QPF Impact with IVP
We can also assess the influence of QPF on stage forecasts by comparing the verification results for the different scenarios. Let's go back to our MAE and ME plots. The QPF versus no QPF made a big difference in the errors and biases of the stage forecasts. The two forecasts with QPF had less error and smaller negative bias with increasing lead time. The QPF versus no QPF scenario overwhelmed any influence of whether there were or were not modifications made in the hydrologic model. Because QPF has a much stronger positive influence on the stage forecast, we expect the QPF errors to have a relatively strong negative influence as well. But a more robust verification study of the QPF amounts would need to be conducted to prove that.
