Lorenzo (2013)

A small tropical cyclone formed from the northern portion of an African tropical wave and a developing surface trough in the central Atlantic. A broad surface low became a tropical depression on 21 October 2013 about 540 nautical miles east-southeast of Bermuda. The system moved north-northeastward, then turned eastward, and lasted until it weakened to a remnant low on 24 October and dissipated as an open trough by 26 October about 730 nmi west-southwest of Flores in the Azores.

Lorenzo remained over open water for its entire life and made no landfalls.

The storm’s peak intensity was 45 kt (about 52 mph), with a minimum central pressure of 1000 mb, reached around 1200 UTC 22 October. This intensity corresponds to a moderate tropical storm (below hurricane strength).

There were no reports of storm surge or measurable rainfall impacts reported in association with Lorenzo; the cyclone remained well offshore and no ships reported sustained tropical-storm-force winds.

No damage or casualties were reported anywhere in connection with Lorenzo.

Noteworthy aspects include that Lorenzo’s development was not well predicted: it was added to the Tropical Weather Outlook only six hours before formation and global models generally did not anticipate its genesis. Forecast track and intensity errors for this small storm were relatively low, and NHC intensity forecasts performed particularly well.