Alert archive / Iowa / Flash Flood Warnings in 2018
Flash Flood Warning 5, NWS Sioux Falls, SD
NWS Sioux Falls, SD issued this flash flood warning at Jun 24, 2018, 4:46 PM CDT for 4 counties in Iowa. It was in force for 4 hr. 1 report 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
- Jun 24, 2018, 4:46 PM CDT (21:46 UTC)
- Expired
- Jun 24, 2018, 8:45 PM CDT
- In force
- 4 hr
- Issued by
- NWS Sioux Falls, SD
- Area
- Storm-based polygon
- Flood severity
- None
Counties Cherokee County, IA, O'Brien County, IA, Plymouth County, IA, Sioux County, IA
The radar
The Sioux Falls radar (KFSD), 108 km from the middle of the area, began a volume at 21:46 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 |
|---|---|---|---|
| Jun 24, 6:09 PM CDT | HEAVY RAIN 4.25 | Marcus, IA |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Omaha, NE (KOAX), launched 12:00Z, 9.8 hours before the alert went out and 180 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
- 824 J/kg
- Mixed-layer CIN
- -153 J/kg
- Mixed-layer LCL
- 1390 m above ground
- 0-6 km bulk shear
- 29 kt
- 0-1 km storm-relative helicity
- 84 m²/s²
- 0-3 km storm-relative helicity
- 96 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.4
The text
As transmitted.
718 WGUS53 KFSD 242146 FFWFSD IAC035-141-149-167-250145- /O.NEW.KFSD.FF.W.0005.180624T2146Z-180625T0145Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ BULLETIN - EAS ACTIVATION REQUESTED Flash Flood Warning National Weather Service Sioux Falls SD 446 PM CDT SUN JUN 24 2018 The National Weather Service in Sioux Falls has issued a * Flash Flood Warning for... Northwestern Cherokee County in northwestern Iowa... Southeastern Sioux County in northwestern Iowa... Northeastern Plymouth County in northwestern Iowa... Southwestern O'Brien County in northwestern Iowa... * Until 845 PM CDT. * At 446 PM CDT, Doppler radar indicated thunderstorms producing heavy rain across the warned area. Up to two inches of rain have already fallen. Flash flooding is expected to begin shortly. * Some locations that will experience flooding include... Remsen, Marcus, Paullina, Cleghorn and Oyens. Additional rainfall amounts of 1 to 2 inches are possible in the warned area. PRECAUTIONARY/PREPAREDNESS ACTIONS... Turn around, don't drown when encountering flooded roads. Most flood deaths occur in vehicles. 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 4306 9558 4277 9570 4267 9611 4288 9605 $$ Weisser
1 follow-up statement
856 WGUS73 KFSD 242346 FFSFSD Flash Flood Statement National Weather Service Sioux Falls SD 646 PM CDT SUN JUN 24 2018 IAC035-141-149-167-250145- /O.CON.KFSD.FF.W.0005.000000T0000Z-180625T0145Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Cherokee IA-Sioux IA-Plymouth IA-O'Brien IA- 646 PM CDT SUN JUN 24 2018 ...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 845 PM CDT FOR NORTHWESTERN CHEROKEE...SOUTHEASTERN SIOUX...NORTHEASTERN PLYMOUTH AND SOUTHWESTERN O'BRIEN COUNTIES... At 644 PM CDT, Doppler radar indicated the heavy rain has moved out of the area. Three to five inches of rain has already fallen. Flash flooding is likely occurring. Scattered thunderstorms this evening may bring additional rounds of heavy rain. Some locations that will experience flooding include... Remsen, Marcus, Paullina, Cleghorn and Oyens. Additional rainfall amounts of one to two are possible in the warned area. PRECAUTIONARY/PREPAREDNESS ACTIONS... Turn around, don't drown when encountering flooded roads. Most flood deaths occur in vehicles. In hilly terrain there are hundreds of low water crossings which are potentially dangerous in heavy rain. Do not attempt to cross flooded roads. Find an alternate route. A Flash Flood Warning means that flooding is imminent or occurring. If you are in the warned area move to higher ground immediately. Residents living along streams and creeks should take immediate precautions to protect life and property. && LAT...LON 4306 9558 4277 9570 4267 9611 4288 9605 $$ Weisser
The office that day
Everything else NWS Sioux Falls, SD issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 24, 4:03 PM CDT | Severe Thunderstorm Warning | FSD | Plymouth | 27 min |
| Jun 24, 4:52 PM CDT | Flash Flood Warning | FSD | Dickinson, Osceola | 4 hr |
| Jun 24, 5:01 PM CDT | Severe Thunderstorm Warning | FSD | Dickinson | 44 min |
| Jun 24, 5:26 PM CDT | Severe Thunderstorm Warning | FSD | Clay, Dickinson | 49 min |
| Jun 24, 5:29 PM CDT | Severe Thunderstorm Warning | FSD | Clay, Dickinson | 46 min |
| Jun 24, 5:36 PM CDT | Flash Flood Warning | FSD | Clay, Dickinson, O'Brien, Osceola | 3 hr |
| Jun 24, 6:18 PM CDT | Severe Thunderstorm Warning | FSD | Buena Vista, Clay | 42 min |
Nearby
Flash Flood Warnings in Iowa, 2018Every flash flood warning in 2018
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.