO MOVING EAST SOUTHEAST AT 15
  MPH.

* THE STORM WILL BE NEAR WATERLOO BY 145 PM CDT AND LA PORTE CITY BY
  155 PM CDT.

THIS IS A DANGEROUS STORM.  DO NOT GO OUTDOORS.




SCHAFER

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, Jul 27, 10:05 AM CDT, 3 hours 36 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-272100-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
1005 AM CDT SUN JUL 27 1997

HAZARD--THUNDERSTORMS PRODUCING LOCALIZED HEAVY RAIN...POSSIBLY
DAMAGING DOWNDRAFTS.

AREA OF CONCERN AND TIMING--THROUGH MID AFTERNOON...TWO AREAS OF
CONCERN...BOTH GENERALLY NORTH OF HIGHWAY 20.

A CLUSTER OF STORMS OVER SOUTHEAST NEBRASKA WAS OCCASIONALLY PRODUCING
WIND GUSTS TO 60 MPH.  THIS WILL MOVE INTO NORTHWEST IOWA BY MIDDAY.

ANOTHER AREA OF DEVELOPING STORMS WAS LOCATED OVER NORTHEAST IOWA. THESE
STORMS WILL CONTINUE TO DEVELOP AND STRENGTHEN THROGH MIDDAY.  IN
ADDITION TO WIND...HAIL IS POSSIBLE WITH THESE STORMS.

OUTLOOK...THUNDERSTORMS COULD DROP SLOWLY INTO CENTRAL IOWA LATE THIS
AFTERNOON OR EVENING.

PRECAUTIONS: ALTHOUGH WIDESPREAD SEVERE WEATHER IS NOT EXPECTED WITH
THESE STORMS...SCATTERED STORMS COULD PRODUCE DAMAGING WINDS OR HAIL.

FELDT
Special weather statement, Jul 27, 10:06 AM CDT, 3 hours 35 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-272100-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
1005 AM CDT SUN JUL 27 1997

HAZARD--THUNDERSTORMS PRODUCING LOCALIZED HEAVY RAIN...POSSIBLY
DAMAGING DOWNDRAFTS.

AREA OF CONCERN AND TIMING--THROUGH MID AFTERNOON...TWO AREAS OF
CONCERN...BOTH GENERALLY NORTH OF HIGHWAY 20.

A CLUSTER OF STORMS OVER SOUTHEAST NEBRASKA WAS OCCASIONALLY PRODUCING
WIND GUSTS TO 60 MPH.  THIS WILL MOVE INTO NORTHWEST IOWA BY MIDDAY.

ANOTHER AREA OF DEVELOPING STORMS WAS LOCATED OVER NORTHEAST IOWA. THESE
STORMS WILL CONTINUE TO DEVELOP AND STRENGTHEN THROGH MIDDAY.  IN
ADDITION TO WIND...HAIL IS POSSIBLE WITH THESE STORMS.

OUTLOOK...THUNDERSTORMS COULD DROP SLOWLY INTO CENTRAL IOWA LATE THIS
AFTERNOON OR EVENING.

PRECAUTIONS: ALTHOUGH WIDESPREAD SEVERE WEATHER IS NOT EXPECTED WITH
THESE STORMS...SCATTERED STORMS COULD PRODUCE DAMAGING WINDS OR HAIL.

FELDT
Special weather statement, Jul 27, 12:30 PM CDT, 1 hour 11 minutes before
IAZ033>039-044>050-057>062-070>075-081>086-092>097-272100

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
1230 PM CDT SUN JUL 27 1997

ADVISORY INFORMATION--A HEAT ADVISORY IS IN EFFECT FOR CENTRAL AND
SOUTHERN IOWA TONIGHT AND SUNDAY...MAINLY ALONG AND SOUTH OF HIGHWAY
30.  THE ADVISORY HAS BEEN CANCELLED NORTH OF HIGHWAY 30 DUE TO
CLOUDS AND RAIN IN THE AREA.

FORECAST CONDITIONS--HEAT INDICES FROM 100 TO 115 THIS AFTERNOON AND
EVENING WILL ONCE AGAIN OCCUR AS TEMPERATURES RISE INTO THE MID OR
UPPER 90S ALONG WITH DEW POINTS IN THE MID 70S TO LOWER 80S.

PRECAUTIONS...THIS WILL BE THE LAST DAY OF OPPRESSIVE HEAT...SO
BE SURE TO TAKE IT EASY AND DRINK PLENTY OF FLUIDS. IF YOU ARE
UNSURE AS TO YOUR ABILITY TO COPE WITH THE HEAT...SEEK ADEQUATE
SHELTER.
Special weather statement, Jul 27, 12:42 PM CDT, 59 minutes before
IAZ033>039-044>050-057>062-070>075-081>086-092>097-272100

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
1230 PM CDT SUN JUL 27 1997

ADVISORY INFORMATION--A HEAT ADVISORY IS IN EFFECT FOR CENTRAL AND
SOUTHERN IOWA TONIGHT AND SUNDAY...MAINLY ALONG AND SOUTH OF HIGHWAY
30.  THE ADVISORY HAS BEEN CANCELLED NORTH OF HIGHWAY 30 DUE TO
CLOUDS AND RAIN IN THE AREA.

FORECAST CONDITIONS--HEAT INDICES FROM 100 TO 115 THIS AFTERNOON AND
EVENING WILL ONCE AGAIN OCCUR AS TEMPERATURES RISE INTO THE MID OR
UPPER 90S ALONG WITH DEW POINTS IN THE MID 70S TO LOWER 80S.

PRECAUTIONS...THIS WILL BE THE LAST DAY OF OPPRESSIVE HEAT...SO
BE SURE TO TAKE IT EASY AND DRINK PLENTY OF FLUIDS. IF YOU ARE
UNSURE AS TO YOUR ABILITY TO COPE WITH THE HEAT...SEEK ADEQUATE
SHELTER.

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 27, 1:38 PM CDTSevere Thunderstorm WarningDMXPocahontas32 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.