Alert archive / Iowa / Flash Flood Warnings in 2017

Flash Flood Warning 6, NWS Des Moines, IA

July 22, 2017Black Hawk County, Bremer County, Butler County, Iowa

NWS Des Moines, IA issued this flash flood warning at Jul 22, 2017, 2:04 AM CDT for Black Hawk County, Bremer County, Butler 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
Jul 22, 2017, 2:04 AM CDT (07:04 UTC)
Expired
Jul 22, 2017, 8:00 AM 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 07:07 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

TimeReportWhereRemark
Jul 22, 7:36 AM CDTFLASH FLOOD3 Ene Readlyn, IASECONDARY ROADS JUST EAST-NORTHEAST OF READLYN ARE COVERED WITH WATER AND HIGHWAY 3 IS CLOSE TO BEING INUNDATED.
Jul 22, 7:36 AM CDTFLASH FLOOD4 W Tripoli, IAWATER OVER PORTIONS OF HIGHWAY 63 WEST OF TRIPOLI. DEPTH UNKNOWN, BUT IS COVERING SEVERAL LOCATIONS OF THE HIGHWAY.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 7.1 hours before the alert went out and 258 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.

Skew-T log-pSkew-T log-p diagram, Minneapolis, MN at 00:00Z on 2017-07-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 337 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Minneapolis, MN at 00:00Z on 2017-07-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 14 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
337 J/kg
Mixed-layer CIN
-126 J/kg
Mixed-layer LCL
981 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
14 m²/s²
0-3 km storm-relative helicity
40 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

As transmitted.

029 
WGUS53 KDMX 220704
FFWDMX
IAC013-017-023-221300-
/O.NEW.KDMX.FF.W.0006.170722T0704Z-170722T1300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Des Moines IA
204 AM CDT SAT JUL 22 2017

The National Weather Service in Des Moines  has issued a

* Flash Flood Warning for...
  Northern Black Hawk County in northeastern Iowa...
  Bremer County in northeastern Iowa...
  Butler County in north central Iowa...

* Until 800 AM CDT.

* At 200 AM CDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Up to two inches of rain have 
  already fallen in portions of the warning and also received heavy 
  rain from Friday morning resulting in saturated ground. Rainfall 
  rates of 2 to 3 inches per hour are likely with these storms 
  and flash flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  Waverly, Allison, Jesup, Denver, Clarksville, Shell Rock, Greene, 
  Waterloo Municipal Airport, Janesville, Dunkerton, Readlyn, 
  Dumont, Plainfield, Bristow, Aredale, Allison Municipal Airport 
  and Waverly Municipal Airport.

Additional rainfall amounts of 2 to 4 are possible in the warned 
area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

Please report flooding to your local law enforcement agency when you
can do so safely.

&&

LAT...LON 4273 9303 4291 9303 4291 9244 4277 9227
      4272 9208 4247 9208 4247 9206 4244 9206

$$

Podrazik
3 follow-up statements
928 
WGUS73 KDMX 220911
FFSDMX

Flash Flood Statement
National Weather Service Des Moines IA
411 AM CDT SAT JUL 22 2017

IAC023-220919-
/O.CAN.KDMX.FF.W.0006.000000T0000Z-170722T1300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Butler IA-
411 AM CDT SAT JUL 22 2017

...THE FLASH FLOOD WARNING FOR BUTLER COUNTY IS CANCELLED...

Flooding is no longer expected to pose a threat. Please continue to
heed any remaining road closures.

LAT...LON 4259 9255 4291 9255 4291 9244 4277 9227
      4272 9208 4247 9208 4247 9206 4244 9206

$$

IAC013-017-221300-
/O.CON.KDMX.FF.W.0006.000000T0000Z-170722T1300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Black Hawk IA-Bremer IA-
411 AM CDT SAT JUL 22 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 800 AM CDT FOR
NORTHERN BLACK HAWK AND BREMER COUNTIES...

At 409 AM CDT, emergency management reported heavy rain due to 
thunderstorms over portions of Bremer County. Up to two to three 
inches of rain have already fallen and flash flooding is expected to 
continue even though the rain has ended.

Some locations that will experience flooding include...
Waverly, Jesup, Denver, Waterloo Municipal Airport, Janesville, 
Dunkerton, Readlyn, Plainfield and Waverly Municipal Airport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

Please report flooding to your local law enforcement agency when you
can do so safely.

&&

LAT...LON 4259 9255 4291 9255 4291 9244 4277 9227
      4272 9208 4247 9208 4247 9206 4244 9206

$$

Podrazik
465 
WGUS73 KDMX 221108
FFSDMX

Flash Flood Statement
National Weather Service Des Moines IA
608 AM CDT SAT JUL 22 2017

IAC013-221115-
/O.CAN.KDMX.FF.W.0006.000000T0000Z-170722T1300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Black Hawk IA-
608 AM CDT SAT JUL 22 2017

...THE FLASH FLOOD WARNING FOR NORTHERN BLACK HAWK COUNTY IS
CANCELLED...

Flash Flooding is no longer expected to pose a threat. Please 
continue to heed any remaining road closures.

LAT...LON 4264 9255 4291 9255 4291 9244 4277 9227
      4272 9208 4264 9208

$$

IAC017-221300-
/O.CON.KDMX.FF.W.0006.000000T0000Z-170722T1300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Bremer IA-
608 AM CDT SAT JUL 22 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 800 AM CDT FOR
BREMER COUNTY...

At 605 AM CDT, emergency management reported flash flooding over 
portions of Bremer County as several roads remain underwater. 
Overnight, radar estimated up to three inches of rain had fallen and 
even though the rain has ceased, flash flooding will continue to 
occur.

Some locations that will experience flooding include...
Waverly, Denver, Janesville, Readlyn, Plainfield and Waverly
Municipal Airport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, country roads, farmland, and other low lying
spots.

Please report flooding to your local law enforcement agency when you
can do so safely.

&&

LAT...LON 4264 9255 4291 9255 4291 9244 4277 9227
      4272 9208 4264 9208

$$

Podrazik
183 
WGUS73 KDMX 221258
FFSDMX

Flash Flood Statement
National Weather Service Des Moines IA
758 AM CDT SAT JUL 22 2017

IAC017-221307-
/O.EXP.KDMX.FF.W.0006.000000T0000Z-170722T1300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Bremer IA-
758 AM CDT SAT JUL 22 2017

...THE FLASH FLOOD WARNING FOR BREMER COUNTY WILL EXPIRE AT 800 AM
CDT...

The heavy rain has ended. However, many roads remain inundated with 
water throughout central and eastern portions of the county. Please 
continue to heed any remaining road closures.

LAT...LON 4264 9255 4291 9255 4291 9244 4277 9227
      4272 9208 4264 9208

$$

Podrazik

The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 21, 9:58 PM CDTSpecial Weather StatementDMXBremer62 min
Jul 21, 10:24 PM CDTFlash Flood WarningDMXBremer15 hr
Jul 22, 3:59 AM CDTHeat AdvisoryDMXAudubon, Cass, Guthrie16 hr
Jul 22, 7:56 AM CDTAreal Flood WarningDMXBremer24 hr
Jul 22, 2:19 PM CDTAreal Flood WarningDMXBremer24 hr

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.