|Tropical storm (SSHWS/NWS)|
|Formed||September 12, 2016|
|Dissipated||September 17, 2016|
|(Extratropical after September 16)|
1-minute sustained: 60 mph (95 km/h) |
|Lowest pressure||994 mbar (hPa); 29.35 inHg|
|Areas affected||Iceland (as extratropical cyclone)|
|Part of the 2016 Atlantic hurricane season|
On September 5, the National Hurricane Center (NHC) noted the possibility of a tropical wave developing into a tropical cyclone over the next several days. The wave struggled to develop initially due to unfavorable conditions. By September 9, the wave had begun to improve in organization, but deep convection associated with the system remained sparse. Convection began to increase on September 11, and an ASCAT pass that evening revealed the presence of tropical storm winds within the system. Although its genesis was somewhat later than expected, Tropical Storm Ian developed at 06:00 UTC on June 12, in the central Atlantic Ocean. Due to wind shear, Ian's convection was disorganized and located slightly away from the center. Ian did strengthen slightly, however, and by late on September 13 its winds had increased to 50 mph.
On September 14, although Ian's intensity did not change much at all, Ian became superimposed with an upper-level low and took on an appearance resembling a subtropical cyclone. Ian transitioned into a subtropical cyclone for 18 hours beginning at 18:00 UTC that day. After deep convection redeveloped closer to Ian's center, Ian once again transitioned back into a tropical storm at 06:00 UTC on September 15.
Ian's intensity changed little on September 15 as it began to accelerate rapidly to the northeast. However, early on September 16, a mid-level eye feature developed within Ian, and it is estimated that Ian reached its peak intensity around 06:00 UTC that day with maximum sustained winds of 60 mph and a minimum pressure of 994 millibars. Immediately after peak, Ian's convection dissipated and it became superimposed with a front, completing Ian's transition to an extratropical cyclone. As an extratropical cyclone, Ian passed near Iceland, although no impacts from the storm have been reported. The extratropical cyclone that was previously Ian was then absorbed a larger one on September 17.