Alert archive / Iowa / Flash Flood Warnings in 2020

Flash Flood Warning 21, NWS Quad Cities, IA

June 26, 2020Keokuk County, Washington County, Iowa

NWS Quad Cities, IA issued this flash flood warning at Jun 26, 2020, 9:54 PM CDT for Keokuk County, Washington County, Iowa. It was in force for 8 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jun 26, 2020, 9:54 PM CDT (02:54 UTC)
Expired
Jun 27, 2020, 5:45 AM CDT
In force
8 hr
Issued by
NWS Quad Cities, IA
Area
Storm-based polygon
Flood severity
None

Counties Keokuk County, IA, Washington County, IA

The radar

The Quad Cities radar (KDVN), 127 km from the middle of the area, began a volume at 02:55 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.

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 2.9 hours before the alert went out and 133 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, Davenport, at 00:00Z on 2020-06-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1679 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, Davenport, at 00:00Z on 2020-06-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 77 square meters per square second.193958Sfc1 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
1679 J/kg
Mixed-layer CIN
-42 J/kg
Mixed-layer LCL
1079 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
77 m²/s²
0-3 km storm-relative helicity
86 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.4

Open this sounding in Storm Lab

The text

As transmitted.

092 
WGUS53 KDVN 270254
FFWDVN
IAC107-183-271045-
/O.NEW.KDVN.FF.W.0021.200627T0254Z-200627T1045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Quad Cities IA/IL
954 PM CDT Fri Jun 26 2020

The National Weather Service in the Quad Cities has issued a

* Flash Flood Warning for...
  Southern Keokuk County in southeastern Iowa...
  Southern Washington County in southeastern Iowa...

* Until 545 AM CDT Saturday.

* At 951 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Around 2 inches of rain has 
  already fallen from around Rubio to Lancaster and Martinsburg. 
  Flash flooding is expected to begin shortly. Expect flooding of 
  streets, creeks, streams and low lying areas.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar indicated.

  IMPACT...Flooding of small creeks and streams, urban areas, 
           highways, streets and underpasses as well as other 
           drainage and low lying areas.

* Some locations that will experience flooding include...
  Washington, Sigourney, Hedrick, Brighton, Richland, Ainsworth,
  Delta, Crawfordsville, Martinsburg, Hayesville, Coppock, Ollie,
  West Chester, Noble, Washington Airport, Lancaster, Marr Park,
  Keokuk County Expo, Haskins and Lake Darling State Park.

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.

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

&&

LAT...LON 4136 9240 4135 9148 4116 9149 4117 9241

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...2-4 inches in 2 hours 

$$

McClure
7 follow-up statements
781 
WGUS73 KDVN 270306
FFSDVN

Flash Flood Statement
National Weather Service Quad Cities IA/IL
1006 PM CDT Fri Jun 26 2020

IAC107-183-271045-
/O.CON.KDVN.FF.W.0021.000000T0000Z-200627T1045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Keokuk IA-Washington IA-
1006 PM CDT Fri Jun 26 2020

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 545 AM CDT
SATURDAY FOR SOUTHERN KEOKUK AND SOUTHERN WASHINGTON COUNTIES...

At 1004 PM CDT, Doppler radar indicated thunderstorms producing 
heavy rain across the warned area. Radar estimates 3 to 4 inches of 
rain have fallen from Martinsburg, to Ollie, Lancaster, to around 
Rubio. Flash flooding is ongoing or expected to begin shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar indicated.

IMPACT...Flooding of small creeks and streams, urban areas, 
         highways, streets and underpasses as well as other drainage 
         and low lying areas.

Some locations that will experience flooding include...
Washington, Sigourney, Hedrick, Brighton, Richland, Ainsworth, Delta,
Crawfordsville, Martinsburg, Hayesville, Coppock, Ollie, West
Chester, Noble, Washington Airport, Lancaster, Marr Park, Keokuk
County Expo, Haskins and Lake Darling State Park.

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.

Flooding is occurring or is imminent. It is important to know where
you are relative to streams, rivers, or creeks which can become
killers in heavy rains. Campers should avoid streams or creeks.

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

&&

LAT...LON 4136 9240 4135 9148 4116 9149 4117 9241

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

McClure
101 
WGUS73 KDVN 270355
FFSDVN

Flash Flood Statement
National Weather Service Quad Cities IA/IL
1055 PM CDT Fri Jun 26 2020

IAC107-183-271045-
/O.CON.KDVN.FF.W.0021.000000T0000Z-200627T1045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Keokuk IA-Washington IA-
1055 PM CDT Fri Jun 26 2020

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 545 AM CDT
SATURDAY FOR SOUTHERN KEOKUK AND SOUTHERN WASHINGTON COUNTIES...

