Alert archive / Iowa / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 4, NWS Des Moines, IA

April 5, 1997Sac County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Apr 5, 1997, 6:56 PM CST for Sac 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
Apr 5, 1997, 6:56 PM CST (00:56 UTC)
Expired
Apr 5, 1997, 7:30 PM CST
In force
34 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 00:56 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

Omaha, NE (KOAX), launched 00:00Z, 0.9 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 00:00Z on 1997-04-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 89 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 00:00Z on 1997-04-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 103 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
89 J/kg
Mixed-layer CIN
-20 J/kg
Mixed-layer LCL
1566 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
103 m²/s²
0-3 km storm-relative helicity
124 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KDSM 060055 RRA
SVRDSM
IAC161-060130-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
656 PM CST SAT APR 5 1997

* SEVERE THUNDERSTORM WARNING FOR
  SAC COUNTY - WEST CENTRAL IOWA

* UNTIL 730 PM CST
 
* SOME AREAS AFFECTED
    ODEBOLT
    LAKE VIEW
    SAC CITY

* AT 654 PM CST RADAR INDICATED A SEVERE THUNDERSTORM 3 MILES SOUTH OF
  ODEBOLT...OR ABOUT 60 MILES SOUTHWEST OF FORT DODGE MOVING NORTHEAST
  AT 30 MPH.

* THE STORM WILL BE NEAR LAKE VIEW BY 705 PM AND THROUGH SAC CITY BY
  715 PM CST.

THIS IS A DANGEROUS STORM.  DO NOT GO OUTDOORS.

SMITH

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, Apr 5, 3:48 PM CST, 3 hours 8 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-052245-

SPECIAL WEATHER STATEMENT...CORRECTED
NATIONAL WEATHER SERVICE DES MOINES IA
342 PM CST SAT APR 5 1997

...THE SEVERE THUNDERSTORM WATCH FOR NORTHERN IOWA HAS BEEN CANCELLED
BUT REMAINS IN EFFECT FOR EASTERN IOWA UNTIL 7 PM CST...

THE THUNDERSTORMS WHICH PRODUCED WIND GUSTS TO 70 MPH HAVE
EXITED CENTRAL IOWA AND CONTINUE TO MOVE NORTHEAST AT 40 MPH.
AS A RESUfLT THE SEVERE THUNDERSTORM WATCH FOR CENTRAL IOWA HAS BEEN
CANCELLED.

CLEARING CONDITIONS WILL MOVE ACROSS IOWA FROM THE SOUTH
THROUGH EARLY EVENING BUT SHOWERS WIILL REDEVELOP ACROSS THE
AREA AFTER 10 PM.

FAB
Special weather statement, Apr 5, 3:49 PM CST, 3 hours 7 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-052245-

SPECIAL WEATHER STATEMENT...CORRECTED
NATIONAL WEATHER SERVICE DES MOINES IA
342 PM CST SAT APR 5 1997

...THE SEVERE THUNDERSTORM WATCH FOR NORTHERN IOWA HAS BEEN CANCELLED
BUT REMAINS IN EFFECT FOR EASTERN IOWA UNTIL 7 PM CST...

THE THUNDERSTORMS WHICH PRODUCED WIND GUSTS TO 70 MPH HAVE
EXITED CENTRAL IOWA AND CONTINUE TO MOVE NORTHEAST AT 40 MPH.
AS A RESULT THE SEVERE THUNDERSTORM WATCH FOR NORTHERN IOWA HAS BEEN
CANCELLED.  THE STORMS WILL CONTINUE TO MOVE ACROSS EASTERN IOWA WHERE
THE WATCH REMAINS IN EFFECT.

CLEARING CONDITIONS WILL MOVE ACROSS IOWA FROM THE SOUTH
THROUGH EARLY EVENING BUT SHOjWERS WIILL REDEVELOP ACROSS THE
AREA AFTER 10 PM.

FAB
Special weather statement, Apr 5, 5:10 PM CST, 1 hour 46 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-060200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
510 PM CST SAT APR 5 1997

...THE SEVERE THUNDERSTORM WATCH THAT WAS IN EFFECT FOR A PORTION OF
EASTERN IOWA HAS BEEN CANCELLED...

THE SEVERE THUNDERSTORM WATCH THAT WAS IN EFFECT FOR A PORTION OF
EASTERN IOWA HAS BEEN CANCELLED. THE STORMS THAT PROMPTED THE ISSUANCE
OF THE WATCH HAVE MOVED RAPIDLY OUT OF THE STATE AND NO LONGER POSE A
THREAT THIS EVENING.

ADDITIONAL SHOWERS AND THUNDERSTORMS WERE MOVING RAPIDLY OUT OF SOUTHWEST
IOWA INTO CENTRAL IOWA. PRESENT INDICATIONS SUGGEST THERE IS THE POTENTIAL
FOR SOME SMALL HAIL WITH THESE STORMS...HOWEVER NO WIDEPSREAD SEVERE WEATHER
IS EXPECTED WITH THESE STORMS AS THEY TRACK ACROSS THE STATE.

SMITH
Special weather statement, Apr 5, 5:11 PM CST, 1 hour 45 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-060200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
510 PM CST SAT APR 5 1997

...THE SEVERE THUNDERSTORM WATCH THAT WAS IN EFFECT FOR A PORTION OF
EASTERN IOWA HAS BEEN CANCELLED...

THE SEVERE THUNDERSTORM WATCH THAT WAS IN EFFECT FOR A PORTION OF
EASTERN IOWA HAS BEEN CANCELLED. THE STORMS THAT PROMPTED THE ISSUANCE
OF THE WATCH HAVE MOVED RAPIDLY OUT OF THE STATE AND NO LONGER POSE A
THREAT THIS EVENING.

ADDITIONAL SHOWERS AND THUNDERSTORMS WERE MOVING RAPIDLY OUT OF SOUTHWEST
IOWA INTO CENTRAL IOWA. PRESENT INDICATIONS SUGGEST THERE IS THE POTENTIAL
FOR SOME SMALL HAIL WITH THESE STORMS...HOWEVER NO WIDEPSREAD SEVERE WEATHER
IS EXPECTED WITH THESE STORMS AS THEY TRACK ACROSS THE STATE.

SMITH
Special weather statement, Apr 5, 6:47 PM CST, 9 minutes before
IAZ033-044>045-060200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
648 PM CST SAT APR 5 1997

...SEVERE THUNDERSTORM WARNING HAS EXPIRED FOR NORTHWEST CRAWFORD
COUNTY...

THE SEVERE THUNDERSTORM WARNING THAT WAS IN EFFECT FOR NORTHWEST
CRAWFORD COUNTY HAS EXPIRED. OTHER THAN THE GOLF BALL SIZE HAIL THAT
WAS REPORTED IN CHARTER OAK AROUND 630 PM...NO OTHER REPORTS WERE
RECEIVED.

SMITH
Special weather statement, Apr 5, 6:48 PM CST, 8 minutes before
IAZ033-044>045-060200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
648 PM CST SAT APR 5 1997

...SEVERE THUNDERSTORM WARNING HAS EXPIRED FOR NORTHWEST CRAWFORD
COUNTY...

THE SEVERE THUNDERSTORM WARNING THAT WAS IN EFFECT FOR NORTHWEST
CRAWFORD COUNTY HAS EXPIRED. OTHER THAN THE GOLF BALL SIZE HAIL THAT
WAS REPORTED IN CHARTER OAK AROUND 630 PM...NO OTHER REPORTS WERE
RECEIVED.

SMITH

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 5, 6:26 PM CSTSevere Thunderstorm WarningDMXCrawford19 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.