Alert archive / Iowa / Flash Flood Warnings in 2007

Flash Flood Warning 49, NWS Des Moines, IA

August 8, 2007Mahaska County, Iowa

NWS Des Moines, IA issued this flash flood warning at Aug 8, 2007, 8:54 PM CDT for Mahaska County, Iowa. It took effect at Aug 8, 2007, 8:59 PM CDT. It was in force for 6 hr. 3 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Aug 8, 2007, 8:54 PM CDT (01:54 UTC)
In effect from
Aug 8, 2007, 8:59 PM CDT
Expired
Aug 9, 2007, 3:00 AM CDT
In force
6 hr
Issued by
NWS Des Moines, IA
Area
Whole counties

County Mahaska County, IA

The radar

The Des Moines radar (KDMX), 100 km from the middle of the area, began a volume at 01:56 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 8, 9:01 PM CDTFLASH FLOODOskaloosa, IAWATER FLOWING OVER ROAD...WAS IMPASSABLE AT THE 600 BLOCK OF GEORGE AVENUE WEST IN OSKALOOSA.
Aug 8, 11:10 PM CDTFLASH FLOOD2 Nne New Sharon, IAWATER FROM THE SOUTH SKUNK RIVER FLOWING OVER 110TH STREET. 2200 BLOCK. FROM MAHASKA COUNTY SHERIFF.
Aug 8, 11:10 PM CDTFLASH FLOOD3 Nne Oskaloosa, IAWATER FLOWING OUT OF FARM FIELD OVER MERINO ROAD. 2300 BLOCK. FROM MAHASKA COUNTY SHERIFF.

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 00:00Z, 1.9 hours before the alert went out and 181 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 00:00Z on 2007-08-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 194 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 00:00Z on 2007-08-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 79 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
194 J/kg
Mixed-layer CIN
-74 J/kg
Mixed-layer LCL
1146 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
79 m²/s²
0-3 km storm-relative helicity
158 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.2

Open this sounding in Storm Lab

The text

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

000 
WGUS53 KDMX 090159
FFWDMX
IAC123-090800-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
854 PM CDT WED AUG 8 2007

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  MAHASKA COUNTY IN SOUTH CENTRAL IOWA...

* UNTIL 300 AM CDT THURSDAY

* AT 852 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  FLASH FLOODING FROM A THUNDERSTORM OVER THE WARNED AREA.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO NEW SHARON
  AND OSKALOOSA.

ADDITIONAL RAINFALL AMOUNTS OF ONE TO THREE INCHES MAY IMPACT 
MAHASKA COUNTY THROUGH AT LEAST MIDNIGHT AS SEVERAL ROUND OF 
THUNDERSTORMS PASS THROUGH SOUTHEAST IOWA.  THESE HEAVY RAINS WILL 
BE IN ADDITION TO WHAT OCCURRED OVER THE PAST FEW DAYS...AS WELL AS 
AROUND TWO INCHES WHICH ALREADY FELL EARLIER THIS EVENING IN A SHORT 
PERIOD OF TIME.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY
ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW
LYING AREAS ARE SUBJECT TO FLOODING.  AT 854 PM...AN AMATEUR RADIO 
OPERATOR REPORTED TORRENTIAL RAINS JUST SOUTH OF OSKALOOSA.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. MOVE
UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS
SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

LAT...LON 4149 9285 4150 9243 4116 9245 4117 9286
TIME...MOT...LOC 0154Z 180DEG 0KT 4133 9249

$$

SMALL
5 follow-up statements
000 
WGUS73 KDMX 090259
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
956 PM CDT WED AUG 8 2007

IAC123-090800-
MAHASKA IA-
956 PM CDT WED AUG 8 2007

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 300 AM CDT FOR
MAHASKA COUNTY...

