In recent years, several infamous billion-dollar flood and tropical cyclone (TC) disasters have been documented in the Northern Hemisphere (NH) (e.g., 2012 TC Sandy, 2013 Alberta Flood, 2016 Germany/France Flood, 2017 TC Harvey). However, there has not been much work investigating the importance of Rex Blocks in these events. Examining EFI, a subset of midlatitude and TC-related floods were examined. The flood associated with TC Harvey, which resulted in 60+ in. of rain in parts of Texas, was amplified by a persistent Rex Block that greatly increased the duration and amount of rainfall. The utility of the EFI in diagnosing and predicting this extreme event is explored.