The US National Oceanographic and Atmospheric Administration (NOAA) forecast Thursday an "above-normal" hurricane season in the Atlantic, with three to six major hurricanes, according to dpa. In total, the six-month season which starts June 1, is expected to deliver 12-18 named storms - with winds of 60 kilometres per hour or more - of which 6-10 could become hurricanes. Of these, 3-6 are expected to reach categories 3, 4 or 5 on the five-tier Saffir-Simpson scale. "(All this indicates) that activity will exceed the seasonal average of 11 named storms, six hurricanes and two major hurricanes," the NOAA said in a statement. The forecast is based among others on factors like a "continuing high activity era," NOAA manager Jane Lubchenco told a press conference Thursday. This trend has led in recent years to a growing number of storms and to increasingly powerful hurricanes. Besides that, Lubchenco cited Atlantic waters that are "warmer than average," as well as the effects of the ongoing, though weakening Pacific climatic phenomenon known as La Nina.