Hurricane Nana was the fourteenth named storm and eighth hurricane of the 1990 Atlantic hurricane season. Nana was the final storm of the season, and developed on October 16 about 350 miles northeast of Puerto Rico. Nana quickly attained hurricane status and briefly threatened Bermuda. Before it could reach the island, however, strong upper-level winds destroyed the system on October 21.
Nana caused no damage and no deaths.
|Formation||October 16, 1990|
|Dissipation||October 21, 1990|
|Highest winds||85 mph|
|Lowest pressure||989 mbar|
|Part of the||1990 Atlantic hurricane season|
Nana developed from a vigorous tropical wave that moved off the coast Africa and across the Cape Verde Islands on October 7. Surface observations along with upper air data from the islands indicate that the wave produced squalls along with a marked low-level wind shift. The upper air data also indicated that conditions were not favorable for development, as upper-level westerly wind shear had apparently already become well-established in the area. Over the next several days, the wave moved westward across the Atlantic Ocean in tandem with a broad upper-level trough, maintaining deep but disorganized convection. On October 13, the wave reached the Lesser Antilles and its northern portion moved northwestward while the southern portion continued westward across the Carribean Sea. The northern portion of the wave developed convection due to strong upper-level divergence caused by an intensifying upper-level trough. As the trough exited the area and wind shear relaxed, convection became better organized. On October 16, satellite imagery along with reports from an Air Force Reserve reconnaissance aircraft indicates that the wave developed into Tropical Depression Sixteen while located about 360 miles northeast of Puerto Rico. The cyclone rapidly intensified, attaining hurricane status at 1800 UTC October 17. Subsequently, Nana turned to the northwest and threatened Bermuda. The threat, however, was rather short-lived, as a fresh blast of upper-level westerly wind shear impinged upon the cyclone, removing the deep convection from the low-level center. Due to the shear, Nana weakened to a tropical depression and drifted southward until dissipation around 1800 UTC October 21.
Nana's remnants could be tracked on satellite images over the next few days as a westward-moving low-level cloud swirl with intermittent bursts of deep convection.
Lack of Retirement
Because it did not affect land, the name Nana was not retired in the Spring of 1991 by the World Meteorological Organization. It is on the list of names to be used for the 2014 Atlantic hurricane season.