Alert archive / Iowa / Severe Thunderstorm Warnings in 1998
Severe Thunderstorm Warning 263, NWS Des Moines, IA
NWS Des Moines, IA issued this severe thunderstorm warning at Jul 15, 1998, 2:05 AM CDT for Hamilton County, Iowa. It was in force for 60 min. No storm report in the archive falls inside the area while it was in force.
The area
The counties it named.
The facts
- Issued
- Jul 15, 1998, 2:05 AM CDT (07:05 UTC)
- Expired
- Jul 15, 1998, 3:05 AM CDT
- In force
- 60 min
- Issued by
- NWS Des Moines, IA
- Area
- Whole counties
County Hamilton County, IA
The radar
The Des Moines radar (KDMX), 73 km from the middle of the area, began a volume at 07:05 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.
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
Omaha, NE (KOAX), launched 00:00Z, 7.1 hours before the alert went out and 250 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
- 2762 J/kg
- Mixed-layer CIN
- -97 J/kg
- Mixed-layer LCL
- 1213 m above ground
- 0-6 km bulk shear
- 21 kt
- 0-1 km storm-relative helicity
- 22 m²/s²
- 0-3 km storm-relative helicity
- 191 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.5
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KDSM 150704 RRA SVRDSM IAC027-073-079-150805- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE DES MOINES IA 205 AM CDT WED JUL 15 1998 THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... CARROLL COUNTY IN WEST CENTRAL IOWA GREENE COUNTY IN WEST CENTRAL IOWA HAMILTON COUNTY IN CENTRAL IOWA * UNTIL 305 AM CDT * AT 202 AM CDT... DOPPLER RADAR INDICATED A LINE OF SEVERE THUNDERSTORMS 14 MILES SOUTH SOUTHEAST OF FORT DODGE OR 6 MILES WEST NORTHWEST OF STRATFORD MOVING SOUTH SOUTHEAST AT 30 MPH. * THIS STORM CAN BE EXPECTED NEAR... STRATFORD NOW CARROLL BY 210 AM CDT JEFFERSON > BY 215 AM CDT WEBSTER CITY BY 208 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 59 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, 1:46 AM CDT | Severe Thunderstorm Warning | DMX | Worth | 64 min |
| Jul 15, 2:05 AM CDT | Severe Thunderstorm Warning | DMX | Carroll, Greene | 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.