Alert archive / Iowa / Flash Flood Warnings in 2007

Flash Flood Warning 99, NWS Des Moines, IA

August 21, 20074 counties in Iowa

NWS Des Moines, IA issued this flash flood warning at Aug 21, 2007, 8:33 PM CDT for 4 counties in Iowa. It was in force for 6 hr. 5 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: Aug 21, 2007, 8:33 PM CDT (01:33 UTC)
Expired: Aug 22, 2007, 2:30 AM CDT
In force: 6 hr
Issued by: NWS Des Moines, IA
Area: Counties, with a storm outline in the text

Counties Franklin County, IA, Humboldt County, IA, Pocahontas County, IA, Wright County, IA

The radar

The Des Moines radar (KDMX), 119 km from the middle of the area, began a volume at 01:36 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
Aug 21, 9:35 PM CDT	FLASH FLOOD	Gilmore City, IA	WATER RUNNING OVER HWY 3 NEAR GILMORE CITY. ROAD IS CLOSED.
Aug 21, 11:40 PM CDT	FLASH FLOOD	Clarion, IA	WATER INTO BASEMENTS FROM HEAVY RAINS SEVERAL OTHER TOWNS GOLDFIELD AND EAGLE GROVE FLOODING.
Aug 21, 11:45 PM CDT	FLASH FLOOD	Humboldt, IA	ROADS CLOSED DUE TO WATER RUNNING OVER ROADS AND NUMEROUS BASEMENTS FLOODED DUE TO HEAVY RAINS.
Aug 22, 12:00 AM CDT	HEAVY RAIN 5.7	Humboldt, IA	RAINFALL THIS EVENING.
Aug 22, 12:32 AM CDT	FLASH FLOOD	Humboldt, IA	EMERGENCY PERSONNEL EVACUATING CARE CENTER IN HUMBOLDT.

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 00:00Z, 1.6 hours before the alert went out and 236 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: 1298 m above ground
0-6 km bulk shear: 65 kt
0-1 km storm-relative helicity: 8 m²/s²
0-3 km storm-relative helicity: 453 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 220134
FFWDMX
IAC069-091-151-197-220730-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
833 PM CDT TUE AUG 21 2007

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  FRANKLIN COUNTY IN NORTH CENTRAL IOWA...
  HUMBOLDT COUNTY IN NORTH CENTRAL IOWA...
  WRIGHT COUNTY IN NORTH CENTRAL IOWA...
  POCAHONTAS COUNTY IN NORTHWEST IOWA...

* UNTIL 230 AM CDT.

* AT 828 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  FLASH FLOODING FROM A THUNDERSTORM 6 MILES SOUTH OF LAURENS...OR   
   ABOUT 19 MILES NORTHEAST OF STORM LAKE...MOVING EAST AT 35 MPH.   
  THE HUNDERSTORMS WILL BE MOVING QUICKLY INTO THE WARNED COUNTIES.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  POCAHONTAS...HUMBOLDT...DAKOTA CITY...EAGLE GROVE...CLARION...
  BELMOND AND HAMPTON.

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.

LAT...LON 4289 9486 4289 9303 4259 9306 4265 9390
      4266 9490
TIME...MOT...LOC 0133Z 269DEG 35KT 4276 9479

$$

FORSTER

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 21, 7:16 PM CDT	Severe Thunderstorm Warning	DMX	Palo Alto	59 min
Aug 21, 7:40 PM CDT	Flash Flood Warning	DMX	Palo Alto	6 hr
Aug 21, 7:49 PM CDT	Tornado Warning	DMX	Humboldt, Pocahontas	41 min
Aug 21, 8:04 PM CDT	Severe Thunderstorm Warning	DMX	Kossuth	56 min
Aug 21, 8:07 PM CDT	Severe Thunderstorm Warning	DMX	Humboldt	53 min
Aug 21, 8:24 PM CDT	Flash Flood Warning	DMX	Winnebago, Worth	6 hr
Aug 21, 8:24 PM CDT	Severe Thunderstorm Warning	DMX	Humboldt, Pocahontas, Webster	66 min
Aug 21, 8:29 PM CDT	Severe Thunderstorm Warning	DMX	Humboldt	46 min
Aug 21, 8:33 PM CDT	Flash Flood Warning	DMX	Franklin, Humboldt, Wright	6 hr
Aug 21, 8:55 PM CDT	Severe Thunderstorm Warning	DMX	Hamilton, Wright	65 min
Aug 21, 9:42 PM CDT	Severe Thunderstorm Warning	DMX	Cerro Gordo	38 min
Aug 21, 10:00 PM CDT	Severe Thunderstorm Warning	DMX	Butler	60 min
Aug 21, 10:06 PM CDT	Flash Flood Warning	DMX	Webster	6 hr
Aug 21, 10:13 PM CDT	Flash Flood Warning	DMX	Bremer, Butler	6 hr
Aug 21, 10:13 PM CDT	Severe Thunderstorm Warning	DMX	Sac	47 min
Aug 21, 10:21 PM CDT	River Flood Warning	DMX	Humboldt	5 days
Aug 21, 10:21 PM CDT	River Flood Warning	DMX	Cerro Gordo, Floyd, Worth	42 hr
Aug 21, 11:07 PM CDT	Flash Flood Warning	DMX	Webster	6 hr
Aug 21, 11:16 PM CDT	Flash Flood Warning	DMX	Grundy, Hardin	6 hr
Aug 21, 11:17 PM CDT	Flash Flood Warning	DMX	Grundy, Hamilton, Hardin	6 hr
Aug 21, 11:32 PM CDT	Severe Thunderstorm Warning	DMX	Crawford	28 min
Aug 22, 3:20 AM CDT	River Flood Warning	DMX	Webster	66 hr
Aug 22, 5:55 AM CDT	River Flood Warning	DMX	Black Hawk	4 days
Aug 22, 5:55 AM CDT	River Flood Warning	DMX	Black Hawk	4 days
Aug 22, 9:57 AM CDT	Severe Thunderstorm Warning	DMX	Sac	48 min
Aug 22, 11:33 AM CDT	Flash Flood Warning	DMX	Calhoun, Sac	6 hr

Nearby

Flash Flood Warnings in Iowa, 2007 Every 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.