COASTAL Implementation Act of 2019 This bill revises the authority of the National Oceanic and Atmospheric Administration (NOAA) to conduct scientific assessments related to storms, including to (1) direct NOAA to seek public input before the Named Storm Event Model (the official meteorological and oceanographic computerized model which replicates the winds, rainfall, and storm surges associated with named storms) takes effect, (2) authorize the deployment of sensors to enhance data collection in coastal states that are at highest risk of experiencing indeterminate losses from an identified named storm, and (3) authorize separate post-storm assessments for each coastal state that is impacted by a single storm.