Alert archive / Iowa / Flash Flood Warnings in 2011

Flash Flood Warning 1, NWS Quad Cities, IA

February 21, 2011Benton County, Iowa

NWS Quad Cities, IA issued this flash flood warning at Feb 21, 2011, 12:16 PM CST for Benton County, Iowa. It was in force for 6 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: Feb 21, 2011, 12:16 PM CST (18:16 UTC)
Expired: Feb 21, 2011, 6:15 PM CST
In force: 6 hr
Issued by: NWS Quad Cities, IA
Area: Storm-based polygon
Flood severity: None

County Benton County, IA

The radar

The Quad Cities radar (KDVN), 138 km from the middle of the area, began a volume at 18:16 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, 6.3 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 524 m above ground
0-6 km bulk shear: 105 kt
0-1 km storm-relative helicity: -21 m²/s²
0-3 km storm-relative helicity: -29 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

978 
WGUS53 KDVN 211816
FFWDVN
IAC011-220015-
/O.NEW.KDVN.FF.W.0001.110221T1816Z-110222T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
1216 PM CST MON FEB 21 2011

THE NATIONAL WEATHER SERVICE IN THE QUAD CITIES HAS ISSUED A

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

* UNTIL 615 PM CST

* AT 1212 PM CST...LOCAL LAW ENFORCEMENT OFFICIALS REPORTED FLASH
  FLOODING FROM AN ICE JAM ALONG THE CEDAR RIVER SOUTHEAST OF
  MOUNT AUBURN.

* THE RIVER IS RISING QUICKLY ON A GRAVEL ROAD BETWEEN 54TH STREET
  DRIVE AND 55TH STREET. THE SHERIFF OFFICE IS IN THE PROCESS OF
  EVACUATING CABINS ALONG THE RIVER BY BOAT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

ICE JAMS CAN DEVELOP AND BREAK UP QUICKLY...RESULTING IN RAPID
FLOODING IMMEDIATELY UP OR DOWNSTREAM OF THE JAM. BE PREPARED TO MOVE
TO A SAFER LOCATION IF FLOODING DEVELOPS.

&&

LAT...LON 4221 9207 4225 9205 4224 9203 4218 9202
      4217 9203

$$

08

2 follow-up statements

504 
WGUS73 KDVN 212151
FFSDVN

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
351 PM CST MON FEB 21 2011

IAC011-220015-
/O.CON.KDVN.FF.W.0001.000000T0000Z-110222T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BENTON IA-
351 PM CST MON FEB 21 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 615 PM CST FOR NORTH
CENTRAL BENTON COUNTY ALONG THE CEDAR RIVER...

AT 347 PM CST...LOCAL LAW ENFORCEMENT OFFICIALS REPORTED THE ICE JAM 
REMAINS IN PLACE ALONG THE CEDAR RIVER. FLOODING CONTINUES BETWEEN 
54TH STREET DRIVE AND 55TH STREET WITH SEVERAL CABINS SURROUNDING BY 
WATER.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

ICE JAMS CAN DEVELOP AND BREAK UP QUICKLY... RESULTING IN RAPID
FLOODING IMMEDIATELY UP OR DOWN STREAM OF THE JAM. BE PREPARED TO
MOVE TO A SAFER LOCATION IF FLOODING DEVELOPS.

&&

LAT...LON 4221 9207 4225 9205 4224 9203 4218 9202
      4217 9203

$$

08

793 
WGUS73 KDVN 220013
FFSDVN

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
613 PM CST MON FEB 21 2011

IAC011-220018-
/O.EXP.KDVN.FF.W.0001.000000T0000Z-110222T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BENTON IA-
613 PM CST MON FEB 21 2011

...THE FLASH FLOOD WARNING WILL EXPIRE AT 615 PM CST FOR NORTH
CENTRAL BENTON COUNTY...

THE ICE JAM CONTINUES WITH STEADY TO LOCALLY HIGHER WATER LEVELS ON 
OR NEAR THE GRAVEL ROAD BETWEEN 54TH STREET DRIVE AND 55TH STREET.

THIS PRODUCT WILL BE ALLOWED TO EXPIRE AND WILL BE REPLACED WITH A 
FLOOD WARNING. 

LAT...LON 4221 9207 4225 9205 4224 9203 4218 9202
      4217 9203

$$

NICHOLS

Nearby

Flash Flood Warnings in Iowa, 2011 Every flash flood warning in 2011

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.