Slow motion
Tropical cyclone rainfall forecasting is important, since between 1970–2004, inland flooding from tropical cyclones caused most of the fatalities from tropical cyclones in the United States. While flooding is common to tropical cyclones near a landmass, there are a few factors which lead to excessive rainfall from tropical cyclones. Slow motion, as was seen during Hurricane Danny and Hurricane Wilma, can lead to high amounts. The presence of topography near the coast, as is the case across much of Mexico, Haiti, the Dominican Republic, much of Central America, Madagascar, Réunion, China, and Japan acts to magnify amounts due to upslope flow into the mountains. Strong upper level forcing from a trough moving through the Westerlies, as was the case during Hurricane Floyd, can lead to excessive amounts even from systems moving at an average forward motion. A combination of two of these factors could be especially crippling, as was seen during Hurricane Mitch in Central America. Therefore, an accurate track forecast is essential in order to produce an accurate tropical cyclone rainfall forecast.