Alert archive / Iowa / Flash Flood Warnings in 2011

Flash Flood Warning 19, NWS Des Moines, IA

June 18, 2011Crawford County, Iowa

NWS Des Moines, IA issued this flash flood warning at Jun 18, 2011, 10:34 AM CDT for Crawford 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
Jun 18, 2011, 10:34 AM CDT (15:34 UTC)
Expired
Jun 18, 2011, 2:30 PM CDT
In force
4 hr
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Flood severity
None

County Crawford County, IA

The radar

The Omaha radar (KOAX), 106 km from the middle of the area, began a volume at 15:38 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

Omaha, NE (KOAX), launched 12:00Z, 3.6 hours before the alert went out and 106 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, Omaha, NE at 12:00Z on 2011-06-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 88 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 12:00Z on 2011-06-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -80 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
88 J/kg
Mixed-layer CIN
-164 J/kg
Mixed-layer LCL
802 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
-80 m²/s²
0-3 km storm-relative helicity
-27 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.

326 
WGUS53 KDMX 181534
FFWDMX
IAC047-181930-
/O.NEW.KDMX.FF.W.0019.110618T1534Z-110618T1930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
1034 AM CDT SAT JUN 18 2011

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTH CENTRAL CRAWFORD COUNTY IN WEST CENTRAL IOWA...

* UNTIL 230 PM CDT

* AT 1033 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE      
  WARNED AREA. RAINFALL TOTALS ARE ESTIMATED TO BE BETWEEN 4 TO 6    
  INCHES.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. FLASH FLOODING IS EXPECTED TO OCCUR OVER MAINLY RURAL AREAS
  OF SOUTH CENTRAL CRAWFORD COUNTY...INCLUDING THE TOWN OF BUCK
  GROVE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...AS WELL AS FARMLAND ALONG THE
BANKS OF CREEKS AND STREAMS.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. TURN AROUND...DONT DROWN.

&&

LAT...LON 4193 9542 4194 9529 4186 9528 4186 9529
      4186 9545

$$

WILKINS
2 follow-up statements
807 
WGUS73 KDMX 181817
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
117 PM CDT SAT JUN 18 2011

IAC047-181930-
/O.CON.KDMX.FF.W.0019.000000T0000Z-110618T1930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CRAWFORD IA-
117 PM CDT SAT JUN 18 2011

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR SOUTH CENTRAL CRAWFORD
COUNTY UNTIL 230 PM CDT...

AT 115 PM CDT...RAIN HAS ENDED ACROSS THE WARNED AREA AND CONDITIONS 
SHOULD BE IMPROVING...BUT ADDITIONAL RAINFALL NORTH OF THE AREA 
CLOUD LEAD TO AREAS OF FLASH FLOODING.

FLASH  IS EXPECTED TO OCCUR OVER MAINLY RURAL AREAS OF SOUTH CENTRAL
CRAWFORD COUNTY...INCLUDING THE TOWN OF BUCK GROVE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS... AS WELL AS FARMLAND ALONG THE
BANKS OF CREEKS AND STREAMS.

A FLASH FLOOD WARNING MEANS THAT FLASH FLOODING IS IMMINENT OR
OCCURRING. IF YOU ARE IN THE WARNING AREA...MOVE TO HIGHER GROUND
IMMEDIATELY. RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE
IMMEDIATE PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO
CROSS SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.

&&

LAT...LON 4193 9542 4194 9529 4186 9528 4186 9529
      4186 9545

$$

WILKINS
719 
WGUS73 KDMX 181920
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
220 PM CDT SAT JUN 18 2011

IAC047-181935-
/O.EXP.KDMX.FF.W.0019.000000T0000Z-110618T1930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CRAWFORD IA-
220 PM CDT SAT JUN 18 2011

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR SOUTH CENTRAL
CRAWFORD COUNTY WILL BE ALLOWED TO EXPIRE AT 230 PM CDT...

EXCESS RUNOFF FROM HEAVY RAIN HAS ENDED OVER THE WARNED AREA. STREAMS
AND CREEKS IN THE WARNED AREA HAVE RECEDED OR WERE BEGINNING TO
RECEDE...ENDING THE FLOOD THREAT. IF FLOODING HAS BEEN OBSERVED...
PLEASE REPORT IT TO YOUR LOCAL LAW ENFORCEMENT AGENCY.

LAT...LON 4193 9542 4194 9529 4186 9528 4186 9529
      4186 9545

$$

WILKINS

The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 17, 9:00 PM CDTSevere Thunderstorm WarningDMXKossuth15 min
Jun 18, 7:29 AM CDTSevere Thunderstorm WarningDMXDecatur, Ringgold, Wayne31 min

Nearby

Flash Flood Warnings in Iowa, 2011Every 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.