Alert archive / Iowa / Flash Flood Warnings in 2016

Flash Flood Warning 21, NWS Quad Cities, IA

August 11, 20164 counties in Iowa

NWS Quad Cities, IA issued this flash flood warning at Aug 11, 2016, 9:31 PM CDT for 4 counties in Iowa. It was in force for 6 hr. 17 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 11, 2016, 9:31 PM CDT (02:31 UTC)
Expired
Aug 12, 2016, 3:30 AM CDT
In force
6 hr
Issued by
NWS Quad Cities, IA
Area
Storm-based polygon
Flood severity
None

Counties Benton County, IA, Iowa County, IA, Johnson County, IA, Linn County, IA

The radar

The Quad Cities radar (KDVN), 121 km from the middle of the area, began a volume at 02:31 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
Aug 11, 9:35 PM CDTHEAVY RAIN 3.5Middle Amana, IAMODERATE TO HEAVY RAIN CONTINUES. LOTS OF STANDING WATER. NO FLASH FLOODING OBSERVED SO FAR.
Aug 11, 9:58 PM CDTHEAVY RAIN 2.751 Sse Cedar Rapids, IA1.00 INCHES IN THE LAST HOUR.
Aug 11, 10:15 PM CDTFLASH FLOODMarengo, IADELAYED REPORT. WATER 16 INCHES DEEP ON ROADS IN TOWN. WATER 18 INCHES DEEP BLOCKING ROAD 1 1/2 MILES NORTH OF TOWN.
Aug 11, 10:25 PM CDTHEAVY RAIN 2.15W Belle Plaine, IA
Aug 11, 10:54 PM CDTHEAVY RAIN 4.7Middle Amana, IA1.2 INCHES SINCE THE LAST UPDATE.
Aug 11, 11:00 PM CDTFLASH FLOODNne Swisher, IALOCAL STREAMS SWOLLEN, GRAVEL WASHED OVER ROADS, STANDING WATER IN 2 RESIDENCE BASEMENTS.6.88 INCHES OF RAIN IN PAST12 HOURS
Aug 11, 11:00 PM CDTFLASH FLOODSwisher, IALOCAL STREAMS SWOLLEN. GRAVEL WASHED ACROSS ROADS. WATER IN BASEMENTS OF 2 HOMES.
Aug 11, 11:04 PM CDTFLASH FLOODSwisher, IATHE CRANDIC RAILROAD EXPERIENCED WASHED OUT TRACKS AND A BRIDGE IN THE SWISHER AREA.
Aug 11, 11:12 PM CDTHEAVY RAIN 2.62 Nnw North Liberty, IA
Aug 11, 11:13 PM CDTFLASH FLOODHiawatha, IAROAD CLOSURE IN TOWN DUE TO WATER OVER THE ROAD.
Aug 11, 11:21 PM CDTHEAVY RAIN 3.751 Sse Cedar Rapids, IAUPDATED TOTAL
Aug 11, 11:30 PM CDTHEAVY RAIN 3.5Atkins, IAVIA TWITTER AND BROADCAST MEDIA
Aug 11, 11:35 PM CDTHEAVY RAIN 2.81 Sw North Liberty, IA
Aug 11, 11:43 PM CDTHEAVY RAIN 1.585 Nw Iowa City, IARAINFALL IN THE LAST 40 MINUTES.
Aug 12, 1:00 AM CDTHEAVY RAIN 2.62Iowa City Municipal Air, IADAILY RAINFALL TOTAL. 2.12 INCHES FELL BETWEEN 10PM AND 1AM.
Aug 12, 1:00 AM CDTHEAVY RAIN 4.91Cedar Rapids Municipal, IADAILY RAINFALL TOTAL. 4.83 INCHES FELL IN THE 6 HRS FROM 7PM TO 1AM.
Aug 12, 1:07 AM CDTHEAVY RAIN 0.982 Nnw North Liberty, IAIN THE LAST 2 HOURS. STORM TOTAL OF 3.58 THUS FAR.

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, 2.5 hours before the alert went out and 127 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 2016-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1433 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 2016-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 117 square meters per square second.1939Sfc1 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
1433 J/kg
Mixed-layer CIN
-78 J/kg
Mixed-layer LCL
1263 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
117 m²/s²
0-3 km storm-relative helicity
158 m²/s²
Significant tornado parameter
0.2
Supercell composite
5.6

Open this sounding in Storm Lab

The text

As transmitted.

