Alert archive / Iowa / Flash Flood Watches in 2009

Flash Flood Watch 8, NWS Des Moines, IA

July 7, 200929 counties in Iowa

NWS Des Moines, IA issued this flash flood watch at Jul 7, 2009, 9:01 PM CDT for 29 counties in Iowa. It was in force for 6 hr.

The area

The counties it named.

The facts

Issued: Jul 7, 2009, 9:01 PM CDT (02:01 UTC)
Expired: Jul 8, 2009, 2:59 AM CDT
In force: 6 hr
Issued by: NWS Des Moines, IA
Flood severity: None

All 29 counties

Adair County, IA, Audubon County, IA, Boone County, IA, Calhoun County, IA, Carroll County, IA, Cass County, IA, Clarke County, IA, Crawford County, IA, Dallas County, IA, Greene County, IA, Guthrie County, IA, Hamilton County, IA, Hardin County, IA, Humboldt County, IA, Jasper County, IA, Lucas County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Monroe County, IA, Pocahontas County, IA, Polk County, IA, Sac County, IA, Story County, IA, Union County, IA, Warren County, IA, Webster County, IA, Wright County, IA

The radar

The Des Moines radar (KDMX), 24 km from the middle of the area, began a volume at 02:01 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, 2.0 hours before the alert went out and 206 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: 27 J/kg
Mixed-layer CIN: -201 J/kg
Mixed-layer LCL: 2298 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 32 m²/s²
0-3 km storm-relative helicity: 157 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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 Jul 7, 6:45 PM CDT, 2 hours 16 minutes earlier.

Area forecast discussion, Jul 7, 6:45 PM CDT, 2 hours 16 minutes before

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Hazardous weather outlook, Jul 7, 4:10 PM CDT, 4 hours 51 minutes before

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In the hours before

Local storm report, Jul 7, 5:06 PM CDT, 3 hours 55 minutes before

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Local storm report, Jul 7, 5:11 PM CDT, 3 hours 50 minutes before

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Local storm report, Jul 7, 5:13 PM CDT, 3 hours 48 minutes before

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Special weather statement, Jul 7, 6:06 PM CDT, 2 hours 55 minutes before

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Special weather statement, Jul 7, 7:35 PM CDT, 1 hour 26 minutes before

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Special weather statement, Jul 7, 8:28 PM CDT, 33 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
Jul 7, 8:59 PM CDT	Severe Thunderstorm Warning	DMX	Kossuth, Palo Alto	46 min

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.