Alert archive / Iowa / Flash Flood Warnings in 2008

Flash Flood Warning 9, NWS Des Moines, IA

May 6, 2008Hamilton County, Hardin County, Iowa

NWS Des Moines, IA issued this flash flood warning at May 6, 2008, 11:54 PM CDT for Hamilton County, Hardin County, Iowa. It was in force for 3 hr. 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: May 6, 2008, 11:54 PM CDT (04:54 UTC)
Expired: May 7, 2008, 3:00 AM CDT
In force: 3 hr
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Flood severity: None

Counties Hamilton County, IA, Hardin County, IA

The radar

The Des Moines radar (KDMX), 85 km from the middle of the area, began a volume at 04:56 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

Time	Report	Where	Remark
May 7, 12:34 AM CDT	FLASH FLOOD	Alden, IA	TWELVE INCHES OF WATER WAS FLOWING OVER COUNTY ROAD D20...OR OLD HIGHWAY 20...AT THE 18000 BLOCK.
May 7, 2:15 AM CDT	HEAVY RAIN 6.25	6 W Iowa Falls, IA	RAIN BEGAN AT 745 PM CDT TUESDAY EVENING AND ENDED AROUND 215 AM CDT WEDNESDAY MORNING...DELAYED REPORT.
May 7, 2:30 AM CDT	FLOOD	Alden, IA	MAYOR OF ALDEN REPORTED THAT THE ALDEN ELEMENTARY SCHOOL IS CLOSED WEDNESDAY DUE TO 4 FEET OF WATER IN BOILER ROOM AND 1 FOOT OF WATER IN CAFETERIA. THE WATER SOFTENER...MAIN COMPRESSOR...AND SEVERAL CHEMICALS HAVE WATER DAMAGE IN BOILER ROOM.

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, 4.9 hours before the alert went out and 253 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: 2257 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 52 m²/s²
0-3 km storm-relative helicity: 83 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.

000 
WGUS53 KDMX 070455
FFWDMX
IAC079-083-070800-
/O.NEW.KDMX.FF.W.0009.080507T0454Z-080507T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
1154 PM CDT TUE MAY 6 2008

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHEASTERN HAMILTON COUNTY IN CENTRAL IOWA...
  HARDIN COUNTY IN CENTRAL IOWA...

* UNTIL 300 AM CDT

* AT 1151 PM CDT...TRAINED WEATHER SPOTTERS REPORTED FLASH FLOODING
  FROM A THUNDERSTORM OVER THE WARNED AREA.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO IOWA FALLS

ADDITIONAL RAINFALL AMOUNTS OF ONE TO TWO INCHES ARE POSSIBLE IN THE 
WARNED AREA. A TRAINED SPOTTER IN ALDEN REPORTED 4.75 INCHES OF 
RAINFALL AT 1150 PM CDT WHICH FELL OVER THE PAST SEVERAL HOURS. 

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.

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.

A FLASH FLOOD WARNING MEANS THAT 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.

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

LAT...LON 4256 9376 4255 9303 4247 9303 4246 9302
      4229 9300 4229 9347 4237 9376
TIME...MOT...LOC 0454Z 180DEG 0KT 4247 9336

$$

VACHALEK

3 follow-up statements

000 
WGUS73 KDMX 070606
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
104 AM CDT WED MAY 7 2008

IAC079-083-070800-
/O.CON.KDMX.FF.W.0009.000000T0000Z-080507T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
HAMILTON IA-HARDIN IA-
104 AM CDT WED MAY 7 2008

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 300 AM CDT FOR
HARDIN AND NORTHEASTERN HAMILTON COUNTIES...

AT 1259 AM CDT...LOCAL LAW ENFORCEMENT OFFICIALS REPORTED FLOODING 
IN THE ALDEN AREA OF HAMILTON COUNTY...WITH 12 INCHES OF WATER 
RUNNING OVER COUNTY ROAD D20 IN THE 18000 BLOCK. REPORTS INDICATE 
THAT FLOODING IS LIMITED IN NORTHEAST HAMILTON COUNTY 

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO IOWA FALLS

ADDITIONAL RAINFALL AMOUNTS OF ONE HALF TO IN INCH ARE POSSIBLE IN 
THE WARNED AREA DURING THE NEXT AREA...ESPECIALLY ACROSS THE EAST 
TWO THIRDS OF HARDIN COUNTY.

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.

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. MOVE TO HIGHER GROUND.

