Alert archive / Iowa / Severe Thunderstorm Warnings in 1996

Severe Thunderstorm Warning 83, NWS Des Moines, IA

June 23, 1996Boone County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jun 23, 1996, 6:36 PM CDT for Boone County, Iowa. It was in force for 29 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
Jun 23, 1996, 6:36 PM CDT (23:36 UTC)
Expired
Jun 23, 1996, 7:05 PM CDT
In force
29 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Boone County, IA

The radar

The Des Moines radar (KDMX), 38 km from the middle of the area, began a volume at 23:37 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 12:00Z, 11.6 hours before the alert went out and 218 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 1996-06-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 70 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 1996-06-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 141 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
70 J/kg
Mixed-layer CIN
-399 J/kg
Mixed-layer LCL
1219 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
141 m²/s²
0-3 km storm-relative helicity
297 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.3

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KDSM 232336
SVRDSM
IAC015-240005-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
636 PM CDT SUN JUN 23 1996

* SEVERE THUNDERSTORM WARNING FOR
  EASTERN BOONE COUNTY - CENTRAL IOWA

* UNTIL 705 PM CDT
 
* SOME LOCATIONS AFFECTED
    LUTHER
    NAPIER
    BOONE
    LEDGES STATE PARK

* AT 634 PM CDT RADAR INDICATED A SEVERE THUNDERSTORM JUST SOUTH OF
  OGDEN...OR 35 MILES NORTHWEST OF DES MOINES MOVING EAST AT 30 MPH.

* THE STORM WILL BE NEAR LUTHER AT 640 PM.

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, Jun 23, 12:42 PM CDT, 5 hours 54 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-232130-

CENTRAL IOWA THUNDERSTORM OUTLOOK...AMENDMENT TO TIMING
NATIONAL WEATHER SERVICE DES MOINES IA
1239 PM CDT SUN JUN 23 1996

HAZARD...WIDELY SCATTERED THUNDERSTORMS...A FEW OF WHICH COULD BECOME
SEVERE WITH DAMAGING WINDS.  ISOLATED TORNADOES MAY ALSO OCCUR BUT THE
MAIN THREAT WILL BE DAMAGING WINDS.  SMALL HAIL IS POSSIBLE...BUT
LARGE HAIL MEETING SEVERE CRITERIA IS NOT EXPECTED.  SOME STORMS COULD
ALSO PRODUCE BETWEEN 1 AND 2 INCHES OF RAIN.

AREA OF CONCERN...ALL OF CENTRAL IOWA

TIMING DETAILS...THIS AFTERNOON AND INTO THE EARLY EVENING HOURS.

METEOROLOGICAL COMMENTS...A WARM FRONT WAS POSITIONED ACROSS EXTREME
SOUTHERN IOWA LATE THIS AFTERNOON AND WAS GRADUALLY MOVING NORTHWARD.
MOISTURE CONVERGENCE WAS MAXIMIZED NEAR THE BOUNDARY WITH THE AIRMASS
BECOMING INCREASINGLY UNSTABLE.  LIFTED INDICES WERE AS LOW AS MINUS 6
TOWARD THE MISSOURI BORDER AND MAY BE DOWN TO MINUS 9 BY LATER THIS
AFTERNOON.  A LAYER OF WARM AIR ALOFT WAS PROHIBITING THE WIDELY
SCATTERED SHOWERS AND THUNDERSTORMS CURRENTLY ACROSS IOWA FROM
BECOMING SEVERE...BUT LATER TODAY THE STORMS MAY BREAK THROUGH THAT
LAYER AS SUNSHINE WARMS THE LOWER LEVELS.  BY MID TO LATE AFTERNOON
THE WARM LAYER...OR CAP...MAY NOT BE ENOUGH TO KEEP STORMS FROM
BECOMING SEVERE AS THE FRONT LIFTS SLOWLY TOWARD THE NORTH INTO
CENTRAL IOWA.

AT THIS TIME THE PRIMARY SEVERE WEATHER THREAT APPEARS TO BE DAMAGING
WINDS.  DIRECTIONAL WIND SHEAR IN THE LOWER TO MIDDLE ATMOSPHERE IS
ALSO SUFFICIENT FOR ISOLATED TORNADIC DEVELOPMENT JUST NORTH OF THE
WARM FRONT.  THE MID LEVELS OF THE AIRMASS CURRENTLY OVER IOWA ARE
QUITE WARM AND MOIST SO LARGE HAIL IS NOT A SIGNIFICANT THREAT.
ALTHOUGH THERE MAY BE BRIEF DOWNPOURS...THE STORMS SHOULD BE MOVING
FAST ENOUGH SO FLASH FLOODING LIKELY WILL NOT OCCUR EITHER.

