Increasing Flood Hazard Posed by Tropical Cyclone Rapid Intensification in a Changing Climate

Abstract

Tropical cyclones (TCs) that undergo rapid intensification (RI) before landfall are notoriously difficult to predict and have caused tremendous damage to coastal regions in the United States. Using downscaled synthetic TCs and physics‐based models for storm tide and rain, we investigate the hazards posed by TCs that rapidly intensify before landfall under both historical and future mid‐emissions climate scenarios. In the downscaled synthetic data, the percentage of TCs experiencing RI is estimated to rise across a significant portion of the North Atlantic basin. Notably, future climate warming causes large increases in the probability of RI within 24 hr of landfall. Also, our analysis shows that RI events induce notably higher rainfall hazard levels than non‐RI events with equivalent TC intensities. As a result, RI events dominate increases in 100‐year rainfall and storm tide levels under climate change for most of the US coastline.

Predictability of Hurricane Storm Surge: An Ensemble Forecasting Approach Using Global Atmospheric Model Data

“…This could be related to many of the ensemble TCs reaching peak intensity prior to landfall and subsequently weakening; however, Figure 3 shows that at 0 UTC 8 and 9 October, the highest V max that any ensemble TC member reaches is 15 kts weaker than Best track. In other words, although forecasting Hurricane Michael's rapid intensification was critical for predicting wind impacts, our results suggest that it was not required to provide useful storm surge risk information [86].…”