NOAA also announced that, as predicted last spring, La Niña has formed in the tropical Pacific Ocean. This favors lower wind shear over the Atlantic Basin, allowing storm clouds to grow and organize. Other climate factors pointing to an active hurricane season are warmer-than-average water in the tropical Atlantic and Caribbean, and the tropical multi-decadal signal, which since 1995 has brought favorable ocean and atmospheric conditions in unison, leading to more active seasons.
"August heralds the start of the most active phase of the Atlantic hurricane season and with the meteorological factors in place, now is the time for everyone living in hurricane prone areas to be prepared," said Jane Lubchenco, Ph.D., under secretary of commerce for oceans and atmosphere and NOAA administrator.
Across the entire Atlantic Basin for the whole season -- June 1 to November 30 -- NOAA's updated outlook is projecting, with a 70 percent probability, a total of (including Alex, Bonnie and Colin):
- 14 to 20 Named Storms (top winds of 39 mph or higher), including:
- 8 to 12 Hurricanes (top winds of 74 mph or higher), of which:
- 4 to 6 could be Major Hurricanes (Category 3, 4 or 5; winds of at least 111 mph)
These ranges are still indicative of an active season, compared to the average of 11 named storms, six hurricanes and two major hurricanes; however, the upper bounds of the ranges have been lowered from the initial outlook in late May, which reflected the possibility of even more early season activity.
"All indications are for considerable activity during the next several months," said Gerry Bell, Ph.D., lead seasonal hurricane forecaster at NOAA's Climate Prediction Center. "As we've seen in past years, storms can come on quickly during the peak months of the season. There remains a high likelihood that the season could be very active, with the potential of being one of the more active on record."