Alert archive / Iowa / Flash Flood Warnings in 2017
Flash Flood Warning 7, NWS Des Moines, IA
NWS Des Moines, IA issued this flash flood warning at Aug 21, 2017, 12:32 AM CDT for Crawford County, Iowa. It was in force for 6 hr. 2 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
- Aug 21, 2017, 12:32 AM CDT (05:32 UTC)
- Expired
- Aug 21, 2017, 6:30 AM CDT
- In force
- 6 hr
- Issued by
- NWS Des Moines, IA
- Area
- Storm-based polygon
- Flood severity
- None
County Crawford County, IA
The radar
The Omaha radar (KOAX), 115 km from the middle of the area, began a volume at 05:32 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 |
|---|---|---|---|
| Aug 21, 4:54 AM CDT | HEAVY RAIN 6.34 | 1 Nne Denison, IA | MEASURED AT AN ONLINE HOME WEATHER STATION. |
| Aug 21, 4:55 AM CDT | HEAVY RAIN 4.03 | 1 Wsw Denison, IA | MEASURED AT AN ONLINE HOME WEATHER STATION. |
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 00:00Z, 5.5 hours before the alert went out and 115 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
- 1704 J/kg
- Mixed-layer CIN
- -211 J/kg
- Mixed-layer LCL
- 1354 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- 144 m²/s²
- 0-3 km storm-relative helicity
- 264 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.5
The text
As transmitted.
322
WGUS53 KDMX 210532
FFWDMX
IAC047-211130-
/O.NEW.KDMX.FF.W.0007.170821T0532Z-170821T1130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Des Moines IA
1232 AM CDT MON AUG 21 2017
The National Weather Service in Des Moines has issued a
* Flash Flood Warning for...
Crawford County in west central Iowa...
* Until 630 AM CDT.
* At 1231 AM CDT, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Two to possibly as much as
three inches of rain have already fallen. Flash flooding is
expected to begin shortly.
* Some locations that will experience flooding include...
Denison, Schleswig, Manilla, Dow City, Charter Oak, Vail, Westside,
Kiron, Deloit, Ricketts, Arion, Buck Grove and Denison Municipal
Airport.
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.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, country roads, farmland, and other low lying
spots.
&&
LAT...LON 4221 9567 4221 9509 4203 9510 4186 9522
4187 9567
$$
Beerends2 follow-up statements
793
WGUS73 KDMX 210759
FFSDMX
Flash Flood Statement
National Weather Service Des Moines IA
259 AM CDT MON AUG 21 2017
IAC047-211130-
/O.CON.KDMX.FF.W.0007.000000T0000Z-170821T1130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Crawford IA-
259 AM CDT MON AUG 21 2017
...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 630 AM CDT FOR
CRAWFORD COUNTY...
At 258 AM CDT, Doppler radar indicated thunderstorms producing heavy
rain across the warned area. Four to over five inches of rain have
fallen. Flash flooding is expected to begin shortly.
Some locations that will experience flooding include...
Denison, Schleswig, Manilla, Dow City, Charter Oak, Vail, Westside,
Kiron, Deloit, Ricketts, Arion, Buck Grove and Denison Municipal
Airport.
Additional rainfall amounts of an inch or more are still possible in
the warned area.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, country roads, farmland, and other low lying
spots.
&&
LAT...LON 4221 9567 4221 9509 4203 9510 4186 9522
4187 9567
$$
Beerends253
WGUS73 KDMX 211000
FFSDMX
Flash Flood Statement
National Weather Service Des Moines IA
500 AM CDT MON AUG 21 2017
IAC047-211130-
/O.CON.KDMX.FF.W.0007.000000T0000Z-170821T1130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Crawford IA-
500 AM CDT MON AUG 21 2017
...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 630 AM CDT FOR
CRAWFORD COUNTY...
At 500 AM CDT, Doppler radar indicated thunderstorms producing heavy
rain across the warned area. Six inches or more of rain have fallen.
Some locations that will experience flooding include...
Denison, Schleswig, Manilla, Dow City, Charter Oak, Vail, Westside,
Kiron, Deloit, Ricketts, Arion, Buck Grove and Denison Municipal
Airport.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, country roads, farmland, and other low lying
spots.
&&
LAT...LON 4221 9567 4221 9509 4203 9510 4186 9522
4187 9567
$$
BeerendsThe office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 20, 11:03 PM CDT | Special Weather Statement | DMX | Crawford | 27 min |
| Aug 20, 11:05 PM CDT | Severe Thunderstorm Warning | DMX | Carroll, Crawford, Sac | 40 min |
| Aug 21, 1:27 AM CDT | Special Weather Statement | DMX | Audubon, Guthrie | 33 min |
| Aug 21, 1:31 AM CDT | Flash Flood Warning | DMX | Audubon, Carroll, Crawford, Guthrie | 6 hr |
| Aug 21, 1:53 AM CDT | Special Weather Statement | DMX | Cass | 22 min |
| Aug 21, 1:55 AM CDT | Severe Thunderstorm Warning | DMX | Emmet, Palo Alto | 35 min |
| Aug 21, 2:07 AM CDT | Severe Thunderstorm Warning | DMX | Adair, Adams, Audubon, Cass, Guthrie | 53 min |
| Aug 21, 2:46 AM CDT | Severe Thunderstorm Warning | DMX | Adair, Adams, Cass, Guthrie, Madison, Union | 44 min |
| Aug 21, 3:02 AM CDT | Special Weather Statement | DMX | Kossuth | 43 min |
| Aug 21, 3:30 AM CDT | Severe Thunderstorm Warning | DMX | Adair, Adams, Ringgold, Taylor, Union | 32 min |
| Aug 21, 9:43 AM CDT | Special Weather Statement | DMX | Calhoun, Humboldt, Pocahontas, Webster | 62 min |
| Aug 21, 11:23 AM CDT | Special Weather Statement | DMX | Humboldt, Pocahontas | 52 min |
| Aug 21, 1:39 PM CDT | Special Weather Statement | DMX | Emmet, Kossuth, Palo Alto | 66 min |
| Aug 21, 2:02 PM CDT | Severe Thunderstorm Warning | DMX | Emmet, Kossuth, Palo Alto | 29 min |
| Aug 21, 3:43 PM CDT | Special Weather Statement | DMX | Calhoun, Carroll, Crawford, Emmet, Humboldt, Kossuth and 4 more | 77 min |
| Aug 21, 5:03 PM CDT | Special Weather Statement | DMX | Audubon, Boone, Cass, Dallas, Greene, Guthrie and 4 more | 57 min |
| Aug 21, 5:37 PM CDT | Special Weather Statement | DMX | Boone, Grundy, Hamilton, Hardin, Story | 53 min |
| Aug 21, 6:04 PM CDT | Special Weather Statement | DMX | Jasper, Polk | 41 min |
| Aug 21, 6:16 PM CDT | Special Weather Statement | DMX | Madison, Warren | 44 min |
| Aug 21, 6:26 PM CDT | Special Weather Statement | DMX | Black Hawk, Grundy, Marshall, Tama | 64 min |
| Aug 21, 6:38 PM CDT | Special Weather Statement | DMX | Jasper, Mahaska, Marion | 52 min |
| Aug 21, 6:52 PM CDT | Special Weather Statement | DMX | Clarke, Lucas, Madison, Union, Warren | 68 min |
| Aug 21, 6:58 PM CDT | Special Weather Statement | DMX | Poweshiek | 47 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.