Alert archive / Iowa / Flash Flood Watches in 2007

Flash Flood Watch 12, NWS Des Moines, IA

August 28, 200731 counties in Iowa

NWS Des Moines, IA issued this flash flood watch at Aug 28, 2007, 3:56 AM CDT for 31 counties in Iowa. It took effect at Aug 28, 2007, 7:00 PM CDT. It was in force for 8 hr.

The area

The counties it named.

The facts

Issued: Aug 28, 2007, 3:56 AM CDT (08:56 UTC)
In effect from: Aug 28, 2007, 7:00 PM CDT
Expired: Aug 29, 2007, 2:36 AM CDT
In force: 8 hr
Issued by: NWS Des Moines, IA
Flood severity: None

All 31 counties

Adair County, IA, Audubon County, IA, Black Hawk County, IA, Boone County, IA, Bremer County, IA, Butler County, IA, Calhoun County, IA, Carroll County, IA, Cass County, IA, Cerro Gordo County, IA, Crawford County, IA, Dallas County, IA, Franklin County, IA, Greene County, IA, Grundy County, IA, Guthrie County, IA, Hamilton County, IA, Hancock County, IA, Hardin County, IA, Humboldt County, IA, Jasper County, IA, Madison County, IA, Marshall County, IA, Pocahontas County, IA, Polk County, IA, Poweshiek County, IA, Sac County, IA, Story County, IA, Tama County, IA, Webster County, IA, Wright County, IA

The radar

The Des Moines radar (KDMX), 51 km from the middle of the area, began a volume at 08:55 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

Minneapolis, MN (KMPX), launched 00:00Z, 8.9 hours before the alert went out and 296 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: 2564 J/kg
Mixed-layer CIN: -230 J/kg
Mixed-layer LCL: 806 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 379 m²/s²
0-3 km storm-relative helicity: 526 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 8.1

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 Aug 27, 11:45 PM CDT, 4 hours 11 minutes earlier.

Area forecast discussion, Aug 27, 11:45 PM CDT, 4 hours 11 minutes before

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Hazardous weather outlook, Aug 27, 10:24 PM CDT, 5 hours 32 minutes before

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        The site you requested is temporarily down for maintenance or an unexpected outage.
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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
Aug 28, 4:59 PM CDT	Severe Thunderstorm Warning	DMX	Sac	46 min
Aug 28, 5:52 PM CDT	Severe Thunderstorm Warning	DMX	Crawford	38 min
Aug 28, 6:02 PM CDT	Flash Flood Warning	DMX	Wright	6 hr
Aug 28, 6:11 PM CDT	Flash Flood Warning	DMX	Calhoun	6 hr
Aug 28, 6:21 PM CDT	Flash Flood Warning	DMX	Crawford	6 hr
Aug 28, 6:21 PM CDT	Tornado Warning	DMX	Carroll, Crawford	24 min
Aug 28, 6:29 PM CDT	Severe Thunderstorm Warning	DMX	Audubon, Guthrie	46 min
Aug 28, 6:38 PM CDT	Flash Flood Warning	DMX	Webster	6 hr
Aug 28, 6:43 PM CDT	Severe Thunderstorm Warning	DMX	Calhoun, Greene, Webster	47 min
Aug 28, 6:46 PM CDT	Tornado Warning	DMX	Carroll, Greene	44 min

Nearby

Flash Flood Watches in Iowa, 2007 Every flash flood watch 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.