Utilizing CIPS Analogs in Extended River Flood Forecasts

Millions of dollars are spent annually to prepare for flooding in communities all across the United States. As emergency flood mitigation efforts can require days to prepare, communities need advanced warning. The accuracy and accountability of the conditional simulations produced by the current models, based solely on climatology, can lead to delayed warnings for homeowners and public service workers as well as excess money being spent during years where flooding did not occur but was projected to. In an effort to improve upon these shortcomings, the implementation of the CIPS (Cooperative Institute for Precipitation Systems) Analogs was proposed. The CIPS Analog System uses the NARR and GEFS numerical models to match forecast weather patterns to those from previous years in an attempt to improve upon the equal-weighted climatological approach that is currently being used. For events that are difficult to predict, such as record breaking, this approach biases (or skews) simulations to years that were the most climatologically similar and mimicked an outcome comparable to the forecasted event. By applying these CIPS based weights to the conditional simulations there is potential to increase the accuracy of forecasts and improve the ability to issue flood warnings sooner ultimately saving lives, properties, money and promoting NOAA’s goal of becoming a Weather-Ready Nation.