Alert archive / Iowa / Flash Flood Warnings in 2018
Flash Flood Warning 33, NWS Des Moines, IA
NWS Des Moines, IA issued this flash flood warning at Sep 2, 2018, 1:34 PM CDT for Black Hawk County, Bremer County, Butler County, Iowa. It was in force for 6 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
- Sep 2, 2018, 1:34 PM CDT (18:34 UTC)
- Expired
- Sep 2, 2018, 7:30 PM CDT
- In force
- 6 hr
- Issued by
- NWS Des Moines, IA
- Area
- Storm-based polygon
- Flood severity
- None
Counties Black Hawk County, IA, Bremer County, IA, Butler County, IA
The radar
The Des Moines radar (KDMX), 149 km from the middle of the area, began a volume at 18:38 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 2, 2:15 PM CDT | FLASH FLOOD | 2 W Plainfield, IA | TRAINED SPOTTER REPORTED THAT MULTIPLE GRAVEL ROADS WEST OF PLAINFIELD HAVE WATER FLOWING OVER THEM, AS MUCH AS 2-3 FEET DEEP. |
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 12:00Z, 6.6 hours before the alert went out and 209 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
- 20 J/kg
- Mixed-layer CIN
- -242 J/kg
- Mixed-layer LCL
- 1345 m above ground
- 0-6 km bulk shear
- 38 kt
- 0-1 km storm-relative helicity
- 7 m²/s²
- 0-3 km storm-relative helicity
- 58 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
The text
As transmitted.
355 WGUS53 KDMX 021834 FFWDMX IAC013-017-023-030030- /O.NEW.KDMX.FF.W.0033.180902T1834Z-180903T0030Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ BULLETIN - EAS ACTIVATION REQUESTED Flash Flood Warning National Weather Service Des Moines IA 134 PM CDT SUN SEP 2 2018 The National Weather Service in Des Moines has issued a * Flash Flood Warning for... Northwestern Black Hawk County in northeastern Iowa... Bremer County in northeastern Iowa... Eastern Butler County in north central Iowa... * Until 730 PM CDT. * At 133 PM CDT, Doppler radar indicated thunderstorms producing heavy rain across the warned area. Up to two inches or more of rain have already fallen. Flash flooding is expected to begin shortly. * Some locations that will experience flooding include... Waverly, Allison, Sumner, Denver, Clarksville, Tripoli, Shell Rock, Greene, Janesville, Readlyn, Plainfield, Frederika, Allison Municipal Airport and Waverly Municipal Airport. Additional rainfall amounts of around 2 inches are possible in the warned area, especially as rainfall moves into eastern areas of the warning. PRECAUTIONARY/PREPAREDNESS ACTIONS... Turn around, don't drown when encountering flooded roads. Most flood deaths occur in vehicles. Excessive runoff from heavy rainfall will cause flooding of small creeks and streams, country roads, farmland, and other low lying spots. && LAT...LON 4261 9284 4291 9283 4291 9208 4264 9208 $$ Curtis
1 follow-up statement
476 WGUS73 KDMX 030027 FFSDMX Flash Flood Statement National Weather Service Des Moines IA 727 PM CDT SUN SEP 2 2018 IAC013-017-023-030033- /O.EXP.KDMX.FF.W.0033.000000T0000Z-180903T0030Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Black Hawk IA-Bremer IA-Butler IA- 727 PM CDT SUN SEP 2 2018 ...THE FLASH FLOOD WARNING FOR NORTHWESTERN BLACK HAWK...BREMER AND EASTERN BUTLER COUNTIES WILL EXPIRE AT 730 PM CDT... The heavy rain has ended for the time being as flash flooding is no longer anticipated, but flooding and standing water continues with water on roads and multiple closures. An Areal Flood Warning will be issued shortly to replace this expiring warning. Please continue to heed any remaining road closures. LAT...LON 4261 9284 4291 9283 4291 9208 4264 9208 $$ Small
The office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 1, 7:02 PM CDT | Special Weather Statement | DMX | Boone, Story | 58 min |
| Sep 1, 7:07 PM CDT | Severe Thunderstorm Warning | DMX | Boone, Dallas, Polk, Story | 38 min |
| Sep 1, 7:14 PM CDT | Severe Thunderstorm Warning | DMX | Jasper, Polk, Story | 46 min |
| Sep 1, 7:36 PM CDT | Severe Thunderstorm Warning | DMX | Jasper, Polk | 54 min |
| Sep 1, 7:51 PM CDT | Severe Thunderstorm Warning | DMX | Dallas, Polk, Story | 39 min |
| Sep 1, 8:16 PM CDT | Severe Thunderstorm Warning | DMX | Mahaska | 14 min |
| Sep 1, 8:50 PM CDT | Severe Thunderstorm Warning | DMX | Boone, Dallas, Polk, Story | 40 min |
| Sep 1, 9:20 PM CDT | Flash Flood Warning | DMX | Boone, Dallas, Polk, Story | 6 hr |
| Sep 1, 9:40 PM CDT | River Flood Warning | DMX | Black Hawk | 10 days |
| Sep 1, 9:59 PM CDT | Flash Flood Warning | DMX | Mahaska, Monroe, Wapello | 5 hr |
| Sep 1, 10:04 PM CDT | Special Weather Statement | DMX | Adair, Adams, Cass | 56 min |
| Sep 1, 10:16 PM CDT | Flash Flood Warning | DMX | Poweshiek | 6 hr |
| Sep 1, 10:47 PM CDT | Flash Flood Warning | DMX | Jasper, Poweshiek | 5 hr |
| Sep 2, 12:40 AM CDT | River Flood Warning | DMX | Jasper, Marion, Polk | 6 hr |
| Sep 2, 1:37 AM CDT | Flash Flood Warning | DMX | Marshall, Story | 2 hr |
| Sep 2, 3:47 AM CDT | Areal Flood Warning | DMX | Jasper, Marshall, Poweshiek, Story | 9 hr |
| Sep 2, 9:45 AM CDT | Flash Flood Watch | DMX | Adair, Adams, Appanoose, Audubon, Black Hawk, Boone and 30 more | 36 hr |
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.