Post-tropical cyclone
A post-tropical cyclone is a former tropical cyclone that no longer possesses enough tropical qualities to be considered a tropical cyclone. The word may refer to a former tropical cyclone undergoing extratropical transition or a tropical cyclone degenerating into a remnant low. A tropical cyclone degenerating into a trough or wave, or having its low level circulation dissipate overland, lacks a cyclonic circulation and is referred as remnants instead of a post-tropical cyclone. However, post-tropical cyclones or remnants can continue producing high winds and heavy rains.
Classification/Other post-tropical cyclones
Classes
Two classes of post-tropical cyclones exist- Extratropical cyclone, which is frontal, sometimes still retains winds of hurricane or tropical storm force. Hurricane Paulette provides a recent example of an extratropical cyclone, in which it no longer has a warm core in higher latitudes when it was over Nova Scotia and all points north in its trajectory.
- Remnant low, which is non-frontal, has maximum sustained winds of less than 34 knots, and mainly consists of stable stratocumulus with little to no convective activity. These shallow systems may meander for some time before opening into a trough of low pressure, or by being absorbed into an extratropical cyclone.
Other post-tropical cyclones
- Eugene
- Michael
- Nadine
- Humberto
- Joaquin
- Matthew
- Jerry
- Paulette
- Guambe
- Linda
- Batsirai
- Emnati
- Blas
- Frank
- Howard
- Kay
Météo-France classifies systems in the South-West Indian Ocean undergoing an extratropical transition or losing tropical characteristics as "post-tropical depressions", since the 2012–13 cyclone season. They would be re-classified as extratropical depressions after completing the process.