The central goal of this proposal is to quantify differences and similarities of tropical cyclone rainfall distribution over land and sea and understand the relationship between hurricane landfall flooding and its rainfall potential when the storm is over ocean. Environmental factors influencing the magnitude and distribution of tropical cyclone landfall precipitation will also be examined. A 7-yr landfalling Atlantic tropical cyclone database of rainfall from Tropical Rainfall Measurement Mission (TRMM)-based NASA Goddard multi-satellite precipitation analysis (TRMM 3B42) has been collected. Categorizations have been made regarding to the storm intensity and location, e.g. over-land or over-ocean. Preliminary studies based on this database have shown that there are indeed major distinctions of cyclone rainfall distribution between over-land and over-ocean stages. However, connecting a storm's rainfall over ocean to its landfall rain provides implications on landfall flooding prediction. It also has been demonstrated that a tropical cyclone's rainfall potential in one day prior to landfall can be used to discriminate among flooding vs. nonflooding storms. The first objective of this proposal is to expand and update the landfalling tropical cyclone database from the Atlantic basin only to global, from 7 years to 8, and to include environmental parameters from the Navy Operational Global Atmospheric Prediction System (NOGAPS) analysis. The second objective is to continue on quantifying differences and similarities of tropical cyclone rainfall distribution over land and oceans for different basins, and developing and verifying the "rain potential" prediction index for landfall flooding of global tropical cyclones. Additionally we will investigate the complicated landfall scenarios in which the rain production is significantly enhanced by terrain interactions and extratropical transition. The third objective is to evaluate TRMM-based rainfall accumulation estimates for extreme events, e.g. tropical cyclones by using ground-based radar and gauge measurements. This will be done mainly for landfall periods. We will not only quantify the relative biases but to have a chance of finding advantages and dis-advantages of these satellite estimates and the underlying physical reasons.
