Ida (2015)

A tropical wave that moved off the west coast of Africa mid‑September developed into a well-defined low on 15 September and became Tropical Depression Nine on 18 September about 650 nautical miles west of the southern Cape Verde Islands. The depression moved generally west‑northwestward and became Tropical Storm Ida on 19 September. Ida meandered over the central Atlantic from 18 to 27 September, turning northwestward and then southeastward as upper‑level troughs and ridges affected its steering flow. The system weakened to a remnant low on 27 September and dissipated by 28 September after interacting with a frontal system.

Ida did not make any landfalls. It remained well east of the Caribbean and North America throughout its life, and no coastal watches or warnings were issued at any time.

The storm’s peak intensity was 45 knots (about 52 mph) with a minimum central pressure of 1001 mb, reached from 0600 to 1800 UTC on 21 September. Ida therefore remained a moderate tropical storm and never reached hurricane strength.

There were no reports of storm surge or significant rainfall impacts associated with Ida in populated areas. No ship reports or surface observations recorded tropical‑storm‑force winds, and the cyclone stayed over open ocean for its entire lifespan.

No damage or casualties were reported in association with Ida. The impacts were limited because the storm stayed far from land.

Forecasts of Ida’s formation were successful well in advance: the system was placed in the Tropical Weather Outlook with a low chance of formation up to 108 hours before genesis and reached a high formation probability 72 hours before formation in the 5‑day outlook. Official track and short‑range intensity forecasts performed at or better than recent averages, though several models showed a westward bias and some guidance overpredicted the chance of Ida becoming a hurricane.