Alert archive / Iowa / Tornado Warnings in 1998
Tornado Warning 1, NWS Omaha, NE
NWS Omaha, NE issued this tornado warning at Apr 6, 1998, 7:32 PM CDT for Mills County, Iowa. It was in force for 33 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
- Apr 6, 1998, 7:32 PM CDT (00:32 UTC)
- Expired
- Apr 6, 1998, 8:05 PM CDT
- In force
- 33 min
- Issued by
- NWS Omaha, NE
- Area
- Whole counties
County Mills County, IA
The radar
The Omaha radar (KOAX), 70 km from the middle of the area, began a volume at 00:31 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
| Time | Report | Where | Remark |
|---|---|---|---|
| Apr 6, 7:50 PM CDT | Hail 2 | Silver City, 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 watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Apr 6, 6:30 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
The nearest sounding before it
Omaha, NE (KOAX), launched 00:00Z, 0.5 hours before the alert went out and 70 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.
- Mixed-layer CAPE
- 25 J/kg
- Mixed-layer CIN
- -306 J/kg
- Mixed-layer LCL
- 711 m above ground
- 0-6 km bulk shear
- 29 kt
- 0-1 km storm-relative helicity
- 158 m²/s²
- 0-3 km storm-relative helicity
- 414 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 3.2
The text
As transmitted, in the capitals the NWS used until 2016.
545 WFUS1 KOMA 070033 RRA TOROMA IAC129-070105- BULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 732 PM CDT MON APR 6 1998 * TORNADO WARNING FOR MILLS COUNTY IN SOUTHWESTERN IOWA * UNTIL 805 PM CDT * SOME LOCATIONS AFFECTED EAST OF GLENWOOD...MALVERN...SILVER CITY * AT 732 PM CDT...A POSSIBLE TORNADO WAS INDICATED BY DOPPLER RADAR 15 MILES SOUTHEAST OF DOWNTOWN OMAHA OR 5 MILES EAST OF GLENWOOD MOVING EAST NORTHEAST AT 15 MPH. PEOPLE IN THE PATH OF THIS TORNADO SHOULD TAKE COVER IMMEDIATELY TO SAVE YOUR LIVES. MOVE TO A STURDY BUILDING...A BASEMENT IF POSSIBLE COVER YOUR HEAD FROM FLYING DEBRIS. GW
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
Local storm report, Apr 6, 3:38 PM CDT, 3 hours 54 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
338 PM CDT MON APR 06 1998
TIME(CDT) .....CITY LOCATION..... STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
105 PM 3 NW WEEPING WATER NE .75 INCH HAIL
04/06/98 CASS
300 PM MAGNOLIA IA 1.5 INCH HAIL
04/06/98 HARRISONLocal storm report, Apr 6, 3:38 PM CDT, 3 hours 54 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
338 PM CDT MON APR 06 1998
TIME(CDT) .....CITY LOCATION..... STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
105 PM 3 NW WEEPING WATER NE .75 INCH HAIL
04/06/98 CASS
300 PM MAGNOLIA IA 1.5 INCH HAIL
04/06/98 HARRISONSpecial weather statement, Apr 6, 5:10 PM CDT, 2 hours 22 minutes before
NEZ011-012-015>018-030>034-042>045-050>053-065>068-078-088>093- IAZ043-055-056-069-079-080-090-091-080000- SEVERE WEATHER OUTLOOK NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 510 PM CDT MON APR 6 1998 ...SEVERE WEATHER OUTLOOK FOR EASTERN NEBRASKA AND SOUTHWEST IOWA... SPOTTER ACTION... STORM SPOTTER ACTIVATION MAY BE NEEDED THIS EVENING IN SOUTHEAST NEBRASKA AND SOUTHWEST IOWA. DISCUSSION... A WARM FRONT FROM WEST OF BEATRICE TO JUST SOUTH OF OMAHA INTO CENTRAL KANSAS WILL BE THE FOCUSING MECHANISM FOR THUNDERSTORM DEVELOPMENT INTO THE EVENING HOURS. WARM...MOIST UNSTABLE AIR WITH FAVORABLE INFLOW AND A FAVORABLE UPPER JET WILL BE CONDUCIVE TO SEVERE THUNDERSTORM DEVELOPMENT. THUNDERSTORMS FIRING INTO NORTHERN KANSAS WILL LIKELY SPREAD INTO SOUTHEAST NEBRASKA. IN ADDITION...STRONG TO SEVERE THUNDERSTORMS ARE ARE POSSIBLE NORTH OF THE WARM FRONT WHERE FAVORABLE WAIR AIR ADVECTION AND CONVERGENCE IS ALSO TAKING PLACE. THE PRIMARY THREAT WILL BE LARGE HAIL...TORNADOES ARE ALSO A RISK DUE TO THE FAVORABLE WIND SHEAR. ZAPOTOCNY
Special weather statement, Apr 6, 5:10 PM CDT, 2 hours 22 minutes before
NEZ011-012-015>018-030>034-042>045-050>053-065>068-078-088>093- IAZ043-055-056-069-079-080-090-091-080000- SEVERE WEATHER OUTLOOK NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 510 PM CDT MON APR 6 1998 ...SEVERE WEATHER OUTLOOK FOR EASTERN NEBRASKA AND SOUTHWEST IOWA... SPOTTER ACTION... STORM SPOTTER ACTIVATION MAY BE NEEDED THIS EVENING IN SOUTHEAST NEBRASKA AND SOUTHWEST IOWA. DISCUSSION... A WARM FRONT FROM WEST OF BEATRICE TO JUST SOUTH OF OMAHA INTO CENTRAL KANSAS WILL BE THE FOCUSING MECHANISM FOR THUNDERSTORM DEVELOPMENT INTO THE EVENING HOURS. WARM...MOIST UNSTABLE AIR WITH FAVORABLE INFLOW AND A FAVORABLE UPPER JET WILL BE CONDUCIVE TO SEVERE THUNDERSTORM DEVELOPMENT. THUNDERSTORMS FIRING INTO NORTHERN KANSAS WILL LIKELY SPREAD INTO SOUTHEAST NEBRASKA. IN ADDITION...STRONG TO SEVERE THUNDERSTORMS ARE ARE POSSIBLE NORTH OF THE WARM FRONT WHERE FAVORABLE WAIR AIR ADVECTION AND CONVERGENCE IS ALSO TAKING PLACE. THE PRIMARY THREAT WILL BE LARGE HAIL...TORNADOES ARE ALSO A RISK DUE TO THE FAVORABLE WIND SHEAR. ZAPOTOCNY
The office that day
Everything else NWS Omaha, NE issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 6, 7:05 PM CDT | Severe Thunderstorm Warning | OAX | Mills, Pottawattamie | 60 min |
| Apr 6, 8:06 PM CDT | Tornado Warning | OAX | Mills, Pottawattamie | 29 min |
| Apr 6, 8:11 PM CDT | Severe Thunderstorm Warning | OAX | Mills | 49 min |
Nearby
Tornado Warnings in Iowa, 1998Every tornado warning in 1998Tornadoes in 1998
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.