AT 951 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE MODERATE TO HEAVY RAINS OVER MAHASKA COUNTY.  RAINFALL 
AMOUNTS OF ONE TO THREE INCHES OF RAIN HAVE LIKELY FALLEN OVER THE 
COUNTY SINCE LATE THIS AFTERNOON...INCLUDING INSTANCES WHERE ONE TO 
TWO INCHES OF THAT RAIN FELL IN AN HOUR OR LESS.  ADDITIONAL 
MODERATE RAIN WITH RAINFALL RATES UP TO A HALF INCH PER HOUR WILL 
CONTINUE UNTIL DIMINISHING BY MIDNIGHT.

AT 901 PM...THE MAHASKA COUNTY SHERIFF REPORTED FLOODING AND WATER 
FLOWING OVER THE ROAD IN THE 600 BLOCK OF GEORGE AVENUE WEST IN 
OSKALOOSA...AND THE 1500 BLOCK OF THIRD AVENUE EAST WITH STALLED 
VEHICLES.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY
ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW
LYING AREAS ARE SUBJECT TO FLOODING.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. MOVE
UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS
SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

TO REPORT FLOODING...HAVE THE NEAREST LAW ENFORCEMENT AGENCY RELAY
YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN DES
MOINES.

LAT...LON 4149 9285 4150 9243 4116 9245 4117 9286
TIME...MOT...LOC 0253Z 180DEG 0KT 4133 9249

$$

SMALL
000 
WGUS73 KDMX 090424
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
1124 PM CDT WED AUG 8 2007

IAC123-090800-
MAHASKA IA-
1124 PM CDT WED AUG 8 2007

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 300 AM CDT FOR
MAHASKA COUNTY...

AT 1112 PM CDT...THE MAHASKA COUNTY SHERIFF CONTINUED TO REPORT 
FLOODING ACROSS THEIR COUNTY.  WATER FROM THE SOUTH SKUNK RIVER WAS 
REPORTED FLOWING OVER THE 2200 BLOCK OF 110TH STREET...STANDING 
WATER WAS ON HIGHWAY 63 NORTH OF TOWN...AND WATER WAS OVER THE 2300 
BLOCK OF MARINO ROAD FLOWING OUT OF A FARM FIELD.  NUMEROUS VEHICLES 
WERE STRANDED IN FLOWING OR STANDING WATER.

POWER OUTAGES WERE REPORTED AS WELL.  PEOPLE WHO DEPEND ON SUMP 
PUMPS TO ELIMINATE EXCESS WATER SHOULD CHECK THEIR BASEMENT OR OTHER 
LOW AREAS FOR RISING WATER OR FLOODING.  A SCHOOLNET RAIN GAGE IN 
OSKALOOSA HAS REPORTED 3.84 INCHES OF RAIN TODAY...MUCH OF IT 
FALLING SINCE 400 PM.  THIS MAINLY OCCURRED DURING THREE INSTANCES 
WHERE ROUGHLY AN INCH OF RAIN FELL IN AN HOUR OR LESS.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL 
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY
ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW
LYING AREAS ARE SUBJECT TO FLOODING.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. MOVE
UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS
SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

LAT...LON 4149 9285 4150 9243 4116 9245 4117 9286
TIME...MOT...LOC 0413Z 180DEG 0KT 4133 9249

$$

SMALL
000 
WGUS73 KDMX 090539
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
1239 AM CDT THU AUG 9 2007

IAC123-090800-
MAHASKA IA-
1239 AM CDT THU AUG 9 2007

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 300 AM CDT FOR
MAHASKA COUNTY...

AT 1229 AM CDT...FLOODING CONTINUED ACROSS PORTIONS OF MAHASKA 
COUNTY.  REPORTS FROM THE MAHASKA COUNTY SHERIFF AT AROUND 1100 PM 
INDICATED THAT WATER FROM THE NORTH SKUNK RIVER WAS REPORTED FLOWING 
OVER THE 2200 BLOCK OF 110TH STREET...STANDING WATER WAS ON HIGHWAY 
63 NORTH OF TOWN...AND WATER WAS OVER THE 2300 BLOCK OF MERINO ROAD 
FLOWING OUT OF A FARM FIELD.  NUMEROUS VEHICLES HAD BEEN STRANDED IN 
FLOWING OR STANDING WATER.

