Iowa Spring Flood Potential BriefingIowa Spring Flood Potential Briefing

Jeff ZoggJeff ZoggSenior HydrologistSenior Hydrologist

National Weather ServiceNational Weather ServiceDes Moines, IADes Moines, IA

February 5, 2009February 5, 2009

“America’s Weather Enterprise: Protecting Lives, Livelihoods, and Your Way of Life”“America’s Weather Enterprise: Protecting Lives, Livelihoods, and Your Way of Life”

“America’s Weather Enterprise: Protecting Lives, Livelihoods, and Your Way of Life”“America’s Weather Enterprise: Protecting Lives, Livelihoods, and Your Way of Life”

HighlightsHighlights

• Spring flood risk: near to above normal in Spring flood risk: near to above normal in most placesmost places

• River basins of most concern:River basins of most concern:– Cedar-Iowa (upper & lower)Cedar-Iowa (upper & lower)– Des Moines (upper & middle)Des Moines (upper & middle)– Rock (upper)Rock (upper)– Floyd (upper)Floyd (upper)

• Ice jam risk: near to above normalIce jam risk: near to above normal

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“America’s Weather Enterprise: Protecting Lives, Livelihoods, and Your Way of Life”“America’s Weather Enterprise: Protecting Lives, Livelihoods, and Your Way of Life”

Highlights (cont’d)Highlights (cont’d)

• Assumptions: next few months—near Assumptions: next few months—near normal weather and snow melt conditionsnormal weather and snow melt conditions

• Typical highest water time framesTypical highest water time frames– Inland Iowa streams & Big Sioux River: mid Inland Iowa streams & Big Sioux River: mid

March to early AprilMarch to early April– Mississippi River: mid April to early MayMississippi River: mid April to early May– Missouri River: mid March to early April*Missouri River: mid March to early April*

* potentially affected by regulation* potentially affected by regulation

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“America’s Weather Enterprise: Protecting Lives, Livelihoods, and Your Way of Life”“America’s Weather Enterprise: Protecting Lives, Livelihoods, and Your Way of Life”

Flood risk (NWS)Flood risk (NWS)

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“America’s Weather Enterprise: Protecting Lives, Livelihoods, and Your Way of Life”“America’s Weather Enterprise: Protecting Lives, Livelihoods, and Your Way of Life”

Flood risk (cont’d) (NWS)Flood risk (cont’d) (NWS)

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“America’s Weather Enterprise: Protecting Lives, Livelihoods, and Your Way of Life”“America’s Weather Enterprise: Protecting Lives, Livelihoods, and Your Way of Life”

Flood risk (cont’d) (NWS)Flood risk (cont’d) (NWS)

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“America’s Weather Enterprise: Protecting Lives, Livelihoods, and Your Way of Life”“America’s Weather Enterprise: Protecting Lives, Livelihoods, and Your Way of Life”

Flood risk (cont’d) (NWS)Flood risk (cont’d) (NWS)

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“America’s Weather Enterprise: Protecting Lives, Livelihoods, and Your Way of Life”“America’s Weather Enterprise: Protecting Lives, Livelihoods, and Your Way of Life”

Flood risk (cont’d) (NWS)Flood risk (cont’d) (NWS)

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“America’s Weather Enterprise: Protecting Lives, Livelihoods, and Your Way of Life”“America’s Weather Enterprise: Protecting Lives, Livelihoods, and Your Way of Life”

Flood risk (cont’d) (NWS)Flood risk (cont’d) (NWS)

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“America’s Weather Enterprise: Protecting Lives, Livelihoods, and Your Way of Life”“America’s Weather Enterprise: Protecting Lives, Livelihoods, and Your Way of Life”

Stream flow (USGS)Stream flow (USGS)

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NowNow

Past monthPast month

“America’s Weather Enterprise: Protecting Lives, Livelihoods, and Your Way of Life”“America’s Weather Enterprise: Protecting Lives, Livelihoods, and Your Way of Life”

Soil moisture (NOAA)Soil moisture (NOAA)

NowNow

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Past monthPast month

“America’s Weather Enterprise: Protecting Lives, Livelihoods, and Your Way of Life”“America’s Weather Enterprise: Protecting Lives, Livelihoods, and Your Way of Life”

Snow pack (NOAA)Snow pack (NOAA)

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Minus normalMinus normal

Snow depthSnow depth

“America’s Weather Enterprise: Protecting Lives, Livelihoods, and Your Way of Life”“America’s Weather Enterprise: Protecting Lives, Livelihoods, and Your Way of Life”

Snow water equivalent (NOAA)Snow water equivalent (NOAA)

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1 year ago1 year ago

NowNow

“America’s Weather Enterprise: Protecting Lives, Livelihoods, and Your Way of Life”“America’s Weather Enterprise: Protecting Lives, Livelihoods, and Your Way of Life”

3-month outlook (NOAA)3-month outlook (NOAA)

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TemperatureTemperature

PrecipitationPrecipitation