Alert archive / Iowa / Severe Thunderstorm Warnings in 1996

Severe Thunderstorm Warning 20, NWS Des Moines, IA

May 9, 1996Clarke County, Lucas County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at May 9, 1996, 12:53 AM CDT for Clarke County, Lucas County, Iowa. It was in force for 32 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 9, 1996, 12:53 AM CDT (05:53 UTC)
Expired
May 9, 1996, 1:25 AM CDT
In force
32 min
Issued by
NWS Des Moines, IA
Area
Whole counties

Counties Clarke County, IA, Lucas County, IA

The radar

The Des Moines radar (KDMX), 79 km from the middle of the area, began a volume at 05:53 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.

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 5.9 hours before the alert went out and 238 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 1996-05-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1091 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 00:00Z on 1996-05-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 94 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
1091 J/kg
Mixed-layer CIN
-45 J/kg
Mixed-layer LCL
739 m above ground
0-6 km bulk shear
55 kt
0-1 km storm-relative helicity
94 m²/s²
0-3 km storm-relative helicity
84 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.2

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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, May 8, 7:52 PM CDT, 5 hours 1 minute before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-090355-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
751 PM CDT WED MAY 8 1996

HAZARD...
SCATTERED SEVERE THUNDERSTORMS PRODUCING HAIL GREATER THAN 1
INCH...DAMAGING WINDS UP TO 70 MPH AND HEAVY RAINFALL. TOTAL
RAINFALL AMOUNTS MAY LOCALLY EXCEED 2 INCHES BY MORNING. WIDESPREAD
GENERAL THUNDERSTORM ACTIVITY IS ALSO FORECAST.

AREA OF CONCERN...
THE GREATEST THREAT OF SEVERE WEATHER EXISTS SOUTHWEST OF A
CARROLL-DES MOINES-CENTERVILLE LINE.

TIMING DETAILS...
THE THREAT OF SEVERE WEATHER WILL INCREASE RAPIDLY THROUGH 10 PM
OVER THE SOUTHWEST CORNER OF IOWA...SOUTHWEST OF A COUNCIL
BLUFFS-LAMONI LINE. STORMS WILL RAPIDLY MOVE NORTHEAST INTO THE REST
OF THE AREA OF CONCERN TOWARDS MIDNIGHT.

METEOROLOGICAL COMMENTS...
A STRONG WARM FRONT WAS PROVIDING THE DIVIDING LINE BETWEEN COOL AND
STABLE AIR NORTH OF IT WITH VERY MOIST AND UNSTABLE AIR TO ITS
SOUTH.  AT 7 PM...THIS BOUNDARY WAS LOCATED FROM FALLS CITY NEBRASKA
TO NEAR LAMONI IOWA AND THEN SOUTHEAST INTO NORTHEAST MISSOURI.
SOUTHERLY FLOW WAS INCREASING THROUGHOUT EASTERN KANSAS AND WESTERN
MISSOURI EARLY THIS EVENING. A LOW-LEVEL BELT OF SOUTHWEST WINDS
AROUND 3000 FT IS INTERSECTING THE WARM FRONT AND PUSHING
IT NORTHEAST INTO SOUTHERN IOWA. THUNDERSTORMS WERE DEVELOPING ALONG
THE BOUNDARY OVER SOUTHEAST NEBRASKA.  NWS DOPPLER RADAR IN JOHNSTON
ALSO INDICATED RAPID SHOWER DEVELOPMENT OVER THE SOUTHERN TWO TIERS
OF COUNTIES IN IOWA.

UPPER AIR BALLOON DATA JUST RECEIVED INDICATES A HIGH POTENTIAL FOR
LARGE HAIL...ESPECIALLY IN SOUTHWEST IOWA INITIALLY. SUFFICIENT WIND
SHEAR ALSO EXISTS IN THE LOWER ATMOSPHERE FOR THE DEVELOPMENT OF
ISOLATED SUPERCELLS ACROSS SOUTHEAST NEBRASKA WHICH MAY PROPOGATE
NORTHEAST INTO SOUTHWEST IOWA...THEREFORE TORNADO DEVELOPMENT CANNOT
BE RULED OUT THIS EVENING THERE.  HOWEVER...WE EXPECT THAT THE
SCATTERED STORMS WILL EVOLVE AND COMBINE TO FORM A LARGER
THUNDERSTORM COMPLEX AND HEAVY RAIN PRODUCER FOR MUCH OF
IOWA...SIMILAR TO LAST NIGHT. AT THIS TIME...FLASH FLOOD POTENTIAL
IS MINIMAL...BUT MAY CHANGE CONSIDERABLY IF THE RAINFALL BEGINS TO
CONCENTRATE OVER LOCALIZED AREAS.

PRECAUTIONS...
A SEVERE WEATHER WATCH WILL LIKELY BE ISSUED FOR EASTERN NEBRASKA
AND POSSIBLY SOUTHWEST IOWA WITHIN THE NEXT HOUR OR SO. EMERGENCY
MANAGERS SHOULD MAINTAIN A STATE OF READINESS FOR SPOTTER
ACTIVATION...INITIALLY\ IN SOUTHWEST IOWA THROUGH 10 PM. ANOTHER CITO
WILL BE ISSUED BY 10 PM UNLESS SEVERE WEATHER BECOMES IMMINENT.
SHORT TERM FORECASTS WILL ALSO BE ISSUED MORE FREQUENTLY AS STORMS
DEVELOP.

KULA
Special weather statement, May 9, 12:45 AM CDT, 8 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
May 8, 9:55 PM CDTSevere Thunderstorm WarningDMXAdams30 min
May 8, 10:19 PM CDTSevere Thunderstorm WarningDMXAdair, Union31 min
May 8, 10:49 PM CDTTornado WarningDMXUnion31 min
May 8, 11:16 PM CDTSevere Thunderstorm WarningDMXDallas29 min
May 8, 11:40 PM CDTSevere Thunderstorm WarningDMXPolk, Warren35 min
May 9, 12:06 AM CDTSevere Thunderstorm WarningDMXDavis34 min
May 9, 5:55 AM CDTSevere Thunderstorm WarningDMXDecatur30 min
May 9, 6:17 AM CDTTornado WarningDMXDecatur33 min
May 9, 6:35 AM CDTTornado WarningDMXWayne30 min
May 9, 10:08 AM CDTSevere Thunderstorm WarningDMXDecatur32 min
May 9, 10:55 AM CDTSevere Thunderstorm WarningDMXWayne30 min
May 9, 11:21 AM CDTSevere Thunderstorm WarningDMXAppanoose34 min
May 9, 11:56 AM CDTSevere Thunderstorm WarningDMXDavis34 min
May 9, 12:39 PM CDTSevere Thunderstorm WarningDMXWayne31 min
May 9, 1:25 PM CDTSevere Thunderstorm WarningDMXMonroe30 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.