Alert archive / Iowa / Severe Thunderstorm Warnings in 1998
Severe Thunderstorm Warning 261, NWS Des Moines, IA
NWS Des Moines, IA issued this severe thunderstorm warning at Jul 15, 1998, 1:46 AM CDT for Worth County, Iowa. It was in force for 64 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
- Jul 15, 1998, 1:46 AM CDT (06:46 UTC)
- Expired
- Jul 15, 1998, 2:50 AM CDT
- In force
- 64 min
- Issued by
- NWS Des Moines, IA
- Area
- Whole counties
County Worth County, IA
The radar
The Minneapolis radar (KMPX), 165 km from the middle of the area, began a volume at 06:49 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 15, 2:26 AM CDT | Thunderstorm Wind 50 | Manly, 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 |
|---|---|---|---|
| Jul 15, 1:30 AM CDT | Severe Thunderstorm Watch | SPC | 4 hr |
The nearest sounding before it
Minneapolis, MN (KMPX), launched 00:00Z, 6.8 hours before the alert went out and 166 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
- 2121 J/kg
- Mixed-layer CIN
- -44 J/kg
- Mixed-layer LCL
- 1376 m above ground
- 0-6 km bulk shear
- 29 kt
- 0-1 km storm-relative helicity
- 59 m²/s²
- 0-3 km storm-relative helicity
- 146 m²/s²
- Significant tornado parameter
- 0.3
- Supercell composite
- 2.5
The text
As transmitted, in the capitals the NWS used until 2016.
879 WUUS1 KDSM 150645 RRA SVRDSM IAC025-033-081-091-151-187-195-197-150750- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE DES MOINES IA 146 AM CDT WED JUL 15 1998 THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... CALHOUN COUNTY IN WEST CENTRAL IOWA CERRO GORDO COUNTY IN NORTH CENTRAL IOWA HANCOCK COUNTY IN NORTH CENTRAL IOWA HUMBOLDT COUNTY IN NORTH CENTRAL IOWA POCAHONTAS COUNTY IN NORTHWESTERN IOWA WEBSTER COUNTY IN CENTRAL IOWA WORTH COUNTY IN NORTH CENTRAL IOWA WRIGHT COUNTY IN NORTH CENTRAL IOWA * UNTIL 250 AM CDT * AT 143 AM CDT... DOPPLER RADAR INDICATED A LINE OF SEVERE THUNDERSTORMS 24 MILES WEST OF MASON CITY OR 2 MILES NORTH NORTHEAST OF DUNCAN MOVING SOUTH SOUTHEAST AT 30 MPH. * THIS STORM CAN BE EXPECTED NEAR... GARNER BY 149 AM CDT VENTURA BY 150 AM CDT KLEMME BY 202 AM CDT BELMOND BY 223 AM CDT MASON CITY BY 155 AM CDT FORT DODGE BY 149 AM CDT THIS STORM HAS A HISTORY OF DAMAGING WIND. GO INSIDE A STURDY BUILDING AND STAY AWAY FROM WINDOWS FORSTER
What forecasters said that day
The local office's own words before this severe thunderstorm 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 14, 10:06 PM CDT, 3 hours 40 minutes before
IAZ004>007-015>017-023>025-033-034-044-151100- CENTRAL IOWA THUNDERSTORM OUTLOOK NATIONAL WEATHER SERVICE DES MOINES IA 1006 PM CDT TUE JUL 14 1998 HAZARD--A LINE OF THUNDERSTORMS WITH STRONG WIND GUSTS TO 50 MPH AND HEAVY RAIN. AREA OF CONCERN--ALONG AND NORTHWEST OF A MASON CITY TO DENISON LINE. TIMING DETAILS--MOVING TOWARDS A SPENCER--ESTHERVILLE--NORTHWOOD BETWEEN 300 AND 500 AM...POSSIBLY SPREADING AS FAR SOUTHEAST AS MASON CITY...CLARION AND DENISON CLOSER TO 600 AM. METEOROLOGICAL COMMENTS--AT 1000 PM...A LINE OF STRONG TO SEVERE THUNDERSTORMS WAS LOCATED FROM NEAR THE TWIN CITIES WEST INTO EAST CENTRAL SOUTH DAKOTA NEAR WATERTOWN. THIS LINE OF STORMS WAS TRENDING A SOUTHWARD PROPAGATION INTO A MOISTURE AND INSTABILITY AXIS LOCATED FROM NORTHEAST NEBRASKA INTO NORTH CENTRAL IOWA. LOW- LEVEL WINDS WERE INCREASING JUST ABOVE THE GROUND INCREASING CONVERGENCE INTO THE STORMS. THERE REMAINS A SLIGHT CHANCE THAT THESE STORMS WILL HOLD TOGETHER INTO THE AREA OF CONCERN LATE TONIGHT. NEGATIVE FACTORS ARE A LACK OF UPPER LEVEL SUPPORT OVER NORTHERN AND NORTHWEST IOWA WITH MORE STABLE AIR TRYING TO WORK INTO THE STATE FROM ILLINOIS AND MISSOURI. PRECAUTIONS--NO IMMEDIATE ACTION IS NEEDED...HOWEVER...IT IS ADVISED THAT SPOTTER GROUPS KEEP CHECKING NATIONAL WEATHER SERVICE SHORT TERM FORECASTS AND ANY UPDATES TONIGHT. KULA
The office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 15, 1:46 AM CDT | Severe Thunderstorm Warning | DMX | Calhoun, Humboldt, Pocahontas, Webster | 64 min |
| Jul 15, 1:46 AM CDT | Severe Thunderstorm Warning | DMX | Cerro Gordo, Hancock, Wright | 64 min |
| Jul 15, 2:05 AM CDT | Severe Thunderstorm Warning | DMX | Carroll, Greene | 60 min |
| Jul 15, 2:05 AM CDT | Severe Thunderstorm Warning | DMX | Hamilton | 60 min |
| Jul 15, 2:22 AM CDT | Severe Thunderstorm Warning | DMX | Hardin | 63 min |
| Jul 15, 2:22 AM CDT | Severe Thunderstorm Warning | DMX | Boone | 63 min |
| Jul 15, 2:30 AM CDT | Severe Thunderstorm Warning | DMX | Crawford | 65 min |
| Jul 15, 3:01 AM CDT | Severe Thunderstorm Warning | DMX | Dallas, Guthrie, Polk | 64 min |
| Jul 15, 3:01 AM CDT | Severe Thunderstorm Warning | DMX | Story | 64 min |
Nearby
Severe Thunderstorm Warnings in Iowa, 1998Every severe thunderstorm warning 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.