2015 Seasonal forecast
|Record high activity||28||15||7|||
|Record low activity||4||2†||0†|||
|TSR||December 9, 2014||13||6||2|||
|TSR||April 9, 2015||11||5||2|||
|CSU||April 9, 2015||7||3||1|||
|* June–November only
† Most recent of several such occurrences. (See all)
Forecasts of hurricane activity are issued before each hurricane season by noted hurricane experts Philip J. Klotzbach, William M. Gray, and their associates at Colorado State University (CSU); and separately by National Oceanic and Atmospheric Administration (NOAA) forecasters.
Klotzbach’s team (formerly led by Gray) defined the average number of storms per season (1981 to 2010) as 12.1 tropical storms, 6.4 hurricanes, 2.7 major hurricanes (storms reaching at least Category 3 strength on the Saffir–Simpson hurricane wind scale), and an Accumulated Cyclone Energy(ACE) index of 96.1. NOAA defines a season as above-normal, near-normal or below-normal by a combination of the number of named storms, the number reaching hurricane strength, the number reaching major hurricane strength, and the ACE index.
On December 9, 2014, Tropical Storm Risk (TSR), a public consortium consisting of experts on insurance, risk management, and seasonal climate forecasting at University College London, issued their first outlook on seasonal hurricane activity during the 2015 season. In their report, the organization forecast activity about 20% below the 1950–2014 average, or about 30% below the 2005–2014 average, totaling to 13 (±4) tropical storms, 6 (±3) hurricanes, 2 (±2) major hurricanes, and a cumulative ACE index of 79 (±58) units. This forecast was largely based on an enhancement of low-level trade winds across the tropical Atlantic during the July to September period. TSR’s report stressed that uncertainty in this forecast existed due to the unpredictability in the El Niño Southern Oscillation and North Atlantic sea surface temperatures. A few months later, on April 9, 2015, the organization updated their report, detailing their prediction of activity 45% below the 1950–2014, or about 50% below the recent 2005–2014 average, with 11 named storms, 5 hurricanes, 2 major hurricanes, and a cumulative ACE index of 56 units. TSR cited what were expected to be cooler than average ocean temperatures across the tropical North Atlantic and Caribbean Sea as reasoning for lower activity. In addition, the report stated that if the ACE forecast for 2015 were to verify, the total values during the 2013–2015 would be the lowest since 1992–1994, possible signalling an end to the active phase of Atlantic hurricane activity that began in 1995.
On April 9, CSU also released their first quantitative forecast for the 2015 hurricane season, predicting 7 named storms, 3 hurricanes, 1 major hurricane, and a cumulative ACE index of 40 units. The combination of cooler than average waters in the tropical and subtropical Atlantic, as well as a developing El Niño predicted to reach at least moderate intensity, were expected to favor one of the least active seasons since the mid-1990s. The probabilities of a major hurricane striking various coastal areas across the Atlantic were lower than average, although CSU stressed that it only takes one landfalling hurricane to make it an active season for residents involved.
2015 Storm names
The following names will be used for named storms that form in the North Atlantic in 2015. Retired names, if any, will be announced by the World Meteorological Organization in the spring of 2016. The names not retired from this list will be used again in the 2021 season. This is the same list used in the 2009 season. The name Joaquin replaced Juan after 2003, but was not used in 2009.