Joyce (2018)

A non-tropical low developed along a stalled front in the northern Atlantic on 10–12 September 2018 about 430–535 nautical miles west‑southwest of Flores Island in the Azores. The system became a subtropical storm on 12 September, transitioned to a tropical storm by 0000 UTC 14 September, and meandered over the north‑central Atlantic through mid‑September. Interactions with nearby Hurricane Helene forced Joyce to turn southward and then eastward. Joyce weakened to a tropical depression by 1200 UTC 16 September and became a remnant low by 0000 UTC 19 September; the remnant low dissipated on 21 September about 550 nmi south‑southwest of Flores.

Joyce did not make any landfalls. The storm remained well away from land during its entire life, tracking generally southwestward early on, then southward and eastward near Helene, and finally east‑northeastward before weakening.

The storm’s maximum sustained winds peaked at 45 knots (about 52 mph) from 0000 to 0600 UTC 15 September, with an estimated minimum central pressure of 995 millibars. At peak intensity Joyce was a moderate tropical storm (below hurricane strength).

There were no reports of storm surge or rainfall impacts associated with Joyce and no coastal watches or warnings were required. No ship or land observations of tropical‑storm‑force winds were recorded in association with the cyclone.

No casualties or damage were reported from Joyce. Regions nearest its track—the Azores well to the east—experienced no known impacts from this storm.

Noteworthy aspects include Joyce’s evolution from an extratropical gale to a subtropical storm and then to a tropical storm at relatively high latitude, and its steering interaction with Hurricane Helene. Forecasting and track guidance showed larger than average errors for this system; official intensity forecasts were generally better than recent averages, but track predictability for Joyce was lower than typical Atlantic tropical cyclones.