RAIN GAGES HAVE REPORTED AROUND FOUR INCHES OF RAIN IN THE FAR 
EASTERN PORTION OF THE COUNTY EAST OF TRACY...AND 3.75 INCHES IN 
OSKALOOSA.  NATIONAL WEATHER SERVICE DOPPLER RADAR ESTIMATES 
INDICATED THAT UP TO FIVE INCHES OF RAIN MAY HAVE FALLEN IN OTHER 
LOCATIONS.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY
ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW
LYING AREAS ARE SUBJECT TO FLOODING.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. MOVE
UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS
SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

LAT...LON 4149 9285 4150 9243 4116 9245 4117 9286
TIME...MOT...LOC 0532Z 180DEG 0KT 4133 9249

$$

SMALL
000 
WGUS73 KDMX 090644
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
140 AM CDT THU AUG 9 2007

IAC123-090800-
MAHASKA IA-
140 AM CDT THU AUG 9 2007

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 300 AM CDT FOR
MAHASKA COUNTY...

AT 140 AM CDT...FLOODING CONTINUED ACROSS PORTIONS OF MAHASKA 
COUNTY.  REPORTS FROM THE MAHASKA COUNTY SHERIFF AT AROUND 1100 PM 
INDICATED THAT WATER FROM THE NORTH SKUNK RIVER WAS REPORTED FLOWING 
OVER THE 2200 BLOCK OF 110TH STREET AND WATER WAS OVER THE 2300 
BLOCK OF MERINO ROAD FLOWING OUT OF A FARM FIELD. NUMEROUS VEHICLES 
HAD BEEN STRANDED IN FLOWING OR STANDING WATER. HOWEVER AT 135 AM 
THE SHERIFFS DEPARTMENT REPORTED THAT HIGHWAY 63 WAS NO LONGER 
CLOSED.

RAIN GAGES HAVE REPORTED AROUND FOUR INCHES OF RAIN IN THE FAR 
EASTERN PORTION OF THE COUNTY EAST OF TRACY...AND 3.75 INCHES IN 
OSKALOOSA.  NATIONAL WEATHER SERVICE DOPPLER RADAR ESTIMATES 
INDICATED THAT UP TO FIVE INCHES OF RAIN MAY HAVE FALLEN IN OTHER 
LOCATIONS. LITTLE IF ANY ADDITIONAL RAIN IS EXPECTED ACROSS THE 
COUNTY OVERNIGHT.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY
ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW
LYING AREAS ARE SUBJECT TO FLOODING.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. MOVE
UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS
SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

LAT...LON 4149 9285 4150 9243 4116 9245 4117 9286
TIME...MOT...LOC 0532Z 180DEG 0KT 4133 9249

$$

MOYER/SMALL
000 
WGUS73 KDMX 090803
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
301 AM CDT THU AUG 9 2007

IAC123-090811-
MAHASKA IA-
301 AM CDT THU AUG 9 2007

...THE FLASH FLOOD WARNING HAS EXPIRED FOR MAHASKA COUNTY...

AT 245 AM CDT...MAHASKA COUNTY LAW ENFORCEMENT REPORTED THAT WATER 
WAS RECEDING AND THAT MOST IF NOT ALL ROADS THAT WERE PREVIOUSLY 
AFFECTED BY FLOOD WATER WERE NOW PASSABLE. NO ADDITIONAL RAINFALL IS 
EXPECTED FOR THE REMAINDER OF THE NIGHT AND DAY.

LAT...LON 4149 9285 4150 9243 4116 9245 4117 9286
TIME...MOT...LOC 0644Z 180DEG 0KT 4133 9249

$$

MOYER

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 8, 7:15 PM CDTTornado WarningDMXTaylor45 min
Aug 8, 7:57 PM CDTSevere Thunderstorm WarningDMXRinggold48 min
Aug 8, 8:02 PM CDTFlash Flood WarningDMXRinggold, Taylor6 hr
Aug 8, 8:32 PM CDTSevere Thunderstorm WarningDMXDecatur43 min

Nearby

Flash Flood Warnings in Iowa, 2007Every flash flood warning in 2007

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.