Alert archive / Iowa / Severe Thunderstorm Warnings in 1996

Severe Thunderstorm Warning 63, NWS Des Moines, IA

June 20, 1996Audubon County, Cass County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jun 20, 1996, 9:25 AM CDT for Audubon County, Cass County, Iowa. It was in force for 30 min. 2 reports 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
Jun 20, 1996, 9:25 AM CDT (14:25 UTC)
Expired
Jun 20, 1996, 9:55 AM CDT
In force
30 min
Issued by
NWS Des Moines, IA
Area
Whole counties

Counties Audubon County, IA, Cass County, IA

The radar

The Des Moines radar (KDMX), 102 km from the middle of the area, began a volume at 14:25 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
Jun 20, 9:41 AM CDTThunderstorm Wind 50Audubon, IA
Jun 20, 9:45 AM CDTThunderstorm Wind 50Audubon, 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

Omaha, NE (KOAX), launched 12:00Z, 2.4 hours before the alert went out and 123 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 12:00Z on 1996-06-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2885 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 12:00Z on 1996-06-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 145 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
2885 J/kg
Mixed-layer CIN
-108 J/kg
Mixed-layer LCL
717 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
145 m²/s²
0-3 km storm-relative helicity
147 m²/s²
Significant tornado parameter
0.0
Supercell composite
10.7

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KDSM 201425
SVRDSM
IAC009-029-201455-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
925 AM CDT THU JUN 20 1996

* SEVERE THUNDERSTORM WARNING FOR
  AUDUBON COUNTY - WEST CENTRAL IOWA
  CASS COUNTY - SOUTHWEST IOWA

* UNTIL 955 AM CDT
 
* SOME LOCATIONS AFFECTED
    AUDUBON
    ATLANTIC
    ANITA
    BRAYTON

* AT 925 AM CDT RADAR INDICATED A SEVERE THUNDERSTORM 20 MILES WEST
  OF AUDUBON...OR 30 TMILES NORTHEAST OF OMAHA MOVING EAST AT 40
  MPH.

* THE STORM WILL BE IN AUDUBON BY 940 AM CDT.

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, Jun 20, 5:41 AM CDT, 3 hours 44 minutes before
IAZ004>011-015>019-023>030-033>042-044>054-057>064-070>078-081>089-
092>099-201130-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
535 AM CDT THU JUN 20 1996

...PARTS OF SEVERE THUNDERSTORM WATCH NUMBER 646 HAS BEEN CANCELLED...

THE STORMS WHICH HAVE HAD A HISTORY OF PRODUCING SEVERE WEATHER HAVE
MOVED SOUTH...THEREFORE THE WATCH HAS BEEN CANCELLED FOR NORTHERN
PORTIONS OF THE WATCH. THOSE COUNTIES CLEARED FROM THE WATCH INCLUDE
EMMET...KOSSUTH...PALO ALTO...POCOHONTAS...HUMBOLT...SAC...CALHOUN...
WEBSTER...CRAWFORD...CARROLL...AND GREEN.

THE REMAINDER OF THE COUNTIES INCLUDED IN THE SEVERE THUNDERSTORM
ARE STILL UNDER THE WATCH UNTIL 700 AM CDT. STAY TUNED FOR LATER

STATEMENTS.

HUNTER
Special weather statement, Jun 20, 7:06 AM CDT, 2 hours 19 minutes before
IAZ004>011-015>019-023>030-033>042-044>054-057>064-070>078-081>089-
092>099-201130-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
700 AM CDT THU JUN 20 1996

...THE THUNDERSTORM WATCH WHICH WAS IN EFFECT UNTIL 700 AM CDT HAS
EXPIRED...

THE STORMS WHICH PRODUCED SEVERE WEATHER OVERNIGHT HAVE
WEAKENED...THUS THE SEVERE THUNDERSTORM WATCH NUMBER 646 HAS BEEN
ALLOWED TO EXPIRE. SCATTERED THUNDERSTORMS PRODUCING HEAVY
RAIN...BRIEFv GUSTY WINDS AND POSSIBLY SMALL HAIL WILL CONTINUE OVER
THE AREA THIS MORNING...HOWEVER NO SEVERE WEATHER IS EXPECTED. STAY
TUNED TO NOAA WEATHER RADIO FOR ANY UPDATES.

HUNTER

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 19, 11:44 PM CDTSevere Thunderstorm WarningDMXSac31 min
Jun 20, 12:39 AM CDTSevere Thunderstorm WarningDMXSac21 min
Jun 20, 1:00 AM CDTSevere Thunderstorm WarningDMXCrawford25 min
Jun 20, 1:16 AM CDTFlash Flood WarningDMXSac3 hr
Jun 20, 1:23 AM CDTSevere Thunderstorm WarningDMXCrawford32 min
Jun 20, 9:49 AM CDTSevere Thunderstorm WarningDMXAdair, Guthrie41 min
Jun 20, 10:16 AM CDTSevere Thunderstorm WarningDMXDallas, Madison44 min
Jun 20, 10:36 AM CDTSevere Thunderstorm WarningDMXPolk, Warren39 min
Jun 20, 10:51 AM CDTSevere Thunderstorm WarningDMXMadison, Union29 min
Jun 20, 1:18 PM CDTFlash Flood WarningDMXAudubon3 hr
Jun 20, 4:23 PM CDTSevere Thunderstorm WarningDMXCrawford37 min
Jun 20, 5:11 PM CDTSevere Thunderstorm WarningDMXCrawford34 min
Jun 20, 5:32 PM CDTSevere Thunderstorm WarningDMXCrawford43 min

Nearby

Severe Thunderstorm Warnings in Iowa, 1996Every severe thunderstorm warning in 1996

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.