Nadine (2018)

A small tropical cyclone formed from a tropical wave that moved off the west coast of Africa on 6 October 2018. A well-defined surface low developed by 1200 UTC 8 October, and the system became a tropical depression around 0600 UTC 9 October about 380 nautical miles southwest of the Cabo Verde Islands. It strengthened to Tropical Storm Nadine about six hours later and moved generally west-northwest to northwest while remaining well east of any land. The storm weakened beginning 10 October as wind shear increased, became a tropical depression by 1800 UTC 12 October, and degenerated into an open wave by 0000 UTC 13 October about 750 n mi west of the Cabo Verde Islands; the remnant wave dissipated near the Lesser Antilles on 16 October.

Nadine did not make any landfalls. The storm stayed over the eastern tropical Atlantic throughout its life and no coastal tropical cyclone watches or warnings were required.

The storm’s maximum sustained winds peaked at 55 kt (about 63 mph) around 0600 UTC 10 October and again at 1200 UTC 10 October. The estimated minimum central pressure at peak intensity was 995 mb. Nadine’s peak intensity corresponds to a strong tropical storm (below hurricane strength).

Because Nadine remained well offshore, there were no reported storm surge observations associated with the cyclone and no measured tropical-storm-force wind reports from ships. The official report lists no rainfall totals or storm-surge heights at land locations because the storm did not affect any populated areas.

There were no reports of damage or casualties—no direct or indirect deaths were attributed to Nadine. The regions closest to the storm, including the Cabo Verde Islands and the eastern tropical Atlantic, reported no impacts from this system.

Notable aspects: Nadine developed rapidly once the southern portion of its parent wave moved over warmer water at unusually low latitude, and a well-defined eye was observed in microwave imagery at peak intensity. The cyclone’s genesis was poorly forecast in advance—the first NHC outlook with a high (>60%) probability of formation appeared only about 6 hours before genesis—but official track and intensity forecasts after formation were generally good, with intensity forecasts performing better than recent five-year averages at many forecast intervals.