At 1045 PM CDT, law enforcement reported creeks and ditches running 
full around the Rubio area. Doppler radar indicates around 4 inches 
of rain have fallen already from Martinsburg to Lancaster, Rubio to
southwest of Washington. Flash flooding is ongoing or likely to 
begin shortly, especially around Main street in Rubio northward to 
near 250th street, and in nearby creeks, streams and low lying 
areas. Radar shows thunderstorms weakening, but some pockets of 
moderate to heavy rain are still occurring over the warned area.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Law enforcement.

IMPACT...Flooding of small creeks and streams, urban areas, 
         highways, streets and underpasses as well as other drainage 
         and low lying areas.

Some locations that will experience flooding include...
Washington, Sigourney, Hedrick, Brighton, Richland, Ainsworth, Delta,
Crawfordsville, Martinsburg, Hayesville, Coppock, Ollie, West
Chester, Noble, Washington Airport, Lancaster, Marr Park, Keokuk
County Expo, Haskins and Lake Darling State Park.

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.

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

&&

LAT...LON 4136 9240 4135 9148 4116 9149 4117 9241

FLASH FLOOD...OBSERVED
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

McClure
228 
WGUS73 KDVN 270436
FFSDVN

Flash Flood Statement
National Weather Service Quad Cities IA/IL
1136 PM CDT Fri Jun 26 2020

IAC107-183-271045-
/O.CON.KDVN.FF.W.0021.000000T0000Z-200627T1045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Keokuk IA-Washington IA-
1136 PM CDT Fri Jun 26 2020

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 545 AM CDT
SATURDAY FOR SOUTHERN KEOKUK AND SOUTHERN WASHINGTON COUNTIES...

At 1130 PM CDT, Doppler radar indicated thunderstorms producing 
heavy rain have moved south of the warned area, with mainly just 
light to occasional moderate rain falling. Doppler radar indicates 4 
to 5 inches of rain have fallen in a few locations between 
Martinsburg and Rubio. Flash flooding is ongoing or expected to 
begin shortly, especially around Rubio, and portions of the Skunk 
River basin, Rock Creek, Competine Creek, Honey Creek, Dutch Creek, 
and Walnut Creek. 

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar indicated.

IMPACT...Flooding of small creeks and streams, urban areas, 
         highways, streets and underpasses as well as other drainage 
         and low lying areas.

Some locations that will experience flooding include...
Washington, Sigourney, Hedrick, Brighton, Richland, Ainsworth, Delta,
Crawfordsville, Martinsburg, Hayesville, Coppock, Ollie, West
Chester, Noble, Washington Airport, Lancaster, Marr Park, Keokuk
County Expo, Haskins and Lake Darling State Park.

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.

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

&&

LAT...LON 4136 9240 4135 9148 4116 9149 4117 9241

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1 INCH IN 1 HOUR

$$

McClure
005 
WGUS73 KDVN 270530
FFSDVN

Flash Flood Statement
National Weather Service Quad Cities IA/IL
1230 AM CDT Sat Jun 27 2020

IAC107-183-271045-
/O.CON.KDVN.FF.W.0021.000000T0000Z-200627T1045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Keokuk IA-Washington IA-
1230 AM CDT Sat Jun 27 2020

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 545 AM CDT
SATURDAY FOR SOUTHERN KEOKUK AND SOUTHERN WASHINGTON COUNTIES...

At 1226 AM CDT, Doppler radar indicated mainly light rain falling. 
However, thunderstorms were redeveloping to the west of the warned 
area. These storms are likely to move back across portions of the 
area overnight. Any flash flooding that occurred earlier may have 
ended, but these additional storms overnight would pose an immediate 
flash flood threat given the saturated ground. 

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar indicated.

IMPACT...Flooding of small creeks and streams, urban areas, 
         highways, streets and underpasses as well as other drainage 
         and low lying areas.

Some locations that will experience flooding include...
Washington, Sigourney, Hedrick, Brighton, Richland, Ainsworth, Delta,
Crawfordsville, Martinsburg, Hayesville, Coppock, Ollie, West
Chester, Noble, Washington Airport, Lancaster, Marr Park, Keokuk
County Expo, Haskins and Lake Darling State Park.

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.

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

&&

LAT...LON 4136 9240 4135 9148 4116 9149 4117 9241

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1 INCH IN 1 HOUR. 

$$

McClure
991 
WGUS73 KDVN 270707
FFSDVN

Flash Flood Statement
National Weather Service Quad Cities IA/IL
207 AM CDT Sat Jun 27 2020

IAC107-183-271045-
/O.CON.KDVN.FF.W.0021.000000T0000Z-200627T1045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Keokuk IA-Washington IA-
207 AM CDT Sat Jun 27 2020

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 545 AM CDT
SATURDAY FOR SOUTHERN KEOKUK AND SOUTHERN WASHINGTON COUNTIES...

At 205 AM CDT, Doppler radar indicated thunderstorms producing heavy 
rain across southern portions of Keokuk County west and south of 
Lancaster. These storms may continue to develop into southern 
Washington County over the next 1 to 2 hours. Flash flooding is 
ongoing or expected to begin shortly. These storms pose an immediate 
flash flood threat given the saturated ground. 

