Alert archive / Iowa / Tornado Warnings in 1998
Tornado Warning 75, NWS Omaha, NE
NWS Omaha, NE issued this tornado warning at Jul 6, 1998, 6:34 PM CDT for Monona County, Iowa. It was in force for 61 min. 2 reports 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
- Jul 6, 1998, 6:34 PM CDT (23:34 UTC)
- Expired
- Jul 6, 1998, 7:35 PM CDT
- In force
- 61 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 23:35 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 |
|---|---|---|---|
| Jul 6, 6:40 PM CDT | Tornado F0 | Blencoe, IA | Brief tornado touchdown. |
| Jul 6, 6:45 PM CDT | Thunderstorm Wind 55 | Moorhead, IA | Trees blown down. |
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 |
|---|---|---|---|
| Jul 6, 5:15 PM CDT | Tornado Watch | SPC | 6 hr |
The nearest sounding before it
Omaha, NE (KOAX), launched 12:00Z, 11.6 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
- 1215 J/kg
- Mixed-layer CIN
- -143 J/kg
- Mixed-layer LCL
- 979 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- 5 m²/s²
- 0-3 km storm-relative helicity
- -19 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KOMA 062334 RRA TOROMA IAC133-070035- BULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 634 PM CDT MON JUL 6 1998 THE NATIONAL WEATHER SERVICE IN OMAHA HAS ISSUED A * TORNADO WARNING FOR... MONONA COUNTY IN WEST CENTRAL IOWA * UNTIL 735 PM CDT * AT 632 PM CDT... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A POSSIBLE TORNADO 19 MILES SOUTH OF SIOUX CITY OR 13 MILES WEST NORTHWEST OF WHITING MOVING EAST SOUTHEAST AT 35 MPH. * THE TORNADO IS EXPECTED TO BE NEAR... WHITING AROUND 650 PM CDT RODNEY AROUND 650 PM CDT LEWIS AND CLARK STATE PARK AROUND 700 PM CDT MAPLETON AROUND 715 PM CDT THIS REPLACES THE SEVERE THUNDERSTORM WARNING FOR MONONA COUNTY. MOVE TO A REINFORCED BUILDING ON THE LOWEST LEVEL AND BE PREPARED FOR DESTRUCTIVE WINDS THAT ACCOMPANY TORNADOES. IN ADDITION TO THE TORNADO THREAT...LARGE HAIL...DAMAGING WINDS AND DANGEROUS LIGHTNING ARE LIKELY. 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, Jul 6, 4:45 PM CDT, 1 hour 49 minutes before
NEZ011-012-015>018-030>034-042>045-050>053-065>068-078-088>093- IAZ043-055-056-069-079-080-090-091-071200- SEVERE WEATHER OUTLOOK NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 445 PM CDT MON JUL 6 1998 ...SEVERE WEATHER OUTLOOK FOR EASTERN NEBRASKA AND SOUTHWEST IOWA... SPOTTER ACTION... STORM SPOTTER ACTIVATION WILL BE REQUIRED ACROSS EASTERN NEBRASKA AND SOUTHWEST IOWA THIS EVENING. DISCUSSION... SEVERE THUNDERSTORMS WERE MOVING INTO NORTHEAST NEBRASKA LATE THIS AFTERNOON WITH A LINE OF STORMS DEVELOPING INTO CENTRAL NEBRASKA. THIS STORM COMPLEX WILL CONTINUE TO MOVE EAST DURING THE EVENING AND IS EXPECTED TO REACH EAST CENTRAL AND SOUTHEAST NEBRASKA AND SOUTHWEST IOWA BETWEEN 7 AND 10 PM. LARGE HAIL AND DAMAGING WINDS WILL BE THE PRIMARY THREAT WITH ISOLATED TORNADOES POSSIBLE. VERY HEAVY RAIN IS ALSO LIKELY WITH THESE STORMS AND SINCE THE GROUND IS ALREADY SATURATED FROM RAINFALL OVER THE PAST TWO DAYS SMALLER STREAMS AND CRE@EKS WILL TEND TO FLOOD QUICKLY. FOBERT
Special weather statement, Jul 6, 4:45 PM CDT, 1 hour 49 minutes before
NEZ011-012-015>018-030>034-042>045-050>053-065>068-078-088>093- IAZ043-055-056-069-079-080-090-091-071200- SEVERE WEATHER OUTLOOK NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 445 PM CDT MON JUL 6 1998 ...SEVERE WEATHER OUTLOOK FOR EASTERN NEBRASKA AND SOUTHWEST IOWA... SPOTTER ACTION... STORM SPOTTER ACTIVATION WILL BE REQUIRED ACROSS EASTERN NEBRASKA AND SOUTHWEST IOWA THIS EVENING. DISCUSSION... SEVERE THUNDERSTORMS WERE MOVING INTO NORTHEAST NEBRASKA LATE THIS AFTERNOON WITH A LINE OF STORMS DEVELOPING INTO CENTRAL NEBRASKA. THIS STORM COMPLEX WILL CONTINUE TO MOVE EAST DURING THE EVENING AND IS EXPECTED TO REACH EAST CENTRAL AND SOUTHEAST NEBRASKA AND SOUTHWEST IOWA BETWEEN 7 AND 10 PM. LARGE HAIL AND DAMAGING WINDS WILL BE THE PRIMARY THREAT WITH ISOLATED TORNADOES POSSIBLE. VERY HEAVY RAIN IS ALSO LIKELY WITH THESE STORMS AND SINCE THE GROUND IS ALREADY SATURATED FROM RAINFALL OVER THE PAST TWO DAYS SMALLER STREAMS AND CRE@EKS WILL TEND TO FLOOD QUICKLY. FOBERT
The office that day
Everything else NWS Omaha, NE issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 6, 6:16 PM CDT | Severe Thunderstorm Warning | OAX | Monona | 64 min |
| Jul 6, 6:49 PM CDT | Tornado Warning | OAX | Harrison | 61 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.