Mobile, AL (WKRG)-Tropical weather can have a lot of names. Have you heard of a tropical cyclone? Confused by what an invest is? What is a tropical wave? All of these terms can be used to describe a storm if as it grows and evolves. So lets start at the beginning.
When energy in the sky moves through the tropics, we often call it a tropical wave or tropical disturbance. Both a wave and a disturbance are just a cluster of scattered showers and thunderstorms. There’s no organization to it. It just means wet weather for those that find themselves in the area.
If meteorologists want to learn more about a tropical wave or disturbance, they may call an invest (like Invest 92-L). Meteorologists will estimate a center of the disturbance and run computer models on that center. It’s important to note that this is still a disturbance, it’s just being investigated. There is still no organization so it can be extremely difficult to pinpoint a center. The estimated center can also be wrong so that means any track projections on the disturbance can easily be incorrect too.
What happens when a disturbance organizes? Then it is called a tropical cyclone (system). A tropical cyclone is a tropically formed storm. It has a counter-clockwise circulation. Also, unlike big storms that spin and move from the Pacific to the Atlantic across the US, this storm does not have any fronts. You won’t ever hear a cold front or warm front mentioned with a tropical cyclone. If a cyclone does grow fronts, it looses it’s classification as tropical and becomes an extratropical cyclone. All tropical depressions, tropical storms, and hurricanes are a tropical cyclone. Subtropical cyclones are cyclones that are mostly tropical but are near a cold front from another storm system outside of the tropics. Often times the tropical cyclone will get absorbed, or become part of the near by cold front and larger storm system.
One newer terms that has come into play is potential tropical cyclone. This is still a tropical disturbance but it is a disturbance that is likely to become a tropical cyclone.
You’re probably very familiar with tropical depression, tropical storm, and hurricane. These are all tropical cyclones that have a set sustained wind speed range. The ranges make up the Saffir-Simpson Scale.
So what is a typhoon? A typhoon is just a hurricane that is in the western Pacific Ocean, near Asia. It a hurricane for a different part of the globe. Don’t confuse this with a monsoon. A monsoon is a seasonal wind. It often lasts for months. It often brings moisture or rain with it but there are such things as dry monsoons too.