Alert archive / Iowa / Flash Flood Warnings in 1998
Flash Flood Warning 1, NWS Omaha, NE
NWS Omaha, NE issued this flash flood warning at Apr 25, 1998, 7:47 PM CDT for Monona County, Iowa. It was in force for 5 hr. No storm report in the archive falls inside the area while it was in force.
The area
The counties it named.
The facts
- Issued
- Apr 25, 1998, 7:47 PM CDT (00:47 UTC)
- Expired
- Apr 26, 1998, 12:45 AM CDT
- In force
- 5 hr
- 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 00:51 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 nearest sounding before it
Omaha, NE (KOAX), launched 00:00Z, 0.8 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
- 892 m above ground
- 0-6 km bulk shear
- 4 kt
- 0-1 km storm-relative helicity
- 16 m²/s²
- 0-3 km storm-relative helicity
- 98 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 260049 FFWOMA IAC133-260545- BULLETIN - EAS ACTIVATION REQUESTED FLASH FLOOD WARNING NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 747 PM CDT SAT APR 25 1998 THE NATIONAL WEATHER SERVICE IN OMAHA HAS ISSUED A * FLASH FLOOD WARNING FOR MONONA COUNTY - IN WEST CENTRAL IOWA * UNTIL 1245 AM CDT * SOME STREAMS AFFECTED THE LITTLE SIOUX RIVER SMALL STREAMS NORTH OF CASTANA SMALL STREAMS WEST OF MAPLETON * CAUSE AND EFFECT RADAR INDICATED TWO TO FOUR INCHES OF RAIN SINCE 5 PM CDT IN THE AREA FROM NORTH AND EAST OF CASTANA TO WEST OF MAPLETON. MORE RAIN WILL LIKELY OCCUR THROUGH MIDNIGHT. RISES COULD ALSO OCCUR ON THE MAPLE RIVER. DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE WATER COVEfRS THE ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS SAFELY. VEHICLES CAUGHT IN RISING WATER SHOULD BE ABANDONED QUICKLY. MOVE TO HIGHER GROUND. MILLER
What forecasters said that day
The local office's own words before this flash flood 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, 2 hours 22 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
Nearby
Flash Flood Warnings in Iowa, 1998Every flash flood 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.