Home > > Accuracy of Long-Range Probability Flood Forecasts for Iowa Rivers > MROI4 QINE exceed 90day

MROI4 QINE exceed 90day

October 28, 2009

Figure 2. An example of an operational long-range flood forecast issued by the NWS on 19 Jan 2009 for the Iowa River at Marengo. The forecast shows the probability of different flow levels in the upcoming season (90 days). The probabilistic forecast (black triangle) can be compared to the forecast model’s historical simulation of past flows over the season (blue circles). For instance, flows in excess of the flood level typically occur about 63% of the time (from late-January to late-March). However, the forecast for the 2009 season calls for a 97% chance of a flood, a significantly elevated risk of flooding. The Iowa River at Marengo did in fact exceed the flood level in February 2009.

Comments on this entry are closed.