The goal of this study is to introduce a novel methodology for the isolation of post-tropical cyclone (PTC) precipitation and to accurately quantify the role of tropical and post-tropical phases of the tropical cyclone (TC) life cycle and their respective contributions to global TC and PTC-related extreme precipitation.
TCs and their associated precipitation can have devastating impacts on the areas affected, with outcomes ranging from mudslides to inland flash flooding. This analysis framework can be further extended to assess model biases and climate projections of TC- and PTC precipitation.
This study uses a dynamical radius derived from the 500 hPa geopotential height in and around the TC to define TC- and PTC-related heavy precipitation, allowing for the analysis of precipitation with tropical origins after the official demise of the original TC. Climatologies are constructed, indicating a maximum in TC- and PTC-related heavy precipitation in the West North Pacific and a secondary maximum in the East North Pacific. PTC-related extreme precipitation accounts for as much as 40% of the annual extreme precipitation in the West North Pacific basin and 3% of extreme precipitation globally.