Alert archive / Iowa / Tornado Warnings in 1998
Tornado Warning 25, NWS Omaha, NE
NWS Omaha, NE issued this tornado warning at May 28, 1998, 8:40 PM CDT for Monona County, Iowa. It was in force for 60 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
- May 28, 1998, 8:40 PM CDT (01:40 UTC)
- Expired
- May 28, 1998, 9:40 PM CDT
- In force
- 60 min
- Issued by
- NWS Omaha, NE
- Area
- Whole counties
County Monona County, IA
The radar
The Omaha radar (KOAX), 88 km from the middle of the area, began a volume at 01:43 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 |
|---|---|---|---|
| May 28, 9:11 PM CDT | Hail 1.75 | Mapleton, 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 |
|---|---|---|---|
| May 28, 4:00 PM CDT | Tornado Watch | SPC | 5 hr |
The nearest sounding before it
Omaha, NE (KOAX), launched 00:00Z, 1.7 hours before the alert went out and 88 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
- 2835 J/kg
- Mixed-layer CIN
- -9 J/kg
- Mixed-layer LCL
- 1954 m above ground
- 0-6 km bulk shear
- 39 kt
- 0-1 km storm-relative helicity
- 64 m²/s²
- 0-3 km storm-relative helicity
- 115 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 7.5
The text
As transmitted, in the capitals the NWS used until 2016.
785 WFUS1 KOMA 290141 RRA TOROMA IAC133-290240- BULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 840 PM CDT THU MAY 28 1998 THE NATIONAL WEATHER SERVICE IN OMAHA HAS ISSUED A * TORNADO WARNING FOR... MONONA COUNTY IN WEST CENTRAL IOWA * UNTIL 940 PM CDT * AT 840 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A DEVELOPING TORNADO 18 MILES SOUTHEAST OF SIOUX CITY OR 10 MILES NORTHWEST OF RODNEY MOVING SOUTHEAST AT 25 MPH. * THE TORNADO IS EXPECTED TO BE NEAR... RODNEY BY 900 PM CDT NEAR MAPLETON BY 905 PM CDT IN ADDITION TO THE THREAT OF A TORNADO WITH THIS STORM...LARGE HAIL AND DAMAGING WINDS ARE LIKELY ACROSS MUCH OF THE COUNTY. THE MAIN TORNADO THREAT IS FROM RODNEY TOWARD MAPLETON. PERSONS IN THE WARNED AREA SHOULD TAKE SHELTER IN A BASEMENT IF AVAILABLE. OTHERWISE GO TO A SMALL INTERIOR ROOM ON THE LOWEST FLOOR. CARS AND MOBILE HOMES SHOULD BE ABANDONED. BCM
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 28, 4:35 PM CDT, 4 hours 5 minutes before
NEZ011-012-015>018-030>034-042>045-050>053-065>068-078-088>093- IAZ043-055-056-069-079-080-090-091-291200- SEVERE WEATHER OUTLOOK NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 435 PM CDT THU MAY 28 1998 ...SEVERE WEATHER OUTLOOK FOR EASTERN NEBRASKA AND SOUTHWEST IOWA... SPOTTER ACTION... STORM SPOTTER ACTIVATION MAY BE REQUIRED TONIGHT ACROSS PARTS OF EASTERN NEBRASKA AND SOUTHWEST IOWA. DISCUSSION... A WEAK FRONTAL BOUNDARY EXTENDING FROM NORTHWEST IOWA TO SOUTHWEST NEBRASKA WILL CONTINUE TO MOVE SLOWLY SOUTHEAST REACHING FAR SOUTHEAST NEBRASKA LATE TONIGHT. THE FRONT COMBINED WITH A MOIST AND EXTREMELY UNSTABLE AIRMASS IS EXPECTED TO TRIGGER SCATTERED THUNDERSTORMS TONIGHT. SOME OF THESE STORMS MAY BECOME SEVERE WITH THE PRIMARY THREAT BEING DAMAGING WINDS...HEAVY RAINFALL AND LOCAL FLASH-FLOODING. THE GREATEST AREA AT RISK FOR SEVERE THUNDERSTORMS WOULD BE NORTH OF A LINE FROM COLUMBUS TO ONAWA IOWA THIS EVENING. LJH
