Since Catarina had a clear eyewall structure bounded by deep convective, dense central overcast, well-defined spiral outer bands and outflow structure, warm water temperatures of 79 Farad , little shear, a warm core low, overall tropical characteristics, and occurred in March (equivalent to September in the Northern Hemisphere, the peak of hurricane season), it was considered to be a hurricane by the National Hurricane Center (NHC) in the United States.