Alert archive / Iowa / Tornado Warnings in 1998
Tornado Warning 58, NWS Des Moines, IA
NWS Des Moines, IA issued this tornado warning at Jul 6, 1998, 7:22 PM CDT for Carroll County, Iowa. It was in force for 33 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, 7:22 PM CDT (00:22 UTC)
- Expired
- Jul 6, 1998, 7:55 PM CDT
- In force
- 33 min
- Issued by
- NWS Des Moines, IA
- Area
- Whole counties
County Carroll County, IA
The radar
The Des Moines radar (KDMX), 100 km from the middle of the area, began a volume at 00:25 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, 7:27 PM CDT | Tornado F0 | Coon Rapids, IA | |
| Jul 6, 7:50 PM CDT | Thunderstorm Wind 50 | Coon Rapids, 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 nearest sounding before it
Omaha, NE (KOAX), launched 00:00Z, 0.4 hours before the alert went out and 148 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
- 5400 J/kg
- Mixed-layer CIN
- -6 J/kg
- Mixed-layer LCL
- 1040 m above ground
- 0-6 km bulk shear
- 39 kt
- 0-1 km storm-relative helicity
- 77 m²/s²
- 0-3 km storm-relative helicity
- 110 m²/s²
- Significant tornado parameter
- 3.7
- Supercell composite
- 14.8
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KDSM 070022 RRA TORDSM IAC027-070055- BULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE DES MOINES IA 722 PM CDT MON JUL 6 1998 THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A * TORNADO WARNING FOR... CARROLL COUNTY IN WEST CENTRAL IOWA * UNTIL 755 PM CDT * AT 721 PM CDT... STORM SPOTTERS REPORTED A TORNADO 48 MILES SOUTHWEST OF FORT DODGE OR 4 MILES EAST NORTHEAST OF DEDHAM MOVING EAST SOUTHEAST AT 5 MPH. * THE TORNA.DO IS EXPECTED TO BE NEAR... COON RAPIDS NOW DEDHAM NOW IF YOU ARE IN A MULTIPLE STORY BUILDING...GO TO A SMALL INTERIOR ROOM AWAY FROM WINDOWS. PYTLAK
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, 4:42 PM CDT, 2 hours 40 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086- 092>097-071100- CENTRAL IOWA THUNDERSTORM OUTLOOK NATIONAL WEATHER SERVICE DES MOINES IA 442 PM CDT MON JUL 6 1998 HAZARD--WIDESPREAD HEAVY RAIN OF 1 TO 3 INCHES AND ISOLATED AMOUNTS UP TO 5. A FEW STORMS COULD ALSO PRODUCE WIND GUSTS TO 80 MPH AND HAIL UP TO GOLFBALL SIZE. AREA OF CONCERN--ALL OF CENTRAL IOWA. TIMING DETAILS--THE HEAVY RAIN THREAT WILL LAST ALL NIGHT AND INTO TUESDAY MORNING. THE SEVERE WEATHER THREAT WILL BE HIGHEST BETWEEN 800 PM AND 300 AM. METEOROLOGICAL COMMENTS--A THUNDERSTORM COMPLEX HAS ALREADY DEVELOPED OVER NORTHEAST NEBRASKA AND SOUTHEAST SOUTH DAKOTA THIS AFTERNOON WITH NUMEROUS SEVERE THUNDERSTORM WARNINGS IN EFFECT. WIND GUSTS UP TO 70 MPH AND 1 INCH DIAMETER HAIL HAVE ALREADY BEEN REPORTED. THIS COMPLEX WILL MOVE INTO IOWA AFTER DARK AS IT FEEDS ON EXTREMELY HIGH MOISTURE VALUES THROUGHOUT THE ATMOSPHERE. PRECIPITABLE WATERS WERE APPROACHING 2 INCHES THIS AFTERNOON WITH SURFACE DEWPOINTS APPROACHING 80 DEGREES. AS THE NIGHT WEARS ON THE THUNDERSTORMS SHOULD BECOME WEAKER...BUT THEY WILL ALSO BEGIN TO TRAIN ALONG AN EAST-WEST STATIONARY FRONT STUCK RIGHT OVER THE HEART OF IOWA. PRECAUTIONS--A FLASH FLOOD WATCH IS ALREADY IN EFFECT FOR THE ENTIRE STATE...AND SEVERE THUNDERSTORM WATCHES MAY BE REQUIRED LATER THIS EVENING. SPOTTER ACTIVATION IS A NEAR CERTAINTY TONIGHT...ESPECIALLY IN THE NORTHWEST HALF OF THE STATE WHERE THE STORMS WILL LIKELY BE AT THEIR STRONGEST LATE THIS EVENING. PYTLAK
