Flood Risks Not As Severe As Last Spring

SIDNEY, IA – National Weather Service Hydrologist David Pearson told a crowd of over 130 people Thursday that while some flooding on the Missouri River is certain, it will not be nearly as severe as last spring.

Last March a heavy rain fell on deep snow over much of the plains that caused the Platte and Missouri rivers to set record highs, including a crest of 30.1 feet at Nebraska City and 40.6 feet at Plattsmouth.

Pearson said while rivers and streams are still running high, last year there was greater flood risk from river ice and deep snow.

Even the snow in the upstream basin is melting gradually this March and mountain snowpack is in the normal range.

 

He expects a change in the weather pattern beginning March 9 that will bring more precipitation to southwest Iowa and the lower river basin, but said overall the wettest weather systems will be east of Iowa.

He said much of the Missouri River basin will be drier than normal through mid-April.

Because of high ground moisture and high levels of water already in the river systems, he said there is a 97 percent chance that rainfall will cause the river to rise to the 18-foot flood stage at Nebraska City.

The chance of a significant flood at 25 feet is forecast at 18 percent, about 15 percent higher than a normal year.

Pearson said, if he gave the same presentation last March, he would not have predicted record flooding.

He said there were a lot of red flags in the Norfolk area and some elevated risk factors, but he said, as much as he would like to claim the skill, he would not have been able to predict the bomb cyclone.

However, he said, the flood risk this year will be determined by rainfall.