Alert archive / Illinois / Flash Flood Warnings in 2012

Flash Flood Warning 11, NWS Quad Cities, IA

August 4, 2012Scott County, Iowa; Henry County, Rock Island County, Illinois

NWS Quad Cities, IA issued this flash flood warning at Aug 4, 2012, 1:39 PM CDT for Scott County, Iowa; Henry County, Rock Island County, Illinois. It was in force for 70 min. 3 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 4, 2012, 1:39 PM CDT (18:39 UTC)
Expired
Aug 4, 2012, 2:49 PM CDT
In force
70 min
Issued by
NWS Quad Cities, IA
Area
Storm-based polygon
Flood severity
None

Counties Scott County, IA, Henry County, IL, Rock Island County, IL

The radar

The Quad Cities radar (KDVN), 9 km from the middle of the area, began a volume at 18:41 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 4, 1:50 PM CDTHEAVY RAIN 1.65 N Davenport, IA15 MINUTES FROM DVN AIRPORT ASOS
Aug 4, 2:27 PM CDTHEAVY RAIN 1.131 W Bettendorf, IAALSO WINDS ESTIMATED AROUND 40 MPH.
Aug 4, 2:40 PM CDTHEAVY RAIN 2.456 N Davenport, IARAIN TOTAL FROM 138PM TO 240 PM. PEAK WIND GUST 52 MPH FROM THE WEST NORTHWEST AT 136PM.

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 12:00Z, 6.7 hours before the alert went out and 9 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 2012-08-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1247 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 12:00Z on 2012-08-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 32 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
1247 J/kg
Mixed-layer CIN
-144 J/kg
Mixed-layer LCL
1158 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
32 m²/s²
0-3 km storm-relative helicity
52 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.8

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

015 
WGUS53 KDVN 041839
FFWDVN
IAC163-ILC073-161-042145-
/O.NEW.KDVN.FF.W.0011.120804T1839Z-120804T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
139 PM CDT SAT AUG 4 2012

THE NATIONAL WEATHER SERVICE IN THE QUAD CITIES HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHERN SCOTT COUNTY IN EAST CENTRAL IOWA...
  THIS INCLUDES THE CITIES OF...DAVENPORT...BETTENDORF...
  WEST CENTRAL HENRY COUNTY IN NORTHWEST ILLINOIS...
  EASTERN ROCK ISLAND COUNTY IN NORTHWEST ILLINOIS...
  THIS INCLUDES THE CITIES OF...ROCK ISLAND...MOLINE...EAST MOLINE...

* UNTIL 445 PM CDT

* AT 137 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
FLASH FLOODING FROM A THUNDERSTORM OVER THE WARNED AREA.  INTENSE 
RAINFALL FROM THUNDERSTORMS WILL CAUSE URBAN AREA FLASH FLOODING.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO THE ENTIRE 
QUAD CITIES METRO AREA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DO NOT DRIVE ON FLOODED ROADS. MOST FATALITIES OCCUR IN VEHICLES
SWEPT AWAY IN FLOOD WATERS AS SHALLOW AS 1 FOOT.

FLOODING OF SMALL STREAMS AND CREEKS...STREETS...UNDERPASSES AND LOW
LYING URBAN AREAS IS LIKELY.

&&

LAT...LON 4165 9074 4166 9024 4137 9023 4137 9073

$$

WOLF
1 follow-up statement
756 
WGUS73 KDVN 041949
FFSDVN

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
249 PM CDT SAT AUG 4 2012

IAC163-ILC073-161-041956-
/O.CAN.KDVN.FF.W.0011.000000T0000Z-120804T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SCOTT IA-HENRY IL-ROCK ISLAND IL-
249 PM CDT SAT AUG 4 2012

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR CENTRAL ROCK
ISLAND...WEST CENTRAL HENRY AND SOUTHERN SCOTT COUNTIES...

LAT...LON 4165 9074 4166 9024 4137 9023 4137 9073

$$

WOLF

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 4, 11:18 AM CDTSpecial Weather StatementDVNBenton, Buchanan, Delaware, Henry, Iowa, Jefferson and 4 more102 min
Aug 4, 12:05 PM CDTSevere Thunderstorm WarningDVNBenton, Buchanan, Delaware, Iowa, Johnson, Keokuk and 2 more55 min
Aug 4, 12:38 PM CDTSevere Thunderstorm WarningDVNCedar, Clinton, Delaware, Dubuque, Jackson, Johnson and 5 more67 min
Aug 4, 12:59 PM CDTSevere Thunderstorm WarningDVNDes Moines, Louisa, Muscatine, Scott76 min
Aug 4, 1:19 PM CDTFlash Flood WarningDVNLinn82 min
Aug 4, 1:36 PM CDTSevere Thunderstorm WarningDVNBureau, Carroll, Henry, Jo Daviess, Putnam, Stephenson and 1 more84 min

Nearby

Flash Flood Warnings in Illinois, 2012Flash Flood Warnings in Iowa, 2012Every flash flood warning in 2012

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.