Special weather statement, Jul 6, 4:58 PM CDT, 2 hours 24 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086- 092>097-071100- CENTRAL IOWA THUNDERSTORM OUTLOOK...UPDATED NATIONAL WEATHER SERVICE DES MOINES IA 458 PM CDT MON JUL 6 1998 HAZARD--WIDESPREAD HEAVY RAIN OF 1 TO 3 INCHES AND ISOLATED AMOUNTS UP TO 5. A FEW STORMS COULD ALSO PRODUCE WIND GUSTS TO 80 MPH AND HAIL UP TO GOLFBALL SIZE. AREA OF CONCERN--ALL OF CENTRAL IOWA. TIMING DETAILS--THE HEAVY RAIN THREAT WILL LAST ALL NIGHT AND INTO TUESDAY MORNING. THE SEVERE WEATHER THREAT WILL BE HIGHEST BETWEEN 800 PM AND 300 AM. METEOROLOGICAL COMMENTS--A THUNDERSTORM COMPLEX HAS ALREADY DEVELOPED OVER NORTHEAST NEBRASKA AND SOUTHEAST SOUTH DAKOTA THIS AFTERNOON WITH NUMEROUS SEVERE THUNDERSTORM WARNINGS IN EFFECT. WIND GUSTS UP TO 70 MPH AND 1 INCH DIAMETER HAIL HAVE ALREADY BEEN REPORTED. THIS COMPLEX WILL MOVE INTO IOWA AFTER DARK AS IT FEEDS ON EXTREMELY HIGH MOISTURE VALUES THROUGHOUT THE ATMOSPHERE. PRECIPITABLE WATERS WERE APPROACHING 2 INCHES THIS AFTERNOON WITH SURFACE DEWPOINTS APPROACHING 80 DEGREES. AS THE NIGHT WEARS ON THE THUNDERSTORMS SHOULD BECOME WEAKER...BUT THEY WILL ALSO BEGIN TO TRAIN ALONG AN EAST-WEST STATIONARY FRONT STUCK RIGHT OVER THE HEART OF IOWA. PRECAUTIONS--A FLASH FLOOD WATCH IS ALREADY IN EFFECT FOR THE ENTIRE STATE...AND A TORNADO WATCH WILL BE ISSUED FOR NORTHWEST IOWA SHORTLY. SPOTTER ACTIVATION IS A NEAR CERTAINTY TONIGHT...ESPECIALLY IN THE NORTHWEST HALF OF THE STATE WHERE THE STORMS WILL LIKELY BE AT THEIR STRONGEST LATE THIS EVENING. PYTLAK UPDATED TO MENTION IMPENDING TORNADO WATCH IN NORTHWEST IOWA
The office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 6, 8:15 PM CDT | Severe Thunderstorm Warning | DMX | Dallas, Guthrie | 35 min |
| Jul 6, 8:46 PM CDT | Flash Flood Warning | DMX | Dallas | 3 hr |
| Jul 6, 8:54 PM CDT | Severe Thunderstorm Warning | DMX | Dallas, Polk | 36 min |
| Jul 6, 9:14 PM CDT | Flash Flood Warning | DMX | Guthrie | 6 hr |
| Jul 6, 9:20 PM CDT | Severe Thunderstorm Warning | DMX | Story | 35 min |
| Jul 6, 9:21 PM CDT | Flash Flood Warning | DMX | Polk | 6 hr |
| Jul 6, 9:29 PM CDT | Severe Thunderstorm Warning | DMX | Jasper, Polk | 46 min |
| Jul 6, 9:35 PM CDT | Tornado Warning | DMX | Polk | 35 min |
| Jul 6, 9:45 PM CDT | Severe Thunderstorm Warning | DMX | Marion, Warren | 45 min |
| Jul 6, 10:00 PM CDT | Tornado Warning | DMX | Marion | 35 min |
| Jul 6, 10:15 PM CDT | Severe Thunderstorm Warning | DMX | Jasper | 35 min |
| Jul 6, 10:37 PM CDT | Severe Thunderstorm Warning | DMX | Marion | 33 min |
| Jul 6, 11:41 PM CDT | Flash Flood Warning | DMX | Dallas | 3 hr |
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.