Breakdown: What is a “potential” tropical cyclone

Breakdown: What is a “potential” tropical cyclone

MEMPHIS, Tenn. (WMC) - Hurricanes, Tropical Storms and Depressions, you hear these terms a lot during the peak of hurricane season. The National Hurricane Center has started naming storms as “potential tropical cyclones”, what are they and why do they exists?

In this episode of The Breakdown, we explain what a “potential” tropical cyclone actually is and why the NHC calls a storm by this term.

In the world of meteorology, a cyclone is a general term used for a weather system, in which the winds around the system rotate inwardly to an area of lower atmospheric pressure. This means an area of low pressure is considered a cyclone. This also means tornado is considered a cyclone.

When it comes to the tropics, a tropical cyclone is a term used to describe any rotating, organized system of clouds and thunderstorms that originates over tropical or subtropical waters and has a closed, low-level circulation. Meaning that a Tropical depression, storms and hurricanes are all tropical cyclones.

The National Hurricane Center in 2017 started issuing watches, warnings and advisories for “potential tropical cyclones”. This is for storms that are not yet a tropical cyclone but pose a threat of brining tropical storm or hurricane conditions to land areas within 48 hours.

Before, the NHC was not allowed to issue any advanced warning unless the storm was a tropical cyclone, but now the NHC can give advanced warnings, thanks to advancements in forecasting skills, to allow people in the path of a developing cyclone more time to prepare for the storm.

The rather confusing part of this relatively new terminology comes from the fact that in the South Pacific and Indian Ocean, they use the term “cyclone” in the region for what we consider Tropical Storm or Hurricanes.

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