Alert archive / Iowa / Tornado Warnings in 1996

Tornado Warning 1, NWS Des Moines, IA

May 8, 1996Union County, Iowa

NWS Des Moines, IA issued this tornado warning at May 8, 1996, 10:49 PM CDT for Union 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 8, 1996, 10:49 PM CDT (03:49 UTC)
Expired: May 8, 1996, 11:20 PM CDT
In force: 31 min
Issued by: NWS Des Moines, IA
Area: Whole counties

County Union County, IA

The radar

The Des Moines radar (KDMX), 89 km from the middle of the area, began a volume at 03:50 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, 3.8 hours before the alert went out and 181 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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

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

000 
TTAA00 KDSM 090350
TORDSM
IAC175-090420-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
1049 PM CDT WED MAY 8 1996

* TORNADO WARNING FOR
  WESTERN UNION COUNTY - SOUTH CENTRAL IOWA

* UNTIL 1120 PM CDT
 
* SOME LOCATIONS AFFECTED
    CRESTON
    CROMWELL
    GREEN VALLEY STATE PARK

* AT 1048 PM CDT SPOTTERS REPORTED A DEVELOPING TORNADO NEAR CROMWELL
  OR 60 MILES SOUTHWEST OF DES MOINES MOVING EAST AT 30 MPH.

* THE S`TORM WILL BE CRESTON BY 11 PM CDT.

IF YOU ARE NEAR THIS DANGEROUS STORM...TAKE COVER IMMEDIATELY IN THE
LOWEST FLOOR AND INNER MOST ROOM OF A BUILDING.

FAB

What forecasters said that day

The local office's own words before this tornado 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, 2 hours 57 minutes 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

The office that day

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

Issued	Product	Office	Counties	Lasted
May 8, 9:55 PM CDT	Severe Thunderstorm Warning	DMX	Adams	30 min
May 8, 10:19 PM CDT	Severe Thunderstorm Warning	DMX	Adair, Union	31 min
May 8, 11:16 PM CDT	Severe Thunderstorm Warning	DMX	Dallas	29 min
May 8, 11:40 PM CDT	Severe Thunderstorm Warning	DMX	Polk, Warren	35 min
May 9, 12:06 AM CDT	Severe Thunderstorm Warning	DMX	Davis	34 min
May 9, 12:53 AM CDT	Severe Thunderstorm Warning	DMX	Clarke, Lucas	32 min
May 9, 5:55 AM CDT	Severe Thunderstorm Warning	DMX	Decatur	30 min
May 9, 6:17 AM CDT	Tornado Warning	DMX	Decatur	33 min
May 9, 6:35 AM CDT	Tornado Warning	DMX	Wayne	30 min
May 9, 10:08 AM CDT	Severe Thunderstorm Warning	DMX	Decatur	32 min
May 9, 10:55 AM CDT	Severe Thunderstorm Warning	DMX	Wayne	30 min
May 9, 11:21 AM CDT	Severe Thunderstorm Warning	DMX	Appanoose	34 min
May 9, 11:56 AM CDT	Severe Thunderstorm Warning	DMX	Davis	34 min
May 9, 12:39 PM CDT	Severe Thunderstorm Warning	DMX	Wayne	31 min
May 9, 1:25 PM CDT	Severe Thunderstorm Warning	DMX	Monroe	30 min

Nearby

Tornado Warnings in Iowa, 1996 Every tornado warning in 1996 Tornadoes 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.