Alert archive / Iowa / Flash Flood Warnings in 1998
Flash Flood Warning 22, NWS Omaha, NE
NWS Omaha, NE issued this flash flood warning at Jul 5, 1998, 6:40 AM CDT for Pottawattamie County, Iowa. It was in force for 4 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
- Jul 5, 1998, 6:40 AM CDT (11:40 UTC)
- Expired
- Jul 5, 1998, 10:40 AM CDT
- In force
- 4 hr
- Issued by
- NWS Omaha, NE
- Area
- Whole counties
County Pottawattamie County, IA
The radar
The Omaha radar (KOAX), 69 km from the middle of the area, began a volume at 11:40 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, 11.7 hours before the alert went out and 69 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
- 1706 J/kg
- Mixed-layer CIN
- -22 J/kg
- Mixed-layer LCL
- 848 m above ground
- 0-6 km bulk shear
- 39 kt
- 0-1 km storm-relative helicity
- 9 m²/s²
- 0-3 km storm-relative helicity
- 171 m²/s²
- Significant tornado parameter
- 0.6
- Supercell composite
- 3.3
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KOMA 051141 FFWOMA IAC155-051540- BULLETIN - EAS ACTIVATION REQUESTED FLASH FLOOD WARNING NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 640 AM CDT SUN JUL 5 1998 THE NATIONAL WEATHER SERVICE IN OMAHA HAS ISSUED A * FLASH FLOOD WARNING FOR... POTTAWATTAMIE COUNTY IN SOUTHWESTERN IOWA * UNTIL 1040 AM CDT * AT 630...NATIONAL WEATHER SERVICE DOPPLER RADAR ESTIMATED THAT UP TO TWO AND A HALF INCHES OF RAIN HAD FALLEN OVER PARTS OF POTTAWATTAMIE COUNTY DURING THE PAST HOUR. AT 625 AM...LOCAL OFFICIALS REPORTED STREET FLOODING IN COUNCIL BLUFFS. DUE TO THE SLOW MOVEMENT AND WIDESPREAD NATURE OF THESE THUNDERSTORMS...AN ADDITIONAL INCH TO TWO INCHES OF RAINFALL WILL BE POSSIBLE OVER POTTAWATTAMIE COUNTY THIS MORNING. SOME STREAMS AFFECTED INCLUDE...SILVER AND MOSQUITO THIS FLASH FLOOD WARNING REPLACES THE URBAN AND SMALL STREAM FLOOD ADVISORY. DO NOT DRIVE INTO AREAS WHERE WATER COVERS THE ROAD. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR V.EHICLE TO CROSS SAFELY. MEAD
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, Jul 5, 5:00 AM CDT, 1 hour 40 minutes before
NEZ011-012-015>018-030>034-042>045-050>053-065>068-078-088>093- IAZ043-055-056-069-079-080-090-091-061200- SEVERE WEATHER OUTLOOK NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 500 AM CDT SUN JUL 5 1998 ...SEVERE WEATHER OUTLOOK FOR EASTERN NEBRASKA AND SOUTHWEST IOWA... SPOTTER ACTION... STORM SPOTTER ACTIVATION MAY BE REQUIRED TODAY IN EASTERN NEBRASKA AND SOUTHWEST IOWA. THERE IS A SMALL CHANCE THAT ACTIVATION MIGHT BE REQUIRED TONIGHT. DISCUSSION... A WARM FRONT FROM EASTERN MOUNTANA TO NORTH CENTRAL KANSAS TO CENTRAL MISSOURI WILL MOVE NORTHEAST TODAY ACROSS EASTERN NEBRASKA AND SOUTHWEST IOWA. THUNDERSTORMS ARE LIKELY AHEAD OF THIS FRONT TODAY... ESPECIALLY THIS MORNING. WHILE THERE IS A CHANCE OF ISOLATED SEVERE WEATHER FROM THESE STORMS...THE PRIMARY PROBLEM WILL BE LOCALLY HEAVY RAINS. THE THUNDERSTORM ACTIVITY WILL MOVE NORTHEAST OF EASTERN NEBRASKA AND SOUTHWEST IOWA BY EARLY AFTERNOON. THERE IS A SMALL CHANCE OF THU.NDERSTORMS TONIGHT. WHILE THE PROBABILITY OF STORMS IS SMALL...ABOUT 10 PERCENT...IF THE STORMS DO DEVELOP THEY MAY BECOME STRONG ENOUGH TO PRODUCE SEVERE WEATHER. POWERS
Special weather statement, Jul 5, 5:00 AM CDT, 1 hour 40 minutes before
NEZ011-012-015>018-030>034-042>045-050>053-065>068-078-088>093- IAZ043-055-056-069-079-080-090-091-061200- SEVERE WEATHER OUTLOOK NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 500 AM CDT SUN JUL 5 1998 ...SEVERE WEATHER OUTLOOK FOR EASTERN NEBRASKA AND SOUTHWEST IOWA... SPOTTER ACTION... STORM SPOTTER ACTIVATION MAY BE REQUIRED TODAY IN EASTERN NEBRASKA AND SOUTHWEST IOWA. THERE IS A SMALL CHANCE THAT ACTIVATION MIGHT BE REQUIRED TONIGHT. DISCUSSION... A WARM FRONT FROM EASTERN MOUNTANA TO NORTH CENTRAL KANSAS TO CENTRAL MISSOURI WILL MOVE NORTHEAST TODAY ACROSS EASTERN NEBRASKA AND SOUTHWEST IOWA. THUNDERSTORMS ARE LIKELY AHEAD OF THIS FRONT TODAY... ESPECIALLY THIS MORNING. WHILE THERE IS A CHANCE OF ISOLATED SEVERE WEATHER FROM THESE STORMS...THE PRIMARY PROBLEM WILL BE LOCALLY HEAVY RAINS. THE THUNDERSTORM ACTIVITY WILL MOVE NORTHEAST OF EASTERN NEBRASKA AND SOUTHWEST IOWA BY EARLY AFTERNOON. THERE IS A SMALL CHANCE OF THU.NDERSTORMS TONIGHT. WHILE THE PROBABILITY OF STORMS IS SMALL...ABOUT 10 PERCENT...IF THE STORMS DO DEVELOP THEY MAY BECOME STRONG ENOUGH TO PRODUCE SEVERE WEATHER. POWERS
Special weather statement, Jul 5, 5:37 AM CDT, 1 hour 3 minutes before
IAZ055-056-069-079-080-NEZ044-045-051>053-051125- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 537 AM CDT SUN JUL 5 1998 THE SEVERE THUNDESTORM WARNING FOR DODGE AND SAUNDERS COUNTIES IN NEBRASKA EXPIRED AT 530 AM CDT. NO SEVERE WEATHER HAS BEEN REPORTED AND THE STORM HAS WEAKENED. OTHER THUNDERSTORMS PRODUCING VERY HEAVY RAIN WERE ALONG A LINE FROM NEAR FREMONT TO NEAR ATLANTIC IOWA. THE RAINS FROM THESE STORMS MAY PRODUCE RAPID FLOODING OF ROADS AND STREETS. MOTORISTS SHOULD BE ESPECIALLY CAREFUL AT NIGHT AND AVOID DRIVING INTO MOVING WATER OF UNKNOWN DEPTH...LOW WATER CROSSINGS AND FLOOD PRONE AREAS. POWERS
The office that day
Everything else NWS Omaha, NE issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 5, 7:12 AM CDT | Flash Flood Warning | OAX | Harrison | 4 hr |
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.