A New Method to estimate Daily Tropical Cyclone Precipitation from the GHCND Rain Gauges

Abstract:

Tropical Cyclone Precipitation (TCP) contributes a large portion of very extreme hydrological events. An accurate estimation of a long term TCP climatology is an essential to understand how it varies in the past and will change in the future. The Global Historical Climatology Network (GHCND) provides a global coverage of territorial surface daily weather observations with a reasonable spatial density. In this study, we will develop a new method to estimate the TCP from the GHCND daily rain observations and other TC Track information. We will focus on all historical storms impacted the North America Continent (from both the Atlantic and the Pacific Sides) in this study. The new method will consider major factors that influence the estimation accuracy, including the variations in spatial density of rain gauges, sizes and the forward speed of storms, and high wind speeds causing the underestimate of precipitation by the rain bucket. We will provide both the point estimation at the rain gauge and gridded product at 0.25 degree. The gridded product will be finally validated by the precipitation estimation from TRMM. We will make tests and tune this method to optimally fit the available historical observations, so it can be applied for other regions in the world in the future.

Key Words: Tropical Cyclone, Precipitation, New Estimation Method