Friday, January 29, 2010

Freezing Cold Now... Flooding For Spring

The first spring flood outlook was just posted from the folks who keep track of all rivers in the state of Iowa. It does not look good for most of the state.

There is a high risk of significant flooding over all of central Iowa and much of the northwest corner of the state. The Des Moines, Raccoon, Iowa and Cedar River basins are at greatest risk.

All the snow and ice that has accumulated over the state this year is the big problem. If we start to warm up very quickly we will have a great risk of record or near-record flooding. This is so dis-heartening for so many who have survived the floods that have become so common over our area.

Ice jams are very possible this spring. The thick ice on rivers and streams has a real tendency to break up and collect as dams under bridges. We then see major localized flooding when the ice creates those ice walls. The water has no where to go but back up the banks of the river.

On top of all this, we also have a pretty decent chance of above normal precipitation in March and April. I take this from trends of the this winter compared to similar Iowa winters in the past. Also, the El nino event this year is much farther west in the Pacific than other El nino years. That means we have warmer waters farther west in the Pacific Ocean. That explains our high snowfall this year and often means more storms in March and April. January and February snows are usually sent farther south. Right along the track that the current winter storm is moving.

In summary... I'm quite concerned about the extra storm action for March and April. The snow we have now is pretty certain to cause major flooding. Pack on more snow, ice and rain in March and April and we will have monumental flooding.


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