156 
WGUS53 KDVN 120231
FFWDVN
IAC011-095-103-113-120830-
/O.NEW.KDVN.FF.W.0021.160812T0231Z-160812T0830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE QUAD CITIES IA/IL
931 PM CDT THU AUG 11 2016

THE NATIONAL WEATHER SERVICE IN THE QUAD CITIES HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  JOHNSON COUNTY IN EAST CENTRAL IOWA...
  LINN COUNTY IN EAST CENTRAL IOWA...
  IOWA COUNTY IN EAST CENTRAL IOWA...
  BENTON COUNTY IN EAST CENTRAL IOWA...

* UNTIL 330 AM CDT FRIDAY

* AT 928 PM CDT...DOPPLER RADAR INDICATED THUNDERSTORMS PRODUCING
  HEAVY RAIN ACROSS THE WARNED AREA. 2 TO 4 INCHES OF RAIN HAVE 
  FALLEN SO FAR...AND ADDITIONAL HEAVY RAIN IS EXPECTED. FLASH 
  FLOODING IS EXPECTED TO BEGIN SHORTLY.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  CEDAR RAPIDS...IOWA CITY...VINTON...MARENGO...WEST BRANCH...MARION...
  CORALVILLE...NORTH LIBERTY...HIAWATHA...MOUNT VERNON...ROBINS...
  WILLIAMSBURG...BELLE PLAINE...CENTER POINT...LISBON...FAIRFAX...SOLON...
  TIFFIN...ELY AND ATKINS.

ADDITIONAL RAINFALL AMOUNTS OF 2 TO 3 INCHES ARE POSSIBLE IN
THE WARNED AREA THROUGH THE EARLY MORNING HOURS. FLOODING OF STREETS
AND ROADS IN URBAN AREAS IS THE MAIN CONCERN. THERE WERE REPORTS OF
STALLED CALLS IN CEDAR RAPIDS EARLIER THIS EVENING. DO NOT DRIVE
THROUGH WATER OF ANY DEPTH.

THIS INCLUDES THE FOLLOWING HIGHWAYS...
 INTERSTATE 80 IN IOWA BETWEEN MILE MARKERS 205 AND 253.
 INTERSTATE 380 BETWEEN MILE MARKERS 1 AND 48.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES AS
WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.

&&

LAT...LON 4230 9230 4229 9136 4162 9137 4163 9230

$$

RP KINNEY
3 follow-up statements
157 
WGUS73 KDVN 120415
FFSDVN

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA/IL
1115 PM CDT THU AUG 11 2016

IAC011-095-103-113-120830-
/O.CON.KDVN.FF.W.0021.000000T0000Z-160812T0830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
JOHNSON IA-LINN IA-IOWA IA-BENTON IA-
1115 PM CDT THU AUG 11 2016

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 330 AM CDT FOR
JOHNSON...LINN...IOWA AND BENTON COUNTIES...

AT 1113 PM CDT...LOCAL LAW ENFORCEMENT REPORTED FLASH FLOODING...WITH
A ROAD CLOSURE IN HIAWATHA AND LOCALIZED FLOODING AROUND CEDAR RAPIDS.
3 TO 5 INCHES OF RAIN HAVE FALLEN SO FAR OVER MUCH OF THE WARNED AREA. 
MORE FLASH FLOODING IS EXPECTED OVERNIGHT.

SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
CEDAR RAPIDS...IOWA CITY...VINTON...MARENGO...WEST BRANCH...MARION...
CORALVILLE...NORTH LIBERTY...HIAWATHA...MOUNT VERNON...ROBINS...
WILLIAMSBURG...BELLE PLAINE...CENTER POINT...LISBON...FAIRFAX...SOLON...
TIFFIN...ELY AND ATKINS.

ADDITIONAL RAINFALL AMOUNTS OF 1 TO 3 INCHES ARE POSSIBLE IN
THE WARNED AREA THROUGH THE EARLY MORNING HOURS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES AS
WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.

&&

LAT...LON 4230 9230 4229 9136 4162 9137 4163 9230

$$

RP KINNEY
760 
WGUS73 KDVN 120553
FFSDVN

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA/IL
1253 AM CDT FRI AUG 12 2016

IAC011-095-103-113-120830-
/O.CON.KDVN.FF.W.0021.000000T0000Z-160812T0830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
JOHNSON IA-LINN IA-IOWA IA-BENTON IA-
1253 AM CDT FRI AUG 12 2016

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 330 AM CDT FOR
JOHNSON...LINN...IOWA AND BENTON COUNTIES...

AT 1248 AM CDT...DOPPLER RADAR INDICATED BETWEEN 3 AND 5.5 INCHES OF
RAIN HAD FALLEN ACROSS MUCH OF THE WARNED AREA. THE HARDEST HIT AREA
APPEARS TO BE SOUTHERN LINN COUNTY AND NORTHERN JOHNSON COUNTY.
WHILE RAIN RATES HAVE DIMINISHED...THE THREAT OF FLASH FLOODING
PERSISTS.

