Atlantic hurricane season of 2009

Abstract

The 2009 Atlantic season was marked by below-average tropical cyclone activity with the formation of nine tropical storms, the fewest since the 1997 Atlantic hurricane season. Of these, three became hurricanes and two strengthened into major hurricanes (category 3 or higher on the Saffir-Simpson Hurricane Wind Scale). In addition, there were two tropical depressions that did not reach storm strength. The numbers of tropical storms and hurricanes were below the long-term averages of 11 named storms and 6 hurricanes, although the number ofmajor hurricanes equaled the long-term average of 2. Many of the cyclones remained relatively weak. Only one tropical cyclone, Tropical Storm Claudette, made landfall in the United States, although Ida affected the northern Gulf Coast as a tropical storm before moving inland as an extratropical cyclone. Hurricane Bill and Tropical Storm Danny indirectly affected the East Coast by producing high surf, rip currents, and beach erosion; Bill also produced tropical storm conditions over Bermuda and parts of Atlantic Canada. Hurricane Idamade landfall in Nicaragua and also affected parts of Honduras, the Yucatan Peninsula of Mexico, and western Cuba. Tropical Storm Erika hadminor effects on the northern Leeward Islands, mainly in the form of light rain, and Tropical Storm Grace moved through the Azores with little impact. The death toll from the 2009 Atlantic tropical cyclones was six. A verification of National Hurricane Center official forecasts during 2009 is also presented. Official track errors and forecast skill set records for accuracy at lead times between 24 and 72 h. Official intensity forecast errors were mostly larger than the previous 5-yr means, although intensity forecast skill was at or above historical highs since the intensity skill baseline [i.e., Decay-Statistical Hurricane Intensity Forecast model version 5 (Decay-SHIFOR5)] errors were well above average. © 2011 American Meteorological Society.