Ian (2016)

A tropical low that began as a wave off Africa developed into Tropical Storm Ian at 0600 UTC on 12 September 2016 about 990 nautical miles southeast of Bermuda. Ian moved generally north-northwest then north ahead of an upper-level trough, briefly acquired subtropical characteristics late on 14 September, then turned northeast and regained tropical characteristics. It strengthened to its peak on 16 September and transitioned to an extratropical cyclone later that day, being absorbed by a larger low by 0600 UTC 17 September. The storm existed from 12–16 September 2016.

Ian did not make any landfalls. It remained over the open North Atlantic for its entire lifetime and there were no coastal watches or warnings issued for land areas.

The storm’s maximum sustained winds reached 50 knots (about 58 mph) at 0600 UTC on 16 September, with a minimum central pressure near 994 mb at that time. Ian’s peak intensity in the best track is listed as 50 knots (with later extratropical winds briefly analyzed up to 55 knots).

Because Ian stayed over the ocean, there were no reported storm surge measurements on land. Rainfall totals on land were not reported in the NHC record for this system; available observations and analyses were from satellites and ocean-based scatterometer data rather than coastal gauges. The NHC used satellite instruments (e.g., ASCAT, AMSU, GPM) and microwave imagery to estimate winds and structure.

There were no reports of damage or casualties associated with Ian. The storm mainly affected oceanic areas and maritime interests rather than populated land regions.

Noteworthy items: Ian briefly became subtropical on 14 September when its strongest convection and winds spread away from the center, then became tropical again before extratropical transition. Genesis occurred later than some long-range forecasts anticipated, and NHC track forecast errors for Ian were larger than recent averages while intensity forecasts were generally better than the 5-year mean; the GFS, GFS ensemble mean, and HCCA models produced relatively low track errors for this cyclone.