Alert archive / Iowa / Flash Flood Warnings in 2017
Flash Flood Warning 9, NWS Des Moines, IA
NWS Des Moines, IA issued this flash flood warning at Sep 21, 2017, 3:40 AM CDT for Wapello County, Iowa. It was in force for 6 hr. 3 reports came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Sep 21, 2017, 3:40 AM CDT (08:40 UTC)
- Expired
- Sep 21, 2017, 9:30 AM CDT
- In force
- 6 hr
- Issued by
- NWS Des Moines, IA
- Area
- Storm-based polygon
- Flood severity
- None
County Wapello County, IA
The radar
The Des Moines radar (KDMX), 136 km from the middle of the area, began a volume at 08:40 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Sep 21, 4:28 AM CDT | HEAVY RAIN 5.3 | 2 Sw Ottumwa, IA | FROM PERSONAL WEATHER STATION ON SW SIDE OF OTTUMWA. |
| Sep 21, 6:20 AM CDT | HEAVY RAIN 5.62 | 1 Sse Ottumwa, IA | MEASURED AT DES MOINES RIVER GAGE IN TOWN. |
| Sep 21, 6:33 AM CDT | HEAVY RAIN 6.08 | 2 Sw Ottumwa, IA | PERSONAL WEATHER STATION IN SW OTTUMWA. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Davenport, (KDVN), launched 00:00Z, 8.7 hours before the alert went out and 179 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
- 1710 J/kg
- Mixed-layer CIN
- -12 J/kg
- Mixed-layer LCL
- 1531 m above ground
- 0-6 km bulk shear
- 20 kt
- 0-1 km storm-relative helicity
- 63 m²/s²
- 0-3 km storm-relative helicity
- 139 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
747 WGUS53 KDMX 210840 FFWDMX IAC179-211430- /O.NEW.KDMX.FF.W.0009.170921T0840Z-170921T1430Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ BULLETIN - EAS ACTIVATION REQUESTED Flash Flood Warning National Weather Service Des Moines IA 340 AM CDT THU SEP 21 2017 The National Weather Service in Des Moines has issued a * Flash Flood Warning for... Wapello County in southeastern Iowa... * Until 930 AM CDT. * At 336 AM CDT, Doppler radar and automated rain gauges indicated thunderstorms producing heavy rain across the warned area. An automated gage on the south side of Ottumwa indicated that 4.26 inches of rain had fallen since midnight with doppler radar estimates of higher amounts, possibly close to six inches, farther east along Highway 34. Flash flooding is expected to begin shortly. * Some locations that will experience flooding include... Ottumwa, Eldon, Agency and Blakesburg. Additional rainfall amounts of 1 inch per hour will likely continue through 430am. PRECAUTIONARY/PREPAREDNESS ACTIONS... Be especially cautious at night when it is harder to recognize the dangers of flooding. && LAT...LON 4090 9264 4099 9264 4115 9218 4090 9218 $$ Small
3 follow-up statements
644 WGUS73 KDMX 210956 FFSDMX Flash Flood Statement National Weather Service Des Moines IA 456 AM CDT THU SEP 21 2017 IAC179-211430- /O.CON.KDMX.FF.W.0009.000000T0000Z-170921T1430Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Wapello IA- 456 AM CDT THU SEP 21 2017 ...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 930 AM CDT FOR WAPELLO COUNTY... At 450 AM CDT, Doppler radar and automated rain gauges indicated thunderstorms producing heavy rain over the warned area. 5.33 inches of rain has fallen on the SW side of Ottumwa with radar estimates of around 7 inches possible east of town toward Agency and along Highway 34. Flash flooding is expected to begin shortly. Some locations that will experience flooding include... Ottumwa, Eldon, Agency and Blakesburg as well as Buckeye and Honey Creeks. PRECAUTIONARY/PREPAREDNESS ACTIONS... Be especially cautious at night when it is harder to recognize the dangers of flooding. In hilly terrain there are hundreds of low water crossings which are potentially dangerous in heavy rain. Do not attempt to cross flooded roads. Find an alternate route. && LAT...LON 4090 9264 4099 9264 4115 9218 4090 9218 $$ Small
814 WGUS73 KDMX 211223 FFSDMX Flash Flood Statement National Weather Service Des Moines IA 723 AM CDT THU SEP 21 2017 IAC179-211430- /O.CON.KDMX.FF.W.0009.000000T0000Z-170921T1430Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Wapello IA- 723 AM CDT THU SEP 21 2017 ...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 930 AM CDT FOR WAPELLO COUNTY... At 720 AM CDT, Doppler radar and automated rain gauges indicated thunderstorms producing heavy rain continued over the warned area. 6.39 inches of rain was already recorded at a home weather station on the southwest side of Ottumwa. Flash flooding is expected to begin shortly. Some locations that will experience flooding include... Ottumwa, Eldon, Agency and Blakesburg as well as Buckeye and Honey Creek. PRECAUTIONARY/PREPAREDNESS ACTIONS... Excessive runoff from heavy rainfall will cause flooding of small creeks and streams, country roads, farmland, and other low lying spots. In hilly terrain there are hundreds of low water crossings which are potentially dangerous in heavy rain. Do not attempt to cross flooded roads. Find an alternate route. && LAT...LON 4090 9264 4099 9264 4115 9218 4090 9218 $$ Small
736 WGUS73 KDMX 211429 FFSDMX Flash Flood Statement National Weather Service Des Moines IA 929 AM CDT THU SEP 21 2017 IAC179-211434- /O.EXP.KDMX.FF.W.0009.000000T0000Z-170921T1430Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Wapello IA- 929 AM CDT THU SEP 21 2017 ...THE FLASH FLOOD WARNING FOR WAPELLO COUNTY WILL EXPIRE AT 930 AM CDT... The Wapello County Sheriff and Emergency Management have indicated the much of the water has receded in and around Ottuwma. There may be some additional rainfall this morning, but the persistent heavy rain has subsided. Rural areas south of Ottumwa may see creeks that or near or in flood, however conditions are expected to improve for the remainder of the day. Please continue to heed any remaining road closures. LAT...LON 4090 9264 4099 9264 4115 9218 4090 9218 $$ Cogil
The office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 21, 3:03 AM CDT | Special Weather Statement | DMX | Wapello | 57 min |
| Sep 21, 4:38 AM CDT | Severe Thunderstorm Warning | DMX | Mahaska, Poweshiek | 52 min |
Nearby
Flash Flood Warnings in Iowa, 2017Every flash flood warning in 2017
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.