Special weather statement, May 28, 4:35 PM CDT, 4 hours 5 minutes before
NEZ011-012-015>018-030>034-042>045-050>053-065>068-078-088>093- IAZ043-055-056-069-079-080-090-091-291200- SEVERE WEATHER OUTLOOK NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 435 PM CDT THU MAY 28 1998 ...SEVERE WEATHER OUTLOOK FOR EASTERN NEBRASKA AND SOUTHWEST IOWA... SPOTTER ACTION... STORM SPOTTER ACTIVATION MAY BE REQUIRED TONIGHT ACROSS PARTS OF EASTERN NEBRASKA AND SOUTHWEST IOWA. DISCUSSION... A WEAK FRONTAL BOUNDARY EXTENDING FROM NORTHWEST IOWA TO SOUTHWEST NEBRASKA WILL CONTINUE TO MOVE SLOWLY SOUTHEAST REACHING FAR SOUTHEAST NEBRASKA LATE TONIGHT. THE FRONT COMBINED WITH A MOIST AND EXTREMELY UNSTABLE AIRMASS IS EXPECTED TO TRIGGER SCATTERED THUNDERSTORMS TONIGHT. SOME OF THESE STORMS MAY BECOME SEVERE WITH THE PRIMARY THREAT BEING DAMAGING WINDS...HEAVY RAINFALL AND LOCAL FLASH-FLOODING. THE GREATEST AREA AT RISK FOR SEVERE THUNDERSTORMS WOULD BE NORTH OF A LINE FROM COLUMBUS TO ONAWA IOWA THIS EVENING. LJH
Local storm report, May 28, 7:45 PM CDT, 55 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
745 PM CDT THU MAY 28 1998
TIME(CDT) .....CITY LOCATION..... STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
0640 PM 6 NE COLERIDGE NE TORNADO
05/28/98 CEDAR INITIAL TOUCHDOWN
0645 PM 10 ESE HARTINGTON NE TORNADO
05/28/98 CEDAR *** 1 INJ ***
3 FARMS DAMAGED NEAR
HIGHWAY 57. TOTAL PATH
LENGTH ABOUT 8 MILES.
INJURY OCCURRED 1 MILE
SOUTHEAST OF HIGHWAY
84/57 JUNCTION
BYRDLocal storm report, May 28, 7:45 PM CDT, 55 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
745 PM CDT THU MAY 28 1998
TIME(CDT) .....CITY LOCATION..... STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
0640 PM 6 NE COLERIDGE NE TORNADO
05/28/98 CEDAR INITIAL TOUCHDOWN
0645 PM 10 ESE HARTINGTON NE TORNADO
05/28/98 CEDAR *** 1 INJ ***
3 FARMS DAMAGED NEAR
HIGHWAY 57. TOTAL PATH
LENGTH ABOUT 8 MILES.
INJURY OCCURRED 1 MILE
SOUTHEAST OF HIGHWAY
84/57 JUNCTION
BYRDThe office that day
Everything else NWS Omaha, NE issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 28, 9:40 PM CDT | Tornado Warning | OAX | Monona | 45 min |
| May 28, 10:18 PM CDT | Tornado Warning | OAX | Harrison | 62 min |
| May 28, 10:25 PM CDT | Severe Thunderstorm Warning | OAX | Monona | 35 min |
| May 28, 10:54 PM CDT | Tornado Warning | OAX | Shelby | 61 min |
| May 28, 11:20 PM CDT | Severe Thunderstorm Warning | OAX | Harrison | 60 min |
| May 28, 11:57 PM CDT | Severe Thunderstorm Warning | OAX | Pottawattamie, Shelby | 63 min |
| May 29, 1:02 AM CDT | Severe Thunderstorm Warning | OAX | Pottawattamie | 58 min |
| May 29, 1:36 AM CDT | Severe Thunderstorm Warning | OAX | Mills, Montgomery | 59 min |
| May 29, 2:33 AM CDT | Severe Thunderstorm Warning | OAX | Fremont, Mills, Montgomery, Page | 47 min |
| May 29, 3:38 AM CDT | Severe Thunderstorm Warning | OAX | Fremont, Page | 62 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.