Alert archive / Iowa / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 100, NWS Des Moines, IA

August 15, 1997Wapello County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Aug 15, 1997, 11:51 PM CDT for Wapello County, Iowa. It was in force for 34 min. 1 report 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
Aug 15, 1997, 11:51 PM CDT (04:51 UTC)
Expired
Aug 16, 1997, 12:25 AM CDT
In force
34 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Wapello County, IA

The radar

The Des Moines radar (KDMX), 134 km from the middle of the area, began a volume at 04:53 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
Aug 15, 11:55 PM CDTThunderstorm Wind 50Ottumwa, 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

Davenport, (KDVN), launched 00:00Z, 4.9 hours before the alert went out and 172 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 00:00Z on 1997-08-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2106 joules per kilogram.LCLEL10008507005003002001001 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 00:00Z on 1997-08-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 87 square meters per square second.19395878Sfc1 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
2106 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
1224 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
87 m²/s²
0-3 km storm-relative helicity
156 m²/s²
Significant tornado parameter
0.7
Supercell composite
5.1

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KDSM 160450 RRA
SVRDSM
IAC179-160525-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
1151 PM CDT FRI AUG 15 1997

* SEVERE THUNDERSTORM WARNING FOR
  NORTHERN WAPELLO COUNTY - SOUTHEASTERN IOWA

* UNTIL 1225 AM CDT
 
* SOME AREAS AFFECTED
    CHILLICOTHE
    HIGHLAND CENTER
    OTTUMWA AIRPORT

* AT 1150 PM CDT RADAR INDICATED A SEVERE THUNDERSTORM 10 MILES WEST OF
  OTTUMWA MOVING NORTHEAST AT 25 MPH.

* THE STORM WILL BE AT CHILLICOTHE BY MIDNIGHT.

THIS IS A DANGEROUS STORM.  DO NOT GO OUTDOORS.




FORSTER

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.