North Atlantic tropical SSTA vs. hurricanes: Climate Impact Company will issue a plethora of tropical cyclone information over the next week or so culminating with the 2021 seasonal outlook next week. A significant predictor for numbers of the most intense storms is the presence of warmer-than-normal deep tropics ocean water as measured by the tropical North Atlantic (TNA) index. During the past 25 years the North Atlantic tropics have typically been somewhat warmer than normal during the core of the tropical cyclone season. When El Nino is present, the influence of the warm tropical waters on tropical cyclone activity is negated. Otherwise, the seasonal activity features above normal number of hurricanes when the tropical North Atlantic index is warm. The TNA index is -0.04 to finish March.