Subtropical Cyclone Lexi

Subtropical Cyclone Lexi, unofficially named by researchers, was a highly unusual subtropical cyclone that formed in May 2018, west of the Chilean coastline. After the 2017-18 South Pacific cyclone season had officially ended, the system was identified outside of the basin's official boundaries in early May, near Alejandro Selkirk Island. Because Lexi developed outside of the official areas of responsibility of the warning agencies in the South Pacific, the storm was not officially included as part of the 2017-18 South Pacific cyclone season.
Meteorological history
The cyclone formed from a cut-off low that developed a low with convection on the surface, at the same time that the maximum winds in height diminished, and so therefore, the vertical wind shear decreased. This allowed the convection to develop almost symmetrically around the center of the low, giving rise to subtropical low characteristics, without associated fronts.
This system formed in water temperatures between , which is usually not supportive of sufficient thunderstorm activity.<ref name="auto"/>
After that time, the storm was identified by researchers and unofficially named Lexi.
 
< Prev   Next >