Alert archive / Iowa / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 112, NWS Des Moines, IA

August 26, 1997Mahaska County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Aug 26, 1997, 10:02 AM CDT for Mahaska County, Iowa. It was in force for 33 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
Aug 26, 1997, 10:02 AM CDT (15:02 UTC)
Expired
Aug 26, 1997, 10:35 AM CDT
In force
33 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Mahaska County, IA

The radar

The Des Moines radar (KDMX), 100 km from the middle of the area, began a volume at 15:01 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, 3.0 hours before the alert went out and 181 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 1997-08-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 41 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 1997-08-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 73 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
41 J/kg
Mixed-layer CIN
-281 J/kg
Mixed-layer LCL
842 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
73 m²/s²
0-3 km storm-relative helicity
130 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.9

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KDSM 261501 RRA
SVRDSM
IAC123-261535-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
1002 AM CDT TUE AUG 26 1997

* SEVERE THUNDERSTORM WARNING FOR
  EASTERN MAHASKA COUNTY - SOUTHEASTERN IOWA

* UNTIL 1035 AM CDT
 
* SOME AREAS AFFECTED
    WRIGHT
    CEDAR
    FREMONT

* AT 1000 AM CDT RADAR INDICATED A SEVERE THUNDERSTORM JUST EAST OF
  OSKALOOSA...OR 20 MILES NORTHWEST OF OTTUMWA MOVING SOUTHEAST AT.
  20 MPH.

* THE STORM WILL BE NEAR WRIGHT BY 1010 AM CDT.

THIS IS A DANGEROUS STORM.  DO NOT GO OUTDOORS.

SMALL

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, Aug 26, 5:34 AM CDT, 4 hours 28 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-271200-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
535 AM CDT TUE AUG 26 1997

HAZARD--NONE.

METEOROLOGICAL COMMENTS--SCATTERED THUNDERSTORMS EARLY THIS MORNING AND
THIS AFTERNOON WILL REMAIN EAST AND SOUTHEAST OF THE DES MOINES NATIONAL
WEATHER SERVICE COUNTY WARNING AREA.  NO THUNDERSTORMS ARE FORECAST THE
REST OF TODAY OR TONIGHT IN CENTRAL IOWA.

PRECAUTIONS--NONE.

KULA

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.