Alert archive / Iowa / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 25, NWS Des Moines, IA

May 18, 1997Adams County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at May 18, 1997, 2:59 AM CDT for Adams County, Iowa. It was in force for 31 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
May 18, 1997, 2:59 AM CDT (07:59 UTC)
Expired
May 18, 1997, 3:30 AM CDT
In force
31 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Adams County, IA

The radar

The Des Moines radar (KDMX), 113 km from the middle of the area, began a volume at 08:01 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

Omaha, NE (KOAX), launched 00:00Z, 8.0 hours before the alert went out and 144 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 1997-05-18Temperature 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, Omaha, NE at 00:00Z on 1997-05-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 37 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3053 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
37 m²/s²
0-3 km storm-relative helicity
112 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.

547 
WUUS1 KDSM 180758 RRA
SVRDSM
IAC003-180830-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
259 AM CDT SUN MAY 18 1997

* SEVERE THUNDERSTORM WARNING FOR
  NORTHERN ADAMS COUNTY - SOUTH CENTRAL IOWA

* UNTIL 330 AM CDT
 
* SOME AREAS AFFECTED
    MOUNT ETNA
    NEVINVILLE
    LAKE ICARIA
    CARBON

* AT 255 AM CDT RADAR INDICATED A SEVERE THUNDERSTORM 70 MILES
  SOUTHWEST OF DES MOINES...JUST WEST OF MOUNT ETNA ON HIGHWAY N28
  MOVING EAST AT 30 MPH.

* THE STORM WILL BE IN MOUNT ETNA AT 310 AM CDT.

THIS IS A DANGEROUS STORM.  DO NOT GO OUTDOORS.

FAB/GF

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

Local storm report, May 17, 10:10 PM CDT, 4 hours 49 minutes before
PRELIMINARY LOCAL STORM REPORT...CORRECTION
NATIONAL WEATHER SERVICE DES MOINES IA
1010 PM CDT FRI MAY 17 1997

TIME(CDT)   .....CITY LOCATION.....  ST   ...EVENT/REMARKS...
DATE(CDT)   ....COUNTY LOCATION....

0727 PM    1 E MURRAY                IA   0.75 INCH HAIL
05/17/97   CLARKE

PYTLAK
CORRECTED TO REMOVE OLDER INFORMATION
Local storm report, May 17, 10:10 PM CDT, 4 hours 49 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
1010 PM CDT FRI MAY 17 1997

TIME(CDT)   .....CITY LOCATION.....  ST   ...EVENT/REMARKS...
DATE(CDT)   ....COUNTY LOCATION....

0727 PM    1 E MURRAY                IA   0.75 INCH HAIL
05/17/97   CLARKE

PYTLAK

05/17/97   MADISON

0650 PM    6 N AFTON                 IA   1.00 INCH HAIL
05/17/97   UNION

0707 PM    2 S LORIMAR               IA   0.75 INCH HAIL
05/17/97   UNION

0722 PM    MURRAY                    IA   0.75 INCH HAIL
05/17/97   CLARKE                         HAIL COVERED GROUND 2
                                          INCHES DEEP

0733 PM    2 S OSCEOLA               IA   1.75 INCH HAIL
05/17/97   CLARKE                         HAIL PARTIALLY STRIPPED
                                          TREES

PYTLAK

The office that day

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

IssuedProductOfficeCountiesLasted
May 18, 3:13 PM CDTSevere Thunderstorm WarningDMXTama27 min
May 18, 3:41 PM CDTSevere Thunderstorm WarningDMXTama34 min
May 18, 4:36 PM CDTSevere Thunderstorm WarningDMXTama19 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.