Alert archive / Iowa / Flash Flood Watches in 2009

Flash Flood Watch 4, NWS Des Moines, IA

March 23, 200911 counties in Iowa

NWS Des Moines, IA issued this flash flood watch at Mar 23, 2009, 3:40 PM CDT for 11 counties in Iowa. It took effect at Mar 24, 2009, 1:00 AM CDT. It was in force for 12 hr.

The area

The counties it named.

The facts

Issued: Mar 23, 2009, 3:40 PM CDT (20:40 UTC)
In effect from: Mar 24, 2009, 1:00 AM CDT
Expired: Mar 24, 2009, 1:00 PM CDT
In force: 12 hr
Issued by: NWS Des Moines, IA
Flood severity: None

Counties Appanoose County, IA, Clarke County, IA, Davis County, IA, Decatur County, IA, Lucas County, IA, Mahaska County, IA, Marion County, IA, Monroe County, IA, Poweshiek County, IA, Wapello County, IA, Wayne County, IA

The radar

The Des Moines radar (KDMX), 97 km from the middle of the area, began a volume at 20:38 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

Davenport, (KDVN), launched 12:00Z, 8.7 hours before the alert went out and 219 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: 1607 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 374 m²/s²
0-3 km storm-relative helicity: 436 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 Mar 23, 1:35 PM CDT, 2 hours 5 minutes earlier.

Area forecast discussion, Mar 23, 1:35 PM CDT, 2 hours 5 minutes before

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Hazardous weather outlook, Mar 23, 5:01 AM CDT, 10 hours 39 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
Mar 23, 3:50 AM CDT	Wind Advisory	DMX	Adair, Adams, Audubon, Black Hawk, Boone, Bremer and 34 more	18 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.