The 2013 Atlantic hurricane season will be an event in the annual cycle of tropical cyclone formation. The season will officially start on June 1 and end on November 30. These dates conventionally delimit the period of each year when most tropical cyclones form in the Atlantic basin. However, the formation of tropical cyclones is possible at any time.
||8 April 2013
||23 May 2013
||15 May 2013
||10 Apr 2013
||15 April 2013
||5 Apr 2013
In advance of, and during, each hurricane season, several forecasts of hurricane activity are issued by national meteorological services, scientific agencies, and noted hurricane experts. These include forecasters from the United States National Oceanic and Atmospheric Administration (NOAA)'s National Hurricane and Climate Prediction Center's, Philip J. Klotzbach, William M. Gray and their associates at Colorado State University (CSU), Tropical Storm Risk, and the United Kingdom's Met Office. The forecasts include weekly and monthly changes in significant factors that help determine the number of tropical storms, hurricanes, and major hurricanes within a particular year. As stated by NOAA and CSU, an average Atlantic hurricane season between 1981-2010 contains roughly 12 tropical storms, 6 hurricanes, 3 major hurricanes, and an Accumulated Cyclone Energy (ACE) Index of 66-103 units. NOAA typically categorizes a season as either above-average, average, of below-average based on the cumulative ACE Index; however, the number of tropical storms, hurricanes, and major hurricanes within a hurricane season is considered occasionally as well.
On December 5, 2012, Tropical Storm Risk (TSR), a public consortium consisting of experts on insurance, risk management, and seasonal climate forecasting at University College London, issued an extended-range forecast predicting an above-average hurricane season. In its report, the organization called for 15.4 (±4.3) named storms, 7.7 (±2.9) hurricanes, 3.4 (±1.6) major hurricanes, and a cumulative Accumulated Cyclone Energy (ACE) index of 134, citing the forecast for slower-than-average trade winds and warmer-than-normal sea surface temperatures. While no value was placed on the number of expected landfalls during the season, TSR stated that the landfalling ACE index was expected to be above average. Four months later, on April 5, Tropical Storm Risk issued their updated forecast, continuing to call for an above-average season with 15.2 (±4.1) named storms, 7.5 (±2.8) hurricanes, 3.4 (±1.6) major hurricanes, and an ACE index of 131; the landfalling ACE index was once again forecast to be higher than normal.
Meanwhile, on April 8, Weather Services International (WSI) issued their first forecast for the hurricane season. In its report, the organization forecast 16 named storms, 9 hurricanes, and 5 major hurricanes, referencing above average sea surface temperatures in the Main Development Region of the Atlantic. The main forecasting uncertainty involved whether or not an El Niño develop prior to the peak of the season. On April 10, Colorado State University (CSU) issued its first forecast for the season, calling for a potentially hyperactive season with 18 named storms, 9 hurricanes, 4 major hurricanes, and an ACE index of 165. In its report, the agency stated that above-average sea surface temperatures in the MDR, below-average forecast wind shear, and the unlikeliness of an El Niño developing prior to the peak of the season would enhance tropical cyclone activity. The probabilities of a major hurricane hitting the Gulf Coast and East Coast were much above-average, while the probability of a major hurricane hitting anywhere along the USA coastline were well above-average as well.
On May 15, the United Kingdom Met Office (UKMO) issued a forecast of a slightly above-average season. They predicted 14 named storms with a 70% chance that the number would be between 10 and 18 and 9 hurricanes with a 70% chance that the number would be between 4 and 14. They also predicted an ACE index of 130 with a 70% chance that the index would be in the range 76 to 184. On May 23, 2013, NOAA issued their first seasonal outlook for the year, stating there was a 70% likelihood of 13 to 20 named storms, of which 7 to 11 could become hurricanes, including 3 to 6 major hurricanes; these ranges are greater than the seasonal average of 12 named storms, 6 hurricanes and 3 major hurricanes. The three main factors contributing to a well above-average to hyperactive hurricane season included above-average sea surface temperatures across much of the Atlantic, the absence of an El Niño in the Pacific, and the continuity of the active era since 1995.
2013 Storm Names
The following names will be used for named storms that form in the North Atlantic in 2013. Retired names, if any, will be announced by the World Meteorological Organization in the spring of 2014. The names not retired from this list will be used again in the 2019 season. This is the same list used in the 2007 season, except for Dorian, Fernand, and Nestor which replaced Dean, Felix, and Noel respectively.