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar indicated.

IMPACT...Flooding of small creeks and streams, urban areas, 
         highways, streets and underpasses as well as other drainage 
         and low lying areas.

Some locations that will experience flooding include...
Washington, Sigourney, Hedrick, Brighton, Richland, Ainsworth, Delta,
Crawfordsville, Martinsburg, Hayesville, Coppock, Ollie, West
Chester, Noble, Washington Airport, Lancaster, Marr Park, Keokuk
County Expo, Haskins and Lake Darling State Park.

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.

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

&&

LAT...LON 4136 9240 4135 9148 4116 9149 4117 9241

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

McClure
757 
WGUS73 KDVN 270929
FFSDVN

Flash Flood Statement
National Weather Service Quad Cities IA/IL
429 AM CDT Sat Jun 27 2020

IAC107-183-271045-
/O.CON.KDVN.FF.W.0021.000000T0000Z-200627T1045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Keokuk IA-Washington IA-
429 AM CDT Sat Jun 27 2020

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 545 AM CDT
SATURDAY FOR SOUTHERN KEOKUK AND SOUTHERN WASHINGTON COUNTIES...

At 424 AM CDT, Doppler radar indicated thunderstorms producing heavy 
rain from around Lancaster to near Talleyrand, and around 
Washington. Radar indicates 2 to over 4 inches of rain have fallen 
across the warned area since last evening. Due to the wet ground 
from this recent heavy rain any additional heavy rain will likely go 
into runoff, and result in the likelihood of flash flooding. 

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar indicated.

IMPACT...Flooding of small creeks and streams, urban areas, 
         highways, streets and underpasses as well as other drainage 
         and low lying areas.

Some locations that will experience flooding include...
Washington, Sigourney, Hedrick, Brighton, Richland, Ainsworth, Delta,
Crawfordsville, Martinsburg, Hayesville, Coppock, Ollie, West
Chester, Noble, Washington Airport, Lancaster, Marr Park, Keokuk
County Expo, Haskins and Lake Darling State Park.

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.

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

&&

LAT...LON 4136 9240 4135 9148 4116 9149 4117 9241

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

McClure
613 
WGUS73 KDVN 271038
FFSDVN

Flash Flood Statement
National Weather Service Quad Cities IA/IL
538 AM CDT Sat Jun 27 2020

IAC107-183-271045-
/O.EXP.KDVN.FF.W.0021.000000T0000Z-200627T1045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Keokuk IA-Washington IA-
538 AM CDT Sat Jun 27 2020

...THE FLASH FLOOD WARNING FOR SOUTHERN KEOKUK AND SOUTHERN
WASHINGTON COUNTIES WILL EXPIRE AT 545 AM CDT SATURDAY...

Flooding is no longer expected to pose a threat. Please continue to 
heed any road closures. Also, please report any previous water over 
road impacts to local law enforcement for relay to the National 
Weather Service.

LAT...LON 4136 9240 4135 9148 4116 9149 4117 9241

$$

McClure

The office that day

Everything else NWS Quad Cities, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 26, 7:05 PM CDTSevere Thunderstorm WarningDVNDes Moines, Henry25 min
Jun 26, 7:07 PM CDTSevere Thunderstorm WarningDVNVan Buren33 min
Jun 26, 7:45 PM CDTSpecial Weather StatementDVNKeokuk45 min
Jun 26, 8:44 PM CDTSpecial Weather StatementDVNDes Moines, Henry, Jefferson, Keokuk, Louisa, Muscatine and 1 more61 min
Jun 26, 9:00 PM CDTSevere Thunderstorm WarningDVNHenry30 min
Jun 26, 9:06 PM CDTRiver Flood WatchDVNDes Moines, Louisa62 hr
Jun 27, 12:08 AM CDTSpecial Weather StatementDVNLee37 min
Jun 27, 12:33 AM CDTSpecial Weather StatementDVNLee27 min
Jun 27, 2:29 AM CDTSpecial Weather StatementDVNJefferson31 min
Jun 27, 7:48 AM CDTSpecial Weather StatementDVNKeokuk, Washington57 min
Jun 27, 10:29 AM CDTRiver Flood WarningDVNDes Moines5 days
Jun 27, 10:29 AM CDTRiver Flood WarningDVNDes Moines, Lee5 days
Jun 27, 2:48 PM CDTSpecial Weather StatementDVNKeokuk, Washington57 min
Jun 27, 3:28 PM CDTSpecial Weather StatementDVNIowa, Johnson62 min
Jun 27, 3:37 PM CDTFlash Flood WarningDVNJohnson2 hr
Jun 27, 4:52 PM CDTSpecial Weather StatementDVNIowa53 min
Jun 27, 5:08 PM CDTFlash Flood WarningDVNCedar, Johnson, Linn83 min

Nearby

Flash Flood Warnings in Iowa, 2020Every flash flood warning in 2020

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.