PRECAUTIONS...SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AS A
SEVERE WEATHER WATCH IS CURRENTLY BEING CONSIDERED.  EVEN THOUGH THERE
IS NOT A THREAT OF WIDESPREAD FLASH FLOODING...ANY BRIEF HEAVY RAINS
COULD CAUSE SMALL STREAM AND URBAN FLOODING.

SMALL
Special weather statement, Jun 23, 5:51 PM CDT, 45 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
550 PM CDT SUN JUN 23 1996

THE FOLLOWING COUNTIES ARE CLEARED FROM TORNADO WATCH 676

NORTHWEST                 NORTH CENTRAL             WEST CENTRAL
CENTRAL

SOME CITIES CLEARED FROM THE WATCH ARE...

ALGONA                    CHEROKEE                  ESTHERVILLE
FORT DODGE                SPENCER                   STORM LAKE
WEBSTER CITY

IN IOWA THE FOLLOWING COUNTIES ARE CLEARED AND NO LONGER IN THE
WATCH...
IAC021-035-041-059-063-141-147-151-240300-
...NORTHWEST...
BUENA VISTA               CHEROKEE                  CLAY
DICKINSON                 EMMET                     O BRIEN
PALO ALTO                 POCAHONTAS

IAC081-091-109-189-195-197-240300-
...NORTH CENTRAL...
HANCOCK                   HUMBOLDT                  KOSSUTH
WINNEBAGO                 WORTH                     WRIGHT

IAC025-093-161-240300-
...WEST CENTRAL...
CALHOUN      D             IDA                       SAC

IAC079-187-240300-
...CENTRAL...
HAMILTON                  WEBSTER
Special weather statement, Jun 23, 5:57 PM CDT, 39 minutes before
SPECIAL WEATHER STATEMENT FOR CLEARING COUNTIES
NATIONAL WEATHER SERVICE DES MOINES IA
556 PM CDT SUN JUN 23 1996

THE FLOOWING COUNTIES HAVE BEEN CLEARED FROM
TORNADO WATCH NUMBER 676...VALID UNTIL 1000 PM CDT...

NORTHWEST                 NORTH CENTRAL             WEST CENTRAL
CENTRAL

CITIES CLEARED FROM THE WATCH ARE...

ALGONA                    CARROLL                   CHEROKEE
DENISON                   ESTHERVILLE               FORT DODGE
SPENCER                   STORM LAKE                WEBSTER CITY

IN IOWA THIS WATCH INCLUDES THE FOLLOWING COUNTIES...

IAC021-035-041-059-063-141-147-151-240300-
...NORTHWEST...
BUENA VISTA               CHEROKEE                  CLAY
DICKINSON                 EMMET                     O BRIEN
PALO ALTO                 POCAHONTAS

IAC081-091-109-189-195-197-240300-
...NORTH CENTRAL...
HANCOCK                   HUMBOLDT                  KOSSUTH
WINNEBAGO                 WORTH                     WRIGHT

IAC025-027-047-073-093-161-240300-
...WEST CENTRAL...
CALHOUN                   CARROLL                   CRAWFORD
GREENE                    IDA                       SAC

IAC079-187-240300-
...CENTRAL...
HAMZILTON                  WEBSTER

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 23, 2:42 PM CDTSevere Thunderstorm WarningDMXDecatur33 min
Jun 23, 3:31 PM CDTSevere Thunderstorm WarningDMXTaylor34 min
Jun 23, 4:33 PM CDTSevere Thunderstorm WarningDMXRinggold47 min
Jun 23, 4:49 PM CDTSevere Thunderstorm WarningDMXDecatur31 min
Jun 23, 4:59 PM CDTSevere Thunderstorm WarningDMXGuthrie36 min
Jun 23, 5:08 PM CDTSevere Thunderstorm WarningDMXAdams32 min
Jun 23, 5:25 PM CDTSevere Thunderstorm WarningDMXUnion35 min
Jun 23, 5:27 PM CDTSevere Thunderstorm WarningDMXTaylor33 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.