LAT...LON 4256 9376 4255 9303 4247 9303 4246 9302
      4229 9300 4229 9347 4237 9376
TIME...MOT...LOC 0604Z 180DEG 0KT 4247 9336

$$

000 
WGUS73 KDMX 070723
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
219 AM CDT WED MAY 7 2008

IAC079-083-070800-
/O.CON.KDMX.FF.W.0009.000000T0000Z-080507T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
HAMILTON IA-HARDIN IA-
219 AM CDT WED MAY 7 2008

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 300 AM CDT FOR
HARDIN AND NORTHEASTERN HAMILTON COUNTIES...

AT 217 AM CDT...FLASH FLOODING WAS STILL OCCURRING...BUT THE RAIN 
HAS ENDED ACROSS THE WARNED AREA. FLASH FLOODING WILL STILL LIKELY 
REMAIN A PROBLEM IN THE ALDEN AREA OF HARDIN COUNTY...WHERE 
PREVIOUS REPORTS OF 12 INCHES OF WATER WAS RUNNING OVER COUNTY ROAD 
D20 IN THE 18000 BLOCK. REPORTS OF FLOODING CONTINUED ACROSS HARDIN 
COUNTY...WITH REPORTS OF FLOODING LIMITED TO NORTHEAST PORTION OF 
HAMILTON COUNTY. 

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO IOWA FALLS

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 4256 9376 4255 9303 4247 9303 4246 9302
      4229 9300 4229 9347 4237 9376
TIME...MOT...LOC 0719Z 180DEG 0KT 4247 9336

$$

ALBRECHT

000 
WGUS73 KDMX 070800
FFSDMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
259 AM CDT WED MAY 7 2008

IAC079-083-070809-
/O.CAN.KDMX.FF.W.0009.000000T0000Z-080507T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
HAMILTON IA-HARDIN IA-
259 AM CDT WED MAY 7 2008

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR HARDIN AND
NORTHEASTERN HAMILTON COUNTIES...

THE HAMILTON COUNTY SHERIFF REPORTED THAT NO ROADS WERE CLOSED IN 
THE COUNTY AND FLOODING WAS NO LONGER OCCURRING.  AN AREAL FLOOD 
WARNING WILL BE ISSUED FOR HARDIN COUNTY...REPLACING THE FLASH FLOOD 
WARNING. 

LAT...LON 4256 9376 4255 9303 4247 9303 4246 9302
      4229 9300 4229 9347 4237 9376
TIME...MOT...LOC 0759Z 180DEG 0KT 4247 9336

$$

BOKSA

The office that day

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

Issued	Product	Office	Counties	Lasted
May 6, 7:17 PM CDT	Severe Thunderstorm Warning	DMX	Hamilton, Webster	43 min
May 6, 7:24 PM CDT	Flash Flood Warning	DMX	Calhoun, Sac, Webster	3 hr
May 6, 7:45 PM CDT	Severe Thunderstorm Warning	DMX	Grundy, Hardin	45 min
May 6, 7:48 PM CDT	Severe Thunderstorm Warning	DMX	Butler, Grundy	42 min
May 6, 7:53 PM CDT	Tornado Warning	DMX	Story	37 min
May 6, 8:15 PM CDT	Severe Thunderstorm Warning	DMX	Grundy, Hardin, Marshall, Tama	45 min
May 6, 8:26 PM CDT	Areal Flood Advisory	DMX	Boone	3 hr
May 6, 8:27 PM CDT	Severe Thunderstorm Warning	DMX	Black Hawk, Bremer, Grundy	48 min
May 6, 8:32 PM CDT	Severe Thunderstorm Warning	DMX	Boone, Story	43 min
May 6, 8:48 PM CDT	Severe Thunderstorm Warning	DMX	Tama	42 min
May 6, 8:55 PM CDT	Areal Flood Advisory	DMX	Story	3 hr
May 6, 9:18 PM CDT	Flash Flood Warning	DMX	Boone	3 hr
May 6, 9:26 PM CDT	Areal Flood Advisory	DMX	Marshall, Tama	3 hr
May 6, 10:30 PM CDT	Areal Flood Advisory	DMX	Calhoun	3 hr
May 6, 10:50 PM CDT	Severe Thunderstorm Warning	DMX	Franklin, Hamilton, Hardin, Wright	40 min
May 6, 11:03 PM CDT	Areal Flood Advisory	DMX	Wright	3 hr
May 7, 1:33 AM CDT	Areal Flood Advisory	DMX	Grundy, Tama	3 hr
May 7, 1:57 AM CDT	Areal Flood Warning	DMX	Franklin, Wright	6 hr
May 7, 3:02 AM CDT	Areal Flood Warning	DMX	Marshall	16 min
May 7, 3:08 AM CDT	Areal Flood Warning	DMX	Hardin	8 hr
May 7, 7:25 AM CDT	River Flood Warning	DMX	Boone, Webster	44 hr

Nearby

Flash Flood Warnings in Iowa, 2008 Every flash flood warning in 2008

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.