Alert archive / Iowa / Flash Flood Warnings in 2016

Flash Flood Warning 28, NWS Des Moines, IA

September 21, 2016Cerro Gordo County, Iowa

NWS Des Moines, IA issued this flash flood warning at Sep 21, 2016, 4:50 PM CDT for Cerro Gordo County, Iowa. It was in force for 6 hr. 1 report 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
Sep 21, 2016, 4:50 PM CDT (21:50 UTC)
Expired
Sep 21, 2016, 10:45 PM CDT
In force
6 hr
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Flood severity
None

County Cerro Gordo County, IA

The radar

The Des Moines radar (KDMX), 149 km from the middle of the area, began a volume at 21:51 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
Sep 21, 7:00 PM CDTFLASH FLOODRockwell, IADELAYED REPORT. COUNTY ROADS FLOODED NEAR ROCKWELL. .

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 9.8 hours before the alert went out and 210 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, Minneapolis, MN at 12:00Z on 2016-09-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 515 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, Minneapolis, MN at 12:00Z on 2016-09-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 17 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
515 J/kg
Mixed-layer CIN
-331 J/kg
Mixed-layer LCL
738 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
17 m²/s²
0-3 km storm-relative helicity
136 m²/s²
Significant tornado parameter
0.0
Supercell composite
8.5

Open this sounding in Storm Lab

The text

As transmitted.

266 
WGUS53 KDMX 212150
FFWDMX
IAC033-220345-
/O.NEW.KDMX.FF.W.0028.160921T2150Z-160922T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
450 PM CDT WED SEP 21 2016

THE NATIONAL WEATHER SERVICE IN DES MOINES  HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHEASTERN CERRO GORDO COUNTY IN NORTH CENTRAL IOWA...

* UNTIL 1045 PM CDT.

* AT 449 PM CDT...DOPPLER RADAR INDICATED THUNDERSTORMS PRODUCING
  HEAVY RAIN ACROSS THE WARNED AREA. UP TO THREE INCHES OF RAIN HAVE
  ALREADY FALLEN. FLASH FLOODING IS EXPECTED TO BEGIN SHORTLY.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  NORA SPRINGS...ROCKWELL...DOUGHERTY AND PORTLAND. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...FARMLAND...AND OTHER LOW LYING
SPOTS.

&&

LAT...LON 4292 9302 4291 9324 4303 9328 4320 9303

$$

SKOW
1 follow-up statement
375 
WGUS73 KDMX 220021
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
721 PM CDT WED SEP 21 2016

IAC033-220345-
/O.CON.KDMX.FF.W.0028.000000T0000Z-160922T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CERRO GORDO IA-
721 PM CDT WED SEP 21 2016

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1045 PM CDT FOR
SOUTHEASTERN CERRO GORDO COUNTY...

AT 720 PM CDT...DOPPLER RADAR INDICATED THUNDERSTORMS PRODUCING
HEAVY RAIN ACROSS THE WARNED AREA. FOUR TO SIX INCHES OF RAIN HAVE
FALLEN. FLASH FLOODING IS EXPECTED TO BEGIN SHORTLY IF IT HAS NOT
ALREADY BEGUN.

SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
NORA SPRINGS...ROCKWELL...DOUGHERTY AND PORTLAND. 

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...COUNTRY ROADS...FARMLAND...AND OTHER LOW LYING
SPOTS.

&&

LAT...LON 4292 9302 4291 9324 4303 9328 4320 9303

$$

SKOW

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 21, 3:26 PM CDTSpecial Weather StatementDMXCerro Gordo49 min
Sep 21, 3:32 PM CDTSevere Thunderstorm WarningDMXCerro Gordo43 min
Sep 21, 4:23 PM CDTSevere Thunderstorm WarningDMXCerro Gordo37 min
Sep 21, 4:57 PM CDTSevere Thunderstorm WarningDMXCerro Gordo31 min
Sep 21, 5:13 PM CDTSevere Thunderstorm WarningDMXButler, Franklin47 min
Sep 21, 5:19 PM CDTTornado WarningDMXButler56 min
Sep 21, 5:45 PM CDTSevere Thunderstorm WarningDMXCerro Gordo, Worth45 min
Sep 21, 6:17 PM CDTTornado WarningDMXButler43 min
Sep 21, 6:33 PM CDTFlash Flood WarningDMXCerro Gordo, Worth6 hr
Sep 21, 6:44 PM CDTSevere Thunderstorm WarningDMXCerro Gordo46 min
Sep 21, 6:58 PM CDTFlash Flood WarningDMXButler12 hr
Sep 21, 6:59 PM CDTTornado WarningDMXBremer, Butler46 min

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.