Alert archive / Iowa / Flash Flood Warnings in 2021
Flash Flood Warning 3, NWS Des Moines, IA
NWS Des Moines, IA issued this flash flood warning at Jul 14, 2021, 8:28 PM CDT for Marshall County, Polk County, Story County, Iowa. It was in force for 6 hr. 4 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
- Jul 14, 2021, 8:28 PM CDT (01:28 UTC)
- Expired
- Jul 15, 2021, 2:04 AM CDT
- In force
- 6 hr
- Issued by
- NWS Des Moines, IA
- Area
- Storm-based polygon
- Flood severity
- None
Counties Marshall County, IA, Polk County, IA, Story County, IA
The radar
The Des Moines radar (KDMX), 32 km from the middle of the area, began a volume at 01:26 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 |
|---|---|---|---|
| Jul 14, 8:30 PM CDT | FLASH FLOOD | 3 Wnw Maxwell, IA | REPORT OF WATER OVER THE ROAD AT 305TH ST AND 630TH AVE. 3 TO 4 INCHES OF RAINFALL IN THIS AREA. |
| Jul 14, 8:40 PM CDT | HEAVY RAIN 5.6 | 2 Nw Maxwell, IA | TOTAL RAINFALL SINCE ABOUT 6 PM. |
| Jul 14, 9:02 PM CDT | FLASH FLOOD | Maxwell, IA | WATER OVER INTERSECTION OF WOODLAWN AND 2ND STREET OF AT LEAST 6 INCHES DEEP. REPORT VIA SOCIAL MEDIA. |
| Jul 14, 9:29 PM CDT | HEAVY RAIN 5.2 | Maxwell, IA |
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, 1.5 hours before the alert went out and 242 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
- 2569 J/kg
- Mixed-layer CIN
- -10 J/kg
- Mixed-layer LCL
- 832 m above ground
- 0-6 km bulk shear
- 38 kt
- 0-1 km storm-relative helicity
- 253 m²/s²
- 0-3 km storm-relative helicity
- 346 m²/s²
- Significant tornado parameter
- 3.2
- Supercell composite
- 23.4
The text
As transmitted.
577
WGUS53 KDMX 150128
FFWDMX
IAC127-153-169-150730-
/O.NEW.KDMX.FF.W.0003.210715T0128Z-210715T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Des Moines IA
828 PM CDT Wed Jul 14 2021
The National Weather Service in Des Moines has issued a
* Flash Flood Warning for...
Southwestern Marshall County in central Iowa...
North Central Polk County in central Iowa...
Southeastern Story County in central Iowa...
* Until 230 AM CDT Thursday.
* At 828 PM CDT, Doppler radar and automated rain gauges indicated
thunderstorms producing heavy rain across the warned area. Between
3 and 4 inches of rain have fallen. Additional rainfall amounts of
1 to 2 inches are possible in the warned area. Flash flooding is
ongoing or expected to begin shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar and automated gauges.
IMPACT...Flash flooding of small creeks and streams, urban
areas, highways, streets and underpasses as well as
other poor drainage and low-lying areas.
* Some locations that will experience flash flooding include...
Huxley, Maxwell, Cambridge, Collins, Alleman and Rhodes.
This includes the following highways...
Interstate 35 between mile markers 101 and 108.
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.
&&
LAT...LON 4186 9362 4196 9357 4201 9323 4187 9317
4187 9323 4186 9328 4186 9329 4186 9335
4182 9364
FLASH FLOOD...RADAR AND GAUGE INDICATED
$$
REV2 follow-up statements
035
WGUS73 KDMX 150341
FFSDMX
Flash Flood Statement
National Weather Service Des Moines IA
1041 PM CDT Wed Jul 14 2021
IAC127-153-169-150730-
/O.CON.KDMX.FF.W.0003.000000T0000Z-210715T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Marshall IA-Polk IA-Story IA-
1041 PM CDT Wed Jul 14 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 230 AM CDT THURSDAY
FOR SOUTHWESTERN MARSHALL, NORTH CENTRAL POLK AND SOUTHEASTERN STORY
COUNTIES...
At 1041 PM CDT, Doppler radar and automated rain gauges indicated
thunderstorm produced heavy rain across the warned area. Up to 6
inches of rain has fallen. Though the rain has ended, flooding may
still be ongoing across the warned area.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar and automated gauges.
IMPACT...Flash flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other poor
drainage and low-lying areas.
Some locations that will experience flash flooding include...
Huxley, Maxwell, Cambridge, Collins, Alleman and Rhodes.
This includes the following highways...
Interstate 35 between mile markers 100 and 109.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be especially cautious at night when it is harder to recognize the
dangers of flooding.
&&
LAT...LON 4186 9362 4196 9357 4201 9323 4187 9317
4187 9323 4186 9328 4186 9329 4186 9335
4182 9364
FLASH FLOOD...RADAR AND GAUGE INDICATED
$$
REV098
WGUS73 KDMX 150704
FFSDMX
Flash Flood Statement
National Weather Service Des Moines IA
204 AM CDT Thu Jul 15 2021
IAC127-153-169-150714-
/O.CAN.KDMX.FF.W.0003.000000T0000Z-210715T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Marshall IA-Polk IA-Story IA-
204 AM CDT Thu Jul 15 2021
...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHWESTERN MARSHALL, NORTH
CENTRAL POLK AND SOUTHEASTERN STORY COUNTIES...
Flood waters have receded and the heavy rain has ended. Flooding is
no longer expected to pose a threat. Please continue to heed
remaining road closures.
LAT...LON 4186 9362 4196 9357 4201 9323 4187 9317
4187 9323 4186 9328 4186 9329 4186 9335
4182 9364
$$
HagenhoffThe office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 14, 7:03 PM CDT | Special Weather Statement | DMX | Story | 42 min |
| Jul 14, 7:23 PM CDT | Severe Thunderstorm Warning | DMX | Jasper, Marshall, Polk, Story | 67 min |
| Jul 14, 7:29 PM CDT | Severe Thunderstorm Warning | DMX | Tama | 14 min |
| Jul 14, 8:10 PM CDT | Tornado Warning | DMX | Marshall | 35 min |
| Jul 14, 8:42 PM CDT | Severe Thunderstorm Warning | DMX | Jasper, Marshall, Polk, Story | 43 min |
| Jul 14, 8:45 PM CDT | Severe Thunderstorm Warning | DMX | Poweshiek, Tama | 45 min |
Nearby
Flash Flood Warnings in Iowa, 2021Every flash flood warning in 2021
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.