Alert archive / Iowa / Flash Flood Watches in 2009

Flash Flood Watch 5, NWS Des Moines, IA

April 26, 200940 counties in Iowa

NWS Des Moines, IA issued this flash flood watch at Apr 26, 2009, 3:38 AM CDT for 40 counties in Iowa. It took effect at Apr 26, 2009, 6:00 PM CDT. It was in force for 9 hr.

The area

The counties it named.

The facts

Issued: Apr 26, 2009, 3:38 AM CDT (08:38 UTC)
In effect from: Apr 26, 2009, 6:00 PM CDT
Expired: Apr 27, 2009, 3:25 AM CDT
In force: 9 hr
Issued by: NWS Des Moines, IA
Flood severity: None

All 40 counties

Adair County, IA, Adams County, IA, Appanoose County, IA, Audubon County, IA, Black Hawk County, IA, Boone County, IA, Bremer County, IA, Butler County, IA, Carroll County, IA, Cass County, IA, Cerro Gordo County, IA, Clarke County, IA, Dallas County, IA, Davis County, IA, Decatur County, IA, Franklin County, IA, Greene County, IA, Grundy County, IA, Guthrie County, IA, Hamilton County, IA, Hardin County, IA, Jasper County, IA, Lucas County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Monroe County, IA, Polk County, IA, Poweshiek County, IA, Ringgold County, IA, Story County, IA, Tama County, IA, Taylor County, IA, Union County, IA, Wapello County, IA, Warren County, IA, Wayne County, IA, Webster County, IA, Wright County, IA

The radar

The Des Moines radar (KDMX), 16 km from the middle of the area, began a volume at 08:38 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 00:00Z, 8.6 hours before the alert went out and 239 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: 620 m above ground
0-6 km bulk shear: 49 kt
0-1 km storm-relative helicity: 129 m²/s²
0-3 km storm-relative helicity: 364 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood watch went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Des Moines, IA wrote its last area forecast discussion before this flash flood watch went out at Apr 26, 3:37 AM CDT, 1 minute earlier.

Area forecast discussion, Apr 26, 3:37 AM CDT, 1 minute before

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Hazardous weather outlook, Apr 25, 9:41 PM CDT, 5 hours 57 minutes before

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In the hours before

Local storm report, Apr 25, 10:15 PM CDT, 5 hours 23 minutes before

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Special weather statement, Apr 25, 10:50 PM CDT, 4 hours 48 minutes before

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Special weather statement, Apr 26, 12:47 AM CDT, 2 hours 51 minutes before

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Special weather statement, Apr 26, 12:56 AM CDT, 2 hours 42 minutes before

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Special weather statement, Apr 26, 1:08 AM CDT, 2 hours 30 minutes before

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Special weather statement, Apr 26, 1:51 AM CDT, 1 hour 47 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 25, 7:28 PM CDT	Severe Thunderstorm Warning	DMX	Dallas, Madison, Warren	24 min
Apr 25, 9:02 PM CDT	River Flood Warning	DMX	Decatur	48 hr
Apr 25, 9:02 PM CDT	River Flood Warning	DMX	Lucas, Wayne	5 days
Apr 25, 9:02 PM CDT	River Flood Warning	DMX	Appanoose, Wayne	55 hr
Apr 25, 9:19 PM CDT	Areal Flood Advisory	DMX	Appanoose, Davis, Wapello	6 hr
Apr 26, 7:10 AM CDT	River Flood Warning	DMX	Taylor	24 hr
Apr 26, 10:40 AM CDT	Severe Thunderstorm Warning	DMX	Adair, Adams, Madison, Union	32 min
Apr 26, 1:15 PM CDT	River Flood Warning	DMX	Polk, Story	27 hr
Apr 26, 1:24 PM CDT	River Flood Warning	DMX	Madison, Warren	48 hr
Apr 26, 2:09 PM CDT	Severe Thunderstorm Warning	DMX	Cass	51 min
Apr 26, 3:19 PM CDT	River Flood Warning	DMX	Madison, Warren	4 days
Apr 26, 3:42 PM CDT	Severe Thunderstorm Warning	DMX	Audubon, Cass	48 min
Apr 26, 3:51 PM CDT	Areal Flood Advisory	DMX	Black Hawk, Grundy, Marshall, Tama	3 hr
Apr 26, 3:51 PM CDT	River Flood Warning	DMX	Story	20 hr
Apr 26, 4:08 PM CDT	Flash Flood Warning	DMX	Black Hawk	6 hr
Apr 26, 4:08 PM CDT	River Flood Warning	DMX	Warren	19 hr
Apr 26, 4:40 PM CDT	Flash Flood Warning	DMX	Adair, Audubon, Cass, Guthrie	6 hr
Apr 26, 4:58 PM CDT	Severe Thunderstorm Warning	DMX	Adair, Audubon, Cass, Guthrie	47 min
Apr 26, 5:17 PM CDT	Areal Flood Advisory	DMX	Dallas, Madison, Polk, Warren	3 hr
Apr 26, 6:04 PM CDT	Severe Thunderstorm Warning	DMX	Clarke, Decatur, Ringgold, Union	41 min
Apr 26, 6:08 PM CDT	Tornado Warning	DMX	Black Hawk, Tama	37 min
Apr 26, 6:23 PM CDT	Severe Thunderstorm Warning	DMX	Jasper, Marshall, Poweshiek, Tama	37 min
Apr 26, 6:29 PM CDT	Flash Flood Warning	DMX	Marshall	6 hr
Apr 26, 6:36 PM CDT	Severe Thunderstorm Warning	DMX	Clarke, Decatur, Lucas, Marion, Warren	39 min
Apr 26, 6:39 PM CDT	Severe Thunderstorm Warning	DMX	Marion, Polk, Warren	51 min
Apr 26, 6:50 PM CDT	Severe Thunderstorm Warning	DMX	Appanoose, Decatur, Lucas, Monroe, Wayne	40 min
Apr 26, 6:56 PM CDT	Severe Thunderstorm Warning	DMX	Tama	26 min
Apr 26, 6:58 PM CDT	Severe Thunderstorm Warning	DMX	Marion	47 min
Apr 26, 6:59 PM CDT	Flash Flood Warning	DMX	Grundy, Marshall, Tama	6 hr

Nearby

Flash Flood Watches in Iowa, 2009 Every flash flood watch in 2009

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.