LOCATIONS UNDER THREAT OF FLASH FLOODING INCLUDE... CEDAR
RAPIDS...IOWA CITY...VINTON...MARENGO...WEST BRANCH...MARION...
CORALVILLE...NORTH LIBERTY...HIAWATHA...MOUNT VERNON...ROBINS...
WILLIAMSBURG...BELLE PLAINE...CENTER POINT...LISBON...FAIRFAX...
SOLON...TIFFIN...ELY AND ATKINS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING...PARTICULARLY ON RURAL ROADS.

IN HILLY TERRAIN THERE ARE LOW WATER CROSSINGS WHICH ARE POTENTIALLY
DANGEROUS IN HEAVY RAIN. DO NOT ATTEMPT TO CROSS FLOODED ROADS. FIND
AN ALTERNATE ROUTE.

PLEASE REPORT FLOODING TO YOUR LOCAL LAW ENFORCEMENT AGENCY WHEN YOU
CAN DO SO SAFELY.

&&

LAT...LON 4230 9230 4229 9136 4162 9137 4163 9230

$$

WOLF
651 
WGUS73 KDVN 120828
FFSDVN

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA/IL
328 AM CDT FRI AUG 12 2016

IAC011-095-103-113-120837-
/O.EXP.KDVN.FF.W.0021.000000T0000Z-160812T0830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
JOHNSON IA-LINN IA-IOWA IA-BENTON IA-
328 AM CDT FRI AUG 12 2016

...THE FLASH FLOOD WARNING FOR JOHNSON...LINN...IOWA AND BENTON
COUNTIES WILL EXPIRE AT 330 AM CDT...

THE HEAVY RAIN HAS ENDED ALTHOUGH LIGHT RAIN WILL CONTINUE FOR A FEW
HOURS. THUS FLASH FLOODING IS NO LONGER EXPECTED TO POSE A THREAT.
PLEASE CONTINUE TO HEED ANY REMAINING ROAD CLOSURES.

LAT...LON 4230 9230 4229 9136 4162 9137 4163 9230

$$

WOLF

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 11, 7:00 PM CDTSpecial Weather StatementDVNBenton, Buchanan, Delaware, Dubuque, Jackson, Jones and 1 more60 min
Aug 11, 7:48 PM CDTFlash Flood WarningDVNLinn3 hr
Aug 11, 8:16 PM CDTSpecial Weather StatementDVNIowa, Jackson, Jones59 min
Aug 11, 8:57 PM CDTSpecial Weather StatementDVNBenton, Cedar, Clinton, Iowa, Jackson, Johnson and 3 more93 min
Aug 11, 9:15 PM CDTRiver Flood WatchDVNClinton, Scott4 days
Aug 11, 9:53 PM CDTRiver Flood WatchDVNIowa, Johnson4 days
Aug 11, 9:53 PM CDTRiver Flood WatchDVNJohnson, Washington4 days
Aug 11, 10:33 PM CDTSpecial Weather StatementDVNBenton, Buchanan, Cedar, Clinton, Delaware, Dubuque and 10 more87 min
Aug 11, 11:05 PM CDTFlash Flood WarningDVNCedar6 hr
Aug 11, 11:53 PM CDTSpecial Weather StatementDVNClinton, Des Moines, Henry, Jefferson, Keokuk, Louisa and 4 more67 min
Aug 12, 2:29 AM CDTSpecial Weather StatementDVNDes Moines, Henry, Jefferson, Louisa, Van Buren2 hr
Aug 12, 7:26 AM CDTRiver Flood WarningDVNClinton, Scott4 days
Aug 12, 8:50 AM CDTRiver Flood WarningDVNCedar, Louisa, Muscatine4 days
Aug 12, 8:50 AM CDTRiver Flood WarningDVNIowa4 days
Aug 12, 8:50 AM CDTRiver Flood WarningDVNJohnson, Washington4 days
Aug 12, 10:05 AM CDTAreal Flood WarningDVNBenton, Buchanan, Cedar, Clinton, Iowa, Johnson and 4 more9 hr
Aug 12, 10:44 AM CDTRiver Flood WatchDVNLouisa6 days
Aug 12, 10:44 AM CDTRiver Flood WatchDVNLouisa5 days
Aug 12, 10:44 AM CDTRiver Flood WatchDVNLouisa5 days

Nearby

Flash Flood Warnings in Iowa, 2016Every flash flood warning in 2016

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.