Alert archive / Iowa / Severe Thunderstorm Warnings in 1998
Severe Thunderstorm Warning 49, NWS Omaha, NE
NWS Omaha, NE issued this severe thunderstorm warning at Apr 25, 1998, 6:51 PM CDT for Monona County, Iowa. It was in force for 34 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
- Apr 25, 1998, 6:51 PM CDT (23:51 UTC)
- Expired
- Apr 25, 1998, 7:25 PM CDT
- In force
- 34 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 23:54 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 |
|---|---|---|---|
| Apr 25, 6:59 PM CDT | Hail 1.25 | Castana, 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 |
|---|---|---|---|
| Apr 25, 6:30 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
The nearest sounding before it
Omaha, NE (KOAX), launched 12:00Z, 11.9 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1241 m above ground
- 0-6 km bulk shear
- 48 kt
- 0-1 km storm-relative helicity
- -48 m²/s²
- 0-3 km storm-relative helicity
- 43 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.3
The text
As transmitted, in the capitals the NWS used until 2016.
301 WUUS1 KOMA 252352 RRA SVROMA IAC133-260025- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 651 PM CDT SAT APR 25 1998 THE NATIONAL WEATHER SERVICE IN OMAHA HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... MONONA COUNTY IN WEST CENTRAL IOWA * UNTIL 725 PM CDT * AT 649 PM CDT... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 30 MILES SOUTH SOUTHEAST OF SIOUX CITY IA OR 4 MILES EAST OF WHITING MOVING NORTH AT 10 MPH. * THE SEVERE THUNDERSTORM IS EXPECTED TO BE NEAR... MAPLETON NOW RODNEY NOW THIS STORM HAS A HISTORY OF LARGE HAIL. GET INTO A REINFORCED SHELTER. STAY AWAY FROM WINDOWS AND GLASS DOORS. MILLER
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, Apr 25, 5:25 PM CDT, 1 hour 26 minutes before
NEZ011-012-015>018-030>034-042>045-050>053-065>068-078-088>093- IAZ043-055-056-069-079-080-090-091-261200- SEVERE WEATHER OUTLOOK NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 525 PM CDT SAT APR 25 1998 ...SEVERE WEATHER OUTLOOK FOR EASTERN NEBRASKA AND SOUTHWEST IOWA... SPOTTER ACTION... STORM SPOTTER GROUPS IN NORTHEAST NEBRASKA AND WEST CENTRAL IOWA MAY BE REQUIRED THIS EVENING. DISCUSSION... A COLD FRONT WAS MOVING ACROSS EXTREME SOUTHEAST NEBRASKA AND SOUTHWEST IOWA LATE THIS AFTERNOON. A LINE OF THUNDERSTORMS WAS DEVELOPING AHEAD OF THIS FRONT JUST EAST OF RED OAK AND CLARINDA IN SOUTHWEST IOWA. THE POTENTIAL FOR SEVERE WEATHER WILL BE MAINLY EAST OF OUR AREA THIS EVENING ASSOCIATED WITH THIS DEVELOPING LINE OF STORMS. ISOLATED STRONG THUNDERSTORMS HAD ALSO DEVELOPED IN NORTHEAST NEBRASKA NORTH OF A NORFOLK TO OMAHA LINE AND SOME OF THESE STORMS MAY APROACH SEVERE LEVELS FOR TIME DURING THE EARLY EVENING. LARGE HAIL AND LOCALLY DAMAGING WINDS WILL BE THE PRIMARY THREAT FROM THESE STORMS. FOBERT
The office that day
Everything else NWS Omaha, NE issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 25, 5:51 PM CDT | Severe Thunderstorm Warning | OAX | Monona | 59 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.