Alert archive / Iowa / Flash Flood Warnings in 2021

Flash Flood Warning 12, NWS Quad Cities, IA

August 12, 2021Van Buren County, Iowa

NWS Quad Cities, IA issued this flash flood warning at Aug 12, 2021, 9:23 AM CDT for Van Buren County, Iowa. It was in force for 4 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
Aug 12, 2021, 9:23 AM CDT (14:23 UTC)
Expired
Aug 12, 2021, 1:31 PM CDT
In force
4 hr
Issued by
NWS Quad Cities, IA
Area
Storm-based polygon
Flood severity
None

County Van Buren County, IA

The radar

The Quad Cities radar (KDVN), 138 km from the middle of the area, began a volume at 14:25 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 12:00Z, 2.4 hours before the alert went out and 144 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 12:00Z on 2021-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 2021-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 27 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2463 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
27 m²/s²
0-3 km storm-relative helicity
71 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

018 
WGUS53 KDVN 121423
FFWDVN
IAC177-122030-
/O.NEW.KDVN.FF.W.0012.210812T1423Z-210812T2030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Quad Cities IA IL
923 AM CDT Thu Aug 12 2021

The National Weather Service in Quad Cities has issued a

* Flash Flood Warning for...
  Northern Van Buren County in southeastern Iowa...

* Until 330 PM CDT Thursday.

* At 923 AM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 3 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.

  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...
  Keosauqua, Birmingham, Stockport, Bentonsport/Vernon, Douds, 
  Leando, Kilbourn, Mount Zion, Van Buren County Fairgrounds, 
  Keosauqua Airport, Utica, Lebanon, Morris Park and Selma.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

&&

LAT...LON 4084 9172 4071 9172 4074 9218 4083 9218
      4088 9218 4090 9218 4090 9172 4089 9172
      4088 9172 4086 9172 4085 9172

FLASH FLOOD...RADAR INDICATED

$$

Gross
2 follow-up statements
997 
WGUS73 KDVN 121633
FFSDVN

Flash Flood Statement
National Weather Service Quad Cities IA IL
1133 AM CDT Thu Aug 12 2021

IAC177-122030-
/O.CON.KDVN.FF.W.0012.000000T0000Z-210812T2030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Van Buren IA-
1133 AM CDT Thu Aug 12 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 330 PM CDT THIS 
AFTERNOON FOR NORTHERN VAN BUREN COUNTY...

At 1133 AM CDT, Doppler radar and automated rain gauges indicated 
thunderstorms producing heavy rain across the warned area. Two 
inches of rain has fallen in Farmington in past 3 hours. Additional 
rainfall amounts up to 1 inch 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...
  Keosauqua, Birmingham, Stockport, Bentonsport/Vernon, Douds, 
  Leando, Kilbourn, Mount Zion, Van Buren County Fairgrounds, 
  Keosauqua Airport, Utica, Lebanon, Morris Park and Selma.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 4084 9172 4071 9172 4074 9218 4083 9218
      4088 9218 4090 9218 4090 9172 4089 9172
      4088 9172 4086 9172 4085 9172

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

Gross
074 
WGUS73 KDVN 121831
FFSDVN

Flash Flood Statement
National Weather Service Quad Cities IA IL
131 PM CDT Thu Aug 12 2021

IAC177-121841-
/O.CAN.KDVN.FF.W.0012.000000T0000Z-210812T2030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Van Buren IA-
131 PM CDT Thu Aug 12 2021

...FLASH FLOOD WARNING IS CANCELLED FOR NORTHERN VAN BUREN COUNTY...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

A Flash Flood Watch remains in effect until 700 AM CDT Friday for 
portions of west central Illinois, southeast Iowa and northeast 
Missouri.

LAT...LON 4084 9172 4071 9172 4074 9218 4083 9218
      4088 9218 4090 9218 4090 9172 4089 9172
      4088 9172 4086 9172 4085 9172

$$

Gross

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 12, 2:09 AM CDTSpecial Weather StatementDVNLee21 min
Aug 12, 2:57 AM CDTHeat AdvisoryDVNLee8 hr
Aug 12, 7:24 AM CDTSpecial Weather StatementDVNVan Buren36 min
Aug 12, 7:26 AM CDTSevere Thunderstorm WarningDVNVan Buren33 min
Aug 12, 9:10 AM CDTSpecial Weather StatementDVNVan Buren50 min
Aug 12, 9:54 AM CDTSpecial Weather StatementDVNLee, Van Buren96 min
Aug 12, 10:32 AM CDTFlash Flood WarningDVNLee, Van Buren6 hr
Aug 12, 11:29 AM CDTSpecial Weather StatementDVNLee, Van Buren91 min
Aug 12, 12:44 PM CDTFlash Flood WatchDVNDes Moines, Lee, Van